diff --git a/MAINTAINERS b/MAINTAINERS
index 1b79767d61..448dc951c5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2164,6 +2164,7 @@ F: hw/vfio/*
 F: include/hw/vfio/
 F: docs/igd-assign.txt
 F: docs/devel/migration/vfio.rst
+F: qapi/vfio.json
 
 vfio-ccw
 M: Eric Farman <farman@linux.ibm.com>
diff --git a/backends/iommufd.c b/backends/iommufd.c
index 76a0204852..c506afbdac 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -72,24 +72,22 @@ static void iommufd_backend_class_init(ObjectClass *oc, void *data)
     object_class_property_add_str(oc, "fd", NULL, iommufd_backend_set_fd);
 }
 
-int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
+bool iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
 {
-    int fd, ret = 0;
+    int fd;
 
     if (be->owned && !be->users) {
         fd = qemu_open_old("/dev/iommu", O_RDWR);
         if (fd < 0) {
             error_setg_errno(errp, errno, "/dev/iommu opening failed");
-            ret = fd;
-            goto out;
+            return false;
         }
         be->fd = fd;
     }
     be->users++;
-out:
-    trace_iommufd_backend_connect(be->fd, be->owned,
-                                  be->users, ret);
-    return ret;
+
+    trace_iommufd_backend_connect(be->fd, be->owned, be->users);
+    return true;
 }
 
 void iommufd_backend_disconnect(IOMMUFDBackend *be)
@@ -106,25 +104,24 @@ out:
     trace_iommufd_backend_disconnect(be->fd, be->users);
 }
 
-int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
-                               Error **errp)
+bool iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
+                                Error **errp)
 {
-    int ret, fd = be->fd;
+    int fd = be->fd;
     struct iommu_ioas_alloc alloc_data  = {
         .size = sizeof(alloc_data),
         .flags = 0,
     };
 
-    ret = ioctl(fd, IOMMU_IOAS_ALLOC, &alloc_data);
-    if (ret) {
+    if (ioctl(fd, IOMMU_IOAS_ALLOC, &alloc_data)) {
         error_setg_errno(errp, errno, "Failed to allocate ioas");
-        return ret;
+        return false;
     }
 
     *ioas_id = alloc_data.out_ioas_id;
-    trace_iommufd_backend_alloc_ioas(fd, *ioas_id, ret);
+    trace_iommufd_backend_alloc_ioas(fd, *ioas_id);
 
-    return ret;
+    return true;
 }
 
 void iommufd_backend_free_id(IOMMUFDBackend *be, uint32_t id)
diff --git a/backends/trace-events b/backends/trace-events
index d45c6e31a6..211e6f374a 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -7,11 +7,11 @@ dbus_vmstate_loading(const char *id) "id: %s"
 dbus_vmstate_saving(const char *id) "id: %s"
 
 # iommufd.c
-iommufd_backend_connect(int fd, bool owned, uint32_t users, int ret) "fd=%d owned=%d users=%d (%d)"
+iommufd_backend_connect(int fd, bool owned, uint32_t users) "fd=%d owned=%d users=%d"
 iommufd_backend_disconnect(int fd, uint32_t users) "fd=%d users=%d"
 iommu_backend_set_fd(int fd) "pre-opened /dev/iommu fd=%d"
 iommufd_backend_map_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, void *vaddr, bool readonly, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" addr=%p readonly=%d (%d)"
 iommufd_backend_unmap_dma_non_exist(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int ret) " Unmap nonexistent mapping: iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" (%d)"
 iommufd_backend_unmap_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" (%d)"
-iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas, int ret) " iommufd=%d ioas=%d (%d)"
+iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas) " iommufd=%d ioas=%d"
 iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%d)"
diff --git a/hw/core/machine.c b/hw/core/machine.c
index c7ceb11501..3442f31f94 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -35,6 +35,7 @@
 
 GlobalProperty hw_compat_9_0[] = {
     {"arm-cpu", "backcompat-cntfrq", "true" },
+    {"vfio-pci", "skip-vsc-check", "false" },
 };
 const size_t hw_compat_9_0_len = G_N_ELEMENTS(hw_compat_9_0);
 
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 7c4caa5938..c12531a788 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -70,14 +70,14 @@ static void vfio_ap_req_notifier_handler(void *opaque)
     }
 }
 
-static void vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
+static bool vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
                                           unsigned int irq, Error **errp)
 {
     int fd;
     size_t argsz;
     IOHandler *fd_read;
     EventNotifier *notifier;
-    struct vfio_irq_info *irq_info;
+    g_autofree struct vfio_irq_info *irq_info = NULL;
     VFIODevice *vdev = &vapdev->vdev;
 
     switch (irq) {
@@ -87,13 +87,13 @@ static void vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
         break;
     default:
         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
-        return;
+        return false;
     }
 
     if (vdev->num_irqs < irq + 1) {
         error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
                    irq, vdev->num_irqs);
-        return;
+        return false;
     }
 
     argsz = sizeof(*irq_info);
@@ -104,28 +104,26 @@ static void vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
               irq_info) < 0 || irq_info->count < 1) {
         error_setg_errno(errp, errno, "vfio: Error getting irq info");
-        goto out_free_info;
+        return false;
     }
 
     if (event_notifier_init(notifier, 0)) {
         error_setg_errno(errp, errno,
                          "vfio: Unable to init event notifier for irq (%d)",
                          irq);
-        goto out_free_info;
+        return false;
     }
 
     fd = event_notifier_get_fd(notifier);
     qemu_set_fd_handler(fd, fd_read, NULL, vapdev);
 
-    if (vfio_set_irq_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
-                               errp)) {
+    if (!vfio_set_irq_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
+                                errp)) {
         qemu_set_fd_handler(fd, NULL, NULL, vapdev);
         event_notifier_cleanup(notifier);
     }
 
-out_free_info:
-    g_free(irq_info);
-
+    return true;
 }
 
 static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
@@ -143,8 +141,8 @@ static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
         return;
     }
 
-    if (vfio_set_irq_signaling(&vapdev->vdev, irq, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+    if (!vfio_set_irq_signaling(&vapdev->vdev, irq, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
         warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
     }
 
@@ -156,23 +154,20 @@ static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
 static void vfio_ap_realize(DeviceState *dev, Error **errp)
 {
     ERRP_GUARD();
-    int ret;
     Error *err = NULL;
     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
     VFIODevice *vbasedev = &vapdev->vdev;
 
-    if (vfio_device_get_name(vbasedev, errp) < 0) {
+    if (!vfio_device_get_name(vbasedev, errp)) {
         return;
     }
 
-    ret = vfio_attach_device(vbasedev->name, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
+    if (!vfio_attach_device(vbasedev->name, vbasedev,
+                            &address_space_memory, errp)) {
         goto error;
     }
 
-    vfio_ap_register_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX, &err);
-    if (err) {
+    if (!vfio_ap_register_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX, &err)) {
         /*
          * Report this error, but do not make it a failing condition.
          * Lack of this IRQ in the host does not prevent normal operation.
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 90e4a53437..2600e62e37 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -379,12 +379,12 @@ read_err:
     css_inject_io_interrupt(sch);
 }
 
-static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
+static bool vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
                                            unsigned int irq,
                                            Error **errp)
 {
     VFIODevice *vdev = &vcdev->vdev;
-    struct vfio_irq_info *irq_info;
+    g_autofree struct vfio_irq_info *irq_info = NULL;
     size_t argsz;
     int fd;
     EventNotifier *notifier;
@@ -405,13 +405,13 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
         break;
     default:
         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
-        return;
+        return false;
     }
 
     if (vdev->num_irqs < irq + 1) {
         error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
                    irq, vdev->num_irqs);
-        return;
+        return false;
     }
 
     argsz = sizeof(*irq_info);
@@ -421,27 +421,26 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
               irq_info) < 0 || irq_info->count < 1) {
         error_setg_errno(errp, errno, "vfio: Error getting irq info");
-        goto out_free_info;
+        return false;
     }
 
     if (event_notifier_init(notifier, 0)) {
         error_setg_errno(errp, errno,
                          "vfio: Unable to init event notifier for irq (%d)",
                          irq);
-        goto out_free_info;
+        return false;
     }
 
     fd = event_notifier_get_fd(notifier);
     qemu_set_fd_handler(fd, fd_read, NULL, vcdev);
 
-    if (vfio_set_irq_signaling(vdev, irq, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
+    if (!vfio_set_irq_signaling(vdev, irq, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
         qemu_set_fd_handler(fd, NULL, NULL, vcdev);
         event_notifier_cleanup(notifier);
     }
 
-out_free_info:
-    g_free(irq_info);
+    return true;
 }
 
 static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
@@ -465,8 +464,8 @@ static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
         return;
     }
 
-    if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+    if (!vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
         warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
     }
 
@@ -475,7 +474,7 @@ static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
     event_notifier_cleanup(notifier);
 }
 
-static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
+static bool vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
 {
     VFIODevice *vdev = &vcdev->vdev;
     struct vfio_region_info *info;
@@ -484,7 +483,7 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
     /* Sanity check device */
     if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
         error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
-        return;
+        return false;
     }
 
     /*
@@ -494,13 +493,13 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
     if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
         error_setg(errp, "vfio: too few regions (%u), expected at least %u",
                    vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);
-        return;
+        return false;
     }
 
     ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
     if (ret) {
         error_setg_errno(errp, -ret, "vfio: Error getting config info");
-        return;
+        return false;
     }
 
     vcdev->io_region_size = info->size;
@@ -554,7 +553,7 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
         g_free(info);
     }
 
-    return;
+    return true;
 
 out_err:
     g_free(vcdev->crw_region);
@@ -562,7 +561,7 @@ out_err:
     g_free(vcdev->async_cmd_region);
     g_free(vcdev->io_region);
     g_free(info);
-    return;
+    return false;
 }
 
 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
@@ -580,7 +579,6 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
     VFIODevice *vbasedev = &vcdev->vdev;
     Error *err = NULL;
-    int ret;
 
     /* Call the class init function for subchannel. */
     if (cdc->realize) {
@@ -590,35 +588,31 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
         }
     }
 
-    if (vfio_device_get_name(vbasedev, errp) < 0) {
+    if (!vfio_device_get_name(vbasedev, errp)) {
         return;
     }
 
-    ret = vfio_attach_device(cdev->mdevid, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
+    if (!vfio_attach_device(cdev->mdevid, vbasedev,
+                            &address_space_memory, errp)) {
         goto out_attach_dev_err;
     }
 
-    vfio_ccw_get_region(vcdev, &err);
-    if (err) {
+    if (!vfio_ccw_get_region(vcdev, &err)) {
         goto out_region_err;
     }
 
-    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
-    if (err) {
+    if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err)) {
         goto out_io_notifier_err;
     }
 
     if (vcdev->crw_region) {
-        vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
-        if (err) {
+        if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX,
+                                            &err)) {
             goto out_irq_notifier_err;
         }
     }
 
-    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
-    if (err) {
+    if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err)) {
         /*
          * Report this error, but do not make it a failing condition.
          * Lack of this IRQ in the host does not prevent normal operation.
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 8f9cbdc026..f9619a1dfb 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -147,10 +147,10 @@ bool vfio_viommu_preset(VFIODevice *vbasedev)
     return vbasedev->bcontainer->space->as != &address_space_memory;
 }
 
-static void vfio_set_migration_error(int err)
+static void vfio_set_migration_error(int ret)
 {
     if (migration_is_setup_or_active()) {
-        migration_file_set_error(err);
+        migration_file_set_error(ret, NULL);
     }
 }
 
@@ -253,12 +253,13 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section)
 
 /* Called with rcu_read_lock held.  */
 static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
-                               ram_addr_t *ram_addr, bool *read_only)
+                               ram_addr_t *ram_addr, bool *read_only,
+                               Error **errp)
 {
     bool ret, mr_has_discard_manager;
 
     ret = memory_get_xlat_addr(iotlb, vaddr, ram_addr, read_only,
-                               &mr_has_discard_manager);
+                               &mr_has_discard_manager, errp);
     if (ret && mr_has_discard_manager) {
         /*
          * Malicious VMs might trigger discarding of IOMMU-mapped memory. The
@@ -288,6 +289,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     hwaddr iova = iotlb->iova + giommu->iommu_offset;
     void *vaddr;
     int ret;
+    Error *local_err = NULL;
 
     trace_vfio_iommu_map_notify(iotlb->perm == IOMMU_NONE ? "UNMAP" : "MAP",
                                 iova, iova + iotlb->addr_mask);
@@ -304,7 +306,8 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
         bool read_only;
 
-        if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
+        if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, &local_err)) {
+            error_report_err(local_err);
             goto out;
         }
         /*
@@ -585,7 +588,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
         return;
     }
 
-    if (vfio_container_add_section_window(bcontainer, section, &err)) {
+    if (!vfio_container_add_section_window(bcontainer, section, &err)) {
         goto fail;
     }
 
@@ -1027,7 +1030,8 @@ static void vfio_device_feature_dma_logging_start_destroy(
     g_free(feature);
 }
 
-static int vfio_devices_dma_logging_start(VFIOContainerBase *bcontainer)
+static int vfio_devices_dma_logging_start(VFIOContainerBase *bcontainer,
+                                          Error **errp)
 {
     struct vfio_device_feature *feature;
     VFIODirtyRanges ranges;
@@ -1038,6 +1042,7 @@ static int vfio_devices_dma_logging_start(VFIOContainerBase *bcontainer)
     feature = vfio_device_feature_dma_logging_start_create(bcontainer,
                                                            &ranges);
     if (!feature) {
+        error_setg_errno(errp, errno, "Failed to prepare DMA logging");
         return -errno;
     }
 
