virtio-iommu: Free [host_]resv_ranges on unset_iommu_devices

We are currently missing the deallocation of the [host_]resv_regions
in case of hot unplug. Also to make things more simple let's rule
out the case where multiple HostIOMMUDevices would be aliased and
attached to the same IOMMUDevice. This allows to remove the handling
of conflicting Host reserved regions. Anyway this is not properly
supported at guest kernel level. On hotunplug the reserved regions
are reset to the ones set by virtio-iommu property.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20240716094619.1713905-4-eric.auger@redhat.com>
Tested-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 28 insertions, 34 deletions

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 2c54c0d..2de41ab 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -538,8 +538,6 @@ static int virtio_iommu_set_host_iova_ranges(VirtIOIOMMU *s, PCIBus *bus,
 {
     IOMMUPciBus *sbus = g_hash_table_lookup(s->as_by_busptr, bus);
     IOMMUDevice *sdev;
-    GList *current_ranges;
-    GList *l, *tmp, *new_ranges = NULL;
     int ret = -EINVAL;
 
     if (!sbus) {
@@ -553,33 +551,10 @@ static int virtio_iommu_set_host_iova_ranges(VirtIOIOMMU *s, PCIBus *bus,
         return ret;
     }
 
-    current_ranges = sdev->host_resv_ranges;
-
-    /* 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;
+        error_setg(errp, "%s virtio-iommu does not support aliased BDF",
+                   __func__);
+        return ret;
     }
 
     range_inverse_array(iova_ranges,
@@ -588,14 +563,31 @@ static int virtio_iommu_set_host_iova_ranges(VirtIOIOMMU *s, PCIBus *bus,
     rebuild_resv_regions(sdev);
 
     return 0;
-error:
-    error_setg(errp, "%s Conflicting host reserved ranges set!",
-               __func__);
-out:
-    g_list_free_full(new_ranges, g_free);
-    return ret;
 }
 
+static void virtio_iommu_unset_host_iova_ranges(VirtIOIOMMU *s, PCIBus *bus,
+                                                int devfn)
+{
+    IOMMUPciBus *sbus = g_hash_table_lookup(s->as_by_busptr, bus);
+    IOMMUDevice *sdev;
+
+    if (!sbus) {
+        return;
+    }
+
+    sdev = sbus->pbdev[devfn];
+    if (!sdev) {
+        return;
+    }
+
+    g_list_free_full(g_steal_pointer(&sdev->host_resv_ranges), g_free);
+    g_list_free_full(sdev->resv_regions, g_free);
+    sdev->host_resv_ranges = NULL;
+    sdev->resv_regions = NULL;
+    add_prop_resv_regions(sdev);
+}
+
+
 static bool check_page_size_mask(VirtIOIOMMU *viommu, uint64_t new_mask,
                                  Error **errp)
 {
@@ -704,6 +696,8 @@ virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
     if (!hiod) {
         return;
     }
+    virtio_iommu_unset_host_iova_ranges(viommu, hiod->aliased_bus,
+                                        hiod->aliased_devfn);
 
     g_hash_table_remove(viommu->host_iommu_devices, &key);
 }