Re: [PATCH v2 1/1] video_video: Add the Virtio Video V4L2 driver

Dmitry Sepp
2020-03-12T11:41:00Z

Hi Keiichi,

Thanks for the detailed review! Hope I didn't miss something.

On Dienstag, 10. März 2020 11:24:45 CET Keiichi Watanabe wrote:
> Thanks Dmitry for submitting this patch!
>
> Sorry for the slow response.
> I implemented virtio-video decoder device for ChromeOS and could play
> a video with this driver on a VM on with several local patches [1].
> I think the driver is implemented well in general, but I found some
> problems to be fixed and a concern:

Great news!

>
> # v4l2-compiance test
> I tried run v4l2-compliance test [2] against this driver, but 8 test
> cases are still failing in my environment.
> Would you mind fixing it to make it pass?
>

Definitely. But i'd rather wait for the spec and the core code to stabilize.

> # Takes a long time to decode the first frame
> When we tried a normal video player application, it takes a long time
> (2+ seconds) until the first frame is displayed.
> We cannot see such a problem when we used our previous virtio-vdec driver
> [3].
>
> I think this is because the application opens the /dev/video device to
> query capability, but the opening the device is an expensive operation
> in the current virtio-video driver implementation.
> This can be improved by moving STREAM_CREATE request from the open
> callback to a place where it's actually needed, as I suggested in the
> previous version.
> Though you listed this problem as one of "Potential improvements", I
> think this is a high priority issue.
>

Ahem.. Sounds a bit strange, we haven't observed that. But it is a valid point
to move STREAM_CREATE, so let's check the delays again when it is done.

> # Timing of dequeue
> This is not a problem but a concern. The current implementation
> processes host responses as 'batches' periodically in
> virtio_video_dequeue_cmd_func.
> As a result, decoded frames are dequeued as batches as well instead of
> being dequeued ASAP.
> e.g. 6 frames are dequeued over 10ms, no frames for 90ms, 6 frames over
> 10ms...
>
> I don't think this is a problem, but it should be aware of this.
> Note that the virtio-video seems to have slightly lower power
> consumption than the old virtio-vdec (~5%). It may be thanks to this
> design choice.
>

Yes, other people also pointed to that already. We need to rethink this
approach.

> --
>
> See my other review comments inline. Note that my patch [4] addresses
> some of them.
> By the way, I guess the prefix of this mail's subject should be
> "virtio_video" instead of "video_video":)
>

Ooops..

> Best regards,
> Keiichi
>
> [1]
> https://chromium-review.googlesource.com/q/hashtag:%22virtio-video%22+(stat
> us:open%20OR%20status:merged) [2]
> https://git.linuxtv.org/v4l-utils.git/tree/utils/v4l2-compliance [3]
> https://lwn.net/Articles/803676/
> [4]
> https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/
> 2060510/7
> On Wed, Feb 19, 2020 at 5:28 AM Dmitry Sepp <dmitry.sepp@opensynergy.com>
wrote:
> > This adds a Virtio based video driver for video streaming device that
> > operates input and output data buffers to share video devices with
> > several guests. The current implementation consist of V4L2 based video
> > driver supporting video functions of decoder and encoder. The device
> > uses command structures to advertise and negotiate stream formats and
> > controls. This allows the driver to modify the processing logic of the
> > device on a per stream basis.
> >
> > Signed-off-by: Dmitry Sepp <dmitry.sepp@opensynergy.com>
> > Signed-off-by: Kiran Pawar <Kiran.Pawar@opensynergy.com>
> > Signed-off-by: Nikolay Martyanov <Nikolay.Martyanov@opensynergy.com>
> > Signed-off-by: Samiullah Khawaja <samiullah.khawaja@opensynergy.com>
> > ---
> >
> > drivers/media/Kconfig | 1 +
> > drivers/media/Makefile | 2 +
> > drivers/media/virtio/Kconfig | 12 +
> > drivers/media/virtio/Makefile | 12 +
> > drivers/media/virtio/virtio_video.h | 402 +++++++
> > drivers/media/virtio/virtio_video_caps.c | 498 +++++++++
> > drivers/media/virtio/virtio_video_dec.c | 427 ++++++++
> > drivers/media/virtio/virtio_video_dec.h | 30 +
> > drivers/media/virtio/virtio_video_device.c | 1079 +++++++++++++++++++
> > drivers/media/virtio/virtio_video_driver.c | 315 ++++++
> > drivers/media/virtio/virtio_video_enc.c | 569 ++++++++++
> > drivers/media/virtio/virtio_video_enc.h | 30 +
> > drivers/media/virtio/virtio_video_helpers.c | 250 +++++
> > drivers/media/virtio/virtio_video_vq.c | 1012 +++++++++++++++++
> > include/uapi/linux/virtio_ids.h | 2 +
> > include/uapi/linux/virtio_video.h | 469 ++++++++
> > 16 files changed, 5110 insertions(+)
> > create mode 100644 drivers/media/virtio/Kconfig
> > create mode 100644 drivers/media/virtio/Makefile
> > create mode 100644 drivers/media/virtio/virtio_video.h
> > create mode 100644 drivers/media/virtio/virtio_video_caps.c
> > create mode 100644 drivers/media/virtio/virtio_video_dec.c
> > create mode 100644 drivers/media/virtio/virtio_video_dec.h
> > create mode 100644 drivers/media/virtio/virtio_video_device.c
> > create mode 100644 drivers/media/virtio/virtio_video_driver.c
> > create mode 100644 drivers/media/virtio/virtio_video_enc.c
> > create mode 100644 drivers/media/virtio/virtio_video_enc.h
> > create mode 100644 drivers/media/virtio/virtio_video_helpers.c
> > create mode 100644 drivers/media/virtio/virtio_video_vq.c
> > create mode 100644 include/uapi/linux/virtio_video.h
> >
> > diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig
> > index 092e7509af9b..b89169e5d24d 100644
> > --- a/drivers/media/Kconfig
> > +++ b/drivers/media/Kconfig
> > @@ -205,6 +205,7 @@ source "drivers/media/pci/Kconfig"
> >
> > source "drivers/media/platform/Kconfig"
> > source "drivers/media/mmc/Kconfig"
> > source "drivers/media/radio/Kconfig"
> >
> > +source "drivers/media/virtio/Kconfig"
> >
> > comment "Supported FireWire (IEEE 1394) Adapters"
> >
> > depends on DVB_CORE && FIREWIRE
> >
> > diff --git a/drivers/media/Makefile b/drivers/media/Makefile
> > index 4a330d0e5e40..1d886730bafd 100644
> > --- a/drivers/media/Makefile
> > +++ b/drivers/media/Makefile
> > @@ -34,6 +34,8 @@ obj-y += rc/
> >
> > obj-$(CONFIG_CEC_CORE) += cec/
> >
> > +obj-$(CONFIG_VIRTIO_VIDEO) += virtio/
> > +
> >
> > #
> > # Finally, merge the drivers that require the core
> > #
> >
> > diff --git a/drivers/media/virtio/Kconfig b/drivers/media/virtio/Kconfig
> > new file mode 100644
> > index 000000000000..82012178254d
> > --- /dev/null
> > +++ b/drivers/media/virtio/Kconfig
> > @@ -0,0 +1,12 @@
> > +# SPDX-License-Identifier: GPL-2.0+
> > +# Video driver for virtio
> > +
> > +config VIRTIO_VIDEO
> > + tristate "Virtio video V4L2 driver"
> > + depends on VIRTIO && VIDEO_DEV && VIDEO_V4L2
> > + select VIDEOBUF2_DMA_SG
> > + select VIDEOBUF2_DMA_CONTIG
> > + select V4L2_MEM2MEM_DEV
> > + help
> > + This is the virtual video driver for virtio.
> > + Say Y or M.
> > diff --git a/drivers/media/virtio/Makefile b/drivers/media/virtio/Makefile
> > new file mode 100644
> > index 000000000000..b17dce4cfc19
> > --- /dev/null
> > +++ b/drivers/media/virtio/Makefile
> > @@ -0,0 +1,12 @@
> > +# SPDX-License-Identifier: GPL-2.0+
> > +
> > +obj-$(CONFIG_VIRTIO_VIDEO) += virtio-video.o
> > +
> > +virtio-video-objs := \
> > + virtio_video_driver.o \
> > + virtio_video_device.o \
> > + virtio_video_vq.o \
> > + virtio_video_dec.o \
> > + virtio_video_enc.o \
> > + virtio_video_caps.o \
> > + virtio_video_helpers.o
> > diff --git a/drivers/media/virtio/virtio_video.h
> > b/drivers/media/virtio/virtio_video.h new file mode 100644
> > index 000000000000..c5a5704326c0
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video.h
> > @@ -0,0 +1,402 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ */
> > +/* Common header for virtio video driver.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
>
> 2020?
>

I'm not sure whether this requires such kind of updates. Probably others know
better.

> > + *
> > + * 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/>.
> > + */
> > +
> > +#ifndef _VIRTIO_VIDEO_H
> > +#define _VIRTIO_VIDEO_H
> > +
> > +#include <linux/virtio.h>
> > +#include <linux/virtio_ids.h>
> > +#include <linux/virtio_config.h>
> > +#include <linux/virtio_video.h>
> > +#include <linux/list.h>
> > +#include <media/v4l2-device.h>
> > +#include <media/v4l2-mem2mem.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/videobuf2-dma-sg.h>
> > +#include <media/videobuf2-dma-contig.h>
> > +
> > +#define DRIVER_NAME "virtio-video"
> > +
> > +#define MIN_BUFS_MIN 0
> > +#define MIN_BUFS_MAX 32
> > +#define MIN_BUFS_STEP 1
> > +#define MIN_BUFS_DEF 1
> > +
> > +enum virtio_video_device_type {
> > + VIRTIO_VIDEO_DEVICE_ENCODER = 0x0100,
> > + VIRTIO_VIDEO_DEVICE_DECODER,
> > +};
> > +
> > +struct video_format_frame {
> > + struct virtio_video_format_frame frame;
> > + struct virtio_video_format_range *frame_rates;
> > +};
> > +
> > +struct video_format {
> > + struct list_head formats_list_entry;
> > + struct virtio_video_format_desc desc;
> > + struct video_format_frame *frames;
> > +};
> > +
> > +struct video_control_fmt_data {
> > + uint32_t min;
> > + uint32_t max;
> > + uint32_t num;
> > + uint32_t skip_mask;
> > + uint32_t *entries;
> > +};
> > +
> > +struct video_control_format {
> > + struct list_head controls_list_entry;
> > + uint32_t format;
> > + struct video_control_fmt_data *profile;
> > + struct video_control_fmt_data *level;
> > +};
> > +
> > +struct video_plane_format {
> > + uint32_t plane_size;
> > + uint32_t stride;
> > +};
> > +
> > +struct video_format_info {
> > + uint32_t fourcc_format;
> > + uint32_t frame_rate;
> > + uint32_t frame_width;
> > + uint32_t frame_height;
> > + uint32_t min_buffers;
> > + uint32_t max_buffers;
> > + struct virtio_video_crop crop;
> > + uint32_t num_planes;
> > + struct video_plane_format plane_format[VIRTIO_VIDEO_MAX_PLANES];
> > + bool is_updated;
> > +};
> > +
> > +struct video_control_info {
> > + uint32_t profile;
> > + uint32_t level;
> > + uint32_t bitrate;
> > + bool is_updated;
> > +};
> > +
> > +struct virtio_video;
> > +struct virtio_video_vbuffer;
> > +
> > +typedef void (*virtio_video_resp_cb)(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf);
> > +
> > +struct virtio_video_vbuffer {
> > + char *buf;
> > + int size;
> > +
> > + void *data_buf;
> > + uint32_t data_size;
> > +
> > + char *resp_buf;
> > + int resp_size;
> > +
> > + void *priv;
> > + virtio_video_resp_cb resp_cb;
> > +
> > + struct list_head list;
> > +};
> > +
> > +struct virtio_video_queue {
> > + struct virtqueue *vq;
> > + spinlock_t qlock;
> > + wait_queue_head_t ack_queue;
> > + struct work_struct dequeue_work;
> > +};
> > +
> > +struct virtio_video {
> > + struct v4l2_device v4l2_dev;
> > + int instance;
>
> unused?
>

Seems to be, but AFAIK you proposed that field, so I thought it would be
something for crosvm.

> > +
> > + struct virtio_device *vdev;
> > + struct virtio_video_queue commandq;
> > + struct virtio_video_queue eventq;
> > + wait_queue_head_t wq;
> > + bool vq_ready;
> > +
> > + struct kmem_cache *vbufs;
> > +
> > + struct idr resource_idr;
> > + spinlock_t resource_idr_lock;
> > + struct idr stream_idr;
> > + spinlock_t stream_idr_lock;
> > +
> > + uint32_t max_caps_len;
> > + uint32_t max_resp_len;
> > + bool got_caps;
> > + bool got_control;
> > +
> > + bool has_iommu;
> > + bool supp_non_contig;
> > + struct list_head devices_list;
> > +
> > + int debug;
> > + int use_dma_mem;
> > +};
> > +
> > +struct virtio_video_device {
> > + struct virtio_video *vv;
> > + struct video_device video_dev;
> > + struct mutex video_dev_mutex;
> > +
> > + struct v4l2_m2m_dev *m2m_dev;
> > +
> > + struct workqueue_struct *workqueue;
> > +
> > + struct list_head devices_list_entry;
> > + /* VIRTIO_VIDEO_FUNC_ */
> > + uint32_t type;
> > +
> > + uint32_t num_input_fmts;
> > + struct list_head input_fmt_list;
> > +
> > + uint32_t num_output_fmts;
> > + struct list_head output_fmt_list;
> > +
> > + struct list_head controls_fmt_list;
> > +};
> > +
> > +enum video_stream_state {
> > + STREAM_STATE_IDLE = 0,
> > + STREAM_STATE_INIT,
> > + STREAM_STATE_METADATA, /* specific to decoder */
> > + STREAM_STATE_RUNNING,
> > + STREAM_STATE_DRAIN,
> > + STREAM_STATE_STOPPED,
> > + STREAM_STATE_RESET, /* specific to encoder */
> > +};
>
> Could you use same state names with state machines in the V4L2
> documentation?
> https://linuxtv.org/downloads/v4l-dvb-apis/uapi/v4l/dev-decoder.html#state-> machine
>
> e.g. Rename STREAM_STATE_METADATA to STREAM_STATE_DYNAMIC_RES_CHANGE
>

Yes, makes sense, was on my personal list already.

> > +
> > +struct virtio_video_stream {
> > + uint32_t stream_id;
> > + enum video_stream_state state;
> > + struct video_device *video_dev;
> > + struct v4l2_fh fh;
> > + struct mutex vq_mutex;
> > + struct v4l2_ctrl_handler ctrl_handler;
> > + struct video_format_info in_info;
> > + struct video_format_info out_info;
> > + struct video_control_info control;
> > + bool src_cleared;
> > + bool dst_cleared;
> > + bool src_destroyed;
> > + bool dst_destroyed;
> > + struct work_struct work;
> > + struct video_format_frame *current_frame;
> > +};
> > +
> > +struct virtio_video_buffer {
> > + struct v4l2_m2m_buffer v4l2_m2m_vb;
> > + uint32_t resource_id;
> > + bool queued;
> > +};
> > +
> > +static inline gfp_t
> > +virtio_video_gfp_flags(struct virtio_video *vv)
> > +{
> > + if (vv->use_dma_mem)
> > + return GFP_DMA;
> > + else
> > + return 0;
> > +}
> > +
> > +static inline const struct vb2_mem_ops *
> > +virtio_video_mem_ops(struct virtio_video *vv)
> > +{
> > + if (vv->supp_non_contig)
> > + return &vb2_dma_sg_memops;
> > + else
> > + return &vb2_dma_contig_memops;
> > +}
> > +
> > +static inline struct virtio_video_device *
> > +to_virtio_vd(struct video_device *video_dev)
> > +{
> > + return container_of(video_dev, struct virtio_video_device,
> > + video_dev);
> > +}
> > +
> > +static inline struct virtio_video_stream *file2stream(struct file *file)
> > +{
> > + return container_of(file->private_data, struct
> > virtio_video_stream, fh); +}
> > +
> > +static inline struct virtio_video_stream *ctrl2stream(struct v4l2_ctrl
> > *ctrl) +{
> > + return container_of(ctrl->handler, struct virtio_video_stream,
> > + ctrl_handler);
> > +}
> > +
> > +static inline struct virtio_video_stream *work2stream(struct work_struct
> > *work) +{
> > + return container_of(work, struct virtio_video_stream, work);
> > +}
> > +
> > +static inline struct virtio_video_buffer *to_virtio_vb(struct vb2_buffer
> > *vb) +{
> > + struct vb2_v4l2_buffer *v4l2_vb = to_vb2_v4l2_buffer(vb);
> > +
> > + return container_of(v4l2_vb, struct virtio_video_buffer,
> > + v4l2_m2m_vb.vb);
> > +}
> > +
> > +static inline uint32_t to_virtio_queue_type(enum v4l2_buf_type type)
> > +{
> > + if (V4L2_TYPE_IS_OUTPUT(type))
> > + return VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
> > + else
> > + return VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
> > +}
> > +
> > +static inline bool within_range(uint32_t min, uint32_t val, uint32_t max)
> > +{
> > + return ((val - min) <= (max - min));
>
> This doesn't validate if (min <= val) holds. For example,
> within_range(1, 0, 0) returns true.
> How about changing this condition to ((min <= val) && (val <= max))?
>

Technically correct. But I deem when min > max the code flow should not even
reach this function and throw and error earlier. We can still update this.

