From 30d40e39bdcb50e67f7cca7bee8bf59234c4ec12 Mon Sep 17 00:00:00 2001
From: Eric Auger <eric.auger@redhat.com>
Date: Thu, 19 Oct 2023 15:45:16 +0200
Subject: [PATCH] virtio-iommu: Implement set_iova_ranges() callback
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The implementation populates the array of per IOMMUDevice
host reserved ranges.

It is forbidden to have conflicting sets of host IOVA ranges
to be applied onto the same IOMMU MR (implied by different
host devices).

In case the callback is called after the probe request has
been issues by the driver, a warning is issued.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: "Michael S. Tsirkin" <mst@redhat.com>
Tested-by: Yanghang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/virtio/virtio-iommu.c         | 67 ++++++++++++++++++++++++++++++++
 include/hw/virtio/virtio-iommu.h |  1 +
 2 files changed, 68 insertions(+)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 13c3c087fe..15aadd6fdd 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -20,6 +20,7 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/iov.h"
+#include "qemu/range.h"
 #include "exec/target_page.h"
 #include "hw/qdev-properties.h"
 #include "hw/virtio/virtio.h"
@@ -1155,6 +1156,71 @@ static int virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr,
     return 0;
 }
 
+/**
+ * virtio_iommu_set_iova_ranges: Conveys the usable IOVA ranges
+ *
+ * The function turns those into reserved ranges. Once some
+ * reserved ranges have been set, new reserved regions cannot be
+ * added outside of the original ones.
+ *
+ * @mr: IOMMU MR
+ * @iova_ranges: list of usable IOVA ranges
+ * @errp: error handle
+ */
+static int virtio_iommu_set_iova_ranges(IOMMUMemoryRegion *mr,
+                                        GList *iova_ranges,
+                                        Error **errp)
+{
+    IOMMUDevice *sdev = container_of(mr, IOMMUDevice, iommu_mr);
+    GList *current_ranges = sdev->host_resv_ranges;
+    GList *l, *tmp, *new_ranges = NULL;
+    int ret = -EINVAL;
+
+    /* check that each new resv region is included in an existing one */
+    if (sdev->host_resv_ranges) {
+        range_inverse_array(iova_ranges,
+                            &new_ranges,
+                            0, UINT64_MAX);
+
+        for (tmp = new_ranges; tmp; tmp = tmp->next) {
+            Range *newr = (Range *)tmp->data;
+            bool included = false;
+
+            for (l = current_ranges; l; l = l->next) {
+                Range * r = (Range *)l->data;
+
+                if (range_contains_range(r, newr)) {
+                    included = true;
+                    break;
+                }
+            }
+            if (!included) {
+                goto error;
+            }
+        }
+        /* all new reserved ranges are included in existing ones */
+        ret = 0;
+        goto out;
+    }
+
+    if (sdev->probe_done) {
+        warn_report("%s: Notified about new host reserved regions after probe",
+                    mr->parent_obj.name);
+    }
+
+    range_inverse_array(iova_ranges,
+                        &sdev->host_resv_ranges,
+                        0, UINT64_MAX);
+
+    return 0;
+error:
+    error_setg(errp, "IOMMU mr=%s Conflicting host reserved ranges set!",
+               mr->parent_obj.name);
+out:
+    g_list_free_full(new_ranges, g_free);
+    return ret;
+}
+
 static void virtio_iommu_system_reset(void *opaque)
 {
     VirtIOIOMMU *s = opaque;
@@ -1450,6 +1516,7 @@ static void virtio_iommu_memory_region_class_init(ObjectClass *klass,
     imrc->replay = virtio_iommu_replay;
     imrc->notify_flag_changed = virtio_iommu_notify_flag_changed;
     imrc->iommu_set_page_size_mask = virtio_iommu_set_page_size_mask;
+    imrc->iommu_set_iova_ranges = virtio_iommu_set_iova_ranges;
 }
 
 static const TypeInfo virtio_iommu_info = {
diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h
index 1dd11ae81a..781ebaea8f 100644
--- a/include/hw/virtio/virtio-iommu.h
+++ b/include/hw/virtio/virtio-iommu.h
@@ -40,6 +40,7 @@ typedef struct IOMMUDevice {
     MemoryRegion root;          /* The root container of the device */
     MemoryRegion bypass_mr;     /* The alias of shared memory MR */
     GList *resv_regions;
+    GList *host_resv_ranges;
     bool probe_done;
 } IOMMUDevice;