diff mbox series

[v7] drm/virtio: Add drm_panic support

Message ID 20250206104300.416014-1-ryasuoka@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v7] drm/virtio: Add drm_panic support | expand

Commit Message

Ryosuke Yasuoka Feb. 6, 2025, 10:42 a.m. UTC 
Virtio gpu supports the drm_panic module, which displays a message to
the screen when a kernel panic occurs. It is supported where it has
vmapped shmem BO.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
---
v7:
- Reject no vmapped shmem BO. Also, insert comment and commit log about
  it.
- Restore MAX_INLINE_* and VBUFFER_SIZE definitions to the old place

v6:
https://lore.kernel.org/all/CAHpthZo=R=Csru2P8NVY8YKaasb2RTyrMYni-=8ri4K=xd8abA@mail.gmail.com/

Based on Dmitry's comment, fix the followings
- Reject external dmabufs backing the GEM object
- Allocate vbuf with kmem_cache_zalloc(..., GFP_ATOMIC) instead of
  drmm_kzalloc().

v5:
https://lore.kernel.org/all/CAHpthZrZ6DjsCQ4baQ80b2vOTdkR=vHDx=10W7DTS4ohxb6=pg@mail.gmail.com/

Based on Dmitry's comment, fix the followings
- Rename virtio_panic_buffer to panic_vbuf
- Remove some unnecessary dummy ret and return directly.
- Reject if the bo is VRAM BO
- Remove virtio_gpu_panic_put_vbuf() before notify
- Add description for panic buffer allocation
- Remove virtio_gpu_panic_object_array and use
  virtio_gpu_panic_array_alloc() to allocate objs instead of static
  allocation in stack.

v4:
https://lore.kernel.org/all/ec721548-0d47-4c40-9e9d-59f58e2181ae@redhat.com/

- As per Dmitry's comment, make virtio_panic_buffer private to
  virtio_gpu_device.

v3:
https://lore.kernel.org/all/09d9815c-9d5b-464b-9362-5b8232d36de1@collabora.com/

- As per Jocelyn's comment, add a finite timeout 500usec in
  virtio_gpu_panic_put_vbuf() to avoid infinite loop

v2:
https://lore.kernel.org/all/d885913e-e81c-488e-8db8-e3f7fae13b2c@redhat.com/

- Remove unnecessary virtio_gpu_vbuffer_inline
- Remove reclaim_list and just call drm_gem_object_put() if there is an
   obj
- Don't wait for an event in virtio_gpu_panic_queue_ctrl_sgs and just
   return -ENOMEM. Also add error handlers for this error.
- Use virtio_gpu_panic_queue_fenced_ctrl_buffer() in
virtio_gpu_panic_cmd_resource_flush
- Remove fence and objs arguments because these are always NULL in panic
   handler.
- Rename virtio_gpu_panic_queue_fenced_ctrl_buffer to
   ..._queue_ctrl_buffer
- Rename virtio_gpu_panic_alloc_cmd to ..._panic_init_cmd

v1:
https://lore.kernel.org/all/c7a4a4cd-ce84-4e87-924d-c1c001fc5d28@redhat.com/

 drivers/gpu/drm/virtio/virtgpu_drv.h   |  11 ++
 drivers/gpu/drm/virtio/virtgpu_gem.c   |  14 +++
 drivers/gpu/drm/virtio/virtgpu_plane.c |  96 ++++++++++++++++
 drivers/gpu/drm/virtio/virtgpu_vq.c    | 151 +++++++++++++++++++++++++
 4 files changed, 272 insertions(+)


base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b

Comments

Dmitry Osipenko Feb. 9, 2025, 5:45 p.m. UTC | #1 
On 2/6/25 13:42, Ryosuke Yasuoka wrote:
> Virtio gpu supports the drm_panic module, which displays a message to
> the screen when a kernel panic occurs. It is supported where it has
> vmapped shmem BO.
> 
> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
> ---

Applied to misc-next, thanks!

