fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-04-04 21:20:37 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

virgl: Set res->maybe_busy to true when creating resources

Browse source 
Currently, res->maybe_busy is false by default. If wait immediately
after the resource is created, virgl_drm_resource_wait() will return
directly without checking the actual state of the kernel, which will
cause synchronization problems, such as:

On Guest:
  pipe_buffer_create [mesa]
    virgl_drm_winsys_resource_create
      virtio_gpu_resource_create_ioctl [kernel]
        virtio_gpu_fence_alloc
        virtio_gpu_object_create
          virtio_gpu_cmd_resource_create_3d
            VIRTIO_GPU_CMD_RESOURCE_CREATE_3D
          virtio_gpu_object_attach
            virtio_gpu_cmd_resource_attach_backing
              VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING
  resource_wait [mesa]
    virgl_drm_resource_wait /* return directly without fence waiting */
  pipe_buffer_map [mesa]
    virgl_drm_resource_map
      virtio_gpu_map_ioctl [kernel]
      os_mmap
  memcpy /* <== here */

On Host (with QEMU):
  VIRTIO_GPU_CMD_RESOURCE_CREATE_3D
    virgl_cmd_create_resource_3d [qemu]
      virgl_renderer_resource_create [virglrenderer]
  VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING
    virgl_resource_attach_backing [qemu]
      virtio_gpu_create_mapping_iov
      virgl_renderer_resource_attach_iov [virglrenderer]
        virgl_resource_attach_iov
          vrend_pipe_resource_attach_iov
            vrend_write_to_iovec /* <== here */
      virtio_gpu_cleanup_mapping_iov [qemu]

In the example above, there is a race condition between memcpy and
vrend_write_to_iovec.

Signed-off-by: Jiang Feng <jiangfeng@kylinos.cn>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17592>
This commit is contained in:
Jiang Feng 2022-07-18 14:53:26 +08:00 • committed by Marge Bot
parent a19dd43082
commit fe9333f7b5
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
View file

@ -455,7 +455,7 @@ alloc:
res = virgl_drm_winsys_resource_create(qws, target, format, bind, width,
height, depth, array_size,
last_level, nr_samples, size,
false);
true);
return res;
}