virtualization: Add virtio-video driver as external module.

This driver should conform WIP spec v3 [1] with some updates for spec v4
[2], and, some unspecified features such as VIRTIO_VIDEO_DEVICE_CAMERA.

Imported from internal OpenSynergy's revision:

  bcc33b6b9e0156b381a70c54d2df02c57b63d270

Kernel was configured with necessary features for this driver:

  enable MEDIA_SUPPORT
  disable MEDIA_SUBDRV_AUTOSELECT
  enable MEDIA_PLATFORM_SUPPORT
  enable VIDEO_VIRTIO

Keep driver as an external module to simplify future updates.

[1]: https://lists.oasis-open.org/archives/virtio-dev/202002/msg00002.html
[2]: https://lists.oasis-open.org/archives/virtio-dev/202006/msg00072.html

Bug-AGL: SPEC-4148
Change-Id: Iea339194b22443f67b3e2ffddca84118357a2f15
Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>

1 files changed, 981 insertions, 0 deletions

diff --git a/meta-egvirt/recipes-kernel/kernel-module-virtio-video/files/virtio_video_vq.c b/meta-egvirt/recipes-kernel/kernel-module-virtio-video/files/virtio_video_vq.c
new file mode 100644
index 00000000..f3c97c7e
--- /dev/null
+++ b/meta-egvirt/recipes-kernel/kernel-module-virtio-video/files/virtio_video_vq.c
@@ -0,0 +1,981 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Driver for virtio video device.
+ *
+ * Copyright 2020 OpenSynergy GmbH.
+ *
+ * Based on drivers/gpu/drm/virtio/virtgpu_vq.c
+ * Copyright (C) 2015 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "virtio_video.h"
+
+#define MAX_INLINE_CMD_SIZE   298
+#define MAX_INLINE_RESP_SIZE  298
+#define VBUFFER_SIZE          (sizeof(struct virtio_video_vbuffer) \
+			       + MAX_INLINE_CMD_SIZE		   \
+			       + MAX_INLINE_RESP_SIZE)
+
+static int virtio_video_queue_event_buffer(struct virtio_video_device *vvd,
+					   struct virtio_video_event *evt);
+static void virtio_video_handle_event(struct virtio_video_device *vvd,
+				      struct virtio_video_event *evt);
+
+void virtio_video_resource_id_get(struct virtio_video_device *vvd, uint32_t *id)
+{
+	int handle;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&vvd->resource_idr_lock);
+	handle = idr_alloc(&vvd->resource_idr, NULL, 1, 0, GFP_NOWAIT);
+	spin_unlock(&vvd->resource_idr_lock);
+	idr_preload_end();
+	*id = handle;
+}
+
+void virtio_video_resource_id_put(struct virtio_video_device *vvd, uint32_t id)
+{
+	spin_lock(&vvd->resource_idr_lock);
+	idr_remove(&vvd->resource_idr, id);
+	spin_unlock(&vvd->resource_idr_lock);
+}
+
+void virtio_video_stream_id_get(struct virtio_video_device *vvd,
+				struct virtio_video_stream *stream,
+				uint32_t *id)
+{
+	int handle;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&vvd->stream_idr_lock);
+	handle = idr_alloc(&vvd->stream_idr, stream, 1, 0, 0);
+	spin_unlock(&vvd->stream_idr_lock);
+	idr_preload_end();
+	*id = handle;
+}
+
+void virtio_video_stream_id_put(struct virtio_video_device *vvd, uint32_t id)
+{
+	spin_lock(&vvd->stream_idr_lock);
+	idr_remove(&vvd->stream_idr, id);
+	spin_unlock(&vvd->stream_idr_lock);
+}
+
+static bool vbuf_is_pending(struct virtio_video_device *vvd,
+			    struct virtio_video_vbuffer *vbuf)
+{
+	struct virtio_video_vbuffer *entry;
+
+	list_for_each_entry(entry, &vvd->pending_vbuf_list, pending_list_entry)
+	{
+		if (entry == vbuf && entry->id == vbuf->id)
+			return true;
+	}
+
+	return false;
+}
+
+static void free_vbuf(struct virtio_video_device *vvd,
+		      struct virtio_video_vbuffer *vbuf)
+{
+	list_del(&vbuf->pending_list_entry);
+	kfree(vbuf->data_buf);
+	kmem_cache_free(vvd->vbufs, vbuf);
+}
+
+void virtio_video_cmd_cb(struct virtqueue *vq)
