[PATCH v2] virtio-gpu: fix unmap the already mapped items

[Li Zhijian]

we go here either (!(*iov)[i].iov_base) or (len != l), so we need to consider
to unmap the 'i'th item as well when the 'i'th item is not nil

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>

---
v2: address Gerd's comments
---
 hw/display/virtio-gpu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 5f0dd7c150..e93f99932a 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -656,6 +656,9 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
             qemu_log_mask(LOG_GUEST_ERROR, "%s: failed to map MMIO memory for"
                           " resource %d element %d\n",
                           __func__, ab->resource_id, i);
+            if ((*iov)[i].iov_base) {
+                i++; /* cleanup the 'i'th map */
+            }
             virtio_gpu_cleanup_mapping_iov(g, *iov, i);
             g_free(ents);
             *iov = NULL;
-- 
2.17.1