From: Gerd Hoffmann <kraxel@xxxxxxxxxx> commit 16065fcdd19ddb9e093192914ac863884f308766 upstream. Bisected guest kernel changes crashing qemu. Landed at "6c1cd97bda drm/virtio: fix resource id handling". Looked again, and noticed we where not only leaking *some* ids, but *all* ids. The old code never ever called virtio_gpu_resource_id_put(). So, commit 6c1cd97bda effectively makes the linux kernel starting re-using IDs after releasing them, and apparently virglrenderer can't deal with that. Oops. This patch puts a temporary stopgap into place for the 5.0 release. Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> Reviewed-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20190208140409.15280-1-kraxel@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/virtio/virtgpu_object.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -28,10 +28,21 @@ static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev, uint32_t *resid) { +#if 0 int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL); if (handle < 0) return handle; +#else + static int handle; + + /* + * FIXME: dirty hack to avoid re-using IDs, virglrenderer + * can't deal with that. Needs fixing in virglrenderer, also + * should figure a better way to handle that in the guest. + */ + handle++; +#endif *resid = handle + 1; return 0; @@ -39,7 +50,9 @@ static int virtio_gpu_resource_id_get(st static void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id) { +#if 0 ida_free(&vgdev->resource_ida, id - 1); +#endif } static void virtio_gpu_ttm_bo_destroy(struct ttm_buffer_object *tbo)