+{
+	struct virtio_video_device *vvd = vq->vdev->priv;
+	struct virtio_video_vbuffer *vbuf;
+	unsigned long flags;
+	unsigned int len;
+
+	spin_lock_irqsave(&vvd->commandq.qlock, flags);
+	while (vvd->commandq.ready) {
+		virtqueue_disable_cb(vq);
+
+		while ((vbuf = virtqueue_get_buf(vq, &len))) {
+			if (!vbuf_is_pending(vvd, vbuf))
+				continue;
+
+			if (vbuf->resp_cb)
+				vbuf->resp_cb(vvd, vbuf);
+
+			if (vbuf->is_sync)
+				complete(&vbuf->reclaimed);
+			else
+				free_vbuf(vvd, vbuf);
+		}
+
+		if (unlikely(virtqueue_is_broken(vq)))
+			break;
+
+		if (virtqueue_enable_cb(vq))
+			break;
+	}
+	spin_unlock_irqrestore(&vvd->commandq.qlock, flags);
+
+	wake_up(&vvd->commandq.reclaim_queue);
+}
+
+void virtio_video_process_events(struct work_struct *work)
+{
+	struct virtio_video_device *vvd = container_of(work,
+			struct virtio_video_device, eventq.work);
+	struct virtqueue *vq = vvd->eventq.vq;
+	struct virtio_video_event *evt;
+	unsigned int len;
+
+	while (vvd->eventq.ready) {
+		virtqueue_disable_cb(vq);
+
+		while ((evt = virtqueue_get_buf(vq, &len))) {
+			virtio_video_handle_event(vvd, evt);
+			virtio_video_queue_event_buffer(vvd, evt);
+		}
+
+		if (unlikely(virtqueue_is_broken(vq)))
+			break;
+
+		if (virtqueue_enable_cb(vq))
+			break;
+	}
+}
+
+void virtio_video_event_cb(struct virtqueue *vq)
+{
+	struct virtio_video_device *vvd = vq->vdev->priv;
+
+	schedule_work(&vvd->eventq.work);
+}
+
+static struct virtio_video_vbuffer *
+virtio_video_get_vbuf(struct virtio_video_device *vvd, int size, int resp_size,
+		      void *resp_buf, virtio_video_resp_cb resp_cb)
+{
+	struct virtio_video_vbuffer *vbuf;
+
+	vbuf = kmem_cache_alloc(vvd->vbufs, GFP_KERNEL);
+	if (!vbuf)
+		return ERR_PTR(-ENOMEM);
+	memset(vbuf, 0, VBUFFER_SIZE);
+
+	BUG_ON(size > MAX_INLINE_CMD_SIZE);
+	vbuf->buf = (void *)vbuf + sizeof(*vbuf);
+	vbuf->size = size;
+
+	vbuf->resp_cb = resp_cb;
+	vbuf->resp_size = resp_size;
+	if (resp_size <= MAX_INLINE_RESP_SIZE && !resp_buf)
+		vbuf->resp_buf = (void *)vbuf->buf + size;
+	else
+		vbuf->resp_buf = resp_buf;
+	BUG_ON(!vbuf->resp_buf);
+
+	return vbuf;
+}
+
+int virtio_video_alloc_vbufs(struct virtio_video_device *vvd)
+{
+	vvd->vbufs =
+		kmem_cache_create("virtio-video-vbufs", VBUFFER_SIZE,
+				  __alignof__(struct virtio_video_vbuffer), 0,
+				  NULL);
+	if (!vvd->vbufs)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void virtio_video_free_vbufs(struct virtio_video_device *vvd)
+{
+	struct virtio_video_vbuffer *vbuf;
+
+	/* Release command buffers. Operation on vbufs here is lock safe,
+           since before device was deinitialized and queues was stopped
+           (in not ready state) */
+	while ((vbuf = virtqueue_detach_unused_buf(vvd->commandq.vq))) {
+		if (vbuf_is_pending(vvd, vbuf))
+			free_vbuf(vvd, vbuf);
+	}
+
+	kmem_cache_destroy(vvd->vbufs);
+	vvd->vbufs = NULL;
+
+	/* Release event buffers */
+	while (virtqueue_detach_unused_buf(vvd->eventq.vq));
+
+	kfree(vvd->evts);
+	vvd->evts = NULL;
+}
+
+static void *virtio_video_alloc_req(struct virtio_video_device *vvd,
+				    struct virtio_video_vbuffer **vbuffer_p,
+				    int size)
+{
+	struct virtio_video_vbuffer *vbuf;
+
+	vbuf = virtio_video_get_vbuf(vvd, size,
+				     sizeof(struct virtio_video_cmd_hdr),
+				     NULL, NULL);
+	if (IS_ERR(vbuf)) {
+		*vbuffer_p = NULL;
+		return ERR_CAST(vbuf);
+	}
+	*vbuffer_p = vbuf;
+
+	return vbuf->buf;
+}
+
+static void *
+virtio_video_alloc_req_resp(struct virtio_video_device *vvd,
+			    virtio_video_resp_cb cb,