@@ -1049,8 +1054,8 @@ static int vfio_devices_dma_logging_start(VFIOContainerBase *bcontainer)
         ret = ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature);
         if (ret) {
             ret = -errno;
-            error_report("%s: Failed to start DMA logging, err %d (%s)",
-                         vbasedev->name, ret, strerror(errno));
+            error_setg_errno(errp, errno, "%s: Failed to start DMA logging",
+                             vbasedev->name);
             goto out;
         }
         vbasedev->dirty_tracking = true;
@@ -1069,20 +1074,19 @@ out:
 static bool vfio_listener_log_global_start(MemoryListener *listener,
                                            Error **errp)
 {
+    ERRP_GUARD();
     VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
                                                  listener);
     int ret;
 
     if (vfio_devices_all_device_dirty_tracking(bcontainer)) {
-        ret = vfio_devices_dma_logging_start(bcontainer);
+        ret = vfio_devices_dma_logging_start(bcontainer, errp);
     } else {
-        ret = vfio_container_set_dirty_page_tracking(bcontainer, true);
+        ret = vfio_container_set_dirty_page_tracking(bcontainer, true, errp);
     }
 
     if (ret) {
-        error_report("vfio: Could not start dirty page tracking, err: %d (%s)",
-                     ret, strerror(-ret));
-        vfio_set_migration_error(ret);
+        error_prepend(errp, "vfio: Could not start dirty page tracking - ");
     }
     return !ret;
 }
@@ -1091,17 +1095,20 @@ static void vfio_listener_log_global_stop(MemoryListener *listener)
 {
     VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
                                                  listener);
+    Error *local_err = NULL;
     int ret = 0;
 
     if (vfio_devices_all_device_dirty_tracking(bcontainer)) {
         vfio_devices_dma_logging_stop(bcontainer);
     } else {
-        ret = vfio_container_set_dirty_page_tracking(bcontainer, false);
+        ret = vfio_container_set_dirty_page_tracking(bcontainer, false,
+                                                     &local_err);
     }
 
     if (ret) {
-        error_report("vfio: Could not stop dirty page tracking, err: %d (%s)",
-                     ret, strerror(-ret));
+        error_prepend(&local_err,
+                      "vfio: Could not stop dirty page tracking - ");
+        error_report_err(local_err);
         vfio_set_migration_error(ret);
     }
 }
@@ -1133,8 +1140,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
 }
 
 int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
-                                    VFIOBitmap *vbmap, hwaddr iova,
-                                    hwaddr size)
+                 VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp)
 {
     VFIODevice *vbasedev;
     int ret;
@@ -1143,10 +1149,10 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
         ret = vfio_device_dma_logging_report(vbasedev, iova, size,
                                              vbmap->bitmap);
         if (ret) {
-            error_report("%s: Failed to get DMA logging report, iova: "
-                         "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx
-                         ", err: %d (%s)",
-                         vbasedev->name, iova, size, ret, strerror(-ret));
+            error_setg_errno(errp, -ret,
+                             "%s: Failed to get DMA logging report, iova: "
+                             "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx,
+                             vbasedev->name, iova, size);
 
             return ret;
         }
@@ -1156,7 +1162,7 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
 }
 
 int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
-                          uint64_t size, ram_addr_t ram_addr)
+                          uint64_t size, ram_addr_t ram_addr, Error **errp)
 {
     bool all_device_dirty_tracking =
         vfio_devices_all_device_dirty_tracking(bcontainer);
@@ -1173,13 +1179,17 @@ int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
 
     ret = vfio_bitmap_alloc(&vbmap, size);
     if (ret) {
+        error_setg_errno(errp, -ret,
+                         "Failed to allocate dirty tracking bitmap");
         return ret;
     }
 
     if (all_device_dirty_tracking) {
-        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
+        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
+                                              errp);
     } else {
-        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
+        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
+                                                errp);
     }
 
     if (ret) {
@@ -1209,6 +1219,7 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     VFIOContainerBase *bcontainer = giommu->bcontainer;
     hwaddr iova = iotlb->iova + giommu->iommu_offset;
     ram_addr_t translated_addr;
+    Error *local_err = NULL;
     int ret = -EINVAL;
 
     trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask);
@@ -1220,16 +1231,22 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     }
 
     rcu_read_lock();
-    if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) {
-        ret = vfio_get_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1,
-                                    translated_addr);
-        if (ret) {
-            error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
-                         "0x%"HWADDR_PRIx") = %d (%s)",
-                         bcontainer, iova, iotlb->addr_mask + 1, ret,
-                         strerror(-ret));
-        }
+    if (!vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL, &local_err)) {
+        error_report_err(local_err);
+        goto out_unlock;
     }
+
+    ret = vfio_get_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1,
+                                translated_addr, &local_err);
+    if (ret) {
+        error_prepend(&local_err,
+                      "vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
+                      "0x%"HWADDR_PRIx") failed - ", bcontainer, iova,
+                      iotlb->addr_mask + 1);
+        error_report_err(local_err);
+    }
+
+out_unlock:
     rcu_read_unlock();
 
 out:
@@ -1246,12 +1263,19 @@ static int vfio_ram_discard_get_dirty_bitmap(MemoryRegionSection *section,
     const ram_addr_t ram_addr = memory_region_get_ram_addr(section->mr) +
                                 section->offset_within_region;
     VFIORamDiscardListener *vrdl = opaque;
+    Error *local_err = NULL;
+    int ret;
 
     /*
      * Sync the whole mapped region (spanning multiple individual mappings)
      * in one go.
      */
-    return vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr);
+    ret = vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr,
+                                &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
+    return ret;
 }
 
 static int
@@ -1283,7 +1307,7 @@ vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainerBase *bcontainer,
 }
 
 static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
-                                  MemoryRegionSection *section)
+                                  MemoryRegionSection *section, Error **errp)
 {
     ram_addr_t ram_addr;
 
@@ -1314,7 +1338,14 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
         }
         return 0;
     } else if (memory_region_has_ram_discard_manager(section->mr)) {
-        return vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
+        int ret;
+
+        ret = vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
+        if (ret) {
+            error_setg(errp,
+                       "Failed to sync dirty bitmap with RAM discard listener");
+        }
+        return ret;
     }
 
     ram_addr = memory_region_get_ram_addr(section->mr) +
@@ -1322,7 +1353,7 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
 
     return vfio_get_dirty_bitmap(bcontainer,
                    REAL_HOST_PAGE_ALIGN(section->offset_within_address_space),
-                   int128_get64(section->size), ram_addr);
+                                 int128_get64(section->size), ram_addr, errp);
 }
 
 static void vfio_listener_log_sync(MemoryListener *listener,
@@ -1331,16 +1362,16 @@ static void vfio_listener_log_sync(MemoryListener *listener,
     VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
                                                  listener);
     int ret;
+    Error *local_err = NULL;
 
     if (vfio_listener_skipped_section(section)) {
         return;
     }
 
     if (vfio_devices_all_dirty_tracking(bcontainer)) {
-        ret = vfio_sync_dirty_bitmap(bcontainer, section);
+        ret = vfio_sync_dirty_bitmap(bcontainer, section, &local_err);
         if (ret) {
-            error_report("vfio: Failed to sync dirty bitmap, err: %d (%s)", ret,
-                         strerror(-ret));
+            error_report_err(local_err);
             vfio_set_migration_error(ret);
         }
     }
@@ -1492,8 +1523,8 @@ retry:
     return info;
 }
 
-int vfio_attach_device(char *name, VFIODevice *vbasedev,
-                       AddressSpace *as, Error **errp)
+bool vfio_attach_device(char *name, VFIODevice *vbasedev,
+                        AddressSpace *as, Error **errp)
 {
     const VFIOIOMMUClass *ops =
         VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY));
diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
index 913ae49077..760d9d0622 100644
--- a/hw/vfio/container-base.c
+++ b/hw/vfio/container-base.c
@@ -31,12 +31,12 @@ int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
     return bcontainer->ops->dma_unmap(bcontainer, iova, size, iotlb);
 }
 
-int vfio_container_add_section_window(VFIOContainerBase *bcontainer,
-                                      MemoryRegionSection *section,
-                                      Error **errp)
+bool vfio_container_add_section_window(VFIOContainerBase *bcontainer,
+                                       MemoryRegionSection *section,
+                                       Error **errp)
 {
     if (!bcontainer->ops->add_window) {
-        return 0;
+        return true;
     }
 
     return bcontainer->ops->add_window(bcontainer, section, errp);
@@ -53,22 +53,22 @@ void vfio_container_del_section_window(VFIOContainerBase *bcontainer,
 }
 
 int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
-                                           bool start)
+                                           bool start, Error **errp)
 {
     if (!bcontainer->dirty_pages_supported) {
         return 0;
     }
 
     g_assert(bcontainer->ops->set_dirty_page_tracking);
-    return bcontainer->ops->set_dirty_page_tracking(bcontainer, start);
+    return bcontainer->ops->set_dirty_page_tracking(bcontainer, start, errp);
 }
 
 int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
-                                      VFIOBitmap *vbmap,
-                                      hwaddr iova, hwaddr size)
+                   VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp)
 {
     g_assert(bcontainer->ops->query_dirty_bitmap);
-    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size);
+    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size,
+                                               errp);
 }
 
 void vfio_container_init(VFIOContainerBase *bcontainer, VFIOAddressSpace *space,
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 77bdec276e..096cc97258 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -130,6 +130,7 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
     };
     bool need_dirty_sync = false;
     int ret;
+    Error *local_err = NULL;
 
     if (iotlb && vfio_devices_all_running_and_mig_active(bcontainer)) {
         if (!vfio_devices_all_device_dirty_tracking(bcontainer) &&
@@ -165,8 +166,9 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
 
     if (need_dirty_sync) {
         ret = vfio_get_dirty_bitmap(bcontainer, iova, size,
-                                    iotlb->translated_addr);
+                                    iotlb->translated_addr, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -209,7 +211,7 @@ static int vfio_legacy_dma_map(const VFIOContainerBase *bcontainer, hwaddr iova,
 
 static int
 vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
-                                    bool start)
+                                    bool start, Error **errp)
 {
     const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                                   bcontainer);
@@ -227,16 +229,15 @@ vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
     ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, &dirty);
     if (ret) {
         ret = -errno;
-        error_report("Failed to set dirty tracking flag 0x%x errno: %d",
-                     dirty.flags, errno);
+        error_setg_errno(errp, errno, "Failed to set dirty tracking flag 0x%x",
+                         dirty.flags);
     }
 
     return ret;
 }
 
 static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
-                                          VFIOBitmap *vbmap,
-                                          hwaddr iova, hwaddr size)
+                      VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp)
 {
     const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                                   bcontainer);
@@ -264,9 +265,10 @@ static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
     ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
     if (ret) {
         ret = -errno;
-        error_report("Failed to get dirty bitmap for iova: 0x%"PRIx64
-                " size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
-                (uint64_t)range->size, errno);
+        error_setg_errno(errp, errno,
+                         "Failed to get dirty bitmap for iova: 0x%"PRIx64
+                         " size: 0x%"PRIx64, (uint64_t)range->iova,
+                         (uint64_t)range->size);
     }
 
     g_free(dbitmap);
@@ -391,21 +393,20 @@ static const VFIOIOMMUClass *vfio_get_iommu_class(int iommu_type, Error **errp)
     return VFIO_IOMMU_CLASS(klass);
 }
 
-static int vfio_set_iommu(VFIOContainer *container, int group_fd,
-                          VFIOAddressSpace *space, Error **errp)
+static bool vfio_set_iommu(VFIOContainer *container, int group_fd,
+                           VFIOAddressSpace *space, Error **errp)
 {
-    int iommu_type, ret;
+    int iommu_type;
     const VFIOIOMMUClass *vioc;
 
     iommu_type = vfio_get_iommu_type(container, errp);
     if (iommu_type < 0) {
-        return iommu_type;
+        return false;
     }
 
-    ret = ioctl(group_fd, VFIO_GROUP_SET_CONTAINER, &container->fd);
-    if (ret) {
+    if (ioctl(group_fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
         error_setg_errno(errp, errno, "Failed to set group container");
-        return -errno;
+        return false;
     }
 
     while (ioctl(container->fd, VFIO_SET_IOMMU, iommu_type)) {
@@ -420,7 +421,7 @@ static int vfio_set_iommu(VFIOContainer *container, int group_fd,
             continue;
         }
         error_setg_errno(errp, errno, "Failed to set iommu for container");
-        return -errno;
+        return false;
     }
 
     container->iommu_type = iommu_type;
@@ -428,11 +429,11 @@ static int vfio_set_iommu(VFIOContainer *container, int group_fd,
     vioc = vfio_get_iommu_class(iommu_type, errp);
     if (!vioc) {
         error_setg(errp, "No available IOMMU models");
-        return -EINVAL;
+        return false;
     }
 
     vfio_container_init(&container->bcontainer, space, vioc);
-    return 0;
+    return true;
 }
 
 static int vfio_get_iommu_info(VFIOContainer *container,
@@ -505,7 +506,7 @@ static void vfio_get_iommu_info_migration(VFIOContainer *container,
     }
 }
 
-static int vfio_legacy_setup(VFIOContainerBase *bcontainer, Error **errp)
+static bool vfio_legacy_setup(VFIOContainerBase *bcontainer, Error **errp)
 {
     VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                             bcontainer);
@@ -515,7 +516,7 @@ static int vfio_legacy_setup(VFIOContainerBase *bcontainer, Error **errp)
     ret = vfio_get_iommu_info(container, &info);
     if (ret) {
         error_setg_errno(errp, -ret, "Failed to get VFIO IOMMU info");
-        return ret;
+        return false;
     }
 
     if (info->flags & VFIO_IOMMU_INFO_PGSIZES) {
@@ -531,11 +532,11 @@ static int vfio_legacy_setup(VFIOContainerBase *bcontainer, Error **errp)
     vfio_get_info_iova_range(info, bcontainer);
 
     vfio_get_iommu_info_migration(container, info);
-    return 0;
+    return true;
 }
 
-static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
-                                  Error **errp)
+static bool vfio_connect_container(VFIOGroup *group, AddressSpace *as,
+                                   Error **errp)
 {
     VFIOContainer *container;
     VFIOContainerBase *bcontainer;
@@ -587,19 +588,18 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
                     error_report("vfio: error disconnecting group %d from"
                                  " container", group->groupid);
                 }
-                return ret;
+                return false;
             }
             group->container = container;
             QLIST_INSERT_HEAD(&container->group_list, group, container_next);
             vfio_kvm_device_add_group(group);
-            return 0;
+            return true;
         }
     }
 
     fd = qemu_open_old("/dev/vfio/vfio", O_RDWR);
     if (fd < 0) {
         error_setg_errno(errp, errno, "failed to open /dev/vfio/vfio");
-        ret = -errno;
         goto put_space_exit;
     }
 
@@ -607,7 +607,6 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     if (ret != VFIO_API_VERSION) {
         error_setg(errp, "supported vfio version: %d, "
                    "reported version: %d", VFIO_API_VERSION, ret);
-        ret = -EINVAL;
         goto close_fd_exit;
     }
 
@@ -615,13 +614,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     container->fd = fd;
     bcontainer = &container->bcontainer;
 
-    ret = vfio_set_iommu(container, group->fd, space, errp);
-    if (ret) {
+    if (!vfio_set_iommu(container, group->fd, space, errp)) {
         goto free_container_exit;
     }
 
-    ret = vfio_cpr_register_container(bcontainer, errp);
-    if (ret) {
+    if (!vfio_cpr_register_container(bcontainer, errp)) {
         goto free_container_exit;
     }
 
@@ -633,8 +630,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
 
     assert(bcontainer->ops->setup);
 
-    ret = bcontainer->ops->setup(bcontainer, errp);
-    if (ret) {
+    if (!bcontainer->ops->setup(bcontainer, errp)) {
         goto enable_discards_exit;
     }
 
@@ -650,7 +646,6 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     memory_listener_register(&bcontainer->listener, bcontainer->space->as);
 
     if (bcontainer->error) {
-        ret = -1;
         error_propagate_prepend(errp, bcontainer->error,
             "memory listener initialization failed: ");
         goto listener_release_exit;
@@ -658,7 +653,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
 
     bcontainer->initialized = true;
 
-    return 0;
+    return true;
 listener_release_exit:
     QLIST_REMOVE(group, container_next);
     QLIST_REMOVE(bcontainer, next);
@@ -683,7 +678,7 @@ close_fd_exit:
 put_space_exit:
     vfio_put_address_space(space);
 
-    return ret;
+    return false;
 }
 
 static void vfio_disconnect_container(VFIOGroup *group)
@@ -770,7 +765,7 @@ static VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp)
     group->groupid = groupid;
     QLIST_INIT(&group->device_list);
 
-    if (vfio_connect_container(group, as, errp)) {
+    if (!vfio_connect_container(group, as, errp)) {
         error_prepend(errp, "failed to setup container for group %d: ",
                       groupid);
         goto close_fd_exit;
@@ -806,8 +801,8 @@ static void vfio_put_group(VFIOGroup *group)
     g_free(group);
 }
 
-static int vfio_get_device(VFIOGroup *group, const char *name,
-                           VFIODevice *vbasedev, Error **errp)
+static bool vfio_get_device(VFIOGroup *group, const char *name,
+                            VFIODevice *vbasedev, Error **errp)
 {
     g_autofree struct vfio_device_info *info = NULL;
     int fd;
@@ -819,14 +814,14 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
         error_append_hint(errp,
                       "Verify all devices in group %d are bound to vfio-<bus> "
                       "or pci-stub and not already in use\n", group->groupid);
-        return fd;
+        return false;
     }
 
     info = vfio_get_device_info(fd);
     if (!info) {
         error_setg_errno(errp, errno, "error getting device info");
         close(fd);
-        return -1;
+        return false;
     }
 
