[PATCH v2 2/7] vdpa: do not save failed dma maps in SVQ iova tree

["Eugenio Pérez" <eperezma@redhat.com>]

If a map fails for whatever reason, it must not be saved in the tree.
Otherwise, qemu will try to unmap it in cleanup, leaving to more errors.

Fixes: 34e3c94eda ("vdpa: Add custom IOTLB translations to SVQ")
Reported-by: Lei Yang <leiyang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 983d3697b0..7e28d2f674 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -176,6 +176,7 @@ static void vhost_vdpa_listener_commit(MemoryListener *listener)
 static void vhost_vdpa_listener_region_add(MemoryListener *listener,
                                            MemoryRegionSection *section)
 {
+    DMAMap mem_region = {};
     struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
     hwaddr iova;
     Int128 llend, llsize;
@@ -212,13 +213,13 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
 
     llsize = int128_sub(llend, int128_make64(iova));
     if (v->shadow_vqs_enabled) {
-        DMAMap mem_region = {
-            .translated_addr = (hwaddr)(uintptr_t)vaddr,
-            .size = int128_get64(llsize) - 1,
-            .perm = IOMMU_ACCESS_FLAG(true, section->readonly),
-        };
+        int r;
 
-        int r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region);
+        mem_region.translated_addr = (hwaddr)(uintptr_t)vaddr,
+        mem_region.size = int128_get64(llsize) - 1,
+        mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly),
+
+        r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region);
         if (unlikely(r != IOVA_OK)) {
             error_report("Can't allocate a mapping (%d)", r);
             goto fail;
@@ -232,11 +233,16 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
                              vaddr, section->readonly);
     if (ret) {
         error_report("vhost vdpa map fail!");
-        goto fail;
+        goto fail_map;
     }
 
     return;
 
+fail_map:
+    if (v->shadow_vqs_enabled) {
+        vhost_iova_tree_remove(v->iova_tree, &mem_region);
+    }
+
 fail:
     /*
      * On the initfn path, store the first error in the container so we
-- 
2.31.1