+			    struct virtio_video_vbuffer **vbuffer_p,
+			    int req_size, int resp_size,
+			    void *resp_buf)
+{
+	struct virtio_video_vbuffer *vbuf;
+
+	vbuf = virtio_video_get_vbuf(vvd, req_size, resp_size, resp_buf, cb);
+	if (IS_ERR(vbuf)) {
+		*vbuffer_p = NULL;
+		return ERR_CAST(vbuf);
+	}
+	*vbuffer_p = vbuf;
+
+	return vbuf->buf;
+}
+
+static int
+virtio_video_queue_cmd_buffer(struct virtio_video_device *vvd,
+			      struct virtio_video_vbuffer *vbuf)
+{
+	unsigned long flags;
+	struct virtqueue *vq = vvd->commandq.vq;
+	struct scatterlist *sgs[3], vreq, vout, vresp;
+	int outcnt = 0, incnt = 0;
+	int ret;
+
+	if (!vvd->commandq.ready)
+		return -ENODEV;
+
+	spin_lock_irqsave(&vvd->commandq.qlock, flags);
+
+	vbuf->id = vvd->vbufs_sent++;
+	list_add_tail(&vbuf->pending_list_entry, &vvd->pending_vbuf_list);
+
+	sg_init_one(&vreq, vbuf->buf, vbuf->size);
+	sgs[outcnt + incnt] = &vreq;
+	outcnt++;
+
+	if (vbuf->data_size) {
+		sg_init_one(&vout, vbuf->data_buf, vbuf->data_size);
+		sgs[outcnt + incnt] = &vout;
+		outcnt++;
+	}
+
+	if (vbuf->resp_size) {
+		sg_init_one(&vresp, vbuf->resp_buf, vbuf->resp_size);
+		sgs[outcnt + incnt] = &vresp;
+		incnt++;
+	}
+
+retry:
+	ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
+	if (ret == -ENOSPC) {
+		spin_unlock_irqrestore(&vvd->commandq.qlock, flags);
+		wait_event(vvd->commandq.reclaim_queue, vq->num_free);
+		spin_lock_irqsave(&vvd->commandq.qlock, flags);
+		goto retry;
+	} else {
+		virtqueue_kick(vq);
+	}
+
+	spin_unlock_irqrestore(&vvd->commandq.qlock, flags);
+
+	return ret;
+}
+
+static int
+virtio_video_queue_cmd_buffer_sync(struct virtio_video_device *vvd,
+				   struct virtio_video_vbuffer *vbuf)
+{
+	int ret;
+	unsigned long rem;
+	unsigned long flags;
+
+	vbuf->is_sync = true;
+	init_completion(&vbuf->reclaimed);
+
+	ret = virtio_video_queue_cmd_buffer(vvd, vbuf);
+	if (ret)
+		return ret;
+
+	rem = wait_for_completion_timeout(&vbuf->reclaimed, 5 * HZ);
+	if (rem == 0)
+		ret = -ETIMEDOUT;
+
+	spin_lock_irqsave(&vvd->commandq.qlock, flags);
+	if (vbuf_is_pending(vvd, vbuf))
+		free_vbuf(vvd, vbuf);
+	spin_unlock_irqrestore(&vvd->commandq.qlock, flags);
+
+	return ret;
+}
+
+static int virtio_video_queue_event_buffer(struct virtio_video_device *vvd,
+					   struct virtio_video_event *evt)
+{
+	int ret;
+	struct scatterlist sg;
+	struct virtqueue *vq = vvd->eventq.vq;
+
+	memset(evt, 0, sizeof(struct virtio_video_event));
+	sg_init_one(&sg, evt, sizeof(struct virtio_video_event));
+
+	ret = virtqueue_add_inbuf(vq, &sg, 1, evt, GFP_KERNEL);
+	if (ret) {
+		v4l2_err(&vvd->v4l2_dev, "failed to queue event buffer\n");
+		return ret;
+	}
+
+	virtqueue_kick(vq);
+
+	return 0;
+}
+
+static void virtio_video_handle_event(struct virtio_video_device *vvd,
+				      struct virtio_video_event *evt)
+{
+	int ret;
+	struct virtio_video_stream *stream;
+	uint32_t stream_id = evt->stream_id;
+	struct video_device *vd = &vvd->video_dev;
+
+	mutex_lock(vd->lock);
+
+	stream = idr_find(&vvd->stream_idr, stream_id);
+	if (!stream) {
+		v4l2_warn(&vvd->v4l2_dev, "stream_id=%u not found for event\n",
+			  stream_id);
+		mutex_unlock(vd->lock);
+		return;
+	}
+
+	switch (le32_to_cpu(evt->event_type)) {
+	case VIRTIO_VIDEO_EVENT_DECODER_RESOLUTION_CHANGED:
+		v4l2_dbg(1, vvd->debug, &vvd->v4l2_dev,
+			 "stream_id=%u: resolution change event\n", stream_id);
+		virtio_video_cmd_get_params(vvd, stream,
+					   VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT);
+		virtio_video_queue_res_chg_event(stream);
+		if (virtio_video_state(stream) == STREAM_STATE_INIT) {