     /*
@@ -841,7 +836,7 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
             error_setg(errp, "Inconsistent setting of support for discarding "
                        "RAM (e.g., balloon) within group");
             close(fd);
-            return -1;
+            return false;
         }
 
         if (!group->ram_block_discard_allowed) {
@@ -862,7 +857,7 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
 
     vbasedev->reset_works = !!(info->flags & VFIO_DEVICE_FLAGS_RESET);
 
-    return 0;
+    return true;
 }
 
 static void vfio_put_base_device(VFIODevice *vbasedev)
@@ -908,37 +903,35 @@ static int vfio_device_groupid(VFIODevice *vbasedev, Error **errp)
  * @name and @vbasedev->name are likely to be different depending
  * on the type of the device, hence the need for passing @name
  */
-static int vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
-                                     AddressSpace *as, Error **errp)
+static bool vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
+                                      AddressSpace *as, Error **errp)
 {
     int groupid = vfio_device_groupid(vbasedev, errp);
     VFIODevice *vbasedev_iter;
     VFIOGroup *group;
     VFIOContainerBase *bcontainer;
-    int ret;
 
     if (groupid < 0) {
-        return groupid;
+        return false;
     }
 
     trace_vfio_attach_device(vbasedev->name, groupid);
 
     group = vfio_get_group(groupid, as, errp);
     if (!group) {
-        return -ENOENT;
+        return false;
     }
 
     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
         if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
             error_setg(errp, "device is already attached");
             vfio_put_group(group);
-            return -EBUSY;
+            return false;
         }
     }
-    ret = vfio_get_device(group, name, vbasedev, errp);
-    if (ret) {
+    if (!vfio_get_device(group, name, vbasedev, errp)) {
         vfio_put_group(group);
-        return ret;
+        return false;
     }
 
     bcontainer = &group->container->bcontainer;
@@ -946,7 +939,7 @@ static int vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
     QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
     QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
 
-    return ret;
+    return true;
 }
 
 static void vfio_legacy_detach_device(VFIODevice *vbasedev)
diff --git a/hw/vfio/cpr.c b/hw/vfio/cpr.c
index 392c2dd95d..87e51fcee1 100644
--- a/hw/vfio/cpr.c
+++ b/hw/vfio/cpr.c
@@ -25,12 +25,12 @@ static int vfio_cpr_reboot_notifier(NotifierWithReturn *notifier,
     return 0;
 }
 
-int vfio_cpr_register_container(VFIOContainerBase *bcontainer, Error **errp)
+bool vfio_cpr_register_container(VFIOContainerBase *bcontainer, Error **errp)
 {
     migration_add_notifier_mode(&bcontainer->cpr_reboot_notifier,
                                 vfio_cpr_reboot_notifier,
                                 MIG_MODE_CPR_REBOOT);
-    return 0;
+    return true;
 }
 
 void vfio_cpr_unregister_container(VFIOContainerBase *bcontainer)
diff --git a/hw/vfio/display.c b/hw/vfio/display.c
index fe624a6c9b..661e921616 100644
--- a/hw/vfio/display.c
+++ b/hw/vfio/display.c
@@ -348,11 +348,11 @@ static const GraphicHwOps vfio_display_dmabuf_ops = {
     .ui_info    = vfio_display_edid_ui_info,
 };
 
-static int vfio_display_dmabuf_init(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_display_dmabuf_init(VFIOPCIDevice *vdev, Error **errp)
 {
     if (!display_opengl) {
         error_setg(errp, "vfio-display-dmabuf: opengl not available");
-        return -1;
+        return false;
     }
 
     vdev->dpy = g_new0(VFIODisplay, 1);
@@ -361,9 +361,12 @@ static int vfio_display_dmabuf_init(VFIOPCIDevice *vdev, Error **errp)
                                           vdev);
     if (vdev->enable_ramfb) {
         vdev->dpy->ramfb = ramfb_setup(errp);
+        if (!vdev->dpy->ramfb) {
+            return false;
+        }
     }
     vfio_display_edid_init(vdev);
-    return 0;
+    return true;
 }
 
 static void vfio_display_dmabuf_exit(VFIODisplay *dpy)
@@ -480,7 +483,7 @@ static const GraphicHwOps vfio_display_region_ops = {
     .gfx_update = vfio_display_region_update,
 };
 
-static int vfio_display_region_init(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_display_region_init(VFIOPCIDevice *vdev, Error **errp)
 {
     vdev->dpy = g_new0(VFIODisplay, 1);
     vdev->dpy->con = graphic_console_init(DEVICE(vdev), 0,
@@ -488,8 +491,11 @@ static int vfio_display_region_init(VFIOPCIDevice *vdev, Error **errp)
                                           vdev);
     if (vdev->enable_ramfb) {
         vdev->dpy->ramfb = ramfb_setup(errp);
+        if (!vdev->dpy->ramfb) {
+            return false;
+        }
     }
-    return 0;
+    return true;
 }
 
 static void vfio_display_region_exit(VFIODisplay *dpy)
@@ -504,7 +510,7 @@ static void vfio_display_region_exit(VFIODisplay *dpy)
 
 /* ---------------------------------------------------------------------- */
 
-int vfio_display_probe(VFIOPCIDevice *vdev, Error **errp)
+bool vfio_display_probe(VFIOPCIDevice *vdev, Error **errp)
 {
     struct vfio_device_gfx_plane_info probe;
     int ret;
@@ -527,11 +533,11 @@ int vfio_display_probe(VFIOPCIDevice *vdev, Error **errp)
 
     if (vdev->display == ON_OFF_AUTO_AUTO) {
         /* not an error in automatic mode */
-        return 0;
+        return true;
     }
 
     error_setg(errp, "vfio: device doesn't support any (known) display method");
-    return -1;
+    return false;
 }
 
 void vfio_display_finalize(VFIOPCIDevice *vdev)
diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
index 47b4096c05..27ea26aa48 100644
--- a/hw/vfio/helpers.c
+++ b/hw/vfio/helpers.c
@@ -107,12 +107,12 @@ static const char *index_to_str(VFIODevice *vbasedev, int index)
     }
 }
 
-int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
-                           int action, int fd, Error **errp)
+bool vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
+                            int action, int fd, Error **errp)
 {
     ERRP_GUARD();
-    struct vfio_irq_set *irq_set;
-    int argsz, ret = 0;
+    g_autofree struct vfio_irq_set *irq_set = NULL;
+    int argsz;
     const char *name;
     int32_t *pfd;
 
@@ -127,16 +127,11 @@ int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
     pfd = (int32_t *)&irq_set->data;
     *pfd = fd;
 
-    if (ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
-        ret = -errno;
-    }
-    g_free(irq_set);
-
-    if (!ret) {
-        return 0;
+    if (!ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
+        return true;
     }
 
-    error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
+    error_setg_errno(errp, errno, "VFIO_DEVICE_SET_IRQS failure");
 
     name = index_to_str(vbasedev, index);
     if (name) {
@@ -147,7 +142,7 @@ int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
     error_prepend(errp,
                   "Failed to %s %s eventfd signaling for interrupt ",
                   fd < 0 ? "tear down" : "set up", action_to_str(action));
-    return ret;
+    return false;
 }
 
 /*
@@ -348,7 +343,7 @@ static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
 int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
                       int index, const char *name)
 {
-    struct vfio_region_info *info;
+    g_autofree struct vfio_region_info *info = NULL;
     int ret;
 
     ret = vfio_get_region_info(vbasedev, index, &info);
@@ -381,8 +376,6 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
         }
     }
 
-    g_free(info);
-
     trace_vfio_region_setup(vbasedev->name, index, name,
                             region->flags, region->fd_offset, region->size);
     return 0;
@@ -599,20 +592,19 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
 
 bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
 {
-    struct vfio_region_info *info = NULL;
+    g_autofree struct vfio_region_info *info = NULL;
     bool ret = false;
 
     if (!vfio_get_region_info(vbasedev, region, &info)) {
         if (vfio_get_region_info_cap(info, cap_type)) {
             ret = true;
         }
-        g_free(info);
     }
 
     return ret;
 }
 
-int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
+bool vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
 {
     ERRP_GUARD();
     struct stat st;
@@ -621,7 +613,7 @@ int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
         if (stat(vbasedev->sysfsdev, &st) < 0) {
             error_setg_errno(errp, errno, "no such host device");
             error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->sysfsdev);
-            return -errno;
+            return false;
         }
         /* User may specify a name, e.g: VFIO platform device */
         if (!vbasedev->name) {
@@ -630,7 +622,7 @@ int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
     } else {
         if (!vbasedev->iommufd) {
             error_setg(errp, "Use FD passing only with iommufd backend");
-            return -EINVAL;
+            return false;
         }
         /*
          * Give a name with fd so any function printing out vbasedev->name
@@ -641,7 +633,7 @@ int vfio_device_get_name(VFIODevice *vbasedev, Error **errp)
         }
     }
 
-    return 0;
+    return true;
 }
 
 void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp)
diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index b31ee79c60..d320d032a7 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -367,8 +367,10 @@ static const MemoryRegionOps vfio_igd_index_quirk = {
 
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
 {
-    struct vfio_region_info *rom = NULL, *opregion = NULL,
-                            *host = NULL, *lpc = NULL;
+    g_autofree struct vfio_region_info *rom = NULL;
+    g_autofree struct vfio_region_info *opregion = NULL;
+    g_autofree struct vfio_region_info *host = NULL;
+    g_autofree struct vfio_region_info *lpc = NULL;
     VFIOQuirk *quirk;
     VFIOIGDQuirk *igd;
     PCIDevice *lpc_bridge;
@@ -426,7 +428,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if ((ret || !rom->size) && !vdev->pdev.romfile) {
         error_report("IGD device %s has no ROM, legacy mode disabled",
                      vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     /*
@@ -437,7 +439,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
         error_report("IGD device %s hotplugged, ROM disabled, "
                      "legacy mode disabled", vdev->vbasedev.name);
         vdev->rom_read_failed = true;
-        goto out;
+        return;
     }
 
     /*
@@ -450,7 +452,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if (ret) {
         error_report("IGD device %s does not support OpRegion access,"
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     ret = vfio_get_dev_region_info(&vdev->vbasedev,
@@ -459,7 +461,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if (ret) {
         error_report("IGD device %s does not support host bridge access,"
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     ret = vfio_get_dev_region_info(&vdev->vbasedev,
@@ -468,7 +470,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if (ret) {
         error_report("IGD device %s does not support LPC bridge access,"
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, 4);
@@ -478,11 +480,11 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
      * try to enable it.  Probably shouldn't be using legacy mode without VGA,
      * but also no point in us enabling VGA if disabled in hardware.
      */
-    if (!(gmch & 0x2) && !vdev->vga && vfio_populate_vga(vdev, &err)) {
+    if (!(gmch & 0x2) && !vdev->vga && !vfio_populate_vga(vdev, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         error_report("IGD device %s failed to enable VGA access, "
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     /* Create our LPC/ISA bridge */
@@ -490,7 +492,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if (ret) {
         error_report("IGD device %s failed to create LPC bridge, "
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     /* Stuff some host values into the VM PCI host bridge */
@@ -498,15 +500,14 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     if (ret) {
         error_report("IGD device %s failed to modify host bridge, "
                      "legacy mode disabled", vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     /* Setup OpRegion access */
-    ret = vfio_pci_igd_opregion_init(vdev, opregion, &err);
-    if (ret) {
+    if (!vfio_pci_igd_opregion_init(vdev, opregion, &err)) {
         error_append_hint(&err, "IGD legacy mode disabled\n");
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
-        goto out;
+        return;
     }
 
     /* Setup our quirk to munge GTT addresses to the VM allocated buffer */
@@ -608,10 +609,4 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     }
 
     trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, ggms_mb + gms_mb);
-
-out:
-    g_free(rom);
-    g_free(opregion);
-    g_free(host);
-    g_free(lpc);
 }
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 8827ffe636..554f9a6292 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -49,9 +49,9 @@ static int iommufd_cdev_unmap(const VFIOContainerBase *bcontainer,
                                      container->ioas_id, iova, size);
 }
 
-static int iommufd_cdev_kvm_device_add(VFIODevice *vbasedev, Error **errp)
+static bool iommufd_cdev_kvm_device_add(VFIODevice *vbasedev, Error **errp)
 {
-    return vfio_kvm_device_add_fd(vbasedev->fd, errp);
+    return !vfio_kvm_device_add_fd(vbasedev->fd, errp);
 }
 
 static void iommufd_cdev_kvm_device_del(VFIODevice *vbasedev)
@@ -63,18 +63,16 @@ static void iommufd_cdev_kvm_device_del(VFIODevice *vbasedev)
     }
 }
 
-static int iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)
+static bool iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)
 {
     IOMMUFDBackend *iommufd = vbasedev->iommufd;
     struct vfio_device_bind_iommufd bind = {
         .argsz = sizeof(bind),
         .flags = 0,
     };
-    int ret;
 
-    ret = iommufd_backend_connect(iommufd, errp);
-    if (ret) {
-        return ret;
+    if (!iommufd_backend_connect(iommufd, errp)) {
+        return false;
     }
 
     /*
@@ -82,15 +80,13 @@ static int iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)
      * in KVM. Especially for some emulated devices, it requires
      * to have kvm information in the device open.
      */
-    ret = iommufd_cdev_kvm_device_add(vbasedev, errp);
-    if (ret) {
+    if (!iommufd_cdev_kvm_device_add(vbasedev, errp)) {
         goto err_kvm_device_add;
     }
 
     /* Bind device to iommufd */
     bind.iommufd = iommufd->fd;
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_BIND_IOMMUFD, &bind);
-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_BIND_IOMMUFD, &bind)) {
         error_setg_errno(errp, errno, "error bind device fd=%d to iommufd=%d",
                          vbasedev->fd, bind.iommufd);
         goto err_bind;
@@ -99,12 +95,12 @@ static int iommufd_cdev_connect_and_bind(VFIODevice *vbasedev, Error **errp)
     vbasedev->devid = bind.out_devid;
     trace_iommufd_cdev_connect_and_bind(bind.iommufd, vbasedev->name,
                                         vbasedev->fd, vbasedev->devid);
-    return ret;
+    return true;
 err_bind:
     iommufd_cdev_kvm_device_del(vbasedev);
 err_kvm_device_add:
     iommufd_backend_disconnect(iommufd);
-    return ret;
+    return false;
 }
 
 static void iommufd_cdev_unbind_and_disconnect(VFIODevice *vbasedev)
@@ -176,10 +172,10 @@ out:
     return ret;
 }
 
-static int iommufd_cdev_attach_ioas_hwpt(VFIODevice *vbasedev, uint32_t id,
+static bool iommufd_cdev_attach_ioas_hwpt(VFIODevice *vbasedev, uint32_t id,
                                          Error **errp)
 {
-    int ret, iommufd = vbasedev->iommufd->fd;
+    int iommufd = vbasedev->iommufd->fd;
     struct vfio_device_attach_iommufd_pt attach_data = {
         .argsz = sizeof(attach_data),
         .flags = 0,
@@ -187,38 +183,38 @@ static int iommufd_cdev_attach_ioas_hwpt(VFIODevice *vbasedev, uint32_t id,
     };
 
