vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support

ioctl(iommufd, IOMMU_HWPT_SET_DIRTY_TRACKING, arg) is the UAPI that
enables or disables dirty page tracking. The ioctl is used if the hwpt
has been created with dirty tracking supported domain (stored in
hwpt::flags) and it is called on the whole list of iommu domains.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

backends/iommufd.c

@@ -238,6 +238,29 @@ bool iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, uint32_t dev_id,
     return true;
 }
 
+bool iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be,
+                                        uint32_t hwpt_id, bool start,
+                                        Error **errp)
+{
+    int ret;
+    struct iommu_hwpt_set_dirty_tracking set_dirty = {
+            .size = sizeof(set_dirty),
+            .hwpt_id = hwpt_id,
+            .flags = start ? IOMMU_HWPT_DIRTY_TRACKING_ENABLE : 0,
+    };
+
+    ret = ioctl(be->fd, IOMMU_HWPT_SET_DIRTY_TRACKING, &set_dirty);
+    trace_iommufd_backend_set_dirty(be->fd, hwpt_id, start, ret ? errno : 0);
+    if (ret) {
+        error_setg_errno(errp, errno,
+                         "IOMMU_HWPT_SET_DIRTY_TRACKING(hwpt_id %u) failed",
+                         hwpt_id);
+        return false;
+    }
+
+    return true;
+}
+
 bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
                                      uint32_t *type, void *data, uint32_t len,
                                      uint64_t *caps, Error **errp)

backends/trace-events

@@ -16,3 +16,4 @@ iommufd_backend_unmap_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t si
 iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas) " iommufd=%d ioas=%d"
 iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, uint32_t pt_id, uint32_t flags, uint32_t hwpt_type, uint32_t len, uint64_t data_ptr, uint32_t out_hwpt_id, int ret) " iommufd=%d dev_id=%u pt_id=%u flags=0x%x hwpt_type=%u len=%u data_ptr=0x%"PRIx64" out_hwpt=%u (%d)"
 iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%d)"
+iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) " iommufd=%d hwpt=%u enable=%d (%d)"

hw/vfio/iommufd.c

@@ -115,6 +115,37 @@ static bool iommufd_hwpt_dirty_tracking(VFIOIOASHwpt *hwpt)
     return hwpt && hwpt->hwpt_flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
 }
 
+static int iommufd_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
+                                           bool start, Error **errp)
+{
+    const VFIOIOMMUFDContainer *container =
+        container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
+    VFIOIOASHwpt *hwpt;
+
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (!iommufd_hwpt_dirty_tracking(hwpt)) {
+            continue;
+        }
+
+        if (!iommufd_backend_set_dirty_tracking(container->be,
+                                                hwpt->hwpt_id, start, errp)) {
+            goto err;
+        }
+    }
+
+    return 0;
+
+err:
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (!iommufd_hwpt_dirty_tracking(hwpt)) {
+            continue;
+        }
+        iommufd_backend_set_dirty_tracking(container->be,
+                                           hwpt->hwpt_id, !start, NULL);
+    }
+    return -EINVAL;
+}
+
 static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 {
     ERRP_GUARD();
@@ -739,6 +770,7 @@ static void vfio_iommu_iommufd_class_init(ObjectClass *klass, void *data)
     vioc->attach_device = iommufd_cdev_attach;
     vioc->detach_device = iommufd_cdev_detach;
     vioc->pci_hot_reset = iommufd_cdev_pci_hot_reset;
+    vioc->set_dirty_page_tracking = iommufd_set_dirty_page_tracking;
 };
 
 static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,

include/sysemu/iommufd.h

@@ -55,6 +55,8 @@ bool iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, uint32_t dev_id,
                                 uint32_t data_type, uint32_t data_len,
                                 void *data_ptr, uint32_t *out_hwpt,
                                 Error **errp);
+bool iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
+                                        bool start, Error **errp);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
 #endif