> > +}
> > +
> > +static inline bool needs_alignment(uint32_t val, uint32_t a)
> > +{
> > + if (a == 0 || IS_ALIGNED(val, a))
> > + return false;
> > +
> > + return true;
> > +}
> > +
> > +int virtio_video_alloc_vbufs(struct virtio_video *vv);
> > +void virtio_video_free_vbufs(struct virtio_video *vv);
> > +int virtio_video_alloc_events(struct virtio_video *vv, size_t num);
> > +
> > +int virtio_video_device_init(struct virtio_video *vv, void *input_buf,
> > + void *output_buf);
> > +void virtio_video_device_deinit(struct virtio_video *vv);
> > +
> > +void virtio_video_stream_id_get(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t *id);
> > +void virtio_video_stream_id_put(struct virtio_video *vv, uint32_t id);
> > +void virtio_video_resource_id_get(struct virtio_video *vv, uint32_t *id);
> > +void virtio_video_resource_id_put(struct virtio_video *vv, uint32_t id);
> > +
> > +int virtio_video_cmd_stream_create(struct virtio_video *vv, uint32_t
> > stream_id, + enum virtio_video_format
> > format, + const char *tag);
> > +int virtio_video_cmd_stream_destroy(struct virtio_video *vv,
> > + uint32_t stream_id);
> > +int virtio_video_cmd_stream_drain(struct virtio_video *vv, uint32_t
> > stream_id); +int virtio_video_cmd_resource_create(struct virtio_video
> > *vv,
> > + uint32_t stream_id, uint32_t
> > resource_id, + uint32_t queue_type,
> > + struct virtio_video_mem_entry *ents,
> > + unsigned int num_planes,
> > + unsigned int *num_entry);
> > +int virtio_video_cmd_resource_destroy_all(struct virtio_video *vv,
> > + struct virtio_video_stream
> > *stream, + uint32_t queue_type);
> > +int virtio_video_cmd_resource_queue(struct virtio_video *vv, uint32_t
> > stream_id, + struct virtio_video_buffer
> > *virtio_vb, + uint32_t data_size[],
> > uint8_t num_data_size, + uint32_t
> > queue_type);
> > +int virtio_video_cmd_queue_clear(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t queue_type);
> > +int virtio_video_query_capability(struct virtio_video *vv, void
> > *resp_buf,
> > + size_t resp_size, uint32_t queue_type);
> > +int virtio_video_query_control_profile(struct virtio_video *vv, void
> > *resp_buf, + size_t resp_size,
> > uint32_t format); +int virtio_video_query_control_level(struct
> > virtio_video *vv, void *resp_buf, +
> > size_t resp_size, uint32_t format); +int
> > virtio_video_cmd_set_params(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + struct video_format_info *format_info,
> > + uint32_t queue_type);
> > +int virtio_video_cmd_get_params(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t queue_type);
> > +int virtio_video_cmd_set_control(struct virtio_video *vv,
> > + uint32_t stream_id,
> > + uint32_t control, uint32_t val);
> > +int virtio_video_cmd_get_control(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t ctrl);
> > +
> > +void virtio_video_queue_res_chg_event(struct virtio_video_stream
> > *stream);
> > +void virtio_video_queue_eos_event(struct virtio_video_stream *stream);
> > +void virtio_video_cmd_ack(struct virtqueue *vq);
> > +void virtio_video_event_ack(struct virtqueue *vq);
> > +void virtio_video_dequeue_cmd_func(struct work_struct *work);
> > +void virtio_video_dequeue_event_func(struct work_struct *work);
> > +void virtio_video_buf_done(struct virtio_video_buffer *virtio_vb,
> > + uint32_t flags, uint64_t timestamp, uint32_t
> > size); +int virtio_video_buf_plane_init(uint32_t idx, uint32_t
> > resource_id, + struct virtio_video_device
> > *vvd,
> > + struct virtio_video_stream *stream,
> > + struct vb2_buffer *vb);
> > +void virtio_video_mark_drain_complete(struct virtio_video_stream *stream,
> > + struct vb2_v4l2_buffer *v4l2_vb);
> > +
> > +int virtio_video_queue_setup(struct vb2_queue *vq, unsigned int
> > *num_buffers, + unsigned int *num_planes,
> > unsigned int sizes[], + struct device
> > *alloc_devs[]);
> > +int virtio_video_buf_init(struct vb2_buffer *vb);
> > +void virtio_video_buf_cleanup(struct vb2_buffer *vb);
> > +int virtio_video_querycap(struct file *file, void *fh,
> > + struct v4l2_capability *cap);
> > +int virtio_video_enum_framesizes(struct file *file, void *fh,
> > + struct v4l2_frmsizeenum *f);
> > +int virtio_video_enum_framemintervals(struct file *file, void *fh,
> > + struct v4l2_frmivalenum *f);
> > +int virtio_video_g_fmt(struct file *file, void *fh, struct v4l2_format
> > *f); +int virtio_video_s_fmt(struct file *file, void *fh, struct
> > v4l2_format *f); +int virtio_video_try_fmt(struct virtio_video_stream
> > *stream,
> > + struct v4l2_format *f);
> > +int virtio_video_reqbufs(struct file *file, void *priv,
> > + struct v4l2_requestbuffers *rb);
> > +int virtio_video_subscribe_event(struct v4l2_fh *fh,
> > + const struct v4l2_event_subscription
> > *sub); +
> > +void virtio_video_free_caps_list(struct list_head *caps_list);
> > +int virtio_video_parse_virtio_capability(struct virtio_video_device *vvd,
> > + void *input_buf, void
> > *output_buf); +void virtio_video_clean_capability(struct
> > virtio_video_device *vvd); +int virtio_video_parse_virtio_control(struct
> > virtio_video_device *vvd); +void virtio_video_clean_control(struct
> > virtio_video_device *vvd); +
> > +uint32_t virtio_video_format_to_v4l2(uint32_t format);
> > +uint32_t virtio_video_control_to_v4l2(uint32_t control);
> > +uint32_t virtio_video_profile_to_v4l2(uint32_t profile);
> > +uint32_t virtio_video_level_to_v4l2(uint32_t level);
> > +uint32_t virtio_video_v4l2_format_to_virtio(uint32_t v4l2_format);
> > +uint32_t virtio_video_v4l2_control_to_virtio(uint32_t v4l2_control);
> > +uint32_t virtio_video_v4l2_profile_to_virtio(uint32_t v4l2_profile);
> > +uint32_t virtio_video_v4l2_level_to_virtio(uint32_t v4l2_level);
> > +
> > +struct video_format *find_video_format(struct list_head *fmts_list,
> > + uint32_t fourcc);
>
> Add a prefix "virtio_video_" like other functions?
>

Yes.

> > +void virtio_video_format_from_info(struct video_format_info *info,
> > + struct v4l2_pix_format_mplane *pix_mp);
> > +void virtio_video_format_fill_default_info(struct video_format_info
> > *dst_info, + struct
> > video_format_info *src_info); +
> > +int virtio_video_g_selection(struct file *file, void *fh,
> > + struct v4l2_selection *sel);
> > +int virtio_video_s_selection(struct file *file, void *fh,
> > + struct v4l2_selection *sel);
> > +
> > +#endif /* _VIRTIO_VIDEO_H */
> > diff --git a/drivers/media/virtio/virtio_video_caps.c
> > b/drivers/media/virtio/virtio_video_caps.c new file mode 100644
> > index 000000000000..2f9d4da92810
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_caps.c
> > @@ -0,0 +1,498 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Driver for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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 <media/v4l2-ioctl.h>
> > +#include <media/videobuf2-dma-sg.h>
> > +
> > +#include "virtio_video.h"
> > +
> > +static void virtio_video_free_frame_rates(struct video_format_frame
> > *frame) +{
> > + if (!frame)
> > + return;
> > +
> > + kfree(frame->frame_rates);
> > +}
> > +
> > +static void virtio_video_free_frames(struct video_format *fmt)
> > +{
> > + size_t idx = 0;
> > +
> > + if (!fmt)
> > + return;
> > +
> > + for (idx = 0; idx < fmt->desc.num_frames; idx++)
> > + virtio_video_free_frame_rates(&fmt->frames[idx]);
> > + kfree(fmt->frames);
> > +}
> > +
> > +static void virtio_video_free_fmt(struct list_head *fmts_list)
> > +{
> > + struct video_format *fmt = NULL;
> > + struct video_format *tmp = NULL;
> > +
> > + list_for_each_entry_safe(fmt, tmp, fmts_list, formats_list_entry)
> > {
> > + list_del(&fmt->formats_list_entry);
> > + virtio_video_free_frames(fmt);
> > + kfree(fmt);
> > + }
> > +}
> > +
> > +static void virtio_video_free_fmts(struct virtio_video_device *vvd)
> > +{
> > + virtio_video_free_fmt(&vvd->input_fmt_list);
> > + virtio_video_free_fmt(&vvd->output_fmt_list);
> > +}
> > +
> > +static void assign_format_range(struct virtio_video_format_range
> > *d_range,
> > + struct virtio_video_format_range *s_range)
>
> Add "virtio_video" prefix?
>

Well, it is static. But adding a prefix won't make any harm.

> > +{
> > + d_range->min = le32_to_cpu(s_range->min);
> > + d_range->max = le32_to_cpu(s_range->max);
> > + d_range->step = le32_to_cpu(s_range->step);
> > +}
> > +
> > +static size_t
> > +virtio_video_parse_virtio_frame_rate(struct virtio_video_device *vvd,
> > + struct virtio_video_format_range
> > *f_rate, + void *buf)
> > +{
> > + struct virtio_video_format_range *virtio_frame_rate = NULL;
>
> Generally speaking, it's a good idea to avoid initializing a local
> pointer with NULL at its declaration if it must be initialized below.
> This is because compilers can raise an error when you forget the
> actual initialization.
>
> Though it's not problematic immediately, could you avoid this?
> Actually, some parts of this patch don't do so.
>

Yes! I absolutely agree with you. That was a subject for an internal
discussion here as several people worked on the code. We will finally get rid
if that next time.

> > + size_t frame_rate_size = sizeof(struct virtio_video_format_range);
> > +
> > + if (!f_rate || !buf || !vvd)
> > + return 0;
> > +
> > + virtio_frame_rate = buf;
> > + assign_format_range(f_rate, virtio_frame_rate);
> > + return frame_rate_size;
> > +}
> > +
> > +static size_t virtio_video_parse_virtio_frame(struct virtio_video_device
> > *vvd, + struct
> > video_format_frame *frm, +
> > void *buf)
> > +{
> > + struct virtio_video *vv = NULL;
> > + struct virtio_video_format_frame *virtio_frame = NULL;
> > + struct virtio_video_format_frame *frame = &frm->frame;
> > + struct virtio_video_format_range *rate = NULL;
> > + size_t idx, offset = 0;
> > + size_t extra_size = 0;
> > +
> > + if (!frame || !buf || !vvd)
> > + return 0;
> > +
> > + vv = vvd->vv;
> > + virtio_frame = buf;
> > +
> > + assign_format_range(&frame->width, &virtio_frame->width);
> > + assign_format_range(&frame->height, &virtio_frame->height);
> > +
> > + frame->num_rates = le32_to_cpu(virtio_frame->num_rates);
> > + frm->frame_rates = kcalloc(frame->num_rates,
> > + sizeof(struct
> > virtio_video_format_range), +
> > GFP_KERNEL);
> > +
> > + offset = sizeof(struct virtio_video_format_frame);
> > + for (idx = 0; idx < frame->num_rates; idx++) {
> > + rate = &frm->frame_rates[idx];
> > + extra_size =
> > + virtio_video_parse_virtio_frame_rate(vvd, rate,
> > + buf +
> > offset);
> > + if (extra_size == 0) {
> > + kfree(frm->frame_rates);
> > + v4l2_err(&vv->v4l2_dev, "failed to parse frame
> > rate\n"); + return 0;
> > + }
> > + offset += extra_size;
> > + }
> > +
> > + return offset;
> > +}
> > +
> > +static size_t virtio_video_parse_virtio_fmt(struct virtio_video_device
> > *vvd, + struct video_format
> > *fmt, void *buf) +{
> > + struct virtio_video *vv = NULL;
> > + struct virtio_video_format_desc *virtio_fmt_desc = NULL;
> > + struct virtio_video_format_desc *fmt_desc = NULL;
> > + struct video_format_frame *frame = NULL;
> > + size_t idx, offset = 0;
> > + size_t extra_size = 0;
> > +
> > + if (!fmt || !buf || !vvd)
> > + return 0;
> > +
> > + vv = vvd->vv;
> > + virtio_fmt_desc = buf;
> > + fmt_desc = &fmt->desc;
> > +
> > + fmt_desc->format =
> > + virtio_video_format_to_v4l2
> > + (le32_to_cpu(virtio_fmt_desc->format));
> > + fmt_desc->mask = le64_to_cpu(virtio_fmt_desc->mask);
> > + fmt_desc->planes_layout =
> > le32_to_cpu(virtio_fmt_desc->planes_layout); +
> > + fmt_desc->num_frames = le32_to_cpu(virtio_fmt_desc->num_frames);
> > + fmt->frames = kcalloc(fmt_desc->num_frames,
> > + sizeof(struct video_format_frame),
> > + GFP_KERNEL);
> > +
> > + offset = sizeof(struct virtio_video_format_desc);
> > + for (idx = 0; idx < fmt_desc->num_frames; idx++) {
> > + frame = &fmt->frames[idx];
> > + extra_size =
> > + virtio_video_parse_virtio_frame(vvd, frame,
> > + buf + offset);
> > + if (extra_size == 0) {
> > + kfree(fmt->frames);
> > + v4l2_err(&vv->v4l2_dev, "failed to parse
> > frame\n");
> > + return 0;
> > + }
> > + offset += extra_size;
> > + }
> > +
> > + return offset;
> > +}
> > +
> > +int virtio_video_parse_virtio_capability(struct virtio_video_device *vvd,
> > + void *input_buf, void
> > *output_buf) +{
> > + struct virtio_video *vv = NULL;
> > + struct virtio_video_query_capability_resp *input_resp = input_buf;
> > + struct virtio_video_query_capability_resp *output_resp =
> > output_buf; + int fmt_idx = 0;
> > + size_t offset = 0;
> > + struct video_format *fmt = NULL;
> > +
> > + if (!input_buf || !output_buf || !vvd)
> > + return -1;
>
> Instead of hard-coding -1, let's use -EINVAL.
> Same comments for all other "return -1" in this patch.
>

Is there any common description of the practice? Didn't see anything like that
in other pieces of the kernel code.

> > +
> > + vv = vvd->vv;
> > +
> > + if (le32_to_cpu(input_resp->num_descs) <= 0 ||
> > + le32_to_cpu(output_resp->num_descs) <= 0) {
> > + v4l2_err(&vv->v4l2_dev, "invalid capability response\n");
> > + return -1;
> > + }
> > +
> > + vvd->num_input_fmts = le32_to_cpu(input_resp->num_descs);
> > + offset = sizeof(struct virtio_video_query_capability_resp);
> > +
> > + for (fmt_idx = 0; fmt_idx < vvd->num_input_fmts; fmt_idx++) {
> > + size_t fmt_size = 0;
> > +
> > + fmt = kzalloc(sizeof(*fmt), GFP_KERNEL);
> > + if (!fmt) {
> > + virtio_video_free_fmts(vvd);
> > + return -1;
> > + }
> > +
> > + fmt_size = virtio_video_parse_virtio_fmt(vvd, fmt,
> > + input_buf +
> > offset); + if (fmt_size == 0) {
> > + v4l2_err(&vv->v4l2_dev, "failed to parse input
> > fmt\n"); + virtio_video_free_fmts(vvd);
> > + kfree(fmt);
> > + return -1;
>
> Instead of returning from here, please add an error label and goto
> statements to centralize error handlings.
> cf.
> https://www.kernel.org/doc/html/v5.4/process/coding-style.html#centralized-> exiting-of-functions

Makes sense.

> > + }
> > + offset += fmt_size;
> > + list_add(&fmt->formats_list_entry, &vvd->input_fmt_list);
> > + }
> > +
> > + vvd->num_output_fmts = le32_to_cpu(output_resp->num_descs);
> > + offset = sizeof(struct virtio_video_query_capability_resp);
> > +
> > + for (fmt_idx = 0; fmt_idx < vvd->num_output_fmts; fmt_idx++) {
> > + size_t fmt_size = 0;
> > +
> > + fmt = kzalloc(sizeof(*fmt), GFP_KERNEL);
> > + if (!fmt) {
> > + virtio_video_free_fmts(vvd);
> > + return -1;
> > + }
> > +
> > + fmt_size = virtio_video_parse_virtio_fmt(vvd, fmt,
> > + output_buf +
> > offset); + if (fmt_size == 0) {
> > + v4l2_err(&vv->v4l2_dev, "failed to parse output
> > fmt\n"); + virtio_video_free_fmts(vvd);
> > + kfree(fmt);
> > + return -1;
> > + }
> > + offset += fmt_size;
> > + list_add(&fmt->formats_list_entry, &vvd->output_fmt_list);
> > + }
> > + return 0;
> > +}
> > +
> > +void virtio_video_clean_capability(struct virtio_video_device *vvd)
> > +{
> > + if (!vvd)
> > + return;
> > + virtio_video_free_fmts(vvd);
> > +}
> > +
> > +static void
> > +virtio_video_free_control_fmt_data(struct video_control_fmt_data *data)
> > +{
> > + if (!data)
> > + return;
> > +
> > + kfree(data->entries);
> > + kfree(data);
> > +}
> > +
> > +static void virtio_video_free_control_formats(struct virtio_video_device
> > *vvd) +{
> > + struct video_control_format *c_fmt = NULL;
> > + struct video_control_format *tmp = NULL;
> > +
> > + list_for_each_entry_safe(c_fmt, tmp, &vvd->controls_fmt_list,
> > + controls_list_entry) {
> > + list_del(&c_fmt->controls_list_entry);
> > + virtio_video_free_control_fmt_data(c_fmt->profile);
> > + virtio_video_free_control_fmt_data(c_fmt->level);
> > + kfree(c_fmt);
> > + }
> > +}
> > +
> > +static int virtio_video_parse_control_levels(struct virtio_video_device
> > *vvd, + struct
> > video_control_format *fmt) +{
> > + int idx, ret = 0;
> > + struct virtio_video_query_control_resp *resp_buf = NULL;
> > + struct virtio_video_query_control_resp_level *l_resp_buf = NULL;
> > + struct virtio_video *vv = NULL;
> > + uint32_t virtio_format, num_levels, mask = 0;
> > + uint32_t *virtio_levels = NULL;
> > + struct video_control_fmt_data *level = NULL;
> > + int max = 0, min = UINT_MAX;
> > + size_t resp_size;
> > +
> > + if (!vvd)
> > + return -EINVAL;
> > +
> > + vv = vvd->vv;
> > + resp_size = vv->max_resp_len;
> > +
> > + virtio_format = virtio_video_v4l2_format_to_virtio(fmt->format);
> > +
> > + resp_buf = kzalloc(resp_size, GFP_KERNEL);
> > + if (IS_ERR(resp_buf)) {
> > + ret = PTR_ERR(resp_buf);
> > + goto err;
> > + }
> > +
> > + vv->got_control = false;
> > + ret = virtio_video_query_control_level(vv, resp_buf, resp_size,
> > + virtio_format);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to query level\n");
> > + goto err;
> > + }
> > +
> > + ret = wait_event_timeout(vv->wq, vv->got_control, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "timed out waiting for query level\n");
> > + ret = -EIO;
> > + goto err;
> > + }
> > +
> > + ret = 0;
> > + l_resp_buf = (void *)((char *)resp_buf + sizeof(*resp_buf));
> > + num_levels = le32_to_cpu(l_resp_buf->num);
> > + if (num_levels == 0)
> > + goto err;
> > +
> > + fmt->level = kzalloc(sizeof(*level), GFP_KERNEL);
> > + if (!fmt->level) {
> > + ret = -ENOMEM;
> > + goto err;
> > + }
> > +
> > + level = fmt->level;
> > + level->entries = kcalloc(num_levels, sizeof(uint32_t),
> > GFP_KERNEL);
> > + if (!level->entries) {
> > + ret = -ENOMEM;
> > + goto err;
> > + }
> > +
> > + virtio_levels = (void *)((char *)l_resp_buf +
> > sizeof(*l_resp_buf));
> > +
> > + for (idx = 0; idx < num_levels; idx++) {
> > + level->entries[idx] =
> > + virtio_video_level_to_v4l2
> > + (le32_to_cpu(virtio_levels[idx]));
> > +
> > + mask = mask | (1 << level->entries[idx]);
> > + if (level->entries[idx] > max)
> > + max = level->entries[idx];
> > + if (level->entries[idx] < min)
> > + min = level->entries[idx];
> > + }
> > + level->min = min;
> > + level->max = max;
> > + level->num = num_levels;
> > + level->skip_mask = ~mask;
>
> > +err:
> "err" is not a good name, as the following 'kfree' must be executed
> even without an error.
> How about renaming it to "out_free_buf" like the example here?
>
> https://www.kernel.org/doc/html/v5.4/process/coding-style.html#centralized-e
> xiting-of-functions

Yes, true.

> > + kfree(resp_buf);
> > + return ret;
> > +}
> > +
> > +static int virtio_video_parse_control_profiles(struct virtio_video_device
> > *vvd, + struct
> > video_control_format *fmt) +{
> > + int idx, ret = 0;
> > + struct virtio_video_query_control_resp *resp_buf = NULL;
> > + struct virtio_video_query_control_resp_profile *p_resp_buf = NULL;
> > + struct virtio_video *vv = NULL;
> > + uint32_t virtio_format, num_profiles, mask = 0;
> > + uint32_t *virtio_profiles = NULL;
> > + struct video_control_fmt_data *profile = NULL;
> > + int max = 0, min = UINT_MAX;
> > + size_t resp_size;
> > +
> > + if (!vvd)
> > + return -EINVAL;
> > +
> > + vv = vvd->vv;
> > + resp_size = vv->max_resp_len;
> > + virtio_format = virtio_video_v4l2_format_to_virtio(fmt->format);
> > + resp_buf = kzalloc(resp_size, GFP_KERNEL);
> > + if (IS_ERR(resp_buf)) {
> > + ret = PTR_ERR(resp_buf);
> > + goto err;
> > + }
> > +
> > + vv->got_control = false;
> > + ret = virtio_video_query_control_profile(vv, resp_buf, resp_size,
> > + virtio_format);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to query profile\n");
> > + goto err;
> > + }
> > +
> > + ret = wait_event_timeout(vv->wq, vv->got_control, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "timed out waiting for query profile\n");
> > + ret = -EIO;
> > + goto err;
> > + }
> > +
> > + ret = 0;
> > + p_resp_buf = (void *)((char *)resp_buf + sizeof(*resp_buf));
> > + num_profiles = le32_to_cpu(p_resp_buf->num);
> > + if (num_profiles == 0)
> > + goto err;
> > +
> > + fmt->profile = kzalloc(sizeof(*profile), GFP_KERNEL);
> > + if (!fmt->profile) {
> > + ret = -ENOMEM;
> > + goto err;
> > + }
> > +
> > + profile = fmt->profile;
> > + profile->entries = kcalloc(num_profiles, sizeof(uint32_t),
> > GFP_KERNEL); + if (!profile->entries) {
> > + ret = -ENOMEM;
> > + goto err;
> > + }
> > +
> > + virtio_profiles = (void *)((char *)p_resp_buf +
> > sizeof(*p_resp_buf)); +
> > + for (idx = 0; idx < num_profiles; idx++) {
> > + profile->entries[idx] =
> > + virtio_video_profile_to_v4l2
> > + (le32_to_cpu(virtio_profiles[idx]));
> > +
> > + mask = mask | (1 << profile->entries[idx]);
> > + if (profile->entries[idx] > max)
> > + max = profile->entries[idx];
> > + if (profile->entries[idx] < min)
> > + min = profile->entries[idx];
> > + }
> > + profile->min = min;
> > + profile->max = max;
> > + profile->num = num_profiles;
> > + profile->skip_mask = ~mask;
>
> > +err:
> same
>
> > + kfree(resp_buf);
> > + return ret;
> > +}
> > +
> > +int virtio_video_parse_virtio_control(struct virtio_video_device *vvd)
> > +{
> > + struct video_format *fmt = NULL;
> > + struct video_control_format *c_fmt = NULL;
> > + struct virtio_video *vv = NULL;
> > + uint32_t virtio_format;
> > + int ret = 0;
> > +
> > + if (!vvd)
> > + return -EINVAL;
> > +
> > + vv = vvd->vv;
> > +
> > + list_for_each_entry(fmt, &vvd->output_fmt_list,
> > formats_list_entry) { + virtio_format =
> > +
> > virtio_video_v4l2_format_to_virtio(fmt->desc.format); + if
> > (virtio_format < VIRTIO_VIDEO_FORMAT_CODED_MIN || +
> > virtio_format > VIRTIO_VIDEO_FORMAT_CODED_MAX) +
> > continue;
> > +
> > + c_fmt = kzalloc(sizeof(*c_fmt), GFP_KERNEL);
> > + if (!c_fmt) {
> > + virtio_video_free_control_formats(vvd);
> > + return -1;
> > + }
> > +
> > + c_fmt->format = fmt->desc.format;
> > + ret = virtio_video_parse_control_profiles(vvd, c_fmt);
> > + if (ret) {
> > + virtio_video_free_control_formats(vvd);
> > + kfree(c_fmt);
>
> These 'free' functions should be called under "err" label.
>

True.

> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to parse control profile\n");
> > + goto err;
> > + }
> > + ret = virtio_video_parse_control_levels(vvd, c_fmt);
> > + if (ret) {
> > + virtio_video_free_control_formats(vvd);
> > + kfree(c_fmt);
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to parse control level\n");
> > + goto err;
> > + }
> > + list_add(&c_fmt->controls_list_entry,
> > &vvd->controls_fmt_list); + }
> > + return 0;
> > +err:
> > + return ret;
> > +}
> > +
> > +void virtio_video_clean_control(struct virtio_video_device *vvd)
> > +{
> > + if (!vvd)
> > + return;
> > +
> > + virtio_video_free_control_formats(vvd);
> > +}
> > diff --git a/drivers/media/virtio/virtio_video_dec.c
> > b/drivers/media/virtio/virtio_video_dec.c new file mode 100644
> > index 000000000000..fc805933fc5e
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_dec.c
> > @@ -0,0 +1,427 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Decoder for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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 <media/v4l2-event.h>
> > +#include <media/v4l2-ioctl.h>
> > +
> > +#include "virtio_video.h"
> > +
> > +static void virtio_video_dec_buf_queue(struct vb2_buffer *vb)
> > +{
> > + int i, ret;
> > + struct vb2_buffer *src_buf;
> > + struct vb2_v4l2_buffer *src_vb;
> > + struct virtio_video_buffer *virtio_vb;
> > + uint32_t data_size[VB2_MAX_PLANES] = {0};
> > + struct vb2_v4l2_buffer *v4l2_vb = to_vb2_v4l2_buffer(vb);
> > + struct virtio_video_stream *stream =
> > vb2_get_drv_priv(vb->vb2_queue); + struct virtio_video_device *vvd
> > = to_virtio_vd(stream->video_dev); + struct virtio_video *vv =
> > vvd->vv;
> > +
> > + v4l2_m2m_buf_queue(stream->fh.m2m_ctx, v4l2_vb);
> > +
> > + if ((stream->state != STREAM_STATE_INIT) ||
> > + !V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
> > + return;
> > +
> > + src_vb = v4l2_m2m_next_src_buf(stream->fh.m2m_ctx);
> > + if (!src_vb) {
> > + v4l2_err(&vv->v4l2_dev, "no src buf during
> > initialization\n"); + return;
> > + }
> > +
> > + src_buf = &src_vb->vb2_buf;
> > + for (i = 0; i < src_buf->num_planes; ++i)
> > + data_size[i] = src_buf->planes[i].bytesused;
> > +
> > + virtio_vb = to_virtio_vb(src_buf);
> > +
> > + ret = virtio_video_cmd_resource_queue(vv, stream->stream_id,
> > + virtio_vb, data_size,
> > + src_buf->num_planes,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to queue an src
> > buffer\n");
> > + return;
> > + }
> > +
> > + virtio_vb->queued = true;
> > + stream->src_cleared = false;
> > + src_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
> > +}
> > +
> > +static int virtio_video_dec_start_streaming(struct vb2_queue *vq,
> > + unsigned int count)
> > +{
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > +
> > + if (!V4L2_TYPE_IS_OUTPUT(vq->type) &&
> > + stream->state >= STREAM_STATE_INIT)
> > + stream->state = STREAM_STATE_RUNNING;
> > +
> > + return 0;
> > +}
> > +
> > +static void virtio_video_dec_stop_streaming(struct vb2_queue *vq)
> > +{
> > + int ret, queue_type;
> > + bool *cleared;
> > + bool is_v4l2_output = V4L2_TYPE_IS_OUTPUT(vq->type);
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct vb2_v4l2_buffer *v4l2_vb;
> > +
> > + if (is_v4l2_output) {
> > + cleared = &stream->src_cleared;
> > + queue_type = VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
> > + } else {
> > + cleared = &stream->dst_cleared;
> > + queue_type = VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
> > + }
> > +
> > + ret = virtio_video_cmd_queue_clear(vv, stream, queue_type);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to clear queue\n");
> > + return;
> > + }
> > +
> > + ret = wait_event_timeout(vv->wq, *cleared, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev, "timed out waiting for queue
> > clear\n"); + return;
> > + }
> > +
> > + for (;;) {
> > + if (is_v4l2_output)
> > + v4l2_vb =
> > v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx); + else
> > + v4l2_vb =
> > v4l2_m2m_dst_buf_remove(stream->fh.m2m_ctx); + if
> > (!v4l2_vb)
> > + break;
> > + v4l2_m2m_buf_done(v4l2_vb, VB2_BUF_STATE_ERROR);
> > + }
> > +}
> > +
> > +static const struct vb2_ops virtio_video_dec_qops = {
> > + .queue_setup = virtio_video_queue_setup,
> > + .buf_init = virtio_video_buf_init,
> > + .buf_cleanup = virtio_video_buf_cleanup,
> > + .buf_queue = virtio_video_dec_buf_queue,
> > + .start_streaming = virtio_video_dec_start_streaming,
> > + .stop_streaming = virtio_video_dec_stop_streaming,
> > + .wait_prepare = vb2_ops_wait_prepare,
> > + .wait_finish = vb2_ops_wait_finish,
> > +};
> > +
> > +static int virtio_video_dec_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + int ret = 0;
> > + struct virtio_video_stream *stream = ctrl2stream(ctrl);
> > +
> > + switch (ctrl->id) {
> > + case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
> > + if (stream->state >= STREAM_STATE_METADATA)
> > + ctrl->val = stream->out_info.min_buffers;
> > + else
> > + ctrl->val = 0;
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops virtio_video_dec_ctrl_ops = {
> > + .g_volatile_ctrl = virtio_video_dec_g_volatile_ctrl,
> > +};
> > +
> > +int virtio_video_dec_init_ctrls(struct virtio_video_stream *stream)
> > +{
> > + struct v4l2_ctrl *ctrl;
> > +
> > + v4l2_ctrl_handler_init(&stream->ctrl_handler, 1);
> > +
> > + ctrl = v4l2_ctrl_new_std(&stream->ctrl_handler,
> > + &virtio_video_dec_ctrl_ops,
> > + V4L2_CID_MIN_BUFFERS_FOR_CAPTURE,
> > + MIN_BUFS_MIN, MIN_BUFS_MAX, MIN_BUFS_STEP,
> > + MIN_BUFS_DEF);
> > + ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
>
> Need to check if ctrl is non-NULL.
>

Yep, I think I was confused as other v4l2 drivers ignored that check.

> > +
> > + if (stream->ctrl_handler.error)
> > + return stream->ctrl_handler.error;
> > +
> > + v4l2_ctrl_handler_setup(&stream->ctrl_handler);
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_dec_init_queues(void *priv, struct vb2_queue *src_vq,
> > + struct vb2_queue *dst_vq)
> > +{
> > + int ret;
> > + struct virtio_video_stream *stream = priv;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct device *dev = vv->v4l2_dev.dev;
> > +
> > + src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
> > + src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> > + src_vq->drv_priv = stream;
> > + src_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
> > + src_vq->ops = &virtio_video_dec_qops;
> > + src_vq->mem_ops = virtio_video_mem_ops(vv);
> > + src_vq->min_buffers_needed = stream->in_info.min_buffers;
> > + src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> > + src_vq->lock = &stream->vq_mutex;
> > + src_vq->gfp_flags = virtio_video_gfp_flags(vv);
> > + src_vq->dev = dev;
> > +
> > + ret = vb2_queue_init(src_vq);
> > + if (ret)
> > + return ret;
> > +
> > + dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
> > + dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> > + dst_vq->drv_priv = stream;
> > + dst_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
> > + dst_vq->ops = &virtio_video_dec_qops;
> > + dst_vq->mem_ops = virtio_video_mem_ops(vv);
> > + dst_vq->min_buffers_needed = stream->out_info.min_buffers;
> > + dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> > + dst_vq->lock = &stream->vq_mutex;
> > + dst_vq->gfp_flags = virtio_video_gfp_flags(vv);
> > + dst_vq->dev = dev;
> > +
> > + return vb2_queue_init(dst_vq);
> > +}
> > +
> > +static int virtio_video_try_decoder_cmd(struct file *file, void *fh,
> > + struct v4l2_decoder_cmd *cmd)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + if (stream->state == STREAM_STATE_DRAIN)
> > + return -EBUSY;
> > +
> > + switch (cmd->cmd) {
> > + case V4L2_DEC_CMD_STOP:
> > + case V4L2_DEC_CMD_START:
> > + if (cmd->flags != 0) {
> > + v4l2_err(&vv->v4l2_dev, "flags=%u are not
> > supported", + cmd->flags);
> > + return -EINVAL;
> > + }
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_decoder_cmd(struct file *file, void *fh,
> > + struct v4l2_decoder_cmd *cmd)
> > +{
> > + int ret;
> > + struct vb2_queue *src_vq, *dst_vq;
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + ret = virtio_video_try_decoder_cmd(file, fh, cmd);
> > + if (ret < 0)
> > + return ret;
> > +
> > + dst_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > + V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> > +
> > + switch (cmd->cmd) {
> > + case V4L2_DEC_CMD_START:
> > + vb2_clear_last_buffer_dequeued(dst_vq);
> > + break;
> > + case V4L2_DEC_CMD_STOP:
> > + src_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > +
> > V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE); +
> > + if (!vb2_is_streaming(src_vq)) {
> > + v4l2_dbg(1, vv->debug,
> > + &vv->v4l2_dev, "output is not
> > streaming\n"); + return 0;
> > + }
> > +
> > + if (!vb2_is_streaming(dst_vq)) {
> > + v4l2_dbg(1, vv->debug,
> > + &vv->v4l2_dev, "capture is not
> > streaming\n"); + return 0;
> > + }
> > +
> > + ret = virtio_video_cmd_stream_drain(vv,
> > stream->stream_id);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to drain
> > stream\n"); + return ret;
> > + }
> > +
> > + stream->state = STREAM_STATE_DRAIN;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_dec_enum_fmt_vid_cap(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format_info *info = NULL;
> > + struct video_format *fmt = NULL;
> > + unsigned long input_mask = 0;
> > + int idx = 0, bit_num = 0;
> > +
> > + if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> > + return -EINVAL;
> > +
> > + if (f->index >= vvd->num_output_fmts)
> > + return -EINVAL;
> > +
> > + info = &stream->in_info;
> > + list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry)
> > { + if (info->fourcc_format == fmt->desc.format) {
> > + input_mask = fmt->desc.mask;
> > + break;
> > + }
> > + }
> > +
> > + if (input_mask == 0)
> > + return -EINVAL;
> > +
> > + list_for_each_entry(fmt, &vvd->output_fmt_list,
> > formats_list_entry) { + if (test_bit(bit_num, &input_mask))
> > {
> > + if (f->index == idx) {
> > + f->pixelformat = fmt->desc.format;
> > + return 0;
> > + }
> > + idx++;
> > + }
> > + bit_num++;
> > + }
> > + return -EINVAL;
> > +}
> > +
> > +
> > +int virtio_video_dec_enum_fmt_vid_out(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format *fmt = NULL;
> > + int idx = 0;
> > +
> > + if (f->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> > + return -EINVAL;
> > +
> > + if (f->index >= vvd->num_input_fmts)
> > + return -EINVAL;
> > +
> > + list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry)
> > { + if (f->index == idx) {
> > + f->pixelformat = fmt->desc.format;
> > + return 0;
> > + }
> > + idx++;
> > + }
> > + return -EINVAL;
> > +}
> > +
> > +static int virtio_video_dec_s_fmt(struct file *file, void *fh,
> > + struct v4l2_format *f)
> > +{
> > + int ret;
> > + struct virtio_video_stream *stream = file2stream(file);
> > +
> > + ret = virtio_video_s_fmt(file, fh, f);
> > + if (ret)
> > + return ret;
> > +
> > + if (V4L2_TYPE_IS_OUTPUT(f->type)) {
> > + if (stream->state == STREAM_STATE_IDLE)
> > + stream->state = STREAM_STATE_INIT;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct v4l2_ioctl_ops virtio_video_dec_ioctl_ops = {
> > + .vidioc_querycap = virtio_video_querycap,
> > +
> > + .vidioc_enum_fmt_vid_cap = virtio_video_dec_enum_fmt_vid_cap,
> > + .vidioc_g_fmt_vid_cap = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_cap = virtio_video_dec_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_cap_mplane =
> > virtio_video_dec_enum_fmt_vid_cap, + .vidioc_g_fmt_vid_cap_mplane
> > = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_cap_mplane = virtio_video_dec_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_out = virtio_video_dec_enum_fmt_vid_out,
> > + .vidioc_g_fmt_vid_out = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_out = virtio_video_dec_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_out_mplane =
> > virtio_video_dec_enum_fmt_vid_out, + .vidioc_g_fmt_vid_out_mplane
> > = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_out_mplane = virtio_video_dec_s_fmt,
> > +
> > + .vidioc_g_selection = virtio_video_g_selection,
> > + .vidioc_s_selection = virtio_video_s_selection,
> > +
> > + .vidioc_try_decoder_cmd = virtio_video_try_decoder_cmd,
> > + .vidioc_decoder_cmd = virtio_video_decoder_cmd,
> > + .vidioc_enum_frameintervals = virtio_video_enum_framemintervals,
> > + .vidioc_enum_framesizes = virtio_video_enum_framesizes,
> > +
> > + .vidioc_reqbufs = virtio_video_reqbufs,
> > + .vidioc_querybuf = v4l2_m2m_ioctl_querybuf,
> > + .vidioc_qbuf = v4l2_m2m_ioctl_qbuf,
> > + .vidioc_dqbuf = v4l2_m2m_ioctl_dqbuf,
> > + .vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf,
> > + .vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
> > + .vidioc_expbuf = v4l2_m2m_ioctl_expbuf,
> > +
> > + .vidioc_streamon = v4l2_m2m_ioctl_streamon,
> > + .vidioc_streamoff = v4l2_m2m_ioctl_streamoff,
> > +
> > + .vidioc_subscribe_event = virtio_video_subscribe_event,
> > + .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> > +};
> > +
> > +int virtio_video_dec_init(struct video_device *vd)
> > +{
> > + ssize_t num;
> > +
> > + vd->ioctl_ops = &virtio_video_dec_ioctl_ops;
> > + num = strscpy(vd->name, "stateful-decoder", sizeof(vd->name));
>
> Don't we want to check the value of "num"?

Yes, probably we should do it.

> Also, how about having a word "virtio" in the name of the driver?

It is already clear from

> + dev_set_name(dev, "%s.%i", DRIVER_NAME, vdev->index);

in probe().

>
> > +
> > + return 0;
> > +}
> > diff --git a/drivers/media/virtio/virtio_video_dec.h
> > b/drivers/media/virtio/virtio_video_dec.h new file mode 100644
> > index 000000000000..0a1252248bbf
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_dec.h
> > @@ -0,0 +1,30 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ */
> > +/* Decoder header for virtio video driver.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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/>.
> > + */
> > +
> > +#ifndef _VIRTIO_VIDEO_DEC_H
> > +#define _VIRTIO_VIDEO_DEC_H
> > +
> > +#include "virtio_video.h"
> > +
> > +int virtio_video_dec_init(struct video_device *vd);
> > +int virtio_video_dec_init_ctrls(struct virtio_video_stream *stream);
> > +int virtio_video_dec_init_queues(void *priv, struct vb2_queue *src_vq,
> > + struct vb2_queue *dst_vq);
> > +
> > +#endif /* _VIRTIO_VIDEO_DEC_H */
> > diff --git a/drivers/media/virtio/virtio_video_device.c
> > b/drivers/media/virtio/virtio_video_device.c new file mode 100644
> > index 000000000000..130e705580d1
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_device.c
> > @@ -0,0 +1,1079 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Driver for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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 <media/v4l2-event.h>
> > +#include <media/v4l2-ioctl.h>
> > +#include <media/videobuf2-dma-sg.h>
> > +
> > +#include "virtio_video.h"
> > +#include "virtio_video_dec.h"
> > +#include "virtio_video_enc.h"
> > +
> > +int virtio_video_queue_setup(struct vb2_queue *vq, unsigned int
> > *num_buffers, + unsigned int *num_planes,
> > unsigned int sizes[], + struct device
> > *alloc_devs[])
> > +{
> > + int i;
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > + struct video_format_info *p_info;
> > +
> > + if (*num_planes)
> > + return 0;
> > +
> > + if (V4L2_TYPE_IS_OUTPUT(vq->type))
> > + p_info = &stream->in_info;
> > + else
> > + p_info = &stream->out_info;
> > +
> > + *num_planes = p_info->num_planes;
> > +
> > + for (i = 0; i < p_info->num_planes; i++)
> > + sizes[i] = p_info->plane_format[i].plane_size;
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_buf_init(struct vb2_buffer *vb)
> > +{
> > + int ret = 0;
> > + unsigned int i, j;
> > + struct scatterlist *sg;
> > + struct virtio_video_mem_entry *ents;
> > + uint32_t num_ents[VIRTIO_VIDEO_MAX_PLANES];
> > + struct sg_table *sgt[VIRTIO_VIDEO_MAX_PLANES];
> > + uint32_t resource_id, nents = 0;
> > + struct vb2_queue *vq = vb->vb2_queue;
> > + enum v4l2_buf_type queue_type = vq->type;
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > + struct virtio_video_buffer *virtio_vb = to_virtio_vb(vb);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + virtio_video_resource_id_get(vv, &resource_id);
> > +
> > + if (vv->supp_non_contig) {
> > + for (i = 0; i < vb->num_planes; i++) {
> > + sgt[i] = vb2_dma_sg_plane_desc(vb, i);
> > + nents += sgt[i]->nents;
> > + }
> > +
> > + ents = kcalloc(nents, sizeof(*ents), GFP_KERNEL);
> > + if (!ents)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < vb->num_planes; ++i) {
> > + for_each_sg(sgt[i]->sgl, sg, sgt[i]->nents, j) {
> > + ents[j].addr = cpu_to_le64(vv->has_iommu
> > + ?
> > sg_dma_address(sg) +
> > : sg_phys(sg)); + ents[j].length =
> > cpu_to_le32(sg->length); + }
> > + num_ents[i] = sgt[i]->nents;
> > + }
> > + } else {
> > + nents = vb->num_planes;
> > +
> > + ents = kcalloc(nents, sizeof(*ents), GFP_KERNEL);
> > + if (!ents)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < vb->num_planes; ++i) {
> > + ents[i].addr =
> > +
> > cpu_to_le64(vb2_dma_contig_plane_dma_addr(vb, +
> > i)); +
> > ents[i].length = cpu_to_le32(vb->planes[i].length); +
> > num_ents[i] = 1;
> > + }
> > + }
> > +
> > + v4l2_dbg(1, vv->debug, &vv->v4l2_dev, "mem entries:\n");
> > + if (vv->debug >= 1) {
> > + for (i = 0; i < nents; i++)
> > + pr_debug("\t%03i: addr=%llx length=%u\n", i,
> > + ents[i].addr, ents[i].length);
> > + }
> > +
> > + ret = virtio_video_cmd_resource_create(vv, stream->stream_id,
> > + resource_id,
> > +
> > to_virtio_queue_type(queue_type), +
> > ents, vb->num_planes, +
> > num_ents);
> > + if (ret) {
> > + virtio_video_resource_id_put(vvd->vv, resource_id);
> > + kfree(ents);
> > +
> > + return ret;
> > + }
> > +
> > + virtio_vb->queued = false;
> > + virtio_vb->resource_id = resource_id;
> > +
> > + return 0;
> > +}
> > +
> > +void virtio_video_buf_cleanup(struct vb2_buffer *vb)
> > +{
> > + struct virtio_video_stream *stream =
> > vb2_get_drv_priv(vb->vb2_queue); + struct virtio_video_buffer
> > *virtio_vb = to_virtio_vb(vb);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + virtio_video_resource_id_put(vv, virtio_vb->resource_id);
> > +}
> > +
> > +int virtio_video_querycap(struct file *file, void *fh,
> > + struct v4l2_capability *cap)
> > +{
> > + struct video_device *video_dev = video_devdata(file);
> > +
> > + strncpy(cap->driver, DRIVER_NAME, sizeof(cap->driver));
> > + strncpy(cap->card, video_dev->name, sizeof(cap->card));
> > + snprintf(cap->bus_info, sizeof(cap->bus_info), "virtio:%s",
> > + video_dev->name);
>
> v4l2-compliance test raises an error on this prefix "virtio:".
> We have two options:
> 1. Move the driver code to /platform/ and use a prefix "platform:"
> like other virtual drivers such as vivid and vicodec.
> 2. Modify v4l2-compliance test.
>
> I'm not sure which is better, though.
>

Yes, I know. I think we should patch the v4l2 utility with the new 'virtio'
bus definition. For example drm tools are aware of the virtio bus.