I've tested v7 with a different capsets, works well. For a non-VT FB the
vmap indeed will be needed. Looking forward to the atomic vmap support.
The rough idea of the atomic vmap helper is to make vmap code paths fail
whenever hitting path that needs to sleep. Likely will be easy to implement.
Jocelyn Falempe Feb. 10, 2025, 11:14 a.m. UTC | #2 
On 09/02/2025 18:45, Dmitry Osipenko wrote:
> On 2/6/25 13:42, Ryosuke Yasuoka wrote:
>> Virtio gpu supports the drm_panic module, which displays a message to
>> the screen when a kernel panic occurs. It is supported where it has
>> vmapped shmem BO.
>>
>> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
>> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
>> ---
> 
> Applied to misc-next, thanks!
> 
> I've tested v7 with a different capsets, works well. For a non-VT FB the
> vmap indeed will be needed. Looking forward to the atomic vmap support.
> The rough idea of the atomic vmap helper is to make vmap code paths fail
> whenever hitting path that needs to sleep. Likely will be easy to implement.
> 

Thanks for your support.

I will see if we can do something for atomic vmap support for shmem.

Best regards,
Ryosuke Yasuoka Feb. 12, 2025, 2:29 p.m. UTC | #3 
On Mon, Feb 10, 2025 at 8:14 PM Jocelyn Falempe <jfalempe@redhat.com> wrote:
>
> On 09/02/2025 18:45, Dmitry Osipenko wrote:
> > On 2/6/25 13:42, Ryosuke Yasuoka wrote:
> >> Virtio gpu supports the drm_panic module, which displays a message to
> >> the screen when a kernel panic occurs. It is supported where it has
> >> vmapped shmem BO.
> >>
> >> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> >> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
> >> ---
> >
> > Applied to misc-next, thanks!
> >
> > I've tested v7 with a different capsets, works well. For a non-VT FB the
> > vmap indeed will be needed. Looking forward to the atomic vmap support.
> > The rough idea of the atomic vmap helper is to make vmap code paths fail
> > whenever hitting path that needs to sleep. Likely will be easy to implement.
> >
>
> Thanks for your support.
>
> I will see if we can do something for atomic vmap support for shmem.
>
> Best regards,
>
> --
>
> Jocelyn
>

Thank you for your kind support.
I'll try to write the atomic vmap support patch soon.

Best regards,
Ryosuke
diff mbox series

Patch

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index f42ca9d8ed10..f17660a71a3e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -310,6 +310,7 @@  int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 				struct drm_device *dev,
 				struct drm_mode_create_dumb *args);
 
+struct virtio_gpu_object_array *virtio_gpu_panic_array_alloc(void);
 struct virtio_gpu_object_array *virtio_gpu_array_alloc(u32 nents);
 struct virtio_gpu_object_array*
 virtio_gpu_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents);
@@ -334,12 +335,21 @@  void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 				    struct virtio_gpu_fence *fence);
 void virtio_gpu_cmd_unref_resource(struct virtio_gpu_device *vgdev,
 				   struct virtio_gpu_object *bo);
+int virtio_gpu_panic_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
+					     uint64_t offset,
+					     uint32_t width, uint32_t height,
+					     uint32_t x, uint32_t y,
+					     struct virtio_gpu_object_array *objs);
 void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 					uint64_t offset,
 					uint32_t width, uint32_t height,
 					uint32_t x, uint32_t y,
 					struct virtio_gpu_object_array *objs,
 					struct virtio_gpu_fence *fence);
+void virtio_gpu_panic_cmd_resource_flush(struct virtio_gpu_device *vgdev,
+					 uint32_t resource_id,
+					 uint32_t x, uint32_t y,
+					 uint32_t width, uint32_t height);
 void virtio_gpu_cmd_resource_flush(struct virtio_gpu_device *vgdev,
 				   uint32_t resource_id,
 				   uint32_t x, uint32_t y,
@@ -408,6 +418,7 @@  void virtio_gpu_ctrl_ack(struct virtqueue *vq);
 void virtio_gpu_cursor_ack(struct virtqueue *vq);
 void virtio_gpu_dequeue_ctrl_func(struct work_struct *work);
 void virtio_gpu_dequeue_cursor_func(struct work_struct *work);
+void virtio_gpu_panic_notify(struct virtio_gpu_device *vgdev);
 void virtio_gpu_notify(struct virtio_gpu_device *vgdev);
 
 int
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 5aab588fc400..dde8fc1a3689 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -148,6 +148,20 @@  void virtio_gpu_gem_object_close(struct drm_gem_object *obj,
 	virtio_gpu_notify(vgdev);
 }
 