     /* Attach device to an IOAS or hwpt within iommufd */
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &attach_data);
-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &attach_data)) {
         error_setg_errno(errp, errno,
                          "[iommufd=%d] error attach %s (%d) to id=%d",
                          iommufd, vbasedev->name, vbasedev->fd, id);
-    } else {
-        trace_iommufd_cdev_attach_ioas_hwpt(iommufd, vbasedev->name,
-                                            vbasedev->fd, id);
+        return false;
     }
-    return ret;
+
+    trace_iommufd_cdev_attach_ioas_hwpt(iommufd, vbasedev->name,
+                                        vbasedev->fd, id);
+    return true;
 }
 
-static int iommufd_cdev_detach_ioas_hwpt(VFIODevice *vbasedev, Error **errp)
+static bool iommufd_cdev_detach_ioas_hwpt(VFIODevice *vbasedev, Error **errp)
 {
-    int ret, iommufd = vbasedev->iommufd->fd;
+    int iommufd = vbasedev->iommufd->fd;
     struct vfio_device_detach_iommufd_pt detach_data = {
         .argsz = sizeof(detach_data),
         .flags = 0,
     };
 
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_DETACH_IOMMUFD_PT, &detach_data);
-    if (ret) {
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_DETACH_IOMMUFD_PT, &detach_data)) {
         error_setg_errno(errp, errno, "detach %s failed", vbasedev->name);
-    } else {
-        trace_iommufd_cdev_detach_ioas_hwpt(iommufd, vbasedev->name);
+        return false;
     }
-    return ret;
+
+    trace_iommufd_cdev_detach_ioas_hwpt(iommufd, vbasedev->name);
+    return true;
 }
 
-static int iommufd_cdev_attach_container(VFIODevice *vbasedev,
-                                         VFIOIOMMUFDContainer *container,
-                                         Error **errp)
+static bool iommufd_cdev_attach_container(VFIODevice *vbasedev,
+                                          VFIOIOMMUFDContainer *container,
+                                          Error **errp)
 {
     return iommufd_cdev_attach_ioas_hwpt(vbasedev, container->ioas_id, errp);
 }
@@ -228,7 +224,7 @@ static void iommufd_cdev_detach_container(VFIODevice *vbasedev,
 {
     Error *err = NULL;
 
-    if (iommufd_cdev_detach_ioas_hwpt(vbasedev, &err)) {
+    if (!iommufd_cdev_detach_ioas_hwpt(vbasedev, &err)) {
         error_report_err(err);
     }
 }
@@ -254,20 +250,19 @@ static int iommufd_cdev_ram_block_discard_disable(bool state)
     return ram_block_uncoordinated_discard_disable(state);
 }
 
-static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
-                                            uint32_t ioas_id, Error **errp)
+static bool iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
+                                             uint32_t ioas_id, Error **errp)
 {
     VFIOContainerBase *bcontainer = &container->bcontainer;
-    struct iommu_ioas_iova_ranges *info;
+    g_autofree struct iommu_ioas_iova_ranges *info = NULL;
     struct iommu_iova_range *iova_ranges;
-    int ret, sz, fd = container->be->fd;
+    int sz, fd = container->be->fd;
 
     info = g_malloc0(sizeof(*info));
     info->size = sizeof(*info);
     info->ioas_id = ioas_id;
 
-    ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);
-    if (ret && errno != EMSGSIZE) {
+    if (ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info) && errno != EMSGSIZE) {
         goto error;
     }
 
@@ -275,8 +270,7 @@ static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
     info = g_realloc(info, sizeof(*info) + sz);
     info->allowed_iovas = (uintptr_t)(info + 1);
 
-    ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);
-    if (ret) {
+    if (ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info)) {
         goto error;
     }
 
@@ -291,18 +285,15 @@ static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
     }
     bcontainer->pgsizes = info->out_iova_alignment;
 
-    g_free(info);
-    return 0;
+    return true;
 
 error:
-    ret = -errno;
-    g_free(info);
     error_setg_errno(errp, errno, "Cannot get IOVA ranges");
-    return ret;
+    return false;
 }
 
-static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
-                               AddressSpace *as, Error **errp)
+static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
+                                AddressSpace *as, Error **errp)
 {
     VFIOContainerBase *bcontainer;
     VFIOIOMMUFDContainer *container;
@@ -317,15 +308,14 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     if (vbasedev->fd < 0) {
         devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
         if (devfd < 0) {
-            return devfd;
+            return false;
         }
         vbasedev->fd = devfd;
     } else {
         devfd = vbasedev->fd;
     }
 
-    ret = iommufd_cdev_connect_and_bind(vbasedev, errp);
-    if (ret) {
+    if (!iommufd_cdev_connect_and_bind(vbasedev, errp)) {
         goto err_connect_bind;
     }
 
@@ -338,7 +328,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
             vbasedev->iommufd != container->be) {
             continue;
         }
-        if (iommufd_cdev_attach_container(vbasedev, container, &err)) {
+        if (!iommufd_cdev_attach_container(vbasedev, container, &err)) {
             const char *msg = error_get_pretty(err);
 
             trace_iommufd_cdev_fail_attach_existing_container(msg);
@@ -356,8 +346,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     }
 
     /* Need to allocate a new dedicated container */
-    ret = iommufd_backend_alloc_ioas(vbasedev->iommufd, &ioas_id, errp);
-    if (ret < 0) {
+    if (!iommufd_backend_alloc_ioas(vbasedev->iommufd, &ioas_id, errp)) {
         goto err_alloc_ioas;
     }
 
@@ -371,8 +360,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     vfio_container_init(bcontainer, space, iommufd_vioc);
     QLIST_INSERT_HEAD(&space->containers, bcontainer, next);
 
-    ret = iommufd_cdev_attach_container(vbasedev, container, errp);
-    if (ret) {
+    if (!iommufd_cdev_attach_container(vbasedev, container, errp)) {
         goto err_attach_container;
     }
 
@@ -381,8 +369,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
         goto err_discard_disable;
     }
 
-    ret = iommufd_cdev_get_info_iova_range(container, ioas_id, &err);
-    if (ret) {
+    if (!iommufd_cdev_get_info_iova_range(container, ioas_id, &err)) {
         error_append_hint(&err,
                    "Fallback to default 64bit IOVA range and 4K page size\n");
         warn_report_err(err);
@@ -394,7 +381,6 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     memory_listener_register(&bcontainer->listener, bcontainer->space->as);
 
     if (bcontainer->error) {
-        ret = -1;
         error_propagate_prepend(errp, bcontainer->error,
                                 "memory listener initialization failed: ");
         goto err_listener_register;
@@ -409,8 +395,7 @@ found_container:
         goto err_listener_register;
     }
 
-    ret = vfio_cpr_register_container(bcontainer, errp);
-    if (ret) {
+    if (!vfio_cpr_register_container(bcontainer, errp)) {
         goto err_listener_register;
     }
 
@@ -433,7 +418,7 @@ found_container:
 
     trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev->num_irqs,
                                    vbasedev->num_regions, vbasedev->flags);
-    return 0;
+    return true;
 
 err_listener_register:
     iommufd_cdev_ram_block_discard_disable(false);
@@ -446,7 +431,7 @@ err_alloc_ioas:
     iommufd_cdev_unbind_and_disconnect(vbasedev);
 err_connect_bind:
     close(vbasedev->fd);
-    return ret;
+    return false;
 }
 
 static void iommufd_cdev_detach(VFIODevice *vbasedev)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 06ae40969b..34d4be2ce1 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -24,6 +24,7 @@
 #include "migration/register.h"
 #include "migration/blocker.h"
 #include "qapi/error.h"
+#include "qapi/qapi-events-vfio.h"
 #include "exec/ramlist.h"
 #include "exec/ram_addr.h"
 #include "pci.h"
@@ -80,9 +81,65 @@ static const char *mig_state_to_str(enum vfio_device_mig_state state)
     }
 }
 
+static VfioMigrationState
+mig_state_to_qapi_state(enum vfio_device_mig_state state)
+{
+    switch (state) {
+    case VFIO_DEVICE_STATE_STOP:
+        return QAPI_VFIO_MIGRATION_STATE_STOP;
+    case VFIO_DEVICE_STATE_RUNNING:
+        return QAPI_VFIO_MIGRATION_STATE_RUNNING;
+    case VFIO_DEVICE_STATE_STOP_COPY:
+        return QAPI_VFIO_MIGRATION_STATE_STOP_COPY;
+    case VFIO_DEVICE_STATE_RESUMING:
+        return QAPI_VFIO_MIGRATION_STATE_RESUMING;
+    case VFIO_DEVICE_STATE_RUNNING_P2P:
+        return QAPI_VFIO_MIGRATION_STATE_RUNNING_P2P;
+    case VFIO_DEVICE_STATE_PRE_COPY:
+        return QAPI_VFIO_MIGRATION_STATE_PRE_COPY;
+    case VFIO_DEVICE_STATE_PRE_COPY_P2P:
+        return QAPI_VFIO_MIGRATION_STATE_PRE_COPY_P2P;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void vfio_migration_send_event(VFIODevice *vbasedev)
+{
+    VFIOMigration *migration = vbasedev->migration;
+    DeviceState *dev = vbasedev->dev;
+    g_autofree char *qom_path = NULL;
+    Object *obj;
+
+    if (!vbasedev->migration_events) {
+        return;
+    }
+
+    g_assert(vbasedev->ops->vfio_get_object);
+    obj = vbasedev->ops->vfio_get_object(vbasedev);
+    g_assert(obj);
+    qom_path = object_get_canonical_path(obj);
+
+    qapi_event_send_vfio_migration(
+        dev->id, qom_path, mig_state_to_qapi_state(migration->device_state));
+}
+
+static void vfio_migration_set_device_state(VFIODevice *vbasedev,
+                                            enum vfio_device_mig_state state)
+{
+    VFIOMigration *migration = vbasedev->migration;
+
+    trace_vfio_migration_set_device_state(vbasedev->name,
+                                          mig_state_to_str(state));
+
+    migration->device_state = state;
+    vfio_migration_send_event(vbasedev);
+}
+
 static int vfio_migration_set_state(VFIODevice *vbasedev,
                                     enum vfio_device_mig_state new_state,
-                                    enum vfio_device_mig_state recover_state)
+                                    enum vfio_device_mig_state recover_state,
+                                    Error **errp)
 {
     VFIOMigration *migration = vbasedev->migration;
     uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
@@ -92,6 +149,16 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
     struct vfio_device_feature_mig_state *mig_state =
         (struct vfio_device_feature_mig_state *)feature->data;
     int ret;
+    g_autofree char *error_prefix =
+        g_strdup_printf("%s: Failed setting device state to %s.",
+                        vbasedev->name, mig_state_to_str(new_state));
+
+    trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state),
+                                   mig_state_to_str(recover_state));
+
+    if (new_state == migration->device_state) {
+        return 0;
+    }
 
     feature->argsz = sizeof(buf);
     feature->flags =
@@ -102,22 +169,24 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
         ret = -errno;
 
         if (recover_state == VFIO_DEVICE_STATE_ERROR) {
-            error_report("%s: Failed setting device state to %s, err: %s. "
-                         "Recover state is ERROR. Resetting device",
-                         vbasedev->name, mig_state_to_str(new_state),
-                         strerror(errno));
+            error_setg_errno(errp, errno,
+                             "%s Recover state is ERROR. Resetting device",
+                             error_prefix);
 
             goto reset_device;
         }
 
-        error_report(
-            "%s: Failed setting device state to %s, err: %s. Setting device in recover state %s",
-                     vbasedev->name, mig_state_to_str(new_state),
-                     strerror(errno), mig_state_to_str(recover_state));
+        error_setg_errno(errp, errno,
+                         "%s Setting device in recover state %s",
+                         error_prefix, mig_state_to_str(recover_state));
 
         mig_state->device_state = recover_state;
         if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
             ret = -errno;
+            /*
+             * If setting the device in recover state fails, report
+             * the error here and propagate the first error.
+             */
             error_report(
                 "%s: Failed setting device in recover state, err: %s. Resetting device",
                          vbasedev->name, strerror(errno));
@@ -125,19 +194,19 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
             goto reset_device;
         }
 
-        migration->device_state = recover_state;
+        vfio_migration_set_device_state(vbasedev, recover_state);
 
         return ret;
     }
 
-    migration->device_state = new_state;
+    vfio_migration_set_device_state(vbasedev, new_state);
     if (mig_state->data_fd != -1) {
         if (migration->data_fd != -1) {
             /*
              * This can happen if the device is asynchronously reset and
              * terminates a data transfer.
              */
-            error_report("%s: data_fd out of sync", vbasedev->name);
+            error_setg(errp, "%s: data_fd out of sync", vbasedev->name);
             close(mig_state->data_fd);
 
             return -EBADF;
@@ -146,8 +215,6 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
         migration->data_fd = mig_state->data_fd;
     }
 
-    trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state));
-
     return 0;
 
 reset_device:
@@ -156,7 +223,7 @@ reset_device:
                  strerror(errno));
     }
 
-    migration->device_state = VFIO_DEVICE_STATE_RUNNING;
+    vfio_migration_set_device_state(vbasedev, VFIO_DEVICE_STATE_RUNNING);
 
     return ret;
 }
@@ -168,10 +235,11 @@ reset_device:
  */
 static int
 vfio_migration_set_state_or_reset(VFIODevice *vbasedev,
-                                  enum vfio_device_mig_state new_state)
+                                  enum vfio_device_mig_state new_state,
+                                  Error **errp)
 {
     return vfio_migration_set_state(vbasedev, new_state,
-                                    VFIO_DEVICE_STATE_ERROR);
+                                    VFIO_DEVICE_STATE_ERROR, errp);
 }
 
 static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev,
@@ -186,21 +254,30 @@ static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev,
     return ret;
 }
 
-static int vfio_save_device_config_state(QEMUFile *f, void *opaque)
+static int vfio_save_device_config_state(QEMUFile *f, void *opaque,
+                                         Error **errp)
 {
     VFIODevice *vbasedev = opaque;
+    int ret;
 
     qemu_put_be64(f, VFIO_MIG_FLAG_DEV_CONFIG_STATE);
 
     if (vbasedev->ops && vbasedev->ops->vfio_save_config) {
-        vbasedev->ops->vfio_save_config(vbasedev, f);
+        ret = vbasedev->ops->vfio_save_config(vbasedev, f, errp);
+        if (ret) {
+            return ret;
+        }
     }
 
     qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
 
     trace_vfio_save_device_config_state(vbasedev->name);
 
-    return qemu_file_get_error(f);
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to save state");
+    }
+    return ret;
 }
 
 static int vfio_load_device_config_state(QEMUFile *f, void *opaque)
@@ -399,10 +476,8 @@ static int vfio_save_setup(QEMUFile *f, void *opaque, Error **errp)
         switch (migration->device_state) {
         case VFIO_DEVICE_STATE_RUNNING:
             ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_PRE_COPY,
-                                           VFIO_DEVICE_STATE_RUNNING);
+                                           VFIO_DEVICE_STATE_RUNNING, errp);
             if (ret) {
-                error_setg(errp, "%s: Failed to set new PRE_COPY state",
-                           vbasedev->name);
                 return ret;
             }
 
@@ -435,13 +510,20 @@ static void vfio_save_cleanup(void *opaque)
 {
     VFIODevice *vbasedev = opaque;
     VFIOMigration *migration = vbasedev->migration;
+    Error *local_err = NULL;
+    int ret;
 