> > +
> > + cap->device_caps = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING;
> > + cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_enum_framesizes(struct file *file, void *fh,
> > + struct v4l2_frmsizeenum *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format *fmt = NULL;
> > + struct video_format_frame *frm = NULL;
> > + struct virtio_video_format_frame *frame = NULL;
> > + int idx = f->index;
> > +
> > + fmt = find_video_format(&vvd->input_fmt_list, f->pixel_format);
> > + if (fmt == NULL)
> > + fmt = find_video_format(&vvd->output_fmt_list,
> > f->pixel_format); + if (fmt == NULL)
> > + return -EINVAL;
> > +
> > + if (idx >= fmt->desc.num_frames)
> > + return -EINVAL;
> > +
> > + frm = &fmt->frames[idx];
> > + frame = &frm->frame;
> > +
> > + if (frame->width.min == frame->width.max &&
> > + frame->height.min == frame->height.max) {
> > + f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
> > + f->discrete.width = frame->width.min;
> > + f->discrete.height = frame->height.min;
> > + return 0;
> > + }
> > +
> > + f->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
> > + f->stepwise.min_width = frame->width.min;
> > + f->stepwise.max_width = frame->width.max;
> > + f->stepwise.min_height = frame->height.min;
> > + f->stepwise.max_height = frame->height.max;
> > + f->stepwise.step_width = frame->width.step;
> > + f->stepwise.step_height = frame->height.step;
> > + return 0;
> > +}
> > +
> > +static bool in_stepped_interval(uint32_t int_start, uint32_t int_end,
> > + uint32_t step, uint32_t point)
>
> How about changing the interface like this?
>
> static bool in_stepped_interval(const struct
> virtio_video_format_range* range, uint32_t point)
>
> > +{
> > + if (point < int_start || point > int_end)
>
> You can use within_range.
>

Yes, this might be more corect.

> > + return false;
> > +
> > + if (step == 0 && int_start == int_end && int_start == point)
> > + return true;
> > +
> > + if (step != 0 && (point - int_start) % step == 0)
> > + return true;
> > +
> > + return false;
> > +}
> > +
> > +int virtio_video_enum_framemintervals(struct file *file, void *fh,
> > + struct v4l2_frmivalenum *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format *fmt = NULL;
> > + struct video_format_frame *frm = NULL;
> > + struct virtio_video_format_frame *frame = NULL;
> > + struct virtio_video_format_range *frate = NULL;
> > + int idx = f->index;
> > + int f_idx = 0;
> > +
> > + fmt = find_video_format(&vvd->input_fmt_list, f->pixel_format);
> > + if (fmt == NULL)
> > + fmt = find_video_format(&vvd->output_fmt_list,
> > f->pixel_format); + if (fmt == NULL)
> > + return -EINVAL;
> > +
> > + for (f_idx = 0; f_idx <= fmt->desc.num_frames; f_idx++) {
> > + frm = &fmt->frames[f_idx];
> > + frame = &frm->frame;
> > + if (in_stepped_interval(frame->width.min,
> > frame->width.max,
> > + frame->width.step, f->width) &&
> > + in_stepped_interval(frame->height.min,
> > frame->height.max, +
> > frame->height.step, f->height)) + break;
> > + }
> > +
> > + if (frame == NULL || f->index >= frame->num_rates)
> > + return -EINVAL;
> > +
> > + frate = &frm->frame_rates[idx];
> > + if (frate->max == frate->min) {
> > + f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
> > + f->discrete.numerator = 1;
> > + f->discrete.denominator = frate->max;
> > + } else {
> > + f->stepwise.min.numerator = 1;
> > + f->stepwise.min.denominator = frate->max;
> > + f->stepwise.max.numerator = 1;
> > + f->stepwise.max.denominator = frate->min;
> > + f->stepwise.step.numerator = 1;
> > + f->stepwise.step.denominator = frate->step;
> > + if (frate->step == 1)
> > + f->type = V4L2_FRMIVAL_TYPE_CONTINUOUS;
> > + else
> > + f->type = V4L2_FRMIVAL_TYPE_STEPWISE;
> > + }
> > + return 0;
> > +}
> > +
> > +
> > +int virtio_video_g_fmt(struct file *file, void *fh, struct v4l2_format
> > *f)
> > +{
> > + struct video_format_info *info;
> > + struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
> > + struct virtio_video_stream *stream = file2stream(file);
> > +
> > + if (!V4L2_TYPE_IS_OUTPUT(f->type))
> > + info = &stream->out_info;
> > + else
> > + info = &stream->in_info;
> > +
> > + virtio_video_format_from_info(info, pix_mp);
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_s_fmt(struct file *file, void *fh, struct v4l2_format
> > *f)
> > +{
> > + int i, ret;
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct video_format_info info;
> > + struct video_format_info *p_info;
> > + uint32_t queue;
> > +
> > + ret = virtio_video_try_fmt(stream, f);
> > + if (ret)
> > + return ret;
> > +
> > + if (V4L2_TYPE_IS_OUTPUT(f->type)) {
> > + virtio_video_format_fill_default_info(&info,
> > &stream->in_info); + queue = VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
> > + } else {
> > + virtio_video_format_fill_default_info(&info,
> > &stream->out_info); + queue =
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
> > + }
> > +
> > + info.frame_width = pix_mp->width;
> > + info.frame_height = pix_mp->height;
> > + info.num_planes = pix_mp->num_planes;
> > + info.fourcc_format = pix_mp->pixelformat;
> > +
> > + for (i = 0; i < info.num_planes; i++) {
> > + info.plane_format[i].stride =
> > +
> > pix_mp->plane_fmt[i].bytesperline;
> > + info.plane_format[i].plane_size =
> > + pix_mp->plane_fmt[i].sizeimage;
> > + }
> > +
> > + virtio_video_cmd_set_params(vv, stream, &info, queue);
> > + virtio_video_cmd_get_params(vv, stream,
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT); + virtio_video_cmd_get_params(vv,
> > stream, VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT); +
> > + if (V4L2_TYPE_IS_OUTPUT(f->type))
> > + p_info = &stream->in_info;
> > + else
> > + p_info = &stream->out_info;
> > +
> > + virtio_video_format_from_info(p_info, pix_mp);
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_g_selection(struct file *file, void *fh,
> > + struct v4l2_selection *sel)
> > +{
> > + struct video_format_info *info = NULL;
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > +
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + if (!V4L2_TYPE_IS_OUTPUT(sel->type))
> > + return -EINVAL;
> > + info = &stream->in_info;
> > + break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + if (V4L2_TYPE_IS_OUTPUT(sel->type))
> > + return -EINVAL;
> > + info = &stream->out_info;
> > + break;
> > + default:
> > + v4l2_err(&vvd->vv->v4l2_dev, "unsupported device type\n");
> > + return -EINVAL;
> > + }
> > +
> > + switch (sel->target) {
> > + case V4L2_SEL_TGT_COMPOSE_BOUNDS:
>
> > + case V4L2_SEL_TGT_COMPOSE_PADDED:
> Can't we support V4L2_SEL_TGT_COMPOSE as well?
>

Yes, but I'm not sure what is the meaning if the settings are not communicated
back and forth with the device.

> > + sel->r.width = info->frame_width;
> > + sel->r.height = info->frame_height;
> > + break;
> > + default:
> > + v4l2_dbg(1, vvd->vv->debug, &vvd->vv->v4l2_dev,
> > + "unsupported/invalid selection target\n");
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_s_selection(struct file *file, void *fh,
> > + struct v4l2_selection *sel)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + int ret;
> > +
> > + stream->out_info.crop.top = sel->r.top;
> > + stream->out_info.crop.left = sel->r.left;
> > + stream->out_info.crop.width = sel->r.width;
> > + stream->out_info.crop.height = sel->r.height;
> > +
> > + ret = virtio_video_cmd_set_params(vv, stream, &stream->out_info,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT);
> > + if (ret < 0)
> > + return -EINVAL;
> > +
> > + /* Get actual selection that was set */
> > + return virtio_video_cmd_get_params(vv, stream,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT);
> > +}
> > +
> > +int virtio_video_try_fmt(struct virtio_video_stream *stream,
> > + struct v4l2_format *f)
> > +{
> > + int i, idx = 0;
> > + struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format *fmt = NULL;
> > + bool found = false;
> > + struct video_format_frame *frm = NULL;
> > + struct virtio_video_format_frame *frame = NULL;
> > +
> > + if (V4L2_TYPE_IS_OUTPUT(f->type))
> > + fmt = find_video_format(&vvd->input_fmt_list,
> > + pix_mp->pixelformat);
> > + else
> > + fmt = find_video_format(&vvd->output_fmt_list,
> > + pix_mp->pixelformat);
> > +
> > + if (!fmt) {
>
> Why is this condition needed?
>

To offer something that does not strictly match the requirement.

> > + if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> > + virtio_video_format_from_info(&stream->out_info,
> > + pix_mp);
> > + else if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> > + virtio_video_format_from_info(&stream->in_info,
> > + pix_mp);
> > + else
> > + return -EINVAL;
> > + return 0;
> > + }
> > +
> > + for (i = 0; i < fmt->desc.num_frames && !found; i++) {
> |
> |width| and |height| don't make any sense for coded formats whose
>
> metadata are in stream, such as VPx and H.264.
>
> So, we should have a if-statement like this before this for-loop:
>
> if (pix_mp->width == 0 && pix_mp->height == 0) {
> stream->current_frame = &fmt->frames[0];
> return 0;
> }
>

Yes, makes sense.

> > + frm = &fmt->frames[i];
> > + frame = &frm->frame;
> > + if (!within_range(frame->width.min, pix_mp->width,
> > + frame->width.max))
> > + continue;
> > +
> > + if (!within_range(frame->height.min, pix_mp->width,
>
> pix_mp->height
>

Oh, thanks.

> > + frame->height.max))
> > + continue;
> > + idx = i;
> > + /*
> > + * Try to find a more suitable frame size. Go with the
> > current + * one otherwise.
> > + */
> > + if (needs_alignment(pix_mp->width, frame->width.step))
> > + continue;
> > +
> > + if (needs_alignment(pix_mp->height, frame->height.step))
> > + continue;
> > +
> > + stream->current_frame = frm;
> > + found = true;
> > + }
> > +
> > + if (!found) {
> > + frm = &fmt->frames[idx];
>
> If num_frames==0, Null-dereference can occur.
> Even though the device is expected to return at least one frame info,
> the driver should add a check to avoid crash.
>

Sounds correct.

> > + frame = &frm->frame;
> > + pix_mp->width = clamp(pix_mp->width, frame->width.min,
> > + frame->width.max);
> > + if (frame->width.step != 0)
> > + pix_mp->width = ALIGN(pix_mp->width,
> > frame->width.step); +
> > + pix_mp->height = clamp(pix_mp->height, frame->height.min,
> > + frame->height.max);
> > + if (frame->height.step != 0)
> > + pix_mp->height = ALIGN(pix_mp->height,
> > + frame->height.step);
> > + stream->current_frame = frm;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_queue_free(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + enum v4l2_buf_type type)
> > +{
> > + int ret;
> > + uint32_t queue_type = to_virtio_queue_type(type);
> > +
> > + ret = virtio_video_cmd_resource_destroy_all(vv, stream,
> > + queue_type);
> > + if (ret)
> > + v4l2_warn(&vv->v4l2_dev,
> > + "failed to destroy resources\n");
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_reqbufs(struct file *file, void *priv,
> > + struct v4l2_requestbuffers *rb)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct v4l2_m2m_ctx *m2m_ctx = stream->fh.m2m_ctx;
> > + struct vb2_queue *vq = v4l2_m2m_get_vq(m2m_ctx, rb->type);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > +
> > + if (rb->count == 0)
> > + virtio_video_queue_free(vvd->vv, stream, vq->type);
> > +
> > + return v4l2_m2m_reqbufs(file, m2m_ctx, rb);
> > +}
> > +
> > +int virtio_video_subscribe_event(struct v4l2_fh *fh,
> > + const struct v4l2_event_subscription
> > *sub)
> > +{
> > + switch (sub->type) {
> > + case V4L2_EVENT_SOURCE_CHANGE:
> > + return v4l2_src_change_event_subscribe(fh, sub);
> > + default:
> > + return -EINVAL;
> > + }
> > +}
> > +
> > +void virtio_video_queue_eos_event(struct virtio_video_stream *stream)
> > +{
> > + static const struct v4l2_event eos_event = {
> > + .type = V4L2_EVENT_EOS
> > + };
> > +
> > + v4l2_event_queue_fh(&stream->fh, &eos_event);
> > +}
> > +
> > +void virtio_video_queue_res_chg_event(struct virtio_video_stream *stream)
> > +{
> > + static const struct v4l2_event ev_src_ch = {
> > + .type = V4L2_EVENT_SOURCE_CHANGE,
> > + .u.src_change.changes =
> > + V4L2_EVENT_SRC_CH_RESOLUTION,
> > + };
> > +
> > + v4l2_event_queue_fh(&stream->fh, &ev_src_ch);
> > +}
> > +
> > +void virtio_video_mark_drain_complete(struct virtio_video_stream *stream,
> > + struct vb2_v4l2_buffer *v4l2_vb)
> > +{
> > + struct vb2_buffer *vb2_buf;
> > +
> > + v4l2_vb->flags |= V4L2_BUF_FLAG_LAST;
> > +
> > + vb2_buf = &v4l2_vb->vb2_buf;
> > + vb2_buf->planes[0].bytesused = 0;
> > +
> > + v4l2_m2m_buf_done(v4l2_vb, VB2_BUF_STATE_DONE);
> > + stream->state = STREAM_STATE_STOPPED;
> > +}
> > +
> > +void virtio_video_buf_done(struct virtio_video_buffer *virtio_vb,
> > + uint32_t flags, uint64_t timestamp, uint32_t
> > size) +{
> > + int i;
> > + enum vb2_buffer_state done_state = VB2_BUF_STATE_DONE;
> > + struct vb2_v4l2_buffer *v4l2_vb = &virtio_vb->v4l2_m2m_vb.vb;
> > + struct vb2_buffer *vb = &v4l2_vb->vb2_buf;
> > + struct vb2_queue *vb2_queue = vb->vb2_queue;
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vb2_queue);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format_info *p_info;
> > +
> > + virtio_vb->queued = false;
> > +
> > + if (flags & VIRTIO_VIDEO_BUFFER_FLAG_ERR)
> > + done_state = VB2_BUF_STATE_ERROR;
> > +
> > + if (flags & VIRTIO_VIDEO_BUFFER_FLAG_IFRAME)
> > + v4l2_vb->flags |= V4L2_BUF_FLAG_KEYFRAME;
> > +
> > + if (flags & VIRTIO_VIDEO_BUFFER_FLAG_BFRAME)
> > + v4l2_vb->flags |= V4L2_BUF_FLAG_BFRAME;
> > +
> > + if (flags & VIRTIO_VIDEO_BUFFER_FLAG_PFRAME)
> > + v4l2_vb->flags |= V4L2_BUF_FLAG_PFRAME;
> > +
> > + if (flags & VIRTIO_VIDEO_BUFFER_FLAG_EOS) {
> > + v4l2_vb->flags |= V4L2_BUF_FLAG_LAST;
> > + stream->state = STREAM_STATE_STOPPED;
> > + virtio_video_queue_eos_event(stream);
> > + }
> > +
> > + if (!V4L2_TYPE_IS_OUTPUT(vb2_queue->type)) {
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + vb->planes[0].bytesused = size;
> > + break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + p_info = &stream->out_info;
> > + for (i = 0; i < p_info->num_planes; i++)
> > + vb->planes[i].bytesused =
> > +
> > p_info->plane_format[i].plane_size;
>
> This is not always correct because the host can returns an empty
> buffer with the EOS flag or the ERR flag.
> In such case, we need to set 0 to bytesused.
>
> However, the current protocol doesn't define how to notify |bytesused|
> for decoder.
> We may need to extend the protocol to have |size| for each plane?
>

Do you mean to provide the actual amount of data written? We can also say the
device must set it to 0 on error.

> > + break;
> > + }
> > +
> > + vb->timestamp = timestamp;
> > + }
> > +
> > + v4l2_m2m_buf_done(v4l2_vb, done_state);
> > +}
> > +
> > +static void virtio_video_worker(struct work_struct *work)
>
> Question:
> Why do you enqueue buffers here instead of in virtio_video_dec_buf_queue?
> Furthermore, I wonder why we have virtio_video_cmd_resource_queue for
> INPUT both in this function and that function.
>

Because according to the state machine sometimes we are not allowed to equeue
buffer in the device.

We call virtio_video_cmd_resource_queue() also in virtio_video_dec_buf_queue()
to decode first buffers and get your metadata ready. You cannot do this from
virtio_video_worker because it is called by the v4l2 subsys only when both
queues are streaming.

> > +{
> > + unsigned int i;
> > + int ret;
> > + struct vb2_buffer *vb2_buf;
> > + struct vb2_v4l2_buffer *src_vb, *dst_vb;
> > + struct virtio_video_buffer *virtio_vb;
> > + struct virtio_video_stream *stream = work2stream(work);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct vb2_queue *src_vq =
> > + v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > + V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
> > + struct vb2_queue *dst_vq =
> > + v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > + V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> > + struct virtio_video *vv = vvd->vv;
> > + uint32_t data_size[VB2_MAX_PLANES] = {0};
> > +
> > + mutex_lock(dst_vq->lock);
>
> Can't we narrow the range that requires the lock?
> How about obtaining a lock just before virtio_video_cmd_resource_queue()?
>
> At least, we can get lock inside of the for-loop to avoid blocking
> another work for a long time.

Let me think about this again. AFAIR there was a reason.