+/* For drm panic */
+struct virtio_gpu_object_array *virtio_gpu_panic_array_alloc(void)
+{
+	struct virtio_gpu_object_array *objs;
+
+	objs = kmalloc(sizeof(struct virtio_gpu_object_array), GFP_ATOMIC);
+	if (!objs)
+		return NULL;
+
+	objs->nents = 0;
+	objs->total = 1;
+	return objs;
+}
+
 struct virtio_gpu_object_array *virtio_gpu_array_alloc(u32 nents)
 {
 	struct virtio_gpu_object_array *objs;
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 42aa554eca9f..a6f5a78f436a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -28,6 +28,8 @@ 
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_atomic_helper.h>
 #include <linux/virtio_dma_buf.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_panic.h>
 
 #include "virtgpu_drv.h"
 
@@ -127,6 +129,30 @@  static int virtio_gpu_plane_atomic_check(struct drm_plane *plane,
 	return ret;
 }
 
+/* For drm panic */
+static int virtio_gpu_panic_update_dumb_bo(struct virtio_gpu_device *vgdev,
+					   struct drm_plane_state *state,
+					   struct drm_rect *rect)
+{
+	struct virtio_gpu_object *bo =
+		gem_to_virtio_gpu_obj(state->fb->obj[0]);
+	struct virtio_gpu_object_array *objs;
+	uint32_t w = rect->x2 - rect->x1;
+	uint32_t h = rect->y2 - rect->y1;
+	uint32_t x = rect->x1;
+	uint32_t y = rect->y1;
+	uint32_t off = x * state->fb->format->cpp[0] +
+		y * state->fb->pitches[0];
+
+	objs = virtio_gpu_panic_array_alloc();
+	if (!objs)
+		return -ENOMEM;
+	virtio_gpu_array_add_obj(objs, &bo->base.base);
+
+	return virtio_gpu_panic_cmd_transfer_to_host_2d(vgdev, off, w, h, x, y,
+							objs);
+}
+
 static void virtio_gpu_update_dumb_bo(struct virtio_gpu_device *vgdev,
 				      struct drm_plane_state *state,
 				      struct drm_rect *rect)
@@ -150,6 +176,24 @@  static void virtio_gpu_update_dumb_bo(struct virtio_gpu_device *vgdev,
 					   objs, NULL);
 }
 
+/* For drm_panic */
+static void virtio_gpu_panic_resource_flush(struct drm_plane *plane,
+					    uint32_t x, uint32_t y,
+					    uint32_t width, uint32_t height)
+{
+	struct drm_device *dev = plane->dev;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_object *bo;
+
+	vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
+	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
+
+	virtio_gpu_panic_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y,
+					    width, height);
+	virtio_gpu_panic_notify(vgdev);
+}
+
 static void virtio_gpu_resource_flush(struct drm_plane *plane,
 				      uint32_t x, uint32_t y,
 				      uint32_t width, uint32_t height)
@@ -446,11 +490,63 @@  static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 	virtio_gpu_cursor_ping(vgdev, output);
 }
 
+static int virtio_drm_get_scanout_buffer(struct drm_plane *plane,
+					 struct drm_scanout_buffer *sb)
+{
+	struct virtio_gpu_object *bo;
+
+	if (!plane->state || !plane->state->fb || !plane->state->visible)
+		return -ENODEV;
+
+	bo = gem_to_virtio_gpu_obj(plane->state->fb->obj[0]);
+
+	/* Only support mapped shmem bo */
+	if (virtio_gpu_is_vram(bo) || bo->base.base.import_attach || !bo->base.vaddr)
+		return -ENODEV;
+
+	iosys_map_set_vaddr(&sb->map[0], bo->base.vaddr);
+
+	sb->format = plane->state->fb->format;
+	sb->height = plane->state->fb->height;
+	sb->width = plane->state->fb->width;
+	sb->pitch[0] = plane->state->fb->pitches[0];
+	return 0;
+}
+
+static void virtio_panic_flush(struct drm_plane *plane)
+{
+	struct virtio_gpu_object *bo;
+	struct drm_device *dev = plane->dev;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct drm_rect rect;
+
+	rect.x1 = 0;
+	rect.y1 = 0;
+	rect.x2 = plane->state->fb->width;
+	rect.y2 = plane->state->fb->height;
+
+	bo = gem_to_virtio_gpu_obj(plane->state->fb->obj[0]);
+
+	if (bo->dumb) {
+		if (virtio_gpu_panic_update_dumb_bo(vgdev, plane->state,
+						    &rect))
+			return;
+	}
+
+	virtio_gpu_panic_resource_flush(plane,
+					plane->state->src_x >> 16,
+					plane->state->src_y >> 16,
+					plane->state->src_w >> 16,
+					plane->state->src_h >> 16);
+}
+
 static const struct drm_plane_helper_funcs virtio_gpu_primary_helper_funcs = {
 	.prepare_fb		= virtio_gpu_plane_prepare_fb,
 	.cleanup_fb		= virtio_gpu_plane_cleanup_fb,
 	.atomic_check		= virtio_gpu_plane_atomic_check,
 	.atomic_update		= virtio_gpu_primary_plane_update,
+	.get_scanout_buffer	= virtio_drm_get_scanout_buffer,
+	.panic_flush		= virtio_panic_flush,
 };
 