     /*
      * Changing device state from STOP_COPY to STOP can take time. Do it here,
      * after migration has completed, so it won't increase downtime.
      */
     if (migration->device_state == VFIO_DEVICE_STATE_STOP_COPY) {
-        vfio_migration_set_state_or_reset(vbasedev, VFIO_DEVICE_STATE_STOP);
+        ret = vfio_migration_set_state_or_reset(vbasedev,
+                                                VFIO_DEVICE_STATE_STOP,
+                                                &local_err);
+        if (ret) {
+            error_report_err(local_err);
+        }
     }
 
     g_free(migration->data_buffer);
@@ -549,11 +631,13 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
     VFIODevice *vbasedev = opaque;
     ssize_t data_size;
     int ret;
+    Error *local_err = NULL;
 
     /* We reach here with device state STOP or STOP_COPY only */
     ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY,
-                                   VFIO_DEVICE_STATE_STOP);
+                                   VFIO_DEVICE_STATE_STOP, &local_err);
     if (ret) {
+        error_report_err(local_err);
         return ret;
     }
 
@@ -566,9 +650,6 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
 
     qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
     ret = qemu_file_get_error(f);
-    if (ret) {
-        return ret;
-    }
 
     trace_vfio_save_complete_precopy(vbasedev->name, ret);
 
@@ -578,27 +659,24 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
 static void vfio_save_state(QEMUFile *f, void *opaque)
 {
     VFIODevice *vbasedev = opaque;
+    Error *local_err = NULL;
     int ret;
 
-    ret = vfio_save_device_config_state(f, opaque);
+    ret = vfio_save_device_config_state(f, opaque, &local_err);
     if (ret) {
-        error_report("%s: Failed to save device config space",
-                     vbasedev->name);
-        qemu_file_set_error(f, ret);
+        error_prepend(&local_err,
+                      "vfio: Failed to save device config space of %s - ",
+                      vbasedev->name);
+        qemu_file_set_error_obj(f, ret, local_err);
     }
 }
 
 static int vfio_load_setup(QEMUFile *f, void *opaque, Error **errp)
 {
     VFIODevice *vbasedev = opaque;
-    int ret;
 
-    ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING,
-                                   vbasedev->migration->device_state);
-    if (ret) {
-        error_setg(errp, "%s: Failed to set RESUMING state", vbasedev->name);
-    }
-    return ret;
+    return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING,
+                                    vbasedev->migration->device_state, errp);
 }
 
 static int vfio_load_cleanup(void *opaque)
@@ -714,19 +792,20 @@ static void vfio_vmstate_change_prepare(void *opaque, bool running,
     VFIODevice *vbasedev = opaque;
     VFIOMigration *migration = vbasedev->migration;
     enum vfio_device_mig_state new_state;
+    Error *local_err = NULL;
     int ret;
 
     new_state = migration->device_state == VFIO_DEVICE_STATE_PRE_COPY ?
                     VFIO_DEVICE_STATE_PRE_COPY_P2P :
                     VFIO_DEVICE_STATE_RUNNING_P2P;
 
-    ret = vfio_migration_set_state_or_reset(vbasedev, new_state);
+    ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
     if (ret) {
         /*
          * Migration should be aborted in this case, but vm_state_notify()
          * currently does not support reporting failures.
          */
-        migration_file_set_error(ret);
+        migration_file_set_error(ret, local_err);
     }
 
     trace_vfio_vmstate_change_prepare(vbasedev->name, running,
@@ -738,6 +817,7 @@ static void vfio_vmstate_change(void *opaque, bool running, RunState state)
 {
     VFIODevice *vbasedev = opaque;
     enum vfio_device_mig_state new_state;
+    Error *local_err = NULL;
     int ret;
 
     if (running) {
@@ -750,13 +830,13 @@ static void vfio_vmstate_change(void *opaque, bool running, RunState state)
                 VFIO_DEVICE_STATE_STOP;
     }
 
-    ret = vfio_migration_set_state_or_reset(vbasedev, new_state);
+    ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
     if (ret) {
         /*
          * Migration should be aborted in this case, but vm_state_notify()
          * currently does not support reporting failures.
          */
-        migration_file_set_error(ret);
+        migration_file_set_error(ret, local_err);
     }
 
     trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
@@ -769,11 +849,23 @@ static int vfio_migration_state_notifier(NotifierWithReturn *notifier,
     VFIOMigration *migration = container_of(notifier, VFIOMigration,
                                             migration_state);
     VFIODevice *vbasedev = migration->vbasedev;
+    Error *local_err = NULL;
+    int ret;
 
     trace_vfio_migration_state_notifier(vbasedev->name, e->type);
 
     if (e->type == MIG_EVENT_PRECOPY_FAILED) {
-        vfio_migration_set_state_or_reset(vbasedev, VFIO_DEVICE_STATE_RUNNING);
+        /*
+         * MigrationNotifyFunc may not return an error code and an Error
+         * object for MIG_EVENT_PRECOPY_FAILED. Hence, report the error
+         * locally and ignore the errp argument.
+         */
+        ret = vfio_migration_set_state_or_reset(vbasedev,
+                                                VFIO_DEVICE_STATE_RUNNING,
+                                                &local_err);
+        if (ret) {
+            error_report_err(local_err);
+        }
     }
     return 0;
 }
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 496fd1ee86..39dae72497 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -1169,8 +1169,8 @@ static void vfio_probe_rtl8168_bar2_quirk(VFIOPCIDevice *vdev, int nr)
  * the table and to write the base address of that memory to the ASLS register
  * of the IGD device.
  */
-int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
-                               struct vfio_region_info *info, Error **errp)
+bool vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
+                                struct vfio_region_info *info, Error **errp)
 {
     int ret;
 
@@ -1181,7 +1181,7 @@ int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
         error_setg(errp, "failed to read IGD OpRegion");
         g_free(vdev->igd_opregion);
         vdev->igd_opregion = NULL;
-        return -EINVAL;
+        return false;
     }
 
     /*
@@ -1206,7 +1206,7 @@ int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
     pci_set_long(vdev->pdev.wmask + IGD_ASLS, ~0);
     pci_set_long(vdev->emulated_config_bits + IGD_ASLS, ~0);
 
-    return 0;
+    return true;
 }
 
 /*
@@ -1536,7 +1536,7 @@ static bool is_valid_std_cap_offset(uint8_t pos)
             pos <= (PCI_CFG_SPACE_SIZE - PCI_CAP_SIZEOF));
 }
 
-static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
 {
     ERRP_GUARD();
     PCIDevice *pdev = &vdev->pdev;
@@ -1545,18 +1545,18 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
     uint8_t tmp;
 
     if (vdev->nv_gpudirect_clique == 0xFF) {
-        return 0;
+        return true;
     }
 
     if (!vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID)) {
         error_setg(errp, "NVIDIA GPUDirect Clique ID: invalid device vendor");
-        return -EINVAL;
+        return false;
     }
 
     if (pci_get_byte(pdev->config + PCI_CLASS_DEVICE + 1) !=
         PCI_BASE_CLASS_DISPLAY) {
         error_setg(errp, "NVIDIA GPUDirect Clique ID: unsupported PCI class");
-        return -EINVAL;
+        return false;
     }
 
     /*
@@ -1572,7 +1572,7 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
                 vdev->config_offset + PCI_CAPABILITY_LIST);
     if (ret != 1 || !is_valid_std_cap_offset(tmp)) {
         error_setg(errp, "NVIDIA GPUDirect Clique ID: error getting cap list");
-        return -EINVAL;
+        return false;
     }
 
     do {
@@ -1590,13 +1590,13 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
         pos = 0xD4;
     } else {
         error_setg(errp, "NVIDIA GPUDirect Clique ID: invalid config space");
-        return -EINVAL;
+        return false;
     }
 
     ret = pci_add_capability(pdev, PCI_CAP_ID_VNDR, pos, 8, errp);
     if (ret < 0) {
         error_prepend(errp, "Failed to add NVIDIA GPUDirect cap: ");
-        return ret;
+        return false;
     }
 
     memset(vdev->emulated_config_bits + pos, 0xFF, 8);
@@ -1608,7 +1608,7 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
     pci_set_byte(pdev->config + pos++, vdev->nv_gpudirect_clique << 3);
     pci_set_byte(pdev->config + pos, 0);
 
-    return 0;
+    return true;
 }
 
 /*
@@ -1629,7 +1629,7 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp)
  */
 #define VMD_SHADOW_CAP_VER 1
 #define VMD_SHADOW_CAP_LEN 24
-static int vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp)
 {
     ERRP_GUARD();
     uint8_t membar_phys[16];
@@ -1639,7 +1639,7 @@ static int vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp)
           vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, 0x467F) ||
           vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, 0x4C3D) ||
           vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, 0x9A0B))) {
-        return 0;
+        return true;
     }
 
     ret = pread(vdev->vbasedev.fd, membar_phys, 16,
@@ -1647,14 +1647,14 @@ static int vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp)
     if (ret != 16) {
         error_report("VMD %s cannot read MEMBARs (%d)",
                      vdev->vbasedev.name, ret);
-        return -EFAULT;
+        return false;
     }
 
     ret = pci_add_capability(&vdev->pdev, PCI_CAP_ID_VNDR, pos,
                              VMD_SHADOW_CAP_LEN, errp);
     if (ret < 0) {
         error_prepend(errp, "Failed to add VMD MEMBAR Shadow cap: ");
-        return ret;
+        return false;
     }
 
     memset(vdev->emulated_config_bits + pos, 0xFF, VMD_SHADOW_CAP_LEN);
@@ -1664,22 +1664,18 @@ static int vfio_add_vmd_shadow_cap(VFIOPCIDevice *vdev, Error **errp)
     pci_set_long(vdev->pdev.config + pos, 0x53484457); /* SHDW */
     memcpy(vdev->pdev.config + pos + 4, membar_phys, 16);
 
-    return 0;
+    return true;
 }
 
-int vfio_add_virt_caps(VFIOPCIDevice *vdev, Error **errp)
+bool vfio_add_virt_caps(VFIOPCIDevice *vdev, Error **errp)
 {
-    int ret;
-
-    ret = vfio_add_nv_gpudirect_cap(vdev, errp);
-    if (ret) {
-        return ret;
+    if (!vfio_add_nv_gpudirect_cap(vdev, errp)) {
+        return false;
     }
 
-    ret = vfio_add_vmd_shadow_cap(vdev, errp);
-    if (ret) {
-        return ret;
+    if (!vfio_add_vmd_shadow_cap(vdev, errp)) {
+        return false;
     }
 
-    return 0;
+    return true;
 }
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 64780d1b79..74a79bdf61 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -116,7 +116,7 @@ static void vfio_intx_eoi(VFIODevice *vbasedev)
     vfio_unmask_single_irqindex(vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
 }
 
-static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
 {
 #ifdef CONFIG_KVM
     int irq_fd = event_notifier_get_fd(&vdev->intx.interrupt);
@@ -124,7 +124,7 @@ static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
     if (vdev->no_kvm_intx || !kvm_irqfds_enabled() ||
         vdev->intx.route.mode != PCI_INTX_ENABLED ||
         !kvm_resamplefds_enabled()) {
-        return;
+        return true;
     }
 
     /* Get to a known interrupt state */
@@ -147,10 +147,10 @@ static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
         goto fail_irqfd;
     }
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_UNMASK,
-                               event_notifier_get_fd(&vdev->intx.unmask),
-                               errp)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_UNMASK,
+                                event_notifier_get_fd(&vdev->intx.unmask),
+                                errp)) {
         goto fail_vfio;
     }
 
@@ -161,7 +161,7 @@ static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
 
     trace_vfio_intx_enable_kvm(vdev->vbasedev.name);
 
-    return;
+    return true;
 
 fail_vfio:
     kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, &vdev->intx.interrupt,
@@ -171,6 +171,9 @@ fail_irqfd:
 fail:
     qemu_set_fd_handler(irq_fd, vfio_intx_interrupt, NULL, vdev);
     vfio_unmask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
+    return false;
+#else
+    return true;
 #endif
 }
 
@@ -226,8 +229,7 @@ static void vfio_intx_update(VFIOPCIDevice *vdev, PCIINTxRoute *route)
         return;
     }
 
-    vfio_intx_enable_kvm(vdev, &err);
-    if (err) {
+    if (!vfio_intx_enable_kvm(vdev, &err)) {
         warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
@@ -259,7 +261,7 @@ static void vfio_irqchip_change(Notifier *notify, void *data)
     vfio_intx_update(vdev, &vdev->intx.route);
 }
 
-static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
 {
     uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
     Error *err = NULL;
@@ -268,7 +270,7 @@ static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
 
 
     if (!pin) {
-        return 0;
+        return true;
     }
 
     vfio_disable_interrupts(vdev);
@@ -290,27 +292,26 @@ static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
     ret = event_notifier_init(&vdev->intx.interrupt, 0);
     if (ret) {
         error_setg_errno(errp, -ret, "event_notifier_init failed");
-        return ret;
+        return false;
     }
     fd = event_notifier_get_fd(&vdev->intx.interrupt);
     qemu_set_fd_handler(fd, vfio_intx_interrupt, NULL, vdev);
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
         qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->intx.interrupt);
-        return -errno;
+        return false;
     }
 
-    vfio_intx_enable_kvm(vdev, &err);
-    if (err) {
+    if (!vfio_intx_enable_kvm(vdev, &err)) {
         warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
     vdev->interrupt = VFIO_INT_INTx;
 
     trace_vfio_intx_enable(vdev->vbasedev.name);
-    return 0;
+    return true;
 }
 
 static void vfio_intx_disable(VFIOPCIDevice *vdev)
@@ -590,9 +591,10 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
                 fd = event_notifier_get_fd(&vector->interrupt);
             }
 
-            if (vfio_set_irq_signaling(&vdev->vbasedev,
-                                       VFIO_PCI_MSIX_IRQ_INDEX, nr,
-                                       VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+            if (!vfio_set_irq_signaling(&vdev->vbasedev,
+                                        VFIO_PCI_MSIX_IRQ_INDEX, nr,
+                                        VFIO_IRQ_SET_ACTION_TRIGGER, fd,
+                                        &err)) {
                 error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
             }
         }
@@ -634,8 +636,9 @@ static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
         int32_t fd = event_notifier_get_fd(&vector->interrupt);
         Error *err = NULL;
 
-        if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX, nr,
-                                   VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+        if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX,
+                                    nr, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
+                                    &err)) {
             error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         }
     }
@@ -833,8 +836,7 @@ static void vfio_msix_disable(VFIOPCIDevice *vdev)
     vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX);
 
     vfio_msi_disable_common(vdev);
-    vfio_intx_enable(vdev, &err);
-    if (err) {
+    if (!vfio_intx_enable(vdev, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
@@ -877,7 +879,7 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
@@ -895,8 +897,6 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
     vdev->rom_size = size = reg_info->size;
     vdev->rom_offset = reg_info->offset;
 
-    g_free(reg_info);
-
     if (!vdev->rom_size) {
         vdev->rom_read_failed = true;
         error_report("vfio-pci: Cannot read device rom at "
@@ -1337,7 +1337,7 @@ static void vfio_disable_interrupts(VFIOPCIDevice *vdev)
     }
 }
 
-static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
+static bool vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
 {
     uint16_t ctrl;
     bool msi_64bit, msi_maskbit;
@@ -1347,7 +1347,7 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
     if (pread(vdev->vbasedev.fd, &ctrl, sizeof(ctrl),
               vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
         error_setg_errno(errp, errno, "failed reading MSI PCI_CAP_FLAGS");
-        return -errno;
+        return false;
     }
     ctrl = le16_to_cpu(ctrl);
 