+			virtio_video_state_update(stream,
+						  STREAM_STATE_DYNAMIC_RES_CHANGE);
+			wake_up(&vvd->wq);
+		}
+		break;
+	case VIRTIO_VIDEO_EVENT_ERROR:
+		v4l2_err(&vvd->v4l2_dev, "stream_id=%i: error event\n",
+			 stream_id);
+		virtio_video_state_update(stream, STREAM_STATE_ERROR);
+		virtio_video_handle_error(stream);
+		break;
+	default:
+		v4l2_warn(&vvd->v4l2_dev, "stream_id=%i: unknown event\n",
+			  stream_id);
+		break;
+	}
+
+	mutex_unlock(vd->lock);
+}
+
+int virtio_video_alloc_events(struct virtio_video_device *vvd)
+{
+	int ret;
+	size_t i;
+	struct virtio_video_event *evts;
+	size_t num =  vvd->eventq.vq->num_free;
+
+	evts = kzalloc(num * sizeof(struct virtio_video_event), GFP_KERNEL);
+	if (!evts) {
+		v4l2_err(&vvd->v4l2_dev, "failed to alloc event buffers!!!\n");
+		return -ENOMEM;
+	}
+	vvd->evts = evts;
+
+	for (i = 0; i < num; i++) {
+		ret = virtio_video_queue_event_buffer(vvd, &evts[i]);
+		if (ret) {
+			v4l2_err(&vvd->v4l2_dev,
+				 "failed to queue event buffer\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_stream_create(struct virtio_video_device *vvd,
+				   uint32_t stream_id,
+				   enum virtio_video_format format,
+				   const char *tag)
+{
+	struct virtio_video_stream_create *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_STREAM_CREATE);
+	req_p->hdr.stream_id = cpu_to_le32(stream_id);
+	req_p->in_mem_type = cpu_to_le32(VIRTIO_VIDEO_MEM_TYPE_GUEST_PAGES);
+	req_p->out_mem_type = cpu_to_le32(VIRTIO_VIDEO_MEM_TYPE_GUEST_PAGES);
+	req_p->coded_format = cpu_to_le32(format);
+	if (strscpy(req_p->tag, tag, sizeof(req_p->tag) - 1) < 0)
+		v4l2_err(&vvd->v4l2_dev, "failed to copy stream tag\n");
+	req_p->tag[sizeof(req_p->tag) - 1] = 0;
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_stream_destroy(struct virtio_video_device *vvd,
+				    uint32_t stream_id)
+{
+	struct virtio_video_stream_destroy *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_STREAM_DESTROY);
+	req_p->hdr.stream_id = cpu_to_le32(stream_id);
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_stream_drain(struct virtio_video_device *vvd,
+				  uint32_t stream_id)
+{
+	struct virtio_video_stream_drain *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_STREAM_DRAIN);
+	req_p->hdr.stream_id = cpu_to_le32(stream_id);
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+int virtio_video_cmd_resource_attach(struct virtio_video_device *vvd,
+				     uint32_t stream_id, uint32_t resource_id,
+				     enum virtio_video_queue_type queue_type,
+				     void *buf, size_t buf_size)
+{
+	struct virtio_video_resource_attach *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->cmd_type = cpu_to_le32(VIRTIO_VIDEO_CMD_RESOURCE_ATTACH);
+	req_p->stream_id = cpu_to_le32(stream_id);
+	req_p->queue_type = cpu_to_le32(queue_type);
+	req_p->resource_id = cpu_to_le32(resource_id);
+
+	vbuf->data_buf = buf;
+	vbuf->data_size = buf_size;
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+int virtio_video_cmd_queue_detach_resources(struct virtio_video_device *vvd,
+				struct virtio_video_stream *stream,
+				enum virtio_video_queue_type queue_type)
+{
+	int ret;
+	struct virtio_video_queue_detach_resources *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->cmd_type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUEUE_DETACH_RESOURCES);
+	req_p->stream_id = cpu_to_le32(stream->stream_id);
+	req_p->queue_type = cpu_to_le32(queue_type);
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for resource destruction for %s\n",
+			 (queue_type == VIRTIO_VIDEO_QUEUE_TYPE_INPUT) ?