>
> > + for (;;) {
> > + dst_vb = v4l2_m2m_next_dst_buf(stream->fh.m2m_ctx);
> > + if (dst_vb == NULL)
> > + break;
> > +
> > + vb2_buf = &dst_vb->vb2_buf;
> > + virtio_vb = to_virtio_vb(vb2_buf);
> > +
> > + for (i = 0; i < vb2_buf->num_planes; ++i)
> > + data_size[i] = vb2_buf->planes[i].bytesused;
> > +
> > + ret = virtio_video_cmd_resource_queue
> > + (vv, stream->stream_id, virtio_vb, data_size,
> > + vb2_buf->num_planes,
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to queue a dst buffer\n");
> > + v4l2_m2m_job_finish(vvd->m2m_dev,
> > stream->fh.m2m_ctx); + mutex_unlock(dst_vq->lock);
> > + return;
> > + }
> > +
> > + virtio_vb->queued = true;
> > + stream->dst_cleared = false;
> > + dst_vb = v4l2_m2m_dst_buf_remove(stream->fh.m2m_ctx);
> > + }
> > + mutex_unlock(dst_vq->lock);
> > +
> > + mutex_lock(src_vq->lock);
> > + for (;;) {
> > + if (stream->state == STREAM_STATE_DRAIN)
> > + break;
> > +
> > + src_vb = v4l2_m2m_next_src_buf(stream->fh.m2m_ctx);
> > + if (src_vb == NULL)
> > + break;
> > +
> > + vb2_buf = &src_vb->vb2_buf;
> > + virtio_vb = to_virtio_vb(vb2_buf);
> > +
> > + for (i = 0; i < vb2_buf->num_planes; ++i)
> > + data_size[i] = vb2_buf->planes[i].bytesused;
> > +
> > + ret = virtio_video_cmd_resource_queue
> > + (vv, stream->stream_id, virtio_vb, data_size,
> > + vb2_buf->num_planes,
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to queue an src buffer\n");
> > + v4l2_m2m_job_finish(vvd->m2m_dev,
> > stream->fh.m2m_ctx); + mutex_unlock(src_vq->lock);
> > + return;
> > + }
> > +
> > + virtio_vb->queued = true;
> > + stream->src_cleared = false;
> > + src_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
> > + }
> > + mutex_unlock(src_vq->lock);
> > +
> > + v4l2_m2m_job_finish(vvd->m2m_dev, stream->fh.m2m_ctx);
> > +}
> > +
> > +static int virtio_video_device_open(struct file *file)
> > +{
> > + int ret;
> > + uint32_t stream_id;
> > + char name[TASK_COMM_LEN];
> > + struct virtio_video_stream *stream;
> > + struct video_format *default_fmt;
> > + enum virtio_video_format format;
> > + struct video_device *video_dev = video_devdata(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + default_fmt =
> > list_first_entry_or_null(&vvd->output_fmt_list, +
> > struct video_format, +
> > formats_list_entry); +
> > break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + default_fmt =
> > list_first_entry_or_null(&vvd->input_fmt_list, +
> > struct video_format, +
> > formats_list_entry); + break;
> > + default:
> > + v4l2_err(&vv->v4l2_dev, "unsupported device type\n");
>
> How about printing vvd->type?
>

Yes, I was thinking of a virtio-video specific print function.

> > + return -EIO;
> > + }
> > +
> > + if (!default_fmt) {
> > + v4l2_err(&vv->v4l2_dev, "device failed to start\n");
> > + return -EIO;
> > + }
> > +
> > + stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> > + if (!stream)
> > + return -ENOMEM;
> > +
> > + get_task_comm(name, current);
> > + format =
> > virtio_video_v4l2_format_to_virtio(default_fmt->desc.format);
> As I mentioned in the previous version, it's better to avoid expensive
> operations like stream creation in open callback because applications
> usually open a video device only to query capabilities.
> We can delay to send stream_create until calling REQBUFS.
>

Yes, this has been discussed already. But this design decision had
implications and it was decided not to implement that at least for the patch
v2.

> > + virtio_video_stream_id_get(vv, stream, &stream_id);
> > + ret = virtio_video_cmd_stream_create(vv, stream_id, format, name);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to create stream\n");
> > + goto err_stream_create;
> > + }
> > +
> > + stream->video_dev = video_dev;
> > + stream->stream_id = stream_id;
> > + stream->state = STREAM_STATE_IDLE;
> > +
> > + ret = virtio_video_cmd_get_params(vv, stream,
> > + VIRTIO_VIDEO_QUEUE_TYPE_INPUT);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get stream in
> > params\n"); + goto err_init_ctrls;
> > + }
> > +
> > + ret = virtio_video_cmd_get_params(vv, stream,
> > + VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get stream out
> > params\n"); + goto err_init_ctrls;
> > + }
> > +
> > + ret = virtio_video_cmd_get_control(vv, stream,
> > + VIRTIO_VIDEO_CONTROL_PROFILE);
>
> Since VIRTIO_VIODE_COTROLs are optional , we shouldn't call it
> unconditonally. Especially, CONTROL_PROFILE is valid only when a special
> type of coded formats is used.
>

Yes, true.

> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get stream profile\n");
> > + goto err_init_ctrls;
> > + }
> > +
> > + ret = virtio_video_cmd_get_control(vv, stream,
> > + VIRTIO_VIDEO_CONTROL_LEVEL);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get stream level\n");
> > + goto err_init_ctrls;
> > + }
> > +
> > + ret = virtio_video_cmd_get_control(vv, stream,
> > + VIRTIO_VIDEO_CONTROL_BITRATE);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get stream bitrate\n");
> > + goto err_init_ctrls;
> > + }
> > +
> > + mutex_init(&stream->vq_mutex);
> > + INIT_WORK(&stream->work, virtio_video_worker);
> > + v4l2_fh_init(&stream->fh, video_dev);
> > + stream->fh.ctrl_handler = &stream->ctrl_handler;
> > +
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + stream->fh.m2m_ctx =
> > + v4l2_m2m_ctx_init(vvd->m2m_dev, stream,
> > + &virtio_video_enc_init_queues);
> > + break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + stream->fh.m2m_ctx =
> > + v4l2_m2m_ctx_init(vvd->m2m_dev, stream,
> > + &virtio_video_dec_init_queues);
> > + break;
> > + default:
> > + v4l2_err(&vv->v4l2_dev, "unsupported device type\n");
> > + goto err_stream_create;
> > + }
> > +
> > + v4l2_m2m_set_src_buffered(stream->fh.m2m_ctx, true);
> > + v4l2_m2m_set_dst_buffered(stream->fh.m2m_ctx, true);
> > + file->private_data = &stream->fh;
> > + v4l2_fh_add(&stream->fh);
> > +
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + ret = virtio_video_enc_init_ctrls(stream);
> > + break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + ret = virtio_video_dec_init_ctrls(stream);
> > + break;
> > + default:
> > + ret = 0;
> > + break;
>
> unreachable or error?
>

I want to provide device specific ops and to get rid of the case statements.

> > + }
> > +
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to init controls\n");
> > + goto err_init_ctrls;
> > + }
> > + return 0;
> > +
> > +err_init_ctrls:
> > + v4l2_fh_del(&stream->fh);
> > + v4l2_fh_exit(&stream->fh);
> > + mutex_lock(video_dev->lock);
> > + v4l2_m2m_ctx_release(stream->fh.m2m_ctx);
> > + mutex_unlock(video_dev->lock);
> > +err_stream_create:
> > + virtio_video_stream_id_put(vv, stream_id);
> > + kfree(stream);
> > +
> > + return ret;
> > +}
> > +
> > +static int virtio_video_device_release(struct file *file)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct video_device *video_dev = video_devdata(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + v4l2_fh_del(&stream->fh);
> > + v4l2_fh_exit(&stream->fh);
> > + mutex_lock(video_dev->lock);
> > + v4l2_m2m_ctx_release(stream->fh.m2m_ctx);
> > + mutex_unlock(video_dev->lock);
> > +
> > + virtio_video_cmd_stream_destroy(vv, stream->stream_id);
> > + virtio_video_stream_id_put(vv, stream->stream_id);
> > +
> > + kfree(stream);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct v4l2_file_operations virtio_video_device_fops = {
> > + .owner = THIS_MODULE,
> > + .open = virtio_video_device_open,
> > + .release = virtio_video_device_release,
> > + .poll = v4l2_m2m_fop_poll,
> > + .unlocked_ioctl = video_ioctl2,
> > + .mmap = v4l2_m2m_fop_mmap,
> > +};
> > +
> > +static void virtio_video_device_run(void *priv)
> > +{
> > + struct virtio_video_stream *stream = priv;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > +
> > + queue_work(vvd->workqueue, &stream->work);
> > +}
> > +
> > +static int virtio_video_device_job_ready(void *priv)
> > +{
> > + struct virtio_video_stream *stream = priv;
> > +
> > + if (stream->state == STREAM_STATE_STOPPED)
> > + return 0;
> > +
> > + if (v4l2_m2m_num_src_bufs_ready(stream->fh.m2m_ctx) > 0 ||
> > + v4l2_m2m_num_dst_bufs_ready(stream->fh.m2m_ctx) > 0)
> > + return 1;
> > +
> > + return 0;
> > +}
> > +
> > +static void virtio_video_device_job_abort(void *priv)
> > +{
> > + struct virtio_video_stream *stream = priv;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > +
> > + v4l2_m2m_job_finish(vvd->m2m_dev, stream->fh.m2m_ctx);
> > +}
> > +
> > +static const struct v4l2_m2m_ops virtio_video_device_m2m_ops = {
> > + .device_run = virtio_video_device_run,
> > + .job_ready = virtio_video_device_job_ready,
> > + .job_abort = virtio_video_device_job_abort,
> > +};
> > +
> > +static int virtio_video_device_register(struct virtio_video_device *vvd)
> > +{
> > + int ret = 0;
> > + struct video_device *vd = NULL;
> > + struct virtio_video *vv = NULL;
> > +
> > + if (!vvd)
> > + return -EINVAL;
> > +
> > + vd = &vvd->video_dev;
> > + vv = vvd->vv;
> > +
> > + switch (vvd->type) {
> > + case VIRTIO_VIDEO_DEVICE_ENCODER:
> > + ret = virtio_video_enc_init(vd);
> > + break;
> > + case VIRTIO_VIDEO_DEVICE_DECODER:
> > + ret = virtio_video_dec_init(vd);
> > + break;
> > + default:
> > + v4l2_err(&vv->v4l2_dev, "unknown device type\n");
> > + return -EINVAL;
> > + }
> > +
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to init device\n");
> > + return ret;
> > + }
> > +
> > + ret = video_register_device(vd, VFL_TYPE_GRABBER, 0);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to register video
> > device\n"); + return ret;
> > + }
> > +
> > + vvd->workqueue = alloc_ordered_workqueue(vd->name,
> > + WQ_MEM_RECLAIM |
> > WQ_FREEZABLE); + if (!vvd->workqueue) {
> > + v4l2_err(&vv->v4l2_dev, "failed to create a workqueue");
> > + video_unregister_device(vd);
> > + return -ENOMEM;
> > + }
> > +
> > + list_add(&vvd->devices_list_entry, &vv->devices_list);
> > + v4l2_info(&vv->v4l2_dev, "Device '%s' registered as
> > /dev/video%d\n", + vd->name, vd->num);
> > +
> > + return 0;
> > +}
> > +
> > +static void virtio_video_device_unregister(struct virtio_video_device
> > *vvd) +{
> > + if (!vvd)
> > + return;
> > +
> > + list_del(&vvd->devices_list_entry);
> > + flush_workqueue(vvd->workqueue);
> > + destroy_workqueue(vvd->workqueue);
> > + video_unregister_device(&vvd->video_dev);
> > +}
> > +
> > +static struct virtio_video_device *
> > +virtio_video_device_create(struct virtio_video *vv)
> > +{
> > + struct device *dev = NULL;
> > + struct video_device *vd = NULL;
> > + struct v4l2_m2m_dev *m2m_dev = NULL;
> > + struct virtio_video_device *vvd = NULL;
> > +
> > + if (!vv)
> > + return ERR_PTR(-EINVAL);
> > +
> > + dev = &vv->vdev->dev;
> > +
> > + vvd = devm_kzalloc(dev, sizeof(*vvd), GFP_KERNEL);
> > + if (!vvd)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + m2m_dev = v4l2_m2m_init(&virtio_video_device_m2m_ops);
> > + if (IS_ERR(m2m_dev)) {
> > + v4l2_err(&vv->v4l2_dev, "failed to init m2m device\n");
> > + goto err;
> > + }
> > +
> > + vvd->vv = vv;
> > + vvd->m2m_dev = m2m_dev;
> > + mutex_init(&vvd->video_dev_mutex);
> > + vd = &vvd->video_dev;
> > + vd->lock = &vvd->video_dev_mutex;
> > + vd->v4l2_dev = &vv->v4l2_dev;
> > + vd->vfl_dir = VFL_DIR_M2M;
> > + vd->ioctl_ops = NULL;
> > + vd->fops = &virtio_video_device_fops;
> > + vd->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_M2M_MPLANE;
> > + vd->release = video_device_release_empty;
> > +
> > + /* Use the selection API instead */
> > + v4l2_disable_ioctl(vd, VIDIOC_CROPCAP);
> > + v4l2_disable_ioctl(vd, VIDIOC_G_CROP);
> > + v4l2_disable_ioctl(vd, VIDIOC_S_CROP);
> > +
> > + video_set_drvdata(vd, vvd);
> > +
> > + INIT_LIST_HEAD(&vvd->input_fmt_list);
> > + INIT_LIST_HEAD(&vvd->output_fmt_list);
> > + INIT_LIST_HEAD(&vvd->controls_fmt_list);
> > +
> > + vvd->num_output_fmts = 0;
> > + vvd->num_input_fmts = 0;
> > +
> > + switch (vv->vdev->id.device) {
> > + case VIRTIO_ID_VIDEO_ENC:
> > + vvd->type = VIRTIO_VIDEO_DEVICE_ENCODER;
> > + break;
> > + case VIRTIO_ID_VIDEO_DEC:
>
> > + default:
> error if it's neither VIDEO_ENC nore VIDEO_DEC?
>

Same as above.

> > + vvd->type = VIRTIO_VIDEO_DEVICE_DECODER;
> > + break;
> > + }
> > +
> > + return vvd;
> > +
> > +err:
> > + devm_kfree(dev, vvd);
> > +
> > + return ERR_CAST(m2m_dev);
> > +}
> > +
> > +void virtio_video_device_destroy(struct virtio_video_device *vvd)
> > +{
> > + if (!vvd)
> > + return;
> > +
> > + v4l2_m2m_release(vvd->m2m_dev);
> > + devm_kfree(&vvd->vv->vdev->dev, vvd);
> > +}
> > +
> > +int virtio_video_device_init(struct virtio_video *vv,
> > + void *input_buf, void *output_buf)
> > +{
> > + int ret = 0;
> > + struct virtio_video_device *vvd = NULL;
> > +
> > + if (!vv || !input_buf || !output_buf)
> > + return -EINVAL;
> > +
> > +
> > + vvd = virtio_video_device_create(vv);
> > + if (IS_ERR(vvd)) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to create virtio video device\n");
> > + ret = PTR_ERR(vvd);
> > + goto failed;
> > + }
> > +
> > + ret = virtio_video_parse_virtio_capability(vvd, input_buf,
> > output_buf); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to parse a function\n");
> > + virtio_video_device_destroy(vvd);
> > + ret = -EINVAL;
> > + goto failed;
> > + }
> > +
> > + ret = virtio_video_parse_virtio_control(vvd);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to query controls\n");
> > + virtio_video_clean_capability(vvd);
> > + virtio_video_device_destroy(vvd);
>
> Please do these cleanups after goto.
>

Ok.

> > + goto failed;
> > + }
> > +
> > + ret = virtio_video_device_register(vvd);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to init virtio video device\n");
> > + virtio_video_clean_control(vvd);
> > + virtio_video_clean_capability(vvd);
> > + virtio_video_device_destroy(vvd);
> > + goto failed;
> > + }
> > +
> > + return 0;
> > +
> > +failed:
> > + virtio_video_device_deinit(vv);
> > +
> > + return ret;
> > +}
> > +
> > +void virtio_video_device_deinit(struct virtio_video *vv)
> > +{
> > + struct virtio_video_device *vvd = NULL, *tmp = NULL;
> > +
> > + list_for_each_entry_safe(vvd, tmp, &vv->devices_list,
> > + devices_list_entry) {
> > + virtio_video_device_unregister(vvd);
> > + virtio_video_clean_control(vvd);
> > + virtio_video_clean_capability(vvd);
> > + virtio_video_device_destroy(vvd);
> > + }
> > +}
> > diff --git a/drivers/media/virtio/virtio_video_driver.c
> > b/drivers/media/virtio/virtio_video_driver.c new file mode 100644
> > index 000000000000..2d4fd7671f4f
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_driver.c
> > @@ -0,0 +1,315 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Driver for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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 <linux/module.h>
> > +#include <linux/version.h>
> > +#include <linux/dma-mapping.h>
> > +
> > +#include "virtio_video.h"
> > +
> > +static unsigned int debug;
> > +module_param(debug, uint, 0644);
> > +
> > +static unsigned int use_dma_mem;
> > +module_param(use_dma_mem, uint, 0644);
> > +MODULE_PARM_DESC(use_dma_mem, "Try to allocate buffers from the DMA
> > zone"); +
> > +static void virtio_video_init_vq(struct virtio_video_queue *vvq,
> > + void (*work_func)(struct work_struct
> > *work)) +{
> > + spin_lock_init(&vvq->qlock);
> > + init_waitqueue_head(&vvq->ack_queue);
> > + INIT_WORK(&vvq->dequeue_work, work_func);
> > +}
> > +
> > +static void *dma_phys_alloc(struct device *dev, size_t size,
> > + dma_addr_t *dma_handle, gfp_t gfp,
> > + unsigned long attrs)
> > +{
> > + void *ret;
> > +
> > + ret = (void *)__get_free_pages(gfp, get_order(size));
> > + if (ret)
> > + *dma_handle = virt_to_phys(ret) -
> > PFN_PHYS(dev->dma_pfn_offset); +
> > + return ret;
> > +}
> > +
> > +static void dma_phys_free(struct device *dev, size_t size,
> > + void *cpu_addr, dma_addr_t dma_addr,
> > + unsigned long attrs)
> > +{
> > + free_pages((unsigned long)cpu_addr, get_order(size));
> > +}
> > +
> > +static dma_addr_t dma_phys_map_page(struct device *dev, struct page
> > *page,
> > + unsigned long offset, size_t size,
> > + enum dma_data_direction dir,
> > + unsigned long attrs)
> > +{
> > + return page_to_phys(page) + offset -
> > PFN_PHYS(dev->dma_pfn_offset);
> > +}
> > +
> > +static int dma_phys_map_sg(struct device *dev, struct scatterlist *sgl,
> > + int nents, enum dma_data_direction dir,
> > + unsigned long attrs)
> > +{
> > + int i;
> > + struct scatterlist *sg;
> > +
> > + for_each_sg(sgl, sg, nents, i) {
> > + dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset);
> > + void *va;
> > +
> > + BUG_ON(!sg_page(sg));
>
> AFAIK, BUG_ON isn't recommended to use.
> At least, /scripts/checkpatch.pl complains it.
>

Yes.