 static const struct drm_plane_helper_funcs virtio_gpu_cursor_helper_funcs = {
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index ad91624df42d..efac4f244d85 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -86,6 +86,22 @@  void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
 	vgdev->vbufs = NULL;
 }
 
+/* For drm_panic */
+static struct virtio_gpu_vbuffer*
+virtio_gpu_panic_get_vbuf(struct virtio_gpu_device *vgdev, int size)
+{
+	struct virtio_gpu_vbuffer *vbuf;
+
+	vbuf = kmem_cache_zalloc(vgdev->vbufs, GFP_ATOMIC);
+
+	vbuf->buf = (void *)vbuf + sizeof(*vbuf);
+	vbuf->size = size;
+	vbuf->resp_cb = NULL;
+	vbuf->resp_size = sizeof(struct virtio_gpu_ctrl_hdr);
+	vbuf->resp_buf = (void *)vbuf->buf + size;
+	return vbuf;
+}
+
 static struct virtio_gpu_vbuffer*
 virtio_gpu_get_vbuf(struct virtio_gpu_device *vgdev,
 		    int size, int resp_size, void *resp_buf,
@@ -137,6 +153,18 @@  virtio_gpu_alloc_cursor(struct virtio_gpu_device *vgdev,
 	return (struct virtio_gpu_update_cursor *)vbuf->buf;
 }
 
+/* For drm_panic */
+static void *virtio_gpu_panic_alloc_cmd_resp(struct virtio_gpu_device *vgdev,
+					     struct virtio_gpu_vbuffer **vbuffer_p,
+					     int cmd_size)
+{
+	struct virtio_gpu_vbuffer *vbuf;
+
+	vbuf = virtio_gpu_panic_get_vbuf(vgdev, cmd_size);
+	*vbuffer_p = vbuf;
+	return (struct virtio_gpu_command *)vbuf->buf;
+}
+
 static void *virtio_gpu_alloc_cmd_resp(struct virtio_gpu_device *vgdev,
 				       virtio_gpu_resp_cb cb,
 				       struct virtio_gpu_vbuffer **vbuffer_p,
@@ -311,6 +339,34 @@  static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents)
 	return sgt;
 }
 
+/* For drm_panic */
+static int virtio_gpu_panic_queue_ctrl_sgs(struct virtio_gpu_device *vgdev,
+					   struct virtio_gpu_vbuffer *vbuf,
+					   int elemcnt,
+					   struct scatterlist **sgs,
+					   int outcnt,
+					   int incnt)
+{
+	struct virtqueue *vq = vgdev->ctrlq.vq;
+	int ret;
+
+	if (vgdev->has_indirect)
+		elemcnt = 1;
+
+	if (vq->num_free < elemcnt)
+		return -ENOMEM;
+
+	ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
+	WARN_ON(ret);
+
+	vbuf->seqno = ++vgdev->ctrlq.seqno;
+	trace_virtio_gpu_cmd_queue(vq, virtio_gpu_vbuf_ctrl_hdr(vbuf), vbuf->seqno);
+
+	atomic_inc(&vgdev->pending_commands);
+
+	return 0;
+}
+
 static int virtio_gpu_queue_ctrl_sgs(struct virtio_gpu_device *vgdev,
 				     struct virtio_gpu_vbuffer *vbuf,
 				     struct virtio_gpu_fence *fence,
@@ -368,6 +424,32 @@  static int virtio_gpu_queue_ctrl_sgs(struct virtio_gpu_device *vgdev,
 	return 0;
 }
 