+			 "OUTPUT" : "CAPTURE");
+	return ret;
+}
+
+static void
+virtio_video_cmd_resource_queue_cb(struct virtio_video_device *vvd,
+				   struct virtio_video_vbuffer *vbuf)
+{
+	uint32_t flags;
+	uint64_t timestamp;
+	struct virtio_video_buffer *virtio_vb = vbuf->priv;
+	struct virtio_video_resource_queue_resp *resp =
+		(struct virtio_video_resource_queue_resp *)vbuf->resp_buf;
+
+	flags = le32_to_cpu(resp->flags);
+	timestamp = le64_to_cpu(resp->timestamp);
+
+	virtio_video_buf_done(virtio_vb, flags, timestamp, resp->data_sizes);
+}
+
+int virtio_video_cmd_resource_queue(struct virtio_video_device *vvd,
+				    uint32_t stream_id,
+				    struct virtio_video_buffer *virtio_vb,
+				    uint32_t data_size[],
+				    uint8_t num_data_size,
+				    enum virtio_video_queue_type queue_type)
+{
+	uint8_t i;
+	struct virtio_video_resource_queue *req_p;
+	struct virtio_video_resource_queue_resp *resp_p;
+	struct virtio_video_vbuffer *vbuf;
+	size_t resp_size = sizeof(struct virtio_video_resource_queue_resp);
+
+	req_p = virtio_video_alloc_req_resp(vvd,
+					    &virtio_video_cmd_resource_queue_cb,
+					    &vbuf, sizeof(*req_p), resp_size,
+					    NULL);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->cmd_type = cpu_to_le32(VIRTIO_VIDEO_CMD_RESOURCE_QUEUE);
+	req_p->stream_id = cpu_to_le32(stream_id);
+	req_p->queue_type = cpu_to_le32(queue_type);
+	req_p->resource_id = cpu_to_le32(virtio_vb->resource_id);
+	req_p->flags = 0;
+	req_p->timestamp =
+		cpu_to_le64(virtio_vb->v4l2_m2m_vb.vb.vb2_buf.timestamp);
+
+	for (i = 0; i < num_data_size; ++i)
+		req_p->data_sizes[i] = cpu_to_le32(data_size[i]);
+
+	resp_p = (struct virtio_video_resource_queue_resp *)vbuf->resp_buf;
+	memset(resp_p, 0, sizeof(*resp_p));
+
+	vbuf->priv = virtio_vb;
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_queue_clear(struct virtio_video_device *vvd,
+				 struct virtio_video_stream *stream,
+				 enum virtio_video_queue_type queue_type)
+{
+	int ret;
+	struct virtio_video_queue_clear *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUEUE_CLEAR);
+	req_p->hdr.stream_id = cpu_to_le32(stream->stream_id);
+	req_p->queue_type = cpu_to_le32(queue_type);
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for %s queue clear\n",
+			 (queue_type == VIRTIO_VIDEO_QUEUE_TYPE_INPUT) ?
