Commit 16065fcd authored Feb 08, 2019 by Gerd Hoffmann Committed by Dave Airlie Feb 11, 2019

drm/virtio: do NOT reuse resource ids



Bisected guest kernel changes crashing qemu.  Landed at
"6c1cd97b 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 6c1cd97b 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@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190208140409.15280-1-kraxel@redhat.com

parent f4bc54b5

drivers/gpu/drm/virtio/virtgpu_object.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -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(struct virtio_gpu_device *vgdev,

		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)