> > + va = sg_virt(sg);
> > + sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va) -
> > offset;
> > + sg_dma_len(sg) = sg->length;
> > + }
> > +
> > + return nents;
> > +}
> > +
> > +const struct dma_map_ops dma_phys_ops = {
> > + .alloc = dma_phys_alloc,
> > + .free = dma_phys_free,
> > + .map_page = dma_phys_map_page,
> > + .map_sg = dma_phys_map_sg,
> > +};
> > +
> > +static int virtio_video_query_cap_resp_buf(struct virtio_video *vv, void
> > + **resp_buf, int queue_type)
> > +{
> > + int ret = 0;
> > + int resp_size = vv->max_caps_len;
> > +
> > + *resp_buf = kzalloc(vv->max_caps_len, GFP_KERNEL);
> > + if (IS_ERR(*resp_buf)) {
> > + ret = PTR_ERR(*resp_buf);
> > + goto err;
> > + }
> > +
> > + vv->got_caps = false;
> > + ret = virtio_video_query_capability(vv, *resp_buf, resp_size,
> > + queue_type);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to query capability\n");
> > + goto err;
> > + }
> > +
> > + ret = wait_event_timeout(vv->wq, vv->got_caps, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev, "timed out waiting for get
> > caps\n"); + ret = -EIO;
> > + goto err;
> > + }
> > +
> > + return 0;
> > +err:
> > + return ret;
> > +}
> > +
> > +static int virtio_video_init(struct virtio_video *vv)
> > +{
> > + int ret = 0;
> > + void *input_resp_buf = NULL;
> > + void *output_resp_buf = NULL;
> > +
> > + if (!vv)
> > + return -EINVAL;
> > +
> > + ret = virtio_video_query_cap_resp_buf(vv, &input_resp_buf,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get input caps\n");
> > + goto err;
> > + }
> > +
> > + ret = virtio_video_query_cap_resp_buf(vv, &output_resp_buf,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT); + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to get output caps\n");
> > + goto err;
> > + }
> > +
> > + ret = virtio_video_device_init(vv, input_resp_buf,
> > output_resp_buf); + if (ret)
> > + v4l2_err(&vv->v4l2_dev, "failed to initialize devices\n");
> > +
> > +err:
> > + kfree(input_resp_buf);
> > + kfree(output_resp_buf);
> > +
> > + return ret;
> > +};
> > +
> > +static int virtio_video_probe(struct virtio_device *vdev)
> > +{
> > + int ret;
> > + struct virtio_video *vv;
> > + struct virtqueue *vqs[2];
> > + struct device *dev = &vdev->dev;
> > +
> > + static const char * const names[] = { "control", "event" };
> > + static vq_callback_t *callbacks[] = {
> > + virtio_video_cmd_ack,
> > + virtio_video_event_ack
> > + };
> > +
> > + if (!virtio_has_feature(vdev,
> > VIRTIO_VIDEO_F_RESOURCE_GUEST_PAGES)) { + dev_err(dev,
> > "device must support guest allocated buffers\n"); + return
> > -ENODEV;
> > + }
> > +
> > + vv = devm_kzalloc(dev, sizeof(*vv), GFP_KERNEL);
> > + if (!vv)
> > + return -ENOMEM;
> > +
> > + vv->vdev = vdev;
> > + vv->debug = debug;
> > + vv->use_dma_mem = use_dma_mem;
> > + vdev->priv = vv;
> > +
> > + spin_lock_init(&vv->resource_idr_lock);
> > + idr_init(&vv->resource_idr);
> > + spin_lock_init(&vv->stream_idr_lock);
> > + idr_init(&vv->stream_idr);
> > +
> > + init_waitqueue_head(&vv->wq);
> > +
> > + if (virtio_has_feature(vdev, VIRTIO_VIDEO_F_RESOURCE_NON_CONTIG))
> > + vv->supp_non_contig = true;
> > +
> > + vv->has_iommu = !virtio_has_iommu_quirk(vdev);
> > + if (!vv->has_iommu)
> > + set_dma_ops(dev, &dma_phys_ops);
> > +
> > + dev_set_name(dev, "%s.%i", DRIVER_NAME, vdev->index);
> > + ret = v4l2_device_register(dev, &vv->v4l2_dev);
> > + if (ret)
> > + goto err_v4l2_reg;
> > +
> > + virtio_video_init_vq(&vv->commandq,
> > virtio_video_dequeue_cmd_func);
> > + virtio_video_init_vq(&vv->eventq,
> > virtio_video_dequeue_event_func);
> > +
> > + ret = virtio_find_vqs(vdev, 2, vqs, callbacks, names, NULL);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to find virt queues\n");
> > + goto err_vqs;
> > + }
> > +
> > + vv->commandq.vq = vqs[0];
> > + vv->eventq.vq = vqs[1];
> > +
> > + ret = virtio_video_alloc_vbufs(vv);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to alloc vbufs\n");
> > + goto err_vbufs;
> > + }
> > +
> > + virtio_cread(vdev, struct virtio_video_config, max_caps_length,
> > + &vv->max_caps_len);
> > + if (!vv->max_caps_len) {
> > + v4l2_err(&vv->v4l2_dev, "max_caps_len is zero\n");
> > + ret = -EINVAL;
> > + goto err_config;
> > + }
> > +
> > + virtio_cread(vdev, struct virtio_video_config, max_resp_length,
> > + &vv->max_resp_len);
> > + if (!vv->max_resp_len) {
> > + v4l2_err(&vv->v4l2_dev, "max_resp_len is zero\n");
> > + ret = -EINVAL;
> > + goto err_config;
> > + }
> > +
> > + ret = virtio_video_alloc_events(vv, vv->eventq.vq->num_free);
> > + if (ret)
> > + goto err_events;
> > +
> > + virtio_device_ready(vdev);
> > + vv->vq_ready = true;
> > + vv->got_caps = false;
> > +
> > + INIT_LIST_HEAD(&vv->devices_list);
> > +
> > + ret = virtio_video_init(vv);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "failed to init virtio video\n");
> > + goto err_init;
> > + }
> > +
> > + return 0;
> > +
> > +err_init:
> > +err_events:
> > +err_config:
> > + virtio_video_free_vbufs(vv);
> > +err_vbufs:
> > + vdev->config->del_vqs(vdev);
> > +err_vqs:
> > + v4l2_device_unregister(&vv->v4l2_dev);
> > +err_v4l2_reg:
> > + devm_kfree(&vdev->dev, vv);
> > +
> > + return ret;
> > +}
> > +
> > +static void virtio_video_remove(struct virtio_device *vdev)
> > +{
> > + struct virtio_video *vv = vdev->priv;
> > +
> > + virtio_video_device_deinit(vv);
> > + virtio_video_free_vbufs(vv);
> > + vdev->config->del_vqs(vdev);
> > + v4l2_device_unregister(&vv->v4l2_dev);
> > + devm_kfree(&vdev->dev, vv);
> > +}
> > +
> > +static struct virtio_device_id id_table[] = {
> > + { VIRTIO_ID_VIDEO_DEC, VIRTIO_DEV_ANY_ID },
> > + { VIRTIO_ID_VIDEO_ENC, VIRTIO_DEV_ANY_ID },
> > + { 0 },
> > +};
> > +
> > +static unsigned int features[] = {
> > + VIRTIO_VIDEO_F_RESOURCE_GUEST_PAGES,
> > + VIRTIO_VIDEO_F_RESOURCE_NON_CONTIG,
> > +};
> > +
> > +static struct virtio_driver virtio_video_driver = {
> > + .feature_table = features,
> > + .feature_table_size = ARRAY_SIZE(features),
> > + .driver.name = DRIVER_NAME,
> > + .driver.owner = THIS_MODULE,
> > + .id_table = id_table,
> > + .probe = virtio_video_probe,
> > + .remove = virtio_video_remove,
> > +};
> > +
> > +module_virtio_driver(virtio_video_driver);
> > +
> > +MODULE_DEVICE_TABLE(virtio, id_table);
> > +MODULE_DESCRIPTION("virtio video driver");
> > +MODULE_AUTHOR("Dmitry Sepp <dmitry.sepp@opensynergy.com>");
> > +MODULE_AUTHOR("Kiran Pawar <kiran.pawar@opensynergy.com>");
> > +MODULE_AUTHOR("Nikolay Martyanov <nikolay.martyanov@opensynergy.com>");
> > +MODULE_AUTHOR("Samiullah Khawaja <samiullah.khawaja@opensynergy.com>");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/media/virtio/virtio_video_enc.c
> > b/drivers/media/virtio/virtio_video_enc.c new file mode 100644
> > index 000000000000..d9bd5f293900
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_enc.c
> > @@ -0,0 +1,569 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Encoder for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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 <media/v4l2-event.h>
> > +#include <media/v4l2-ioctl.h>
> > +
> > +#include "virtio_video.h"
> > +
> > +static void virtio_video_enc_buf_queue(struct vb2_buffer *vb)
> > +{
> > + struct vb2_v4l2_buffer *v4l2_vb = to_vb2_v4l2_buffer(vb);
> > + struct virtio_video_stream *stream =
> > vb2_get_drv_priv(vb->vb2_queue); +
> > + v4l2_m2m_buf_queue(stream->fh.m2m_ctx, v4l2_vb);
> > +
> > +}
> > +
> > +static int virtio_video_enc_start_streaming(struct vb2_queue *vq,
> > + unsigned int count)
> > +{
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > + bool input_queue = V4L2_TYPE_IS_OUTPUT(vq->type);
> > +
> > + if (stream->state == STREAM_STATE_INIT ||
> > + (!input_queue && stream->state == STREAM_STATE_RESET) ||
> > + (input_queue && stream->state == STREAM_STATE_STOPPED))
> > + stream->state = STREAM_STATE_RUNNING;
> > +
> > + return 0;
> > +}
> > +
> > +static void virtio_video_enc_stop_streaming(struct vb2_queue *vq)
> > +{
> > + int ret, queue_type;
> > + bool *cleared;
> > + bool is_v4l2_output = V4L2_TYPE_IS_OUTPUT(vq->type);
> > + struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct vb2_v4l2_buffer *v4l2_vb;
> > +
> > + if (is_v4l2_output) {
> > + cleared = &stream->src_cleared;
> > + queue_type = VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
> > + } else {
> > + cleared = &stream->dst_cleared;
> > + queue_type = VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
> > + }
> > +
> > + ret = virtio_video_cmd_queue_clear(vv, stream, queue_type);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to clear queue\n");
> > + return;
> > + }
> > +
> > + ret = wait_event_timeout(vv->wq, *cleared, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev, "timed out waiting for queue
> > clear\n"); + return;
> > + }
> > +
> > + for (;;) {
> > + if (is_v4l2_output)
> > + v4l2_vb =
> > v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx); + else
> > + v4l2_vb =
> > v4l2_m2m_dst_buf_remove(stream->fh.m2m_ctx); + if
> > (!v4l2_vb)
> > + break;
> > + v4l2_m2m_buf_done(v4l2_vb, VB2_BUF_STATE_ERROR);
> > + }
> > +
> > + if (is_v4l2_output)
> > + stream->state = STREAM_STATE_STOPPED;
> > + else
> > + stream->state = STREAM_STATE_RESET;
> > +}
> > +
> > +static const struct vb2_ops virtio_video_enc_qops = {
> > + .queue_setup = virtio_video_queue_setup,
> > + .buf_init = virtio_video_buf_init,
> > + .buf_cleanup = virtio_video_buf_cleanup,
> > + .buf_queue = virtio_video_enc_buf_queue,
> > + .start_streaming = virtio_video_enc_start_streaming,
> > + .stop_streaming = virtio_video_enc_stop_streaming,
> > + .wait_prepare = vb2_ops_wait_prepare,
> > + .wait_finish = vb2_ops_wait_finish,
> > +};
> > +
> > +static int virtio_video_enc_s_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + int ret = 0;
> > + struct virtio_video_stream *stream = ctrl2stream(ctrl);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + uint32_t control, value;
> > +
> > + control = virtio_video_v4l2_control_to_virtio(ctrl->id);
> > +
> > + switch (ctrl->id) {
> > + case V4L2_CID_MPEG_VIDEO_BITRATE:
> > + ret = virtio_video_cmd_set_control(vv, stream->stream_id,
> > + control, ctrl->val);
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_LEVEL:
> > + value = virtio_video_v4l2_level_to_virtio(ctrl->val);
> > + ret = virtio_video_cmd_set_control(vv, stream->stream_id,
> > + control, value);
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_PROFILE:
> > + value = virtio_video_v4l2_profile_to_virtio(ctrl->val);
> > + ret = virtio_video_cmd_set_control(vv, stream->stream_id,
> > + control, value);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int virtio_video_enc_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + int ret = 0;
> > + struct virtio_video_stream *stream = ctrl2stream(ctrl);
> > +
> > + switch (ctrl->id) {
> > + case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT:
> > + if (stream->state >= STREAM_STATE_INIT)
> > + ctrl->val = stream->in_info.min_buffers;
> > + else
> > + ctrl->val = 0;
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops virtio_video_enc_ctrl_ops = {
> > + .g_volatile_ctrl = virtio_video_enc_g_volatile_ctrl,
> > + .s_ctrl = virtio_video_enc_s_ctrl,
> > +};
> > +
> > +int virtio_video_enc_init_ctrls(struct virtio_video_stream *stream)
> > +{
> > + struct v4l2_ctrl *ctrl;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct video_control_format *c_fmt = NULL;
> > +
> > + v4l2_ctrl_handler_init(&stream->ctrl_handler, 1);
> > +
> > + ctrl = v4l2_ctrl_new_std(&stream->ctrl_handler,
> > + &virtio_video_enc_ctrl_ops,
> > + V4L2_CID_MIN_BUFFERS_FOR_OUTPUT,
> > + MIN_BUFS_MIN, MIN_BUFS_MAX, MIN_BUFS_STEP,
> > + MIN_BUFS_DEF);
> > + ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
> > +
> > + list_for_each_entry(c_fmt, &vvd->controls_fmt_list,
> > + controls_list_entry) {
> > + switch (c_fmt->format) {
> > + case V4L2_PIX_FMT_H264:
> > + if (c_fmt->profile)
> > + v4l2_ctrl_new_std_menu
> > + (&stream->ctrl_handler,
> > + &virtio_video_enc_ctrl_ops,
> > + V4L2_CID_MPEG_VIDEO_H264_PROFILE,
> > + c_fmt->profile->max,
> > + c_fmt->profile->skip_mask,
> > + c_fmt->profile->min);
> > +
> > + if (c_fmt->level)
> > + v4l2_ctrl_new_std_menu
> > + (&stream->ctrl_handler,
> > + &virtio_video_enc_ctrl_ops,
> > + V4L2_CID_MPEG_VIDEO_H264_LEVEL,
> > + c_fmt->level->max,
> > + c_fmt->level->skip_mask,
> > + c_fmt->level->min);
> > + break;
> > + default:
> > + v4l2_dbg(1, vv->debug,
> > + &vv->v4l2_dev, "unsupported format\n");
> > + break;
> > + }
> > + }
> > +
> > + if (stream->control.bitrate) {
> > + v4l2_ctrl_new_std(&stream->ctrl_handler,
> > + &virtio_video_enc_ctrl_ops,
> > + V4L2_CID_MPEG_VIDEO_BITRATE,
> > + 1, stream->control.bitrate,
> > + 1, stream->control.bitrate);
> > + }
> > +
> > + if (stream->ctrl_handler.error)
> > + return stream->ctrl_handler.error;
> > +
> > + v4l2_ctrl_handler_setup(&stream->ctrl_handler);
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_enc_init_queues(void *priv, struct vb2_queue *src_vq,
> > + struct vb2_queue *dst_vq)
> > +{
> > + int ret;
> > + struct virtio_video_stream *stream = priv;
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct device *dev = vv->v4l2_dev.dev;
> > +
> > + src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
> > + src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> > + src_vq->drv_priv = stream;
> > + src_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
> > + src_vq->ops = &virtio_video_enc_qops;
> > + src_vq->mem_ops = virtio_video_mem_ops(vv);
> > + src_vq->min_buffers_needed = stream->in_info.min_buffers;
> > + src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> > + src_vq->lock = &stream->vq_mutex;
> > + src_vq->gfp_flags = virtio_video_gfp_flags(vv);
> > + src_vq->dev = dev;
> > +
> > + ret = vb2_queue_init(src_vq);
> > + if (ret)
> > + return ret;
> > +
> > + dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
> > + dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> > + dst_vq->drv_priv = stream;
> > + dst_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
> > + dst_vq->ops = &virtio_video_enc_qops;
> > + dst_vq->mem_ops = virtio_video_mem_ops(vv);
> > + dst_vq->min_buffers_needed = stream->out_info.min_buffers;
> > + dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> > + dst_vq->lock = &stream->vq_mutex;
> > + dst_vq->gfp_flags = virtio_video_gfp_flags(vv);
> > + dst_vq->dev = dev;
> > +
> > + return vb2_queue_init(dst_vq);
> > +}
> > +
> > +static int virtio_video_try_encoder_cmd(struct file *file, void *fh,
> > + struct v4l2_encoder_cmd *cmd)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + if (stream->state == STREAM_STATE_DRAIN)
> > + return -EBUSY;
> > +
> > + switch (cmd->cmd) {
> > + case V4L2_ENC_CMD_STOP:
> > + case V4L2_ENC_CMD_START:
> > + if (cmd->flags != 0) {
> > + v4l2_err(&vv->v4l2_dev, "flags=%u are not
> > supported", + cmd->flags);
> > + return -EINVAL;
> > + }
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_encoder_cmd(struct file *file, void *fh,
> > + struct v4l2_encoder_cmd *cmd)
> > +{
> > + int ret;
> > + struct vb2_queue *src_vq, *dst_vq;
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = video_drvdata(file);
> > + struct virtio_video *vv = vvd->vv;
> > +
> > + ret = virtio_video_try_encoder_cmd(file, fh, cmd);
> > + if (ret < 0)
> > + return ret;
> > +
> > + dst_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > + V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> > +
> > + switch (cmd->cmd) {
> > + case V4L2_ENC_CMD_START:
> > + vb2_clear_last_buffer_dequeued(dst_vq);
> > + stream->state = STREAM_STATE_RUNNING;
> > + break;
> > + case V4L2_ENC_CMD_STOP:
> > + src_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
> > +
> > V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE); +
> > + if (!vb2_is_streaming(src_vq)) {
> > + v4l2_dbg(1, vv->debug,
> > + &vv->v4l2_dev, "output is not
> > streaming\n"); + return 0;
> > + }
> > +
> > + if (!vb2_is_streaming(dst_vq)) {
> > + v4l2_dbg(1, vv->debug,
> > + &vv->v4l2_dev, "capture is not
> > streaming\n"); + return 0;
> > + }
> > +
> > + ret = virtio_video_cmd_stream_drain(vv,
> > stream->stream_id);
> > + if (ret) {
> > + v4l2_err(&vv->v4l2_dev, "failed to drain
> > stream\n"); + return ret;
> > + }
> > +
> > + stream->state = STREAM_STATE_DRAIN;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_enc_enum_fmt_vid_cap(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format *fmt = NULL;
> > + int idx = 0;
> > +
> > + if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> > + return -EINVAL;
> > +
> > + if (f->index >= vvd->num_output_fmts)
> > + return -EINVAL;
> > +
> > + list_for_each_entry(fmt, &vvd->output_fmt_list,
> > formats_list_entry) { + if (f->index == idx) {
> > + f->pixelformat = fmt->desc.format;
> > + return 0;
> > + }
> > + idx++;
> > + }
> > + return -EINVAL;
> > +}
> > +
> > +static int virtio_video_enc_enum_fmt_vid_out(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct video_format_info *info = NULL;
> > + struct video_format *fmt = NULL;
> > + unsigned long output_mask = 0;
> > + int idx = 0, bit_num = 0;
> > +
> > + if (f->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> > + return -EINVAL;
> > +
> > + if (f->index >= vvd->num_input_fmts)
> > + return -EINVAL;
> > +
> > + info = &stream->out_info;
> > + list_for_each_entry(fmt, &vvd->output_fmt_list,
> > formats_list_entry) { + if (info->fourcc_format ==
> > fmt->desc.format) {
> > + output_mask = fmt->desc.mask;
> > + break;
> > + }
> > + }
> > +
> > + if (output_mask == 0)
> > + return -EINVAL;
> > +
> > + list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry)
> > { + if (test_bit(bit_num, &output_mask)) {
> > + if (f->index == idx) {
> > + f->pixelformat = fmt->desc.format;
> > + return 0;
> > + }
> > + idx++;
> > + }
> > + bit_num++;
> > + }
> > + return -EINVAL;
> > +}
> > +
> > +static int virtio_video_enc_s_fmt(struct file *file, void *fh,
> > + struct v4l2_format *f)
> > +{
> > + int ret;
> > + struct virtio_video_stream *stream = file2stream(file);
> > +
> > + ret = virtio_video_s_fmt(file, fh, f);
> > + if (ret)
> > + return ret;
> > +
> > + if (!V4L2_TYPE_IS_OUTPUT(f->type)) {
> > + if (stream->state == STREAM_STATE_IDLE)
> > + stream->state = STREAM_STATE_INIT;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_enc_try_framerate(struct virtio_video_stream
> > *stream, + unsigned int fps)
> > +{
> > + int rate_idx;
> > + struct video_format_frame *frame = NULL;
> > +
> > + if (stream->current_frame == NULL)
> > + return -EINVAL;
> > +
> > + frame = stream->current_frame;
> > + for (rate_idx = 0; rate_idx < frame->frame.num_rates; rate_idx++)
> > {
> > + struct virtio_video_format_range *frame_rate =
> > + &frame->frame_rates[rate_idx];
> > +
> > + if (within_range(frame_rate->min, fps, frame_rate->max))
> > + return 0;
> > + }
> > +
> > + return -EINVAL;
> > +}
> > +
> > +static void virtio_video_timeperframe_from_info(struct video_format_info
> > *info, + struct v4l2_fract
> > *timeperframe) +{
> > + timeperframe->numerator = info->frame_rate;
> > + timeperframe->denominator = 1;
> > +}
> > +
> > +static int virtio_video_enc_g_parm(struct file *file, void *priv,
> > + struct v4l2_streamparm *a)
> > +{
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct v4l2_outputparm *out = &a->parm.output;
> > + struct v4l2_fract *timeperframe = &out->timeperframe;
> > +
> > + if (!V4L2_TYPE_IS_OUTPUT(a->type)) {
> > + v4l2_err(&vv->v4l2_dev,
> > + "getting FPS is only possible for the output
> > queue\n"); + return -EINVAL;
> > + }
> > +
> > + out->capability = V4L2_CAP_TIMEPERFRAME;
> > + virtio_video_timeperframe_from_info(&stream->in_info,
> > timeperframe); +
> > + return 0;
> > +}
> > +
> > +static int virtio_video_enc_s_parm(struct file *file, void *priv,
> > + struct v4l2_streamparm *a)
> > +{
> > + int ret;
> > + u64 frame_interval, frame_rate;
> > + struct video_format_info info;
> > + struct virtio_video_stream *stream = file2stream(file);
> > + struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
> > + struct virtio_video *vv = vvd->vv;
> > + struct v4l2_outputparm *out = &a->parm.output;
> > + struct v4l2_fract *timeperframe = &out->timeperframe;
> > +
> > + if (V4L2_TYPE_IS_OUTPUT(a->type)) {
> > + frame_interval = timeperframe->numerator *
> > (u64)USEC_PER_SEC; + do_div(frame_interval,
> > timeperframe->denominator); + if (!frame_interval)
> > + return -EINVAL;
> > +
> > + frame_rate = (u64)USEC_PER_SEC;
> > + do_div(frame_rate, frame_interval);
> > + } else {
> > + v4l2_err(&vv->v4l2_dev,
> > + "setting FPS is only possible for the output
> > queue\n"); + return -EINVAL;
> > + }
> > +
> > + ret = virtio_video_enc_try_framerate(stream, frame_rate);
> > + if (ret)
> > + return ret;
> > +
> > + virtio_video_format_fill_default_info(&info, &stream->in_info);
> > + info.frame_rate = frame_rate;
> > +
> > + virtio_video_cmd_set_params(vv, stream, &info,
> > + VIRTIO_VIDEO_QUEUE_TYPE_INPUT);
> > + virtio_video_cmd_get_params(vv, stream,
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT); + virtio_video_cmd_get_params(vv,
> > stream, VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT); +
> > + out->capability = V4L2_CAP_TIMEPERFRAME;
> > + virtio_video_timeperframe_from_info(&stream->in_info,
> > timeperframe); +
> > + return 0;
> > +}
> > +
> > +static const struct v4l2_ioctl_ops virtio_video_enc_ioctl_ops = {
> > + .vidioc_querycap = virtio_video_querycap,
> > +
> > + .vidioc_enum_fmt_vid_cap = virtio_video_enc_enum_fmt_vid_cap,
> > + .vidioc_g_fmt_vid_cap = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_cap = virtio_video_enc_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_cap_mplane =
> > virtio_video_enc_enum_fmt_vid_cap, + .vidioc_g_fmt_vid_cap_mplane
> > = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_cap_mplane = virtio_video_enc_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_out = virtio_video_enc_enum_fmt_vid_out,
> > + .vidioc_g_fmt_vid_out = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_out = virtio_video_enc_s_fmt,
> > +
> > + .vidioc_enum_fmt_vid_out_mplane =
> > virtio_video_enc_enum_fmt_vid_out, + .vidioc_g_fmt_vid_out_mplane
> > = virtio_video_g_fmt,
> > + .vidioc_s_fmt_vid_out_mplane = virtio_video_enc_s_fmt,
> > +
> > + .vidioc_try_encoder_cmd = virtio_video_try_encoder_cmd,
> > + .vidioc_encoder_cmd = virtio_video_encoder_cmd,
> > + .vidioc_enum_frameintervals = virtio_video_enum_framemintervals,
> > + .vidioc_enum_framesizes = virtio_video_enum_framesizes,
> > +
> > + .vidioc_g_selection = virtio_video_g_selection,
> > + .vidioc_s_selection = virtio_video_s_selection,
> > +
> > + .vidioc_reqbufs = virtio_video_reqbufs,
> > + .vidioc_querybuf = v4l2_m2m_ioctl_querybuf,
> > + .vidioc_qbuf = v4l2_m2m_ioctl_qbuf,
> > + .vidioc_dqbuf = v4l2_m2m_ioctl_dqbuf,
> > + .vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf,
> > + .vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
> > + .vidioc_expbuf = v4l2_m2m_ioctl_expbuf,
> > +
> > + .vidioc_streamon = v4l2_m2m_ioctl_streamon,
> > + .vidioc_streamoff = v4l2_m2m_ioctl_streamoff,
> > +
> > + .vidioc_s_parm = virtio_video_enc_s_parm,
> > + .vidioc_g_parm = virtio_video_enc_g_parm,
> > +
> > + .vidioc_subscribe_event = virtio_video_subscribe_event,
> > + .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> > +};
> > +
> > +int virtio_video_enc_init(struct video_device *vd)
> > +{
> > + ssize_t num;
> > +
> > + vd->ioctl_ops = &virtio_video_enc_ioctl_ops;
> > + num = strscpy(vd->name, "stateful-encoder", sizeof(vd->name));
> > +
> > + return 0;
> > +}
> > diff --git a/drivers/media/virtio/virtio_video_enc.h
> > b/drivers/media/virtio/virtio_video_enc.h new file mode 100644
> > index 000000000000..3d2a27a8e08c
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_enc.h
> > @@ -0,0 +1,30 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ */
> > +/* Encoder header for virtio video driver.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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/>.
> > + */
> > +
> > +#ifndef _VIRTIO_VIDEO_ENC_H
> > +#define _VIRTIO_VIDEO_ENC_H
> > +
> > +#include "virtio_video.h"
> > +
> > +int virtio_video_enc_init(struct video_device *vd);
> > +int virtio_video_enc_init_ctrls(struct virtio_video_stream *stream);
> > +int virtio_video_enc_init_queues(void *priv, struct vb2_queue *src_vq,
> > + struct vb2_queue *dst_vq);
> > +
> > +#endif /* _VIRTIO_VIDEO_ENC_H */
> > diff --git a/drivers/media/virtio/virtio_video_helpers.c
> > b/drivers/media/virtio/virtio_video_helpers.c new file mode 100644
> > index 000000000000..bc4754e7ca78
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_helpers.c
> > @@ -0,0 +1,250 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Driver for virtio video device.
> > + *
> > + * Copyright 2019 OpenSynergy GmbH.
> > + *
> > + * 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"
> > +
> > +struct virtio_video_convert_table {
> > + uint32_t virtio_value;
> > + uint32_t v4l2_value;
> > +};
> > +
> > +static struct virtio_video_convert_table level_table[] = {
> > + { VIRTIO_VIDEO_LEVEL_H264_1_0, V4L2_MPEG_VIDEO_H264_LEVEL_1_0 },
> > + { VIRTIO_VIDEO_LEVEL_H264_1_1, V4L2_MPEG_VIDEO_H264_LEVEL_1_1 },
> > + { VIRTIO_VIDEO_LEVEL_H264_1_2, V4L2_MPEG_VIDEO_H264_LEVEL_1_2 },
> > + { VIRTIO_VIDEO_LEVEL_H264_1_3, V4L2_MPEG_VIDEO_H264_LEVEL_1_3 },
> > + { VIRTIO_VIDEO_LEVEL_H264_2_0, V4L2_MPEG_VIDEO_H264_LEVEL_2_0 },
> > + { VIRTIO_VIDEO_LEVEL_H264_2_1, V4L2_MPEG_VIDEO_H264_LEVEL_2_1 },
> > + { VIRTIO_VIDEO_LEVEL_H264_2_2, V4L2_MPEG_VIDEO_H264_LEVEL_2_2 },
> > + { VIRTIO_VIDEO_LEVEL_H264_3_0, V4L2_MPEG_VIDEO_H264_LEVEL_3_0 },
> > + { VIRTIO_VIDEO_LEVEL_H264_3_1, V4L2_MPEG_VIDEO_H264_LEVEL_3_1 },
> > + { VIRTIO_VIDEO_LEVEL_H264_3_2, V4L2_MPEG_VIDEO_H264_LEVEL_3_2 },
> > + { VIRTIO_VIDEO_LEVEL_H264_4_0, V4L2_MPEG_VIDEO_H264_LEVEL_4_0 },
> > + { VIRTIO_VIDEO_LEVEL_H264_4_1, V4L2_MPEG_VIDEO_H264_LEVEL_4_1 },
> > + { VIRTIO_VIDEO_LEVEL_H264_4_2, V4L2_MPEG_VIDEO_H264_LEVEL_4_2 },
> > + { VIRTIO_VIDEO_LEVEL_H264_5_0, V4L2_MPEG_VIDEO_H264_LEVEL_5_0 },
> > + { VIRTIO_VIDEO_LEVEL_H264_5_1, V4L2_MPEG_VIDEO_H264_LEVEL_5_1 },
> > + { 0 },
> > +};
> > +
> > +uint32_t virtio_video_level_to_v4l2(uint32_t level)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(level_table); idx++) {
> > + if (level_table[idx].virtio_value == level)
> > + return level_table[idx].v4l2_value;
> > + }
> > +
> > + return 0;
>
> 0 is a valid profile. e.g. V4L2_MPEG_VIDEO_H264_LEVEL_1_0 == 0.
> How about returning a negative number for errors?
>