+/* For drm_panic */
+static int virtio_gpu_panic_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
+					      struct virtio_gpu_vbuffer *vbuf)
+{
+	struct scatterlist *sgs[3], vcmd, vresp;
+	int elemcnt = 0, outcnt = 0, incnt = 0;
+
+	/* set up vcmd */
+	sg_init_one(&vcmd, vbuf->buf, vbuf->size);
+	elemcnt++;
+	sgs[outcnt] = &vcmd;
+	outcnt++;
+
+	/* set up vresp */
+	if (vbuf->resp_size) {
+		sg_init_one(&vresp, vbuf->resp_buf, vbuf->resp_size);
+		elemcnt++;
+		sgs[outcnt + incnt] = &vresp;
+		incnt++;
+	}
+
+	return virtio_gpu_panic_queue_ctrl_sgs(vgdev, vbuf,
+					       elemcnt, sgs,
+					       outcnt, incnt);
+}
+
 static int virtio_gpu_queue_fenced_ctrl_buffer(struct virtio_gpu_device *vgdev,
 					       struct virtio_gpu_vbuffer *vbuf,
 					       struct virtio_gpu_fence *fence)
@@ -422,6 +504,21 @@  static int virtio_gpu_queue_fenced_ctrl_buffer(struct virtio_gpu_device *vgdev,
 	return ret;
 }
 
+/* For drm_panic */
+void virtio_gpu_panic_notify(struct virtio_gpu_device *vgdev)
+{
+	bool notify;
+
+	if (!atomic_read(&vgdev->pending_commands))
+		return;
+
+	atomic_set(&vgdev->pending_commands, 0);
+	notify = virtqueue_kick_prepare(vgdev->ctrlq.vq);
+
+	if (notify)
+		virtqueue_notify(vgdev->ctrlq.vq);
+}
+
 void virtio_gpu_notify(struct virtio_gpu_device *vgdev)
 {
 	bool notify;
@@ -567,6 +664,29 @@  void virtio_gpu_cmd_set_scanout(struct virtio_gpu_device *vgdev,
 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
 }
 
+/* For drm_panic */
+void virtio_gpu_panic_cmd_resource_flush(struct virtio_gpu_device *vgdev,
+					  uint32_t resource_id,
+					  uint32_t x, uint32_t y,
+					  uint32_t width, uint32_t height)
+{
+	struct virtio_gpu_resource_flush *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+
+	cmd_p = virtio_gpu_panic_alloc_cmd_resp(vgdev, &vbuf, sizeof(*cmd_p));
+	memset(cmd_p, 0, sizeof(*cmd_p));
+	vbuf->objs = NULL;
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_FLUSH);
+	cmd_p->resource_id = cpu_to_le32(resource_id);
+	cmd_p->r.width = cpu_to_le32(width);
+	cmd_p->r.height = cpu_to_le32(height);
+	cmd_p->r.x = cpu_to_le32(x);
+	cmd_p->r.y = cpu_to_le32(y);
+
+	virtio_gpu_panic_queue_ctrl_buffer(vgdev, vbuf);
+}
+
 void virtio_gpu_cmd_resource_flush(struct virtio_gpu_device *vgdev,
 				   uint32_t resource_id,
 				   uint32_t x, uint32_t y,
@@ -591,6 +711,37 @@  void virtio_gpu_cmd_resource_flush(struct virtio_gpu_device *vgdev,
 	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, fence);
 }
 
+/* For drm_panic */
+int virtio_gpu_panic_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
+					     uint64_t offset,
+					     uint32_t width, uint32_t height,
+					     uint32_t x, uint32_t y,
+					     struct virtio_gpu_object_array *objs)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(objs->objs[0]);
+	struct virtio_gpu_transfer_to_host_2d *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
+
+	if (virtio_gpu_is_shmem(bo) && use_dma_api)
+		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
+					    bo->base.sgt, DMA_TO_DEVICE);
+
+	cmd_p = virtio_gpu_panic_alloc_cmd_resp(vgdev, &vbuf, sizeof(*cmd_p));
+	memset(cmd_p, 0, sizeof(*cmd_p));
+	vbuf->objs = objs;
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D);
+	cmd_p->resource_id = cpu_to_le32(bo->hw_res_handle);
+	cmd_p->offset = cpu_to_le64(offset);
+	cmd_p->r.width = cpu_to_le32(width);
+	cmd_p->r.height = cpu_to_le32(height);
+	cmd_p->r.x = cpu_to_le32(x);
+	cmd_p->r.y = cpu_to_le32(y);
+
+	return virtio_gpu_panic_queue_ctrl_buffer(vgdev, vbuf);
+}
+
 void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 					uint64_t offset,
 					uint32_t width, uint32_t height,