virtio-gpu: Don't ignore virgl_renderer_resource_map() error

When virgl_renderer_resource_map() fails, we should try to map the
uninitialized data pointer and size because it will fail or crash Qemu.
We also should record whether mapping was successful in order to not
to remove the uninitialized memory region, which will crash Qemu.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

hw/display/virtio-gpu-virgl.c

@@ -497,6 +497,8 @@ static void virgl_cmd_resource_map_blob(VirtIOGPU *g,
     ret = virgl_renderer_resource_map(res->resource_id, &data, &size);
     if (ret) {
         g_print("Virgl blob resource map error: %s\n", strerror(-ret));
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
     }
 
     memory_region_init_ram_device_ptr(&res->region, OBJECT(g), NULL, size, data);
@@ -507,6 +509,8 @@ static void virgl_cmd_resource_map_blob(VirtIOGPU *g,
     resp.hdr.type = VIRTIO_GPU_RESP_OK_MAP_INFO;
     virgl_renderer_resource_get_map_info(mblob.resource_id, &resp.map_info);
     virtio_gpu_ctrl_response(g, cmd, &resp.hdr, sizeof(resp));
+
+    res->mapped = true;
 }
 
 static void virgl_cmd_resource_unmap_blob(VirtIOGPU *g,
@@ -532,11 +536,20 @@ static void virgl_cmd_resource_unmap_blob(VirtIOGPU *g,
         return;
     }
 
+    if (!res->mapped) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already unmapped %d\n",
+                      __func__, ublob.resource_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+
     memory_region_set_enabled(&res->region, false);
     memory_region_del_subregion(&g->parent_obj.hostmem, &res->region);
     object_unparent(OBJECT(&res->region));
 
     virgl_renderer_resource_unmap(ublob.resource_id);
+
+    res->mapped = false;
 }
 
 void virtio_gpu_virgl_process_cmd(VirtIOGPU *g,

include/hw/virtio/virtio-gpu.h

@@ -57,6 +57,7 @@ struct virtio_gpu_simple_resource {
     uint8_t *remapped;
 
     MemoryRegion region;
+    bool mapped;
 
     QTAILQ_ENTRY(virtio_gpu_simple_resource) next;
 };