Yes, maybe. We used to have UNSPEC and INVAL, but upstream people asked to
remove that.

> > +}
> > +
> > +uint32_t virtio_video_v4l2_level_to_virtio(uint32_t v4l2_level)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(level_table); idx++) {
> > + if (level_table[idx].v4l2_value == v4l2_level)
> > + return level_table[idx].virtio_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static struct virtio_video_convert_table profile_table[] = {
> > + { VIRTIO_VIDEO_PROFILE_H264_BASELINE,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE },
> > + { VIRTIO_VIDEO_PROFILE_H264_MAIN,
> > V4L2_MPEG_VIDEO_H264_PROFILE_MAIN }, + {
> > VIRTIO_VIDEO_PROFILE_H264_EXTENDED,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED },
> > + { VIRTIO_VIDEO_PROFILE_H264_HIGH,
> > V4L2_MPEG_VIDEO_H264_PROFILE_HIGH }, + {
> > VIRTIO_VIDEO_PROFILE_H264_HIGH10PROFILE,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10 },
> > + { VIRTIO_VIDEO_PROFILE_H264_HIGH422PROFILE,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422},
> > + { VIRTIO_VIDEO_PROFILE_H264_HIGH444PREDICTIVEPROFILE,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE },
> > + { VIRTIO_VIDEO_PROFILE_H264_SCALABLEBASELINE,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE },
> > + { VIRTIO_VIDEO_PROFILE_H264_SCALABLEHIGH,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH },
> > + { VIRTIO_VIDEO_PROFILE_H264_STEREOHIGH,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH },
> > + { VIRTIO_VIDEO_PROFILE_H264_MULTIVIEWHIGH,
> > + V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH },
> > + { 0 },
>
> How about VP9's profiles?
>

We don't use those for now. Please propose what exactly to add.

> > +};
> > +
> > +uint32_t virtio_video_profile_to_v4l2(uint32_t profile)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(profile_table); idx++) {
> > + if (profile_table[idx].virtio_value == profile)
> > + return profile_table[idx].v4l2_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +uint32_t virtio_video_v4l2_profile_to_virtio(uint32_t v4l2_profile)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(profile_table); idx++) {
> > + if (profile_table[idx].v4l2_value == v4l2_profile)
> > + return profile_table[idx].virtio_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static struct virtio_video_convert_table format_table[] = {
> > + { VIRTIO_VIDEO_FORMAT_ARGB8888, V4L2_PIX_FMT_ARGB32 },
> > + { VIRTIO_VIDEO_FORMAT_BGRA8888, V4L2_PIX_FMT_ABGR32 },
> > + { VIRTIO_VIDEO_FORMAT_NV12, V4L2_PIX_FMT_NV12 },
> > + { VIRTIO_VIDEO_FORMAT_YUV420, V4L2_PIX_FMT_YUV420 },
> > + { VIRTIO_VIDEO_FORMAT_YVU420, V4L2_PIX_FMT_YVU420 },
> > + { VIRTIO_VIDEO_FORMAT_MPEG2, V4L2_PIX_FMT_MPEG2 },
> > + { VIRTIO_VIDEO_FORMAT_MPEG4, V4L2_PIX_FMT_MPEG4 },
> > + { VIRTIO_VIDEO_FORMAT_H264, V4L2_PIX_FMT_H264 },
> > + { VIRTIO_VIDEO_FORMAT_HEVC, V4L2_PIX_FMT_HEVC },
> > + { VIRTIO_VIDEO_FORMAT_VP8, V4L2_PIX_FMT_VP8 },
> > + { VIRTIO_VIDEO_FORMAT_VP9, V4L2_PIX_FMT_VP9 },
> > + { 0 },
> > +};
> > +
> > +uint32_t virtio_video_format_to_v4l2(uint32_t format)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(format_table); idx++) {
> > + if (format_table[idx].virtio_value == format)
> > + return format_table[idx].v4l2_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +uint32_t virtio_video_v4l2_format_to_virtio(uint32_t v4l2_format)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(format_table); idx++) {
> > + if (format_table[idx].v4l2_value == v4l2_format)
> > + return format_table[idx].virtio_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static struct virtio_video_convert_table control_table[] = {
> > + { VIRTIO_VIDEO_CONTROL_BITRATE, V4L2_CID_MPEG_VIDEO_BITRATE },
> > + { VIRTIO_VIDEO_CONTROL_PROFILE, V4L2_CID_MPEG_VIDEO_H264_PROFILE
> > },
> > + { VIRTIO_VIDEO_CONTROL_LEVEL, V4L2_CID_MPEG_VIDEO_H264_LEVEL },
> > + { 0 },
> > +};
> > +
> > +uint32_t virtio_video_control_to_v4l2(uint32_t control)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(control_table); idx++) {
> > + if (control_table[idx].virtio_value == control)
> > + return control_table[idx].v4l2_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +uint32_t virtio_video_v4l2_control_to_virtio(uint32_t v4l2_control)
> > +{
> > + size_t idx;
> > +
> > + for (idx = 0; idx < ARRAY_SIZE(control_table); idx++) {
> > + if (control_table[idx].v4l2_value == v4l2_control)
> > + return control_table[idx].virtio_value;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +uint32_t virtio_video_get_format_from_virtio_profile(uint32_t
> > virtio_profile) +{
> > + if (virtio_profile >= VIRTIO_VIDEO_PROFILE_H264_MIN &&
> > + virtio_profile <= VIRTIO_VIDEO_PROFILE_H264_MAX)
> > + return VIRTIO_VIDEO_FORMAT_H264;
> > + else if (virtio_profile >= VIRTIO_VIDEO_PROFILE_HEVC_MIN &&
> > + virtio_profile <= VIRTIO_VIDEO_PROFILE_HEVC_MAX)
> > + return VIRTIO_VIDEO_FORMAT_HEVC;
> > + else if (virtio_profile >= VIRTIO_VIDEO_PROFILE_VP8_MIN &&
> > + virtio_profile <= VIRTIO_VIDEO_PROFILE_VP8_MAX)
> > + return VIRTIO_VIDEO_FORMAT_VP8;
> > + else if (virtio_profile >= VIRTIO_VIDEO_PROFILE_VP9_MIN &&
> > + virtio_profile <= VIRTIO_VIDEO_PROFILE_VP9_MAX)
> > + return VIRTIO_VIDEO_FORMAT_VP9;
> > +
> > + return 0;
> > +}
> > +
> > +struct video_format *find_video_format(struct list_head *fmts_list,
> > + uint32_t format)
> > +{
> > + struct video_format *fmt = NULL;
> > +
> > + list_for_each_entry(fmt, fmts_list, formats_list_entry) {
> > + if (fmt->desc.format == format)
> > + return fmt;
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > +void virtio_video_format_from_info(struct video_format_info *info,
> > + struct v4l2_pix_format_mplane *pix_mp)
> > +{
> > + int i;
> > +
> > + pix_mp->width = info->frame_width;
> > + pix_mp->height = info->frame_height;
> > + pix_mp->field = V4L2_FIELD_NONE;
> > + pix_mp->colorspace = V4L2_COLORSPACE_REC709;
> > + pix_mp->xfer_func = 0;
> > + pix_mp->ycbcr_enc = 0;
> > + pix_mp->quantization = 0;
> > + memset(pix_mp->reserved, 0, sizeof(pix_mp->reserved));
> > + memset(pix_mp->plane_fmt[0].reserved, 0,
> > + sizeof(pix_mp->plane_fmt[0].reserved));
> > +
> > + pix_mp->num_planes = info->num_planes;
> > + pix_mp->pixelformat = info->fourcc_format;
> > +
> > + for (i = 0; i < info->num_planes; i++) {
> > + pix_mp->plane_fmt[i].bytesperline =
> > + info->plane_format[i].stride;
> > + pix_mp->plane_fmt[i].sizeimage =
> > + info->plane_format[i].plane_size;
> > + }
> > +}
> > +
> > +void virtio_video_format_fill_default_info(struct video_format_info
> > *dst_info, + struct
> > video_format_info *src_info) +{
> > + memcpy(dst_info, src_info, sizeof(*dst_info));
> > +}
> > diff --git a/drivers/media/virtio/virtio_video_vq.c
> > b/drivers/media/virtio/virtio_video_vq.c new file mode 100644
> > index 000000000000..4679e6b49cf3
> > --- /dev/null
> > +++ b/drivers/media/virtio/virtio_video_vq.c
> > @@ -0,0 +1,1012 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Driver for virtio video device.
> > + *
> > + * Copyright 2019 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)
> > +
> > +void virtio_video_resource_id_get(struct virtio_video *vv, uint32_t *id)
>
> How about renaming virtio_video_resource_id_{get,put} to
> {virtio_video_resource_id_alloc, remove}?
> It sounds like a function "*_get" doesn't have any side effect but it does.
>

That was derived from virtio-gpu. Well, get + side effects is something from
some specific paradigm, not sure it is a rule.