@@ -1360,14 +1360,14 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
     ret = msi_init(&vdev->pdev, pos, entries, msi_64bit, msi_maskbit, &err);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
-            return 0;
+            return true;
         }
         error_propagate_prepend(errp, err, "msi_init failed: ");
-        return ret;
+        return false;
     }
     vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
 
-    return 0;
+    return true;
 }
 
 static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev)
@@ -1447,13 +1447,13 @@ static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev)
     }
 }
 
-static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
 {
     int target_bar = -1;
     size_t msix_sz;
 
     if (!vdev->msix || vdev->msix_relo == OFF_AUTOPCIBAR_OFF) {
-        return;
+        return true;
     }
 
     /* The actual minimum size of MSI-X structures */
@@ -1476,7 +1476,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
         if (target_bar < 0) {
             error_setg(errp, "No automatic MSI-X relocation available for "
                        "device %04x:%04x", vdev->vendor_id, vdev->device_id);
-            return;
+            return false;
         }
     } else {
         target_bar = (int)(vdev->msix_relo - OFF_AUTOPCIBAR_BAR0);
@@ -1486,7 +1486,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
     if (vdev->bars[target_bar].ioport) {
         error_setg(errp, "Invalid MSI-X relocation BAR %d, "
                    "I/O port BAR", target_bar);
-        return;
+        return false;
     }
 
     /* Cannot use a BAR in the "shadow" of a 64-bit BAR */
@@ -1494,7 +1494,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
          target_bar > 0 && vdev->bars[target_bar - 1].mem64) {
         error_setg(errp, "Invalid MSI-X relocation BAR %d, "
                    "consumed by 64-bit BAR %d", target_bar, target_bar - 1);
-        return;
+        return false;
     }
 
     /* 2GB max size for 32-bit BARs, cannot double if already > 1G */
@@ -1502,7 +1502,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
         !vdev->bars[target_bar].mem64) {
         error_setg(errp, "Invalid MSI-X relocation BAR %d, "
                    "no space to extend 32-bit BAR", target_bar);
-        return;
+        return false;
     }
 
     /*
@@ -1537,6 +1537,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
 
     trace_vfio_msix_relo(vdev->vbasedev.name,
                          vdev->msix->table_bar, vdev->msix->table_offset);
+    return true;
 }
 
 /*
@@ -1547,7 +1548,7 @@ static void vfio_pci_relocate_msix(VFIOPCIDevice *vdev, Error **errp)
  * need to first look for where the MSI-X table lives.  So we
  * unfortunately split MSI-X setup across two functions.
  */
-static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
 {
     uint8_t pos;
     uint16_t ctrl;
@@ -1559,25 +1560,25 @@ static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
 
     pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
     if (!pos) {
-        return;
+        return true;
     }
 
     if (pread(fd, &ctrl, sizeof(ctrl),
               vdev->config_offset + pos + PCI_MSIX_FLAGS) != sizeof(ctrl)) {
         error_setg_errno(errp, errno, "failed to read PCI MSIX FLAGS");
-        return;
+        return false;
     }
 
     if (pread(fd, &table, sizeof(table),
               vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
         error_setg_errno(errp, errno, "failed to read PCI MSIX TABLE");
-        return;
+        return false;
     }
 
     if (pread(fd, &pba, sizeof(pba),
               vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
         error_setg_errno(errp, errno, "failed to read PCI MSIX PBA");
-        return;
+        return false;
     }
 
     ctrl = le16_to_cpu(ctrl);
@@ -1595,7 +1596,7 @@ static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
     if (ret < 0) {
         error_setg_errno(errp, -ret, "failed to get MSI-X irq info");
         g_free(msix);
-        return;
+        return false;
     }
 
     msix->noresize = !!(irq_info.flags & VFIO_IRQ_INFO_NORESIZE);
@@ -1627,7 +1628,7 @@ static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
             error_setg(errp, "hardware reports invalid configuration, "
                        "MSIX PBA outside of specified BAR");
             g_free(msix);
-            return;
+            return false;
         }
     }
 
@@ -1638,10 +1639,10 @@ static void vfio_msix_early_setup(VFIOPCIDevice *vdev, Error **errp)
 
     vfio_pci_fixup_msix_region(vdev);
 
-    vfio_pci_relocate_msix(vdev, errp);
+    return vfio_pci_relocate_msix(vdev, errp);
 }
 
-static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
+static bool vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
 {
     int ret;
     Error *err = NULL;
@@ -1657,11 +1658,11 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
     if (ret < 0) {
         if (ret == -ENOTSUP) {
             warn_report_err(err);
-            return 0;
+            return true;
         }
 
         error_propagate(errp, err);
-        return ret;
+        return false;
     }
 
     /*
@@ -1695,7 +1696,7 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
         memory_region_set_enabled(&vdev->pdev.msix_table_mmio, false);
     }
 
-    return 0;
+    return true;
 }
 
 static void vfio_teardown_msi(VFIOPCIDevice *vdev)
@@ -1974,8 +1975,8 @@ static void vfio_pci_disable_rp_atomics(VFIOPCIDevice *vdev)
     }
 }
 
-static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
-                               Error **errp)
+static bool vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
+                                Error **errp)
 {
     uint16_t flags;
     uint8_t type;
@@ -1989,7 +1990,7 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
 
         error_setg(errp, "assignment of PCIe type 0x%x "
                    "devices is not currently supported", type);
-        return -EINVAL;
+        return false;
     }
 
     if (!pci_bus_is_express(pci_get_bus(&vdev->pdev))) {
@@ -2022,7 +2023,7 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
         }
 
         if (pci_bus_is_express(bus)) {
-            return 0;
+            return true;
         }
 
     } else if (pci_bus_is_root(pci_get_bus(&vdev->pdev))) {
@@ -2060,7 +2061,7 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
              * Legacy endpoints don't belong on the root complex.  Windows
              * seems to be happier with devices if we skip the capability.
              */
-            return 0;
+            return true;
         }
 
     } else {
@@ -2096,12 +2097,12 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
     pos = pci_add_capability(&vdev->pdev, PCI_CAP_ID_EXP, pos, size,
                              errp);
     if (pos < 0) {
-        return pos;
+        return false;
     }
 
     vdev->pdev.exp.exp_cap = pos;
 
-    return pos;
+    return true;
 }
 
 static void vfio_check_pcie_flr(VFIOPCIDevice *vdev, uint8_t pos)
@@ -2134,12 +2135,34 @@ static void vfio_check_af_flr(VFIOPCIDevice *vdev, uint8_t pos)
     }
 }
 
-static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
+static bool vfio_add_vendor_specific_cap(VFIOPCIDevice *vdev, int pos,
+                                         uint8_t size, Error **errp)
+{
+    PCIDevice *pdev = &vdev->pdev;
+
+    pos = pci_add_capability(pdev, PCI_CAP_ID_VNDR, pos, size, errp);
+    if (pos < 0) {
+        return false;
+    }
+
+    /*
+     * Exempt config space check for Vendor Specific Information during
+     * restore/load.
+     * Config space check is still enforced for 3 byte VSC header.
+     */
+    if (vdev->skip_vsc_check && size > 3) {
+        memset(pdev->cmask + pos + 3, 0, size - 3);
+    }
+
+    return true;
+}
+
+static bool vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
 {
     ERRP_GUARD();
     PCIDevice *pdev = &vdev->pdev;
     uint8_t cap_id, next, size;
-    int ret;
+    bool ret;
 
     cap_id = pdev->config[pos];
     next = pdev->config[pos + PCI_CAP_LIST_NEXT];
@@ -2160,9 +2183,8 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
      * will be changed as we unwind the stack.
      */
     if (next) {
-        ret = vfio_add_std_cap(vdev, next, errp);
-        if (ret) {
-            return ret;
+        if (!vfio_add_std_cap(vdev, next, errp)) {
+            return false;
         }
     } else {
         /* Begin the rebuild, use QEMU emulated list bits */
@@ -2170,9 +2192,8 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
         vdev->emulated_config_bits[PCI_CAPABILITY_LIST] = 0xff;
         vdev->emulated_config_bits[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
 
-        ret = vfio_add_virt_caps(vdev, errp);
-        if (ret) {
-            return ret;
+        if (!vfio_add_virt_caps(vdev, errp)) {
+            return false;
         }
     }
 
@@ -2196,25 +2217,27 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
     case PCI_CAP_ID_PM:
         vfio_check_pm_reset(vdev, pos);
         vdev->pm_cap = pos;
-        ret = pci_add_capability(pdev, cap_id, pos, size, errp);
+        ret = pci_add_capability(pdev, cap_id, pos, size, errp) >= 0;
         break;
     case PCI_CAP_ID_AF:
         vfio_check_af_flr(vdev, pos);
-        ret = pci_add_capability(pdev, cap_id, pos, size, errp);
+        ret = pci_add_capability(pdev, cap_id, pos, size, errp) >= 0;
+        break;
+    case PCI_CAP_ID_VNDR:
+        ret = vfio_add_vendor_specific_cap(vdev, pos, size, errp);
         break;
     default:
-        ret = pci_add_capability(pdev, cap_id, pos, size, errp);
+        ret = pci_add_capability(pdev, cap_id, pos, size, errp) >= 0;
         break;
     }
 
-    if (ret < 0) {
+    if (!ret) {
         error_prepend(errp,
                       "failed to add PCI capability 0x%x[0x%x]@0x%x: ",
                       cap_id, size, pos);
-        return ret;
     }
 
-    return 0;
+    return ret;
 }
 
 static int vfio_setup_rebar_ecap(VFIOPCIDevice *vdev, uint16_t pos)
@@ -2360,23 +2383,21 @@ static void vfio_add_ext_cap(VFIOPCIDevice *vdev)
     return;
 }
 
-static int vfio_add_capabilities(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_add_capabilities(VFIOPCIDevice *vdev, Error **errp)
 {
     PCIDevice *pdev = &vdev->pdev;
-    int ret;
 
     if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) ||
         !pdev->config[PCI_CAPABILITY_LIST]) {
-        return 0; /* Nothing to add */
+        return true; /* Nothing to add */
     }
 
-    ret = vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST], errp);
-    if (ret) {
-        return ret;
+    if (!vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST], errp)) {
+        return false;
     }
 
     vfio_add_ext_cap(vdev);
-    return 0;
+    return true;
 }
 
 void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
@@ -2421,8 +2442,7 @@ void vfio_pci_post_reset(VFIOPCIDevice *vdev)
     Error *err = NULL;
     int nr;
 
-    vfio_intx_enable(vdev, &err);
-    if (err) {
+    if (!vfio_intx_enable(vdev, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
@@ -2586,11 +2606,12 @@ static const VMStateDescription vmstate_vfio_pci_config = {
     }
 };
 
-static void vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f)
+static int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp)
 {
     VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
 
-    vmstate_save_state(f, &vmstate_vfio_pci_config, vdev, NULL);
+    return vmstate_save_state_with_err(f, &vmstate_vfio_pci_config, vdev, NULL,
+                                       errp);
 }
 
 static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
@@ -2642,10 +2663,10 @@ static VFIODeviceOps vfio_pci_ops = {
     .vfio_load_config = vfio_pci_load_config,
 };
 
-int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
+bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     int ret;
 
     ret = vfio_get_region_info(vbasedev, VFIO_PCI_VGA_REGION_INDEX, &reg_info);
@@ -2653,7 +2674,7 @@ int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
         error_setg_errno(errp, -ret,
                          "failed getting region info for VGA region index %d",
                          VFIO_PCI_VGA_REGION_INDEX);
-        return ret;
+        return false;
     }
 
     if (!(reg_info->flags & VFIO_REGION_INFO_FLAG_READ) ||
@@ -2662,8 +2683,7 @@ int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
         error_setg(errp, "unexpected VGA info, flags 0x%lx, size 0x%lx",
                    (unsigned long)reg_info->flags,
                    (unsigned long)reg_info->size);
-        g_free(reg_info);
-        return -EINVAL;
+        return false;
     }
 
     vdev->vga = g_new0(VFIOVGA, 1);
@@ -2671,8 +2691,6 @@ int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
     vdev->vga->fd_offset = reg_info->offset;
     vdev->vga->fd = vdev->vbasedev.fd;
 
-    g_free(reg_info);
-
     vdev->vga->region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
     vdev->vga->region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
     QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_MEM].quirks);
@@ -2707,31 +2725,31 @@ int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
                      &vdev->vga->region[QEMU_PCI_VGA_IO_LO].mem,
                      &vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem);
 
-    return 0;
+    return true;
 }
 
-static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
+static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info *reg_info;
+    g_autofree struct vfio_region_info *reg_info = NULL;
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
     int i, ret = -1;
 
     /* Sanity check device */
     if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PCI)) {
         error_setg(errp, "this isn't a PCI device");
-        return;
+        return false;
     }
 
     if (vbasedev->num_regions < VFIO_PCI_CONFIG_REGION_INDEX + 1) {
         error_setg(errp, "unexpected number of io regions %u",
                    vbasedev->num_regions);
-        return;
+        return false;
     }
 
     if (vbasedev->num_irqs < VFIO_PCI_MSIX_IRQ_INDEX + 1) {
         error_setg(errp, "unexpected number of irqs %u", vbasedev->num_irqs);
-        return;
+        return false;
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
@@ -2743,7 +2761,7 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
 
         if (ret) {
             error_setg_errno(errp, -ret, "failed to get region %d info", i);
-            return;
+            return false;
         }
 
         QLIST_INIT(&vdev->bars[i].quirks);
@@ -2753,7 +2771,7 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
                                VFIO_PCI_CONFIG_REGION_INDEX, &reg_info);
     if (ret) {
         error_setg_errno(errp, -ret, "failed to get config info");
-        return;
+        return false;
     }
 
     trace_vfio_populate_device_config(vdev->vbasedev.name,
@@ -2767,14 +2785,11 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
     }
     vdev->config_offset = reg_info->offset;
 
-    g_free(reg_info);
-
     if (vdev->features & VFIO_FEATURE_ENABLE_VGA) {
-        ret = vfio_populate_vga(vdev, errp);
-        if (ret) {
+        if (!vfio_populate_vga(vdev, errp)) {
             error_append_hint(errp, "device does not support "
                               "requested feature x-vga\n");
-            return;
+            return false;
         }
     }
 
@@ -2791,6 +2806,8 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
                     "Could not enable error recovery for the device",
                     vbasedev->name);
     }
+
+    return true;
 }
 
 static void vfio_pci_put_device(VFIOPCIDevice *vdev)
@@ -2847,8 +2864,8 @@ static void vfio_register_err_notifier(VFIOPCIDevice *vdev)
     fd = event_notifier_get_fd(&vdev->err_notifier);
     qemu_set_fd_handler(fd, vfio_err_notifier_handler, NULL, vdev);
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->err_notifier);
@@ -2864,8 +2881,8 @@ static void vfio_unregister_err_notifier(VFIOPCIDevice *vdev)
         return;
     }
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
     qemu_set_fd_handler(event_notifier_get_fd(&vdev->err_notifier),
@@ -2912,8 +2929,8 @@ static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
     fd = event_notifier_get_fd(&vdev->req_notifier);
     qemu_set_fd_handler(fd, vfio_req_notifier_handler, NULL, vdev);
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
-                           VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->req_notifier);
@@ -2930,8 +2947,8 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
         return;
     }
 