+			 "OUTPUT" : "CAPTURE");
+	return ret;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_query_capability(struct virtio_video_device *vvd,
+				      void *resp_buf, size_t resp_size,
+				      enum virtio_video_queue_type queue_type)
+{
+	int ret;
+	struct virtio_video_query_capability *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req_resp(vvd, NULL, &vbuf, sizeof(*req_p),
+					    resp_size, resp_buf);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUERY_CAPABILITY);
+	req_p->queue_type = cpu_to_le32(queue_type);
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for capabilities for %s\n",
+			 (queue_type == VIRTIO_VIDEO_QUEUE_TYPE_INPUT) ?
+			 "OUTPUT" : "CAPTURE");
+	return ret;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_query_control_level(struct virtio_video_device *vvd,
+				     void *resp_buf, size_t resp_size,
+				     enum virtio_video_format format)
+{
+	int ret;
+	struct virtio_video_query_control *req_p;
+	struct virtio_video_query_control_level *ctrl_l;
+	struct virtio_video_vbuffer *vbuf;
+	uint32_t req_size = 0;
+
+	req_size = sizeof(struct virtio_video_query_control) +
+		sizeof(struct virtio_video_query_control_level);
+
+	req_p = virtio_video_alloc_req_resp(vvd, NULL, &vbuf, req_size,
+					    resp_size, resp_buf);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUERY_CONTROL);
+	req_p->control = cpu_to_le32(VIRTIO_VIDEO_CONTROL_LEVEL);
+	ctrl_l = (void *)((char *)req_p +
+			  sizeof(struct virtio_video_query_control));
+	ctrl_l->format = cpu_to_le32(format);
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for level query\n");
+	return ret;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_query_control_profile(struct virtio_video_device *vvd,
+				       void *resp_buf, size_t resp_size,
+				       enum virtio_video_format format)
+{
+	int ret;
+	struct virtio_video_query_control *req_p;
+	struct virtio_video_query_control_profile *ctrl_p;
+	struct virtio_video_vbuffer *vbuf;
+	uint32_t req_size = 0;
+
+	req_size = sizeof(struct virtio_video_query_control) +
+		sizeof(struct virtio_video_query_control_profile);
+
+	req_p = virtio_video_alloc_req_resp(vvd, NULL, &vbuf, req_size,
+					    resp_size, resp_buf);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUERY_CONTROL);
+	req_p->control = cpu_to_le32(VIRTIO_VIDEO_CONTROL_PROFILE);
+	ctrl_p = (void *)((char *)req_p +
+			  sizeof(struct virtio_video_query_control));
+	ctrl_p->format = cpu_to_le32(format);
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for profile query\n");
+	return ret;
+}
+
+static void
+virtio_video_cmd_get_params_cb(struct virtio_video_device *vvd,
+			       struct virtio_video_vbuffer *vbuf)
+{
+	int i;
+	struct virtio_video_get_params_resp *resp =
+		(struct virtio_video_get_params_resp *)vbuf->resp_buf;
+	struct virtio_video_params *params = &resp->params;
+	struct virtio_video_stream *stream = vbuf->priv;
+	enum virtio_video_queue_type queue_type;
+	struct video_format_info *format_info;
+
+	queue_type = le32_to_cpu(params->queue_type);
+	if (queue_type == VIRTIO_VIDEO_QUEUE_TYPE_INPUT)
+		format_info = &stream->in_info;
+	else
+		format_info = &stream->out_info;
+
+	format_info->frame_rate = le32_to_cpu(params->frame_rate);
+	format_info->frame_width = le32_to_cpu(params->frame_width);
+	format_info->frame_height = le32_to_cpu(params->frame_height);
+	format_info->min_buffers = le32_to_cpu(params->min_buffers);
+	format_info->max_buffers = le32_to_cpu(params->max_buffers);
+	format_info->fourcc_format =
+		virtio_video_format_to_v4l2(le32_to_cpu(params->format));
+
+	format_info->crop.top = le32_to_cpu(params->crop.top);
+	format_info->crop.left = le32_to_cpu(params->crop.left);
+	format_info->crop.width = le32_to_cpu(params->crop.width);
+	format_info->crop.height = le32_to_cpu(params->crop.height);
+