-    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+    if (!vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
     qemu_set_fd_handler(event_notifier_get_fd(&vdev->req_notifier),
@@ -2946,12 +2963,12 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     ERRP_GUARD();
     VFIOPCIDevice *vdev = VFIO_PCI(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
-    char *tmp, *subsys;
-    Error *err = NULL;
+    char *subsys;
     int i, ret;
     bool is_mdev;
     char uuid[UUID_STR_LEN];
-    char *name;
+    g_autofree char *name = NULL;
+    g_autofree char *tmp = NULL;
 
     if (vbasedev->fd < 0 && !vbasedev->sysfsdev) {
         if (!(~vdev->host.domain || ~vdev->host.bus ||
@@ -2970,7 +2987,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
                             vdev->host.slot, vdev->host.function);
     }
 
-    if (vfio_device_get_name(vbasedev, errp) < 0) {
+    if (!vfio_device_get_name(vbasedev, errp)) {
         return;
     }
 
@@ -2982,7 +2999,6 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
      */
     tmp = g_strdup_printf("%s/subsystem", vbasedev->sysfsdev);
     subsys = realpath(tmp, NULL);
-    g_free(tmp);
     is_mdev = subsys && (strcmp(subsys, "/sys/bus/mdev") == 0);
     free(subsys);
 
@@ -3001,16 +3017,12 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
         name = g_strdup(vbasedev->name);
     }
 
-    ret = vfio_attach_device(name, vbasedev,
-                             pci_device_iommu_address_space(pdev), errp);
-    g_free(name);
-    if (ret) {
+    if (!vfio_attach_device(name, vbasedev,
+                            pci_device_iommu_address_space(pdev), errp)) {
         goto error;
     }
 
-    vfio_populate_device(vdev, &err);
-    if (err) {
-        error_propagate(errp, err);
+    if (!vfio_populate_device(vdev, errp)) {
         goto error;
     }
 
@@ -3103,16 +3115,13 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     vfio_bars_prepare(vdev);
 
-    vfio_msix_early_setup(vdev, &err);
-    if (err) {
-        error_propagate(errp, err);
+    if (!vfio_msix_early_setup(vdev, errp)) {
         goto error;
     }
 
     vfio_bars_register(vdev);
 
-    ret = vfio_add_capabilities(vdev, errp);
-    if (ret) {
+    if (!vfio_add_capabilities(vdev, errp)) {
         goto out_teardown;
     }
 
@@ -3126,7 +3135,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     if (!vdev->igd_opregion &&
         vdev->features & VFIO_FEATURE_ENABLE_IGD_OPREGION) {
-        struct vfio_region_info *opregion;
+        g_autofree struct vfio_region_info *opregion = NULL;
 
         if (vdev->pdev.qdev.hotplugged) {
             error_setg(errp,
@@ -3144,9 +3153,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
             goto out_teardown;
         }
 
-        ret = vfio_pci_igd_opregion_init(vdev, opregion, errp);
-        g_free(opregion);
-        if (ret) {
+        if (!vfio_pci_igd_opregion_init(vdev, opregion, errp)) {
             goto out_teardown;
         }
     }
@@ -3169,15 +3176,13 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
                                              vfio_intx_routing_notifier);
         vdev->irqchip_change_notifier.notify = vfio_irqchip_change;
         kvm_irqchip_add_change_notifier(&vdev->irqchip_change_notifier);
-        ret = vfio_intx_enable(vdev, errp);
-        if (ret) {
+        if (!vfio_intx_enable(vdev, errp)) {
             goto out_deregister;
         }
     }
 
     if (vdev->display != ON_OFF_AUTO_OFF) {
-        ret = vfio_display_probe(vdev, errp);
-        if (ret) {
+        if (!vfio_display_probe(vdev, errp)) {
             goto out_deregister;
         }
     }
@@ -3362,6 +3367,8 @@ static Property vfio_pci_dev_properties[] = {
                     VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false),
     DEFINE_PROP_ON_OFF_AUTO("enable-migration", VFIOPCIDevice,
                             vbasedev.enable_migration, ON_OFF_AUTO_AUTO),
+    DEFINE_PROP_BOOL("migration-events", VFIOPCIDevice,
+                     vbasedev.migration_events, false),
     DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false),
     DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice,
                      vbasedev.ram_block_discard_allowed, false),
@@ -3390,6 +3397,7 @@ static Property vfio_pci_dev_properties[] = {
     DEFINE_PROP_LINK("iommufd", VFIOPCIDevice, vbasedev.iommufd,
                      TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
 #endif
+    DEFINE_PROP_BOOL("skip-vsc-check", VFIOPCIDevice, skip_vsc_check, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 6e64a2654e..bf67df2fbc 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -177,6 +177,7 @@ struct VFIOPCIDevice {
     OnOffAuto ramfb_migrate;
     bool defer_kvm_irq_routing;
     bool clear_parent_atomics_on_exit;
+    bool skip_vsc_check;
     VFIODisplay *dpy;
     Notifier irqchip_change_notifier;
 };
@@ -211,7 +212,7 @@ void vfio_bar_quirk_setup(VFIOPCIDevice *vdev, int nr);
 void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr);
 void vfio_bar_quirk_finalize(VFIOPCIDevice *vdev, int nr);
 void vfio_setup_resetfn_quirk(VFIOPCIDevice *vdev);
-int vfio_add_virt_caps(VFIOPCIDevice *vdev, Error **errp);
+bool vfio_add_virt_caps(VFIOPCIDevice *vdev, Error **errp);
 void vfio_quirk_reset(VFIOPCIDevice *vdev);
 VFIOQuirk *vfio_quirk_alloc(int nr_mem);
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr);
@@ -224,14 +225,14 @@ bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name);
 int vfio_pci_get_pci_hot_reset_info(VFIOPCIDevice *vdev,
                                     struct vfio_pci_hot_reset_info **info_p);
 
-int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp);
+bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp);
 
-int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
-                               struct vfio_region_info *info,
-                               Error **errp);
+bool vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
+                                struct vfio_region_info *info,
+                                Error **errp);
 
 void vfio_display_reset(VFIOPCIDevice *vdev);
-int vfio_display_probe(VFIOPCIDevice *vdev, Error **errp);
+bool vfio_display_probe(VFIOPCIDevice *vdev, Error **errp);
 void vfio_display_finalize(VFIOPCIDevice *vdev);
 
 extern const VMStateDescription vfio_display_vmstate;
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index dcd2365fb3..a85c199c76 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -115,18 +115,17 @@ static int vfio_set_trigger_eventfd(VFIOINTp *intp,
     VFIODevice *vbasedev = &intp->vdev->vbasedev;
     int32_t fd = event_notifier_get_fd(intp->interrupt);
     Error *err = NULL;
-    int ret;
 
     qemu_set_fd_handler(fd, (IOHandler *)handler, NULL, intp);
 
-    ret = vfio_set_irq_signaling(vbasedev, intp->pin, 0,
-                                 VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err);
-    if (ret) {
+    if (!vfio_set_irq_signaling(vbasedev, intp->pin, 0,
+                                VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vbasedev->name);
         qemu_set_fd_handler(fd, NULL, NULL, NULL);
+        return -EINVAL;
     }
 
-    return ret;
+    return 0;
 }
 
 /*
@@ -355,15 +354,14 @@ static int vfio_set_resample_eventfd(VFIOINTp *intp)
     int32_t fd = event_notifier_get_fd(intp->unmask);
     VFIODevice *vbasedev = &intp->vdev->vbasedev;
     Error *err = NULL;
-    int ret;
 
     qemu_set_fd_handler(fd, NULL, NULL, NULL);
-    ret = vfio_set_irq_signaling(vbasedev, intp->pin, 0,
-                                 VFIO_IRQ_SET_ACTION_UNMASK, fd, &err);
-    if (ret) {
+    if (!vfio_set_irq_signaling(vbasedev, intp->pin, 0,
+                                VFIO_IRQ_SET_ACTION_UNMASK, fd, &err)) {
         error_reportf_err(err, VFIO_MSG_PREFIX, vbasedev->name);
+        return -EINVAL;
     }
-    return ret;
+    return 0;
 }
 
 /**
@@ -443,7 +441,7 @@ static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
  * @errp: error object
  *
  */
-static int vfio_populate_device(VFIODevice *vbasedev, Error **errp)
+static bool vfio_populate_device(VFIODevice *vbasedev, Error **errp)
 {
     VFIOINTp *intp, *tmp;
     int i, ret = -1;
@@ -452,7 +450,7 @@ static int vfio_populate_device(VFIODevice *vbasedev, Error **errp)
 
     if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
         error_setg(errp, "this isn't a platform device");
-        return ret;
+        return false;
     }
 
     vdev->regions = g_new0(VFIORegion *, vbasedev->num_regions);
@@ -489,12 +487,11 @@ static int vfio_populate_device(VFIODevice *vbasedev, Error **errp)
                                                     irq.flags);
             intp = vfio_init_intp(vbasedev, irq, errp);
             if (!intp) {
-                ret = -1;
                 goto irq_err;
             }
         }
     }
-    return 0;
+    return true;
 irq_err:
     timer_del(vdev->mmap_timer);
     QLIST_FOREACH_SAFE(intp, &vdev->intp_list, next, tmp) {
@@ -509,7 +506,7 @@ reg_error:
         g_free(vdev->regions[i]);
     }
     g_free(vdev->regions);
-    return ret;
+    return false;
 }
 
 /* specialized functions for VFIO Platform devices */
@@ -529,10 +526,8 @@ static VFIODeviceOps vfio_platform_ops = {
  * fd retrieval, resource query.
  * Precondition: the device name must be initialized
  */
-static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
+static bool vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
 {
-    int ret;
-
     /* @fd takes precedence over @sysfsdev which takes precedence over @host */
     if (vbasedev->fd < 0 && vbasedev->sysfsdev) {
         g_free(vbasedev->name);
@@ -540,30 +535,28 @@ static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
     } else if (vbasedev->fd < 0) {
         if (!vbasedev->name || strchr(vbasedev->name, '/')) {
             error_setg(errp, "wrong host device name");
-            return -EINVAL;
+            return false;
         }
 
         vbasedev->sysfsdev = g_strdup_printf("/sys/bus/platform/devices/%s",
                                              vbasedev->name);
     }
 
-    ret = vfio_device_get_name(vbasedev, errp);
-    if (ret) {
-        return ret;
+    if (!vfio_device_get_name(vbasedev, errp)) {
+        return false;
     }
 
-    ret = vfio_attach_device(vbasedev->name, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
-        return ret;
+    if (!vfio_attach_device(vbasedev->name, vbasedev,
+                            &address_space_memory, errp)) {
+        return false;
     }
 
-    ret = vfio_populate_device(vbasedev, errp);
-    if (ret) {
-        vfio_detach_device(vbasedev);
+    if (vfio_populate_device(vbasedev, errp)) {
+        return true;
     }
 
-    return ret;
+    vfio_detach_device(vbasedev);
+    return false;
 }
 
 /**
@@ -580,7 +573,7 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
     VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
     SysBusDevice *sbdev = SYS_BUS_DEVICE(dev);
     VFIODevice *vbasedev = &vdev->vbasedev;
-    int i, ret;
+    int i;
 
     qemu_mutex_init(&vdev->intp_mutex);
 
@@ -588,9 +581,8 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
                                 vbasedev->sysfsdev : vbasedev->name,
                                 vdev->compat);
 
-    ret = vfio_base_device_init(vbasedev, errp);
-    if (ret) {
-        goto out;
+    if (!vfio_base_device_init(vbasedev, errp)) {
+        goto init_err;
     }
 
     if (!vdev->compat) {
@@ -622,11 +614,9 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
         }
         sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
     }
-out:
-    if (!ret) {
-        return;
-    }
+    return;
 
+init_err:
     if (vdev->vbasedev.name) {
         error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     } else {
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
index 0d949bb728..47b040f1bc 100644
--- a/hw/vfio/spapr.c
+++ b/hw/vfio/spapr.c
@@ -323,7 +323,7 @@ static int vfio_spapr_create_window(VFIOContainer *container,
     return 0;
 }
 
-static int
+static bool
 vfio_spapr_container_add_section_window(VFIOContainerBase *bcontainer,
                                         MemoryRegionSection *section,
                                         Error **errp)
@@ -351,13 +351,13 @@ vfio_spapr_container_add_section_window(VFIOContainerBase *bcontainer,
             error_setg(errp, "Container %p can't map guest IOVA region"
                        " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx, container,
                        iova, end);
-            return -EINVAL;
+            return false;
         }
-        return 0;
+        return true;
     }
 
     if (container->iommu_type != VFIO_SPAPR_TCE_v2_IOMMU) {
-        return 0;
+        return true;
     }
 
     /* For now intersections are not allowed, we may relax this later */
@@ -373,14 +373,14 @@ vfio_spapr_container_add_section_window(VFIOContainerBase *bcontainer,
                 section->offset_within_address_space +
                     int128_get64(section->size) - 1,
                 hostwin->min_iova, hostwin->max_iova);
-            return -EINVAL;
+            return false;
         }
     }
 
     ret = vfio_spapr_create_window(container, section, &pgsize);
     if (ret) {
         error_setg_errno(errp, -ret, "Failed to create SPAPR window");
-        return ret;
+        return false;
     }
 
     vfio_host_win_add(scontainer, section->offset_within_address_space,
@@ -406,14 +406,14 @@ vfio_spapr_container_add_section_window(VFIOContainerBase *bcontainer,
                                      "vfio: failed GROUP_SET_SPAPR_TCE for "
                                      "KVM VFIO device %d and group fd %d",
                                      param.tablefd, param.groupfd);
-                    return -errno;
+                    return false;
                 }
                 trace_vfio_spapr_group_attach(param.groupfd, param.tablefd);
             }
         }
     }
 #endif
-    return 0;
+    return true;
 }
 
 static void
@@ -458,8 +458,8 @@ static void vfio_spapr_container_release(VFIOContainerBase *bcontainer)
     }
 }
 
-static int vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
-                                      Error **errp)
+static bool vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
+                                       Error **errp)
 {
     VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                             bcontainer);
@@ -480,7 +480,7 @@ static int vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
         ret = ioctl(fd, VFIO_IOMMU_ENABLE);
         if (ret) {
             error_setg_errno(errp, errno, "failed to enable container");
-            return -errno;
+            return false;
         }
     } else {
         scontainer->prereg_listener = vfio_prereg_listener;
@@ -488,7 +488,6 @@ static int vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
         memory_listener_register(&scontainer->prereg_listener,
                                  &address_space_memory);
         if (bcontainer->error) {
-            ret = -1;
             error_propagate_prepend(errp, bcontainer->error,
                     "RAM memory listener initialization failed: ");
             goto listener_unregister_exit;
@@ -500,7 +499,6 @@ static int vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
     if (ret) {
         error_setg_errno(errp, errno,
                          "VFIO_IOMMU_SPAPR_TCE_GET_INFO failed");
-        ret = -errno;
         goto listener_unregister_exit;
     }
 
@@ -527,13 +525,13 @@ static int vfio_spapr_container_setup(VFIOContainerBase *bcontainer,
                           0x1000);
     }
 
-    return 0;
+    return true;
 
 listener_unregister_exit:
     if (v2) {
         memory_listener_unregister(&scontainer->prereg_listener);
     }
-    return ret;
+    return false;
 }
 
 static void vfio_iommu_spapr_class_init(ObjectClass *klass, void *data)
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index f0474b244b..64161bf6f4 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -152,7 +152,8 @@ vfio_load_device_config_state(const char *name) " (%s)"
 vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
 vfio_load_state_device_data(const char *name, uint64_t data_size, int ret) " (%s) size 0x%"PRIx64" ret %d"
 vfio_migration_realize(const char *name) " (%s)"
-vfio_migration_set_state(const char *name, const char *state) " (%s) state %s"
+vfio_migration_set_device_state(const char *name, const char *state) " (%s) state %s"
+vfio_migration_set_state(const char *name, const char *new_state, const char *recover_state) " (%s) new state %s, recover state %s"
 vfio_migration_state_notifier(const char *name, int state) " (%s) state %d"
 vfio_save_block(const char *name, int data_size) " (%s) data_size %d"
 vfio_save_cleanup(const char *name) " (%s)"
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index e827b9175f..ed99ab8745 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -208,6 +208,7 @@ static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     void *vaddr;
     int ret;
     Int128 llend;
+    Error *local_err = NULL;
 
     if (iotlb->target_as != &address_space_memory) {
         error_report("Wrong target AS \"%s\", only system memory is allowed",
@@ -227,7 +228,9 @@ static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
         bool read_only;
 