+	format_info->num_planes = le32_to_cpu(params->num_planes);
+	for (i = 0; i < le32_to_cpu(params->num_planes); i++) {
+		struct virtio_video_plane_format *plane_formats =
+						 &params->plane_formats[i];
+		struct video_plane_format *plane_format =
+						 &format_info->plane_format[i];
+
+		plane_format->plane_size =
+				 le32_to_cpu(plane_formats->plane_size);
+		plane_format->stride = le32_to_cpu(plane_formats->stride);
+	}
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_get_params(struct virtio_video_device *vvd,
+				struct virtio_video_stream *stream,
+				enum virtio_video_queue_type queue_type)
+{
+	int ret;
+	struct virtio_video_get_params *req_p;
+	struct virtio_video_vbuffer *vbuf;
+	struct virtio_video_get_params_resp *resp_p;
+	size_t resp_size = sizeof(struct virtio_video_get_params_resp);
+
+	req_p = virtio_video_alloc_req_resp(vvd,
+					&virtio_video_cmd_get_params_cb,
+					&vbuf, sizeof(*req_p), resp_size,
+					NULL);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_GET_PARAMS);
+	req_p->hdr.stream_id = cpu_to_le32(stream->stream_id);
+	req_p->queue_type = cpu_to_le32(queue_type);
+
+	resp_p = (struct virtio_video_get_params_resp *)vbuf->resp_buf;
+
+	vbuf->priv = stream;
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for get_params\n");
+	return ret;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int
+virtio_video_cmd_set_params(struct virtio_video_device *vvd,
+			    struct virtio_video_stream *stream,
+			    struct video_format_info *format_info,
+			    enum virtio_video_queue_type queue_type)
+{
+	int i;
+	struct virtio_video_set_params *req_p;
+	struct virtio_video_vbuffer *vbuf;
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_SET_PARAMS);
+	req_p->hdr.stream_id = cpu_to_le32(stream->stream_id);
+	req_p->params.queue_type = cpu_to_le32(queue_type);
+	req_p->params.frame_rate = cpu_to_le32(format_info->frame_rate);
+	req_p->params.frame_width = cpu_to_le32(format_info->frame_width);
+	req_p->params.frame_height = cpu_to_le32(format_info->frame_height);
+	req_p->params.format = virtio_video_v4l2_format_to_virtio(
+				 cpu_to_le32(format_info->fourcc_format));
+	req_p->params.min_buffers = cpu_to_le32(format_info->min_buffers);
+	req_p->params.max_buffers = cpu_to_le32(format_info->max_buffers);
+	req_p->params.num_planes = cpu_to_le32(format_info->num_planes);
+
+	for (i = 0; i < format_info->num_planes; i++) {
+		struct virtio_video_plane_format *plane_formats =
+			&req_p->params.plane_formats[i];
+		struct video_plane_format *plane_format =
+			&format_info->plane_format[i];
+		plane_formats->plane_size =
+				 cpu_to_le32(plane_format->plane_size);
+		plane_formats->stride = cpu_to_le32(plane_format->stride);
+	}
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+
+static void
+virtio_video_cmd_get_ctrl_profile_cb(struct virtio_video_device *vvd,
+				     struct virtio_video_vbuffer *vbuf)
+{
+	struct virtio_video_get_control_resp *resp =
+		(struct virtio_video_get_control_resp *)vbuf->resp_buf;
+	struct virtio_video_control_val_profile *resp_p = NULL;
+	struct virtio_video_stream *stream = vbuf->priv;
+	struct video_control_info *control = &stream->control;
+
+	resp_p = (void *)((char *)resp +
+			  sizeof(struct virtio_video_get_control_resp));
+
+	control->profile = le32_to_cpu(resp_p->profile);
+}
+
+static void
+virtio_video_cmd_get_ctrl_level_cb(struct virtio_video_device *vvd,
+				   struct virtio_video_vbuffer *vbuf)
+{
+	struct virtio_video_get_control_resp *resp =
+		(struct virtio_video_get_control_resp *)vbuf->resp_buf;
+	struct virtio_video_control_val_level *resp_p;
+	struct virtio_video_stream *stream = vbuf->priv;
+	struct video_control_info *control = &stream->control;
+
+	resp_p = (void *)((char *)resp +
+			  sizeof(struct virtio_video_get_control_resp));
+
+	control->level = le32_to_cpu(resp_p->level);
+}
+
+static void
+virtio_video_cmd_get_ctrl_bitrate_cb(struct virtio_video_device *vvd,
+				     struct virtio_video_vbuffer *vbuf)
+{
+	struct virtio_video_get_control_resp *resp =
+		(struct virtio_video_get_control_resp *)vbuf->resp_buf;
+	struct virtio_video_control_val_bitrate *resp_p = NULL;
+	struct virtio_video_stream *stream = vbuf->priv;
+	struct video_control_info *control = &stream->control;
+
+	resp_p = (void *)((char *) resp +
+			  sizeof(struct virtio_video_get_control_resp));
+
+	control->bitrate = le32_to_cpu(resp_p->bitrate);
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_get_control(struct virtio_video_device *vvd,
+				 struct virtio_video_stream *stream,
+				 enum virtio_video_control_type control)
+{
+	int ret;
+	struct virtio_video_get_control *req_p;
+	struct virtio_video_get_control_resp *resp_p;
+	struct virtio_video_vbuffer *vbuf;
+	size_t resp_size = sizeof(struct virtio_video_get_control_resp);
+	virtio_video_resp_cb cb;
+
+	switch (control) {
+	case VIRTIO_VIDEO_CONTROL_PROFILE:
+		resp_size += sizeof(struct virtio_video_control_val_profile);
+		cb = &virtio_video_cmd_get_ctrl_profile_cb;
+		break;
+	case VIRTIO_VIDEO_CONTROL_LEVEL:
+		resp_size += sizeof(struct virtio_video_control_val_level);
+		cb = &virtio_video_cmd_get_ctrl_level_cb;
+		break;
+	case VIRTIO_VIDEO_CONTROL_BITRATE:
+		resp_size += sizeof(struct virtio_video_control_val_bitrate);
+		cb = &virtio_video_cmd_get_ctrl_bitrate_cb;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	req_p = virtio_video_alloc_req_resp(vvd, cb, &vbuf,
+					    sizeof(*req_p), resp_size, NULL);
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_GET_CONTROL);
+	req_p->hdr.stream_id = cpu_to_le32(stream->stream_id);
+	req_p->control = cpu_to_le32(control);
+
+	resp_p = (struct virtio_video_get_control_resp *)vbuf->resp_buf;
+
+	vbuf->priv = stream;
+
+	ret = virtio_video_queue_cmd_buffer_sync(vvd, vbuf);
+	if (ret == -ETIMEDOUT)
+		v4l2_err(&vvd->v4l2_dev,
+			 "timed out waiting for get_control\n");
+	return ret;
+}
+
+// TODO: replace virtio_video_cmd_hdr accoring to specification v4
+int virtio_video_cmd_set_control(struct virtio_video_device *vvd,
+				 uint32_t stream_id,
+				 enum virtio_video_control_type control,
+				 uint32_t value)
+{
+	struct virtio_video_set_control *req_p;
+	struct virtio_video_vbuffer *vbuf;
+	struct virtio_video_control_val_level *ctrl_l;
+	struct virtio_video_control_val_profile *ctrl_p;
+	struct virtio_video_control_val_bitrate *ctrl_b;
+	size_t size;
+
+	if (value == 0)
+		return -EINVAL;
+
+	switch (control) {
+	case VIRTIO_VIDEO_CONTROL_PROFILE:
+		size = sizeof(struct virtio_video_control_val_profile);
+		break;
+	case VIRTIO_VIDEO_CONTROL_LEVEL:
+		size = sizeof(struct virtio_video_control_val_level);
+		break;
+	case VIRTIO_VIDEO_CONTROL_BITRATE:
+		size = sizeof(struct virtio_video_control_val_bitrate);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	req_p = virtio_video_alloc_req(vvd, &vbuf, size + sizeof(*req_p));
+	if (IS_ERR(req_p))
+		return PTR_ERR(req_p);
+
+	req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_SET_CONTROL);
+	req_p->hdr.stream_id = cpu_to_le32(stream_id);
+	req_p->control = cpu_to_le32(control);
+
+	switch (control) {
+	case VIRTIO_VIDEO_CONTROL_PROFILE:
+		ctrl_p = (void *)((char *)req_p +
+				  sizeof(struct virtio_video_set_control));
+		ctrl_p->profile = cpu_to_le32(value);
+		break;
+	case VIRTIO_VIDEO_CONTROL_LEVEL:
+		ctrl_l = (void *)((char *)req_p +
+				 sizeof(struct virtio_video_set_control));
+		ctrl_l->level = cpu_to_le32(value);
+		break;
+	case VIRTIO_VIDEO_CONTROL_BITRATE:
+		ctrl_b = (void *)((char *)req_p +
+				 sizeof(struct virtio_video_set_control));
+		ctrl_b->bitrate = cpu_to_le32(value);
+		break;
+	}
+
+	return virtio_video_queue_cmd_buffer(vvd, vbuf);
+}
+