-        if (!memory_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, NULL)) {
+        if (!memory_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, NULL,
+                                  &local_err)) {
+            error_report_err(local_err);
             return;
         }
         ret = vhost_vdpa_dma_map(s, VHOST_VDPA_GUEST_PA_ASID, iova,
diff --git a/include/exec/memory.h b/include/exec/memory.h
index d417d7f363..9cdd64e9c6 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -774,9 +774,22 @@ void ram_discard_manager_register_listener(RamDiscardManager *rdm,
 void ram_discard_manager_unregister_listener(RamDiscardManager *rdm,
                                              RamDiscardListener *rdl);
 
+/**
+ * memory_get_xlat_addr: Extract addresses from a TLB entry
+ *
+ * @iotlb: pointer to an #IOMMUTLBEntry
+ * @vaddr: virtual address
+ * @ram_addr: RAM address
+ * @read_only: indicates if writes are allowed
+ * @mr_has_discard_manager: indicates memory is controlled by a
+ *                          RamDiscardManager
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
 bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
                           ram_addr_t *ram_addr, bool *read_only,
-                          bool *mr_has_discard_manager);
+                          bool *mr_has_discard_manager, Error **errp);
 
 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
 typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index d66e27db02..4cb1ab8645 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -115,6 +115,7 @@ typedef struct VFIODevice {
     bool no_mmap;
     bool ram_block_discard_allowed;
     OnOffAuto enable_migration;
+    bool migration_events;
     VFIODeviceOps *ops;
     unsigned int num_irqs;
     unsigned int num_regions;
@@ -133,7 +134,30 @@ struct VFIODeviceOps {
     int (*vfio_hot_reset_multi)(VFIODevice *vdev);
     void (*vfio_eoi)(VFIODevice *vdev);
     Object *(*vfio_get_object)(VFIODevice *vdev);
-    void (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f);
+
+    /**
+     * @vfio_save_config
+     *
+     * Save device config state
+     *
+     * @vdev: #VFIODevice for which to save the config
+     * @f: #QEMUFile where to send the data
+     * @errp: pointer to Error*, to store an error if it happens.
+     *
+     * Returns zero to indicate success and negative for error
+     */
+    int (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f, Error **errp);
+
+    /**
+     * @vfio_load_config
+     *
+     * Load device config state
+     *
+     * @vdev: #VFIODevice for which to load the config
+     * @f: #QEMUFile where to get the data
+     *
+     * Returns zero to indicate success and negative for error
+     */
     int (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f);
 };
 
@@ -183,8 +207,8 @@ void vfio_spapr_container_deinit(VFIOContainer *container);
 void vfio_disable_irqindex(VFIODevice *vbasedev, int index);
 void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index);
 void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index);
-int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
-                           int action, int fd, Error **errp);
+bool vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
+                            int action, int fd, Error **errp);
 void vfio_region_write(void *opaque, hwaddr addr,
                            uint64_t data, unsigned size);
 uint64_t vfio_region_read(void *opaque,
@@ -198,14 +222,14 @@ void vfio_region_exit(VFIORegion *region);
 void vfio_region_finalize(VFIORegion *region);
 void vfio_reset_handler(void *opaque);
 struct vfio_device_info *vfio_get_device_info(int fd);
-int vfio_attach_device(char *name, VFIODevice *vbasedev,
-                       AddressSpace *as, Error **errp);
+bool vfio_attach_device(char *name, VFIODevice *vbasedev,
+                        AddressSpace *as, Error **errp);
 void vfio_detach_device(VFIODevice *vbasedev);
 
 int vfio_kvm_device_add_fd(int fd, Error **errp);
 int vfio_kvm_device_del_fd(int fd, Error **errp);
 
-int vfio_cpr_register_container(VFIOContainerBase *bcontainer, Error **errp);
+bool vfio_cpr_register_container(VFIOContainerBase *bcontainer, Error **errp);
 void vfio_cpr_unregister_container(VFIOContainerBase *bcontainer);
 
 extern const MemoryRegionOps vfio_region_ops;
@@ -250,13 +274,12 @@ vfio_devices_all_running_and_mig_active(const VFIOContainerBase *bcontainer);
 bool
 vfio_devices_all_device_dirty_tracking(const VFIOContainerBase *bcontainer);
 int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
-                                    VFIOBitmap *vbmap, hwaddr iova,
-                                    hwaddr size);
+                VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp);
 int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
-                          uint64_t size, ram_addr_t ram_addr);
+                          uint64_t size, ram_addr_t ram_addr, Error **errp);
 
 /* Returns 0 on success, or a negative errno. */
-int vfio_device_get_name(VFIODevice *vbasedev, Error **errp);
+bool vfio_device_get_name(VFIODevice *vbasedev, Error **errp);
 void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp);
 void vfio_device_init(VFIODevice *vbasedev, int type, VFIODeviceOps *ops,
                       DeviceState *dev, bool ram_discard);
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 3582d5f97a..2776481fc9 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -76,16 +76,15 @@ int vfio_container_dma_map(VFIOContainerBase *bcontainer,
 int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
                              hwaddr iova, ram_addr_t size,
                              IOMMUTLBEntry *iotlb);
-int vfio_container_add_section_window(VFIOContainerBase *bcontainer,
-                                      MemoryRegionSection *section,
-                                      Error **errp);
+bool vfio_container_add_section_window(VFIOContainerBase *bcontainer,
+                                       MemoryRegionSection *section,
+                                       Error **errp);
 void vfio_container_del_section_window(VFIOContainerBase *bcontainer,
                                        MemoryRegionSection *section);
 int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
-                                           bool start);
+                                           bool start, Error **errp);
 int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
-                                      VFIOBitmap *vbmap,
-                                      hwaddr iova, hwaddr size);
+                   VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp);
 
 void vfio_container_init(VFIOContainerBase *bcontainer,
                          VFIOAddressSpace *space,
@@ -111,29 +110,55 @@ struct VFIOIOMMUClass {
     InterfaceClass parent_class;
 
     /* basic feature */
-    int (*setup)(VFIOContainerBase *bcontainer, Error **errp);
+    bool (*setup)(VFIOContainerBase *bcontainer, Error **errp);
     int (*dma_map)(const VFIOContainerBase *bcontainer,
                    hwaddr iova, ram_addr_t size,
                    void *vaddr, bool readonly);
     int (*dma_unmap)(const VFIOContainerBase *bcontainer,
                      hwaddr iova, ram_addr_t size,
                      IOMMUTLBEntry *iotlb);
-    int (*attach_device)(const char *name, VFIODevice *vbasedev,
-                         AddressSpace *as, Error **errp);
+    bool (*attach_device)(const char *name, VFIODevice *vbasedev,
+                          AddressSpace *as, Error **errp);
     void (*detach_device)(VFIODevice *vbasedev);
+
     /* migration feature */
+
+    /**
+     * @set_dirty_page_tracking
+     *
+     * Start or stop dirty pages tracking on VFIO container
+     *
+     * @bcontainer: #VFIOContainerBase on which to de/activate dirty
+     *              page tracking
+     * @start: indicates whether to start or stop dirty pages tracking
+     * @errp: pointer to Error*, to store an error if it happens.
+     *
+     * Returns zero to indicate success and negative for error
+     */
     int (*set_dirty_page_tracking)(const VFIOContainerBase *bcontainer,
-                                   bool start);
+                                   bool start, Error **errp);
+    /**
+     * @query_dirty_bitmap
+     *
+     * Get bitmap of dirty pages from container
+     *
+     * @bcontainer: #VFIOContainerBase from which to get dirty pages
+     * @vbmap: #VFIOBitmap internal bitmap structure
+     * @iova: iova base address
+     * @size: size of iova range
+     * @errp: pointer to Error*, to store an error if it happens.
+     *
+     * Returns zero to indicate success and negative for error
+     */
     int (*query_dirty_bitmap)(const VFIOContainerBase *bcontainer,
-                              VFIOBitmap *vbmap,
-                              hwaddr iova, hwaddr size);
+                VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error **errp);
     /* PCI specific */
     int (*pci_hot_reset)(VFIODevice *vbasedev, bool single);
 
     /* SPAPR specific */
-    int (*add_window)(VFIOContainerBase *bcontainer,
-                      MemoryRegionSection *section,
-                      Error **errp);
+    bool (*add_window)(VFIOContainerBase *bcontainer,
+                       MemoryRegionSection *section,
+                       Error **errp);
     void (*del_window)(VFIOContainerBase *bcontainer,
                        MemoryRegionSection *section);
     void (*release)(VFIOContainerBase *bcontainer);
diff --git a/include/migration/misc.h b/include/migration/misc.h
index bf7339cc1e..bfadc5613b 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -97,7 +97,7 @@ void migration_add_notifier_mode(NotifierWithReturn *notify,
 
 void migration_remove_notifier(NotifierWithReturn *notify);
 bool migration_is_running(void);
-void migration_file_set_error(int err);
+void migration_file_set_error(int ret, Error *err);
 
 /* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */
 bool migration_in_incoming_postcopy(void);
diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
index 9af27ebd6c..293bfbe967 100644
--- a/include/sysemu/iommufd.h
+++ b/include/sysemu/iommufd.h
@@ -23,11 +23,11 @@ struct IOMMUFDBackend {
     /*< public >*/
 };
 
-int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp);
+bool iommufd_backend_connect(IOMMUFDBackend *be, Error **errp);
 void iommufd_backend_disconnect(IOMMUFDBackend *be);
 
-int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
-                               Error **errp);
+bool iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
+                                Error **errp);
 void iommufd_backend_free_id(IOMMUFDBackend *be, uint32_t id);
 int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova,
                             ram_addr_t size, void *vaddr, bool readonly);
diff --git a/migration/migration.c b/migration/migration.c
index e88b24f1e6..70d66a441b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2994,13 +2994,15 @@ static MigThrError postcopy_pause(MigrationState *s)
     }
 }
 
-void migration_file_set_error(int err)
+void migration_file_set_error(int ret, Error *err)
 {
     MigrationState *s = current_migration;
 
     WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) {
         if (s->to_dst_file) {
-            qemu_file_set_error(s->to_dst_file, err);
+            qemu_file_set_error_obj(s->to_dst_file, ret, err);
+        } else if (err) {
+            error_report_err(err);
         }
     }
 }
diff --git a/qapi/meson.build b/qapi/meson.build
index c92af6e063..e7bc54e5d0 100644
--- a/qapi/meson.build
+++ b/qapi/meson.build
@@ -52,6 +52,7 @@ qapi_all_modules = [
   'stats',
   'trace',
   'transaction',
+  'vfio',
   'virtio',
   'yank',
 ]
diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json
index 5e33da7228..b1581988e4 100644
--- a/qapi/qapi-schema.json
+++ b/qapi/qapi-schema.json
@@ -78,5 +78,6 @@
 { 'include': 'pci.json' }
 { 'include': 'stats.json' }
 { 'include': 'virtio.json' }
+{ 'include': 'vfio.json' }
 { 'include': 'cryptodev.json' }
 { 'include': 'cxl.json' }
diff --git a/qapi/vfio.json b/qapi/vfio.json
new file mode 100644
index 0000000000..a0e5013188
--- /dev/null
+++ b/qapi/vfio.json
@@ -0,0 +1,67 @@
+# -*- Mode: Python -*-
+# vim: filetype=python
+#
+
+##
+# = VFIO devices
+##
+
+##
+# @VfioMigrationState:
+#
+# An enumeration of the VFIO device migration states.
+#
+# @stop: The device is stopped.
+#
+# @running: The device is running.
+#
+# @stop-copy: The device is stopped and its internal state is available
+#     for reading.
+#
+# @resuming: The device is stopped and its internal state is available
+#     for writing.
+#
+# @running-p2p: The device is running in the P2P quiescent state.
+#
+# @pre-copy: The device is running, tracking its internal state and its
+#     internal state is available for reading.
+#
+# @pre-copy-p2p: The device is running in the P2P quiescent state,
+#     tracking its internal state and its internal state is available
+#     for reading.
+#
+# Since: 9.1
+##
+{ 'enum': 'VfioMigrationState',
+  'data': [ 'stop', 'running', 'stop-copy', 'resuming', 'running-p2p',
+            'pre-copy', 'pre-copy-p2p' ],
+  'prefix': 'QAPI_VFIO_MIGRATION_STATE' }
+
+##
+# @VFIO_MIGRATION:
+#
+# This event is emitted when a VFIO device migration state is changed.
+#
+# @device-id: The device's id, if it has one.
+#
+# @qom-path: The device's QOM path.
+#
+# @device-state: The new changed device migration state.
+#
+# Since: 9.1
+#
+# Example:
+#
+#     <- { "timestamp": { "seconds": 1713771323, "microseconds": 212268 },
+#          "event": "VFIO_MIGRATION",
+#          "data": {
+#              "device-id": "vfio_dev1",
+#              "qom-path": "/machine/peripheral/vfio_dev1",
+#              "device-state": "stop" } }
+##
+{ 'event': 'VFIO_MIGRATION',
+  'data': {
+      'device-id': 'str',
+      'qom-path': 'str',
+      'device-state': 'VfioMigrationState'
+  } }
diff --git a/system/memory.c b/system/memory.c
index 642a449f8c..9540caa8a1 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -2179,7 +2179,7 @@ void ram_discard_manager_unregister_listener(RamDiscardManager *rdm,
 /* Called with rcu_read_lock held.  */
 bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
                           ram_addr_t *ram_addr, bool *read_only,
-                          bool *mr_has_discard_manager)
+                          bool *mr_has_discard_manager, Error **errp)
 {
     MemoryRegion *mr;
     hwaddr xlat;
@@ -2197,7 +2197,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
     mr = address_space_translate(&address_space_memory, iotlb->translated_addr,
                                  &xlat, &len, writable, MEMTXATTRS_UNSPECIFIED);
     if (!memory_region_is_ram(mr)) {
-        error_report("iommu map to non memory area %" HWADDR_PRIx "", xlat);
+        error_setg(errp, "iommu map to non memory area %" HWADDR_PRIx "", xlat);
         return false;
     } else if (memory_region_has_ram_discard_manager(mr)) {
         RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr);
@@ -2216,8 +2216,8 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
          * were already restored before IOMMUs are restored.
          */
         if (!ram_discard_manager_is_populated(rdm, &tmp)) {
-            error_report("iommu map to discarded memory (e.g., unplugged via"
-                         " virtio-mem): %" HWADDR_PRIx "",
+            error_setg(errp, "iommu map to discarded memory (e.g., unplugged"
+                         " via virtio-mem): %" HWADDR_PRIx "",
                          iotlb->translated_addr);
             return false;
         }
@@ -2228,7 +2228,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
      * check that it did not truncate too much.
      */
     if (len & iotlb->addr_mask) {
-        error_report("iommu has granularity incompatible with target AS");
+        error_setg(errp, "iommu has granularity incompatible with target AS");
         return false;
     }