> > +{
> > + int handle;
> > +
> > + idr_preload(GFP_KERNEL);
> > + spin_lock(&vv->resource_idr_lock);
> > + handle = idr_alloc(&vv->resource_idr, NULL, 1, 0, GFP_NOWAIT);
> > + spin_unlock(&vv->resource_idr_lock);
> > + idr_preload_end();
> > + *id = handle;
> > +}
> > +
> > +void virtio_video_resource_id_put(struct virtio_video *vv, uint32_t id)
> > +{
> > + spin_lock(&vv->resource_idr_lock);
> > + idr_remove(&vv->resource_idr, id);
> > + spin_unlock(&vv->resource_idr_lock);
> > +}
> > +
> > +void virtio_video_stream_id_get(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t *id)
> > +{
> > + int handle;
> > +
> > + idr_preload(GFP_KERNEL);
> > + spin_lock(&vv->stream_idr_lock);
> > + handle = idr_alloc(&vv->stream_idr, stream, 1, 0, 0);
> > + spin_unlock(&vv->stream_idr_lock);
> > + idr_preload_end();
> > + *id = handle;
> > +}
> > +
> > +void virtio_video_stream_id_put(struct virtio_video *vv, uint32_t id)
> > +{
> > + spin_lock(&vv->stream_idr_lock);
> > + idr_remove(&vv->stream_idr, id);
> > + spin_unlock(&vv->stream_idr_lock);
> > +}
> > +
> > +void virtio_video_cmd_ack(struct virtqueue *vq)
> > +{
> > + struct virtio_video *vv = vq->vdev->priv;
> > +
> > + schedule_work(&vv->commandq.dequeue_work);
> > +}
> > +
> > +void virtio_video_event_ack(struct virtqueue *vq)
> > +{
> > + struct virtio_video *vv = vq->vdev->priv;
> > +
> > + schedule_work(&vv->eventq.dequeue_work);
> > +}
> > +
> > +static struct virtio_video_vbuffer *
> > +virtio_video_get_vbuf(struct virtio_video *vv, int size,
> > + int resp_size, void *resp_buf,
> > + virtio_video_resp_cb resp_cb)
> > +{
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + vbuf = kmem_cache_alloc(vv->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;
> > +}
> > +
> > +static void free_vbuf(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + if (!vbuf->resp_cb &&
> > + vbuf->resp_size > MAX_INLINE_RESP_SIZE)
> > + kfree(vbuf->resp_buf);
> > + kfree(vbuf->data_buf);
> > + kmem_cache_free(vv->vbufs, vbuf);
> > +}
> > +
> > +static void reclaim_vbufs(struct virtqueue *vq, struct list_head
> > *reclaim_list) +{
> > + struct virtio_video_vbuffer *vbuf;
> > + unsigned int len;
> > + struct virtio_video *vv = vq->vdev->priv;
> > + int freed = 0;
> > +
> > + while ((vbuf = virtqueue_get_buf(vq, &len))) {
> > + list_add_tail(&vbuf->list, reclaim_list);
> > + freed++;
> > + }
> > + if (freed == 0)
> > + v4l2_dbg(1, vv->debug, &vv->v4l2_dev,
> > + "zero vbufs reclaimed\n");
> > +}
> > +
> > +static void detach_vbufs(struct virtqueue *vq, struct list_head
> > *detach_list) +{
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + while ((vbuf = virtqueue_detach_unused_buf(vq)) != NULL)
> > + list_add_tail(&vbuf->list, detach_list);
> > +}
> > +
> > +static void virtio_video_deatch_vbufs(struct virtio_video *vv)
> > +{
> > + struct list_head detach_list;
> > + struct virtio_video_vbuffer *entry, *tmp;
> > +
> > + INIT_LIST_HEAD(&detach_list);
> > +
> > + detach_vbufs(vv->eventq.vq, &detach_list);
> > + detach_vbufs(vv->commandq.vq, &detach_list);
> > +
> > + if (list_empty(&detach_list))
> > + return;
> > +
> > + list_for_each_entry_safe(entry, tmp, &detach_list, list) {
> > + list_del(&entry->list);
> > + free_vbuf(vv, entry);
> > + }
> > +}
> > +
> > +int virtio_video_alloc_vbufs(struct virtio_video *vv)
> > +{
> > + vv->vbufs =
> > + kmem_cache_create("virtio-video-vbufs", VBUFFER_SIZE,
> > + __alignof__(struct
> > virtio_video_vbuffer), 0, + NULL);
> > + if (!vv->vbufs)
> > + return -ENOMEM;
> > +
> > + return 0;
> > +}
> > +
> > +void virtio_video_free_vbufs(struct virtio_video *vv)
> > +{
> > + virtio_video_deatch_vbufs(vv);
> > + kmem_cache_destroy(vv->vbufs);
> > + vv->vbufs = NULL;
> > +}
> > +
> > +static void *virtio_video_alloc_req(struct virtio_video *vv,
> > + struct virtio_video_vbuffer
> > **vbuffer_p, + int size)
> > +{
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + vbuf = virtio_video_get_vbuf(vv, 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 *vv,
> > + 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(vv, req_size, resp_size, resp_buf,
> > cb); + if (IS_ERR(vbuf)) {
> > + *vbuffer_p = NULL;
> > + return ERR_CAST(vbuf);
> > + }
> > + *vbuffer_p = vbuf;
> > +
> > + return vbuf->buf;
> > +}
> > +
> > +void virtio_video_dequeue_cmd_func(struct work_struct *work)
> > +{
> > + struct virtio_video *vv =
> > + container_of(work, struct virtio_video,
> > + commandq.dequeue_work);
> > + struct list_head reclaim_list;
> > + struct virtio_video_vbuffer *entry, *tmp;
> > + struct virtio_video_cmd_hdr *resp;
> > +
> > + INIT_LIST_HEAD(&reclaim_list);
> > + spin_lock(&vv->commandq.qlock);
> > + do {
> > + virtqueue_disable_cb(vv->commandq.vq);
> > + reclaim_vbufs(vv->commandq.vq, &reclaim_list);
> > +
> > + } while (!virtqueue_enable_cb(vv->commandq.vq));
> > + spin_unlock(&vv->commandq.qlock);
> > +
> > + list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
> > + resp = (struct virtio_video_cmd_hdr *)entry->resp_buf;
> > + if (resp->type >=
> > + cpu_to_le32(VIRTIO_VIDEO_RESP_ERR_INVALID_OPERATION))
> > + v4l2_dbg(1, vv->debug, &vv->v4l2_dev,
> > + "response 0x%x\n",
> > le32_to_cpu(resp->type)); + if (entry->resp_cb)
> > + entry->resp_cb(vv, entry);
> > +
> > + list_del(&entry->list);
> > + free_vbuf(vv, entry);
> > + }
> > + wake_up(&vv->commandq.ack_queue);
> > +}
> > +
> > +void virtio_video_dequeue_event_func(struct work_struct *work)
> > +{
> > + struct virtio_video *vv =
> > + container_of(work, struct virtio_video,
> > + eventq.dequeue_work);
> > + struct list_head reclaim_list;
> > + struct virtio_video_vbuffer *entry, *tmp;
> > +
> > + INIT_LIST_HEAD(&reclaim_list);
> > + spin_lock(&vv->eventq.qlock);
> > + do {
> > + virtqueue_disable_cb(vv->eventq.vq);
> > + reclaim_vbufs(vv->eventq.vq, &reclaim_list);
> > +
> > + } while (!virtqueue_enable_cb(vv->eventq.vq));
> > + spin_unlock(&vv->eventq.qlock);
> > +
> > + list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
> > + entry->resp_cb(vv, entry);
> > + list_del(&entry->list);
> > + }
> > + wake_up(&vv->eventq.ack_queue);
> > +}
> > +
> > +static int
> > +virtio_video_queue_cmd_buffer_locked(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + struct virtqueue *vq = vv->commandq.vq;
> > + struct scatterlist *sgs[3], vreq, vout, vresp;
> > + int outcnt = 0, incnt = 0;
> > + int ret;
> > +
> > + if (!vv->vq_ready)
> > + return -ENODEV;
> > +
> > + 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(&vv->commandq.qlock);
> > + wait_event(vv->commandq.ack_queue, vq->num_free);
> > + spin_lock(&vv->commandq.qlock);
> > + goto retry;
> > + } else {
> > + virtqueue_kick(vq);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int virtio_video_queue_cmd_buffer(struct virtio_video *vv,
> > + struct virtio_video_vbuffer
> > *vbuf) +{
> > + int ret;
> > +
> > + spin_lock(&vv->commandq.qlock);
> > + ret = virtio_video_queue_cmd_buffer_locked(vv, vbuf);
> > + spin_unlock(&vv->commandq.qlock);
> > +
> > + return ret;
> > +}
> > +
> > +static int virtio_video_queue_event_buffer(struct virtio_video *vv,
> > + struct virtio_video_vbuffer
> > *vbuf) +{
> > + int ret;
> > + struct scatterlist vresp;
> > + struct virtqueue *vq = vv->eventq.vq;
> > +
> > + spin_lock(&vv->eventq.qlock);
> > + sg_init_one(&vresp, vbuf->resp_buf, vbuf->resp_size);
> > + ret = virtqueue_add_inbuf(vq, &vresp, 1, vbuf, GFP_ATOMIC);
> > + spin_unlock(&vv->eventq.qlock);
> > + if (ret)
> > + return ret;
> > +
> > + virtqueue_kick(vq);
> > +
> > + return 0;
> > +}
> > +
> > +static void virtio_video_event_cb(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + int ret;
> > + struct virtio_video_stream *stream;
> > + struct virtio_video_event *event =
> > + (struct virtio_video_event *)vbuf->resp_buf;
> > +
> > + stream = idr_find(&vv->stream_idr, event->stream_id);
> > + if (!stream) {
> > + v4l2_warn(&vv->v4l2_dev, "no stream %u found for event\n",
> > + event->stream_id);
> > + return;
> > + }
> > +
> > + switch (le32_to_cpu(event->event_type)) {
> > + case VIRTIO_VIDEO_EVENT_DECODER_RESOLUTION_CHANGED:
> > + virtio_video_cmd_get_params(vv, stream,
> > +
> > VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT);
> > + virtio_video_queue_res_chg_event(stream);
> > + if (stream->state == STREAM_STATE_INIT) {
> > + stream->state = STREAM_STATE_METADATA;
> > + wake_up(&vv->wq);
> > + }
> > + break;
> > + default:
> > + v4l2_warn(&vv->v4l2_dev, "failed to queue event
> > buffer\n");
> > + break;
> > + }
> > +
> > + memset(vbuf->resp_buf, 0, vbuf->resp_size);
> > + ret = virtio_video_queue_event_buffer(vv, vbuf);
> > + if (ret)
> > + v4l2_warn(&vv->v4l2_dev, "queue event buffer failed\n");
> > +}
> > +
> > +int virtio_video_alloc_events(struct virtio_video *vv, size_t num)
> > +{
> > + int ret;
> > + size_t i;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + for (i = 0; i < num; i++) {
> > + vbuf = virtio_video_get_vbuf(vv, 0,
> > + sizeof(struct
> > virtio_video_event), + NULL,
> > virtio_video_event_cb); + if (IS_ERR(vbuf))
> > + return PTR_ERR(vbuf);
> > +
> > + ret = virtio_video_queue_event_buffer(vv, vbuf);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int virtio_video_cmd_stream_create(struct virtio_video *vv, 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(vv, &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);
> > + strncpy(req_p->tag, tag, sizeof(req_p->tag) - 1);
> > + req_p->tag[sizeof(req_p->tag) - 1] = 0;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +int virtio_video_cmd_stream_destroy(struct virtio_video *vv, uint32_t
> > stream_id) +{
> > + struct virtio_video_stream_destroy *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req(vv, &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(vv, vbuf);
> > +}
> > +
> > +int virtio_video_cmd_stream_drain(struct virtio_video *vv, uint32_t
> > stream_id) +{
> > + struct virtio_video_stream_drain *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req(vv, &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(vv, vbuf);
> > +}
> > +
> > +int virtio_video_cmd_resource_create(struct virtio_video *vv,
> > + uint32_t stream_id, uint32_t
> > resource_id, + uint32_t queue_type,
> > + struct virtio_video_mem_entry *ents,
> > + unsigned int num_planes,
> > + unsigned int *num_entry)
> > +{
> > + unsigned int i = 0, nents = 0;
> > + struct virtio_video_resource_create *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req(vv, &vbuf, sizeof(*req_p));
> > + if (IS_ERR(req_p))
> > + return PTR_ERR(req_p);
> > +
> > + req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_RESOURCE_CREATE);
> > + req_p->hdr.stream_id = cpu_to_le32(stream_id);
> > + req_p->resource_id = cpu_to_le32(resource_id);
> > + req_p->queue_type = cpu_to_le32(queue_type);
> > + req_p->num_planes = cpu_to_le32(num_planes);
> > +
> > + for (i = 0; i < num_planes; i++) {
> > + nents += num_entry[i];
> > + req_p->num_entries[i] = cpu_to_le32(num_entry[i]);
> > + }
> > +
> > + vbuf->data_buf = ents;
> > + vbuf->data_size = sizeof(*ents) * nents;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +int virtio_video_cmd_resource_destroy_all(struct virtio_video *vv,
> > + struct virtio_video_stream
> > *stream, + enum
> > virtio_video_queue_type qtype) +{
> > + struct virtio_video_resource_destroy_all *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req(vv, &vbuf, sizeof(*req_p));
> > + if (IS_ERR(req_p))
> > + return PTR_ERR(req_p);
> > +
> > + req_p->hdr.type =
> > cpu_to_le32(VIRTIO_VIDEO_CMD_RESOURCE_DESTROY_ALL); +
> > req_p->hdr.stream_id = cpu_to_le32(stream->stream_id);
> > + req_p->queue_type = cpu_to_le32(qtype);
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
>
> We should make DESTROY_ALL a synchrounous command.
> It seems that stream->{src,dst}_destroyed is defined but not used.
>

Yes, true.

> > +}
> > +
> > +static void
> > +virtio_video_cmd_resource_queue_cb(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + uint32_t flags, bytesused;
> > + 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);
> > + bytesused = le32_to_cpu(resp->size);
> > + timestamp = le64_to_cpu(resp->timestamp);
> > +
> > + virtio_video_buf_done(virtio_vb, flags, timestamp, bytesused);
> > +}
> > +
> > +int virtio_video_cmd_resource_queue(struct virtio_video *vv, uint32_t
> > stream_id, + struct virtio_video_buffer
> > *virtio_vb, + uint32_t data_size[],
> > + uint8_t num_data_size, uint32_t
> > 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(vv,
> > +
> > &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->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_RESOURCE_QUEUE);
> > + req_p->hdr.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->num_data_sizes = num_data_size;
> > + 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(vv, vbuf);
> > +}
> > +
> > +static void
> > +virtio_video_cmd_queue_clear_cb(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + struct virtio_video_stream *stream = vbuf->priv;
> > + struct virtio_video_queue_clear *req_p =
> > + (struct virtio_video_queue_clear *)vbuf->buf;
> > +
> > + if (le32_to_cpu(req_p->queue_type) ==
> > VIRTIO_VIDEO_QUEUE_TYPE_INPUT) + stream->src_cleared =
> > true;
> > + else
> > + stream->dst_cleared = true;
> > +
> > + wake_up(&vv->wq);
> > +}
> > +
> > +int virtio_video_cmd_queue_clear(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t queue_type)
> > +{
> > + struct virtio_video_queue_clear *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req_resp
> > + (vv, &virtio_video_cmd_queue_clear_cb,
> > + &vbuf, sizeof(*req_p),
> > + sizeof(struct virtio_video_cmd_hdr), NULL);
> > + 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);
> > +
> > + vbuf->priv = stream;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +static void
> > +virtio_video_query_caps_cb(struct virtio_video *vv,
> > + struct virtio_video_vbuffer *vbuf)
> > +{
> > + bool *got_resp_p = vbuf->priv;
> > + *got_resp_p = true;
> > + wake_up(&vv->wq);
> > +}
> > +
> > +int virtio_video_query_capability(struct virtio_video *vv, void
> > *resp_buf,
> > + size_t resp_size, uint32_t queue_type)
> > +{
> > + struct virtio_video_query_capability *req_p = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > +
> > + if (!vv || !resp_buf)
> > + return -1;
> > +
> > + req_p = virtio_video_alloc_req_resp(vv,
> > &virtio_video_query_caps_cb, +
> > &vbuf, sizeof(*req_p), resp_size, +
> > resp_buf);
> > + if (IS_ERR(req_p))
> > + return -1;
> > +
> > + req_p->hdr.type = cpu_to_le32(VIRTIO_VIDEO_CMD_QUERY_CAPABILITY);
> > + req_p->queue_type = cpu_to_le32(queue_type);
> > +
> > + vbuf->priv = &vv->got_caps;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +int virtio_video_query_control_level(struct virtio_video *vv, void
> > *resp_buf, + size_t resp_size,
> > uint32_t format) +{
> > + struct virtio_video_query_control *req_p = NULL;
> > + struct virtio_video_query_control_level *ctrl_l = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > + uint32_t req_size = 0;
> > +
> > + if (!vv || !resp_buf)
> > + return -1;
> > +
> > + req_size = sizeof(struct virtio_video_query_control) +
> > + sizeof(struct virtio_video_query_control_level);
> > +
> > + req_p = virtio_video_alloc_req_resp(vv,
> > &virtio_video_query_caps_cb, +
> > &vbuf, req_size, resp_size, +
> > resp_buf);
> > + if (IS_ERR(req_p))
> > + return -1;
> > +
> > + 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);
> > +
> > + vbuf->priv = &vv->got_control;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +int virtio_video_query_control_profile(struct virtio_video *vv, void
> > *resp_buf, + size_t resp_size,
> > uint32_t format) +{
> > + struct virtio_video_query_control *req_p = NULL;
> > + struct virtio_video_query_control_profile *ctrl_p = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > + uint32_t req_size = 0;
> > +
> > + if (!vv || !resp_buf)
> > + return -1;
> > +
> > + req_size = sizeof(struct virtio_video_query_control) +
> > + sizeof(struct virtio_video_query_control_profile);
> > +
> > + req_p = virtio_video_alloc_req_resp(vv,
> > &virtio_video_query_caps_cb, +
> > &vbuf, req_size, resp_size, +
> > resp_buf);
> > + if (IS_ERR(req_p))
> > + return -1;
> > +
> > + 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);
> > +
> > + vbuf->priv = &vv->got_control;
> > +
> > + return virtio_video_queue_cmd_buffer(vv, vbuf);
> > +}
> > +
> > +static void
> > +virtio_video_cmd_get_params_cb(struct virtio_video *vv,
> > + 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 = NULL;
> > +
> > + 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;
> > +
> > + if (!format_info)
> > + return;
> > +
> > + 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);
> > + }
> > +
> > + format_info->is_updated = true;
> > + wake_up(&vv->wq);
> > +}
> > +
> > +int virtio_video_cmd_get_params(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t queue_type)
> > +{
> > + int ret;
> > + struct virtio_video_get_params *req_p = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > + struct virtio_video_get_params_resp *resp_p;
> > + struct video_format_info *format_info = NULL;
> > + size_t resp_size = sizeof(struct virtio_video_get_params_resp);
> > +
> > + if (!vv || !stream)
> > + return -1;
> > +
> > + req_p = virtio_video_alloc_req_resp(vv,
> > + &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;
> > + memset(resp_p, 0, sizeof(*resp_p));
> > +
> > + if (req_p->queue_type == VIRTIO_VIDEO_QUEUE_TYPE_INPUT)
> > + format_info = &stream->in_info;
> > + else
> > + format_info = &stream->out_info;
> > +
> > + format_info->is_updated = false;
> > +
> > + vbuf->priv = stream;
> > + ret = virtio_video_queue_cmd_buffer(vv, vbuf);
> > + if (ret)
> > + return ret;
> > +
> > + ret = wait_event_timeout(vv->wq,
> > + format_info->is_updated, 5 * HZ);
> > + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev, "timed out waiting for
> > get_params\n"); + return -1;
> > + }
> > + return 0;
> > +}
> > +
> > +int
> > +virtio_video_cmd_set_params(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + struct video_format_info *format_info,
> > + uint32_t queue_type)
>
> I think we need to make SET_PARAMS synchronous?
> Even get_params is synchrnous and called after set_params, get_params
> can return parameters that is not changed by set_params.
>

Usually we do get after set. So we probably just need to merge those into
update_params or something like that.

> > +{
> > + int i;
> > + struct virtio_video_set_params *req_p;
> > + struct virtio_video_vbuffer *vbuf;
> > +
> > + req_p = virtio_video_alloc_req(vv, &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(vv, vbuf);
> > +}
> > +
> > +static void
> > +virtio_video_cmd_get_ctrl_profile_cb(struct virtio_video *vv,
> > + 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;
> > +
> > + if (!control)
> > + return;
> > +
> > + resp_p = (void *)((char *) resp +
> > + sizeof(struct virtio_video_get_control_resp));
> > +
> > + control->profile = le32_to_cpu(resp_p->profile);
> > + control->is_updated = true;
> > + wake_up(&vv->wq);
> > +}
> > +
> > +static void
> > +virtio_video_cmd_get_ctrl_level_cb(struct virtio_video *vv,
> > + 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 = NULL;
> > + struct virtio_video_stream *stream = vbuf->priv;
> > + struct video_control_info *control = &stream->control;
> > +
> > + if (!control)
> > + return;
> > +
> > + resp_p = (void *)((char *)resp +
> > + sizeof(struct virtio_video_get_control_resp));
> > +
> > + control->level = le32_to_cpu(resp_p->level);
> > + control->is_updated = true;
> > + wake_up(&vv->wq);
> > +}
> > +
> > +static void
> > +virtio_video_cmd_get_ctrl_bitrate_cb(struct virtio_video *vv,
> > + 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;
> > +
> > + if (!control)
> > + return;
> > +
> > + resp_p = (void *)((char *) resp +
> > + sizeof(struct virtio_video_get_control_resp));
> > +
> > + control->bitrate = le32_to_cpu(resp_p->bitrate);
> > + control->is_updated = true;
> > + wake_up(&vv->wq);
> > +}
> > +
> > +int virtio_video_cmd_get_control(struct virtio_video *vv,
> > + struct virtio_video_stream *stream,
> > + uint32_t virtio_ctrl)
> > +{
> > + int ret = 0;
> > + struct virtio_video_get_control *req_p = NULL;
> > + struct virtio_video_get_control_resp *resp_p = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > + size_t resp_size = sizeof(struct virtio_video_get_control_resp);
> > + virtio_video_resp_cb cb;
> > +
> > + if (!vv)
> > + return -1;
> > +
> > + switch (virtio_ctrl) {
> > + 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 -1;
> > + }
> > +
> > + req_p = virtio_video_alloc_req_resp(vv, 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(virtio_ctrl);
> > +
> > + resp_p = (struct virtio_video_get_control_resp *)vbuf->resp_buf;
> > + memset(resp_p, 0, resp_size);
> > +
> > + stream->control.is_updated = false;
> > +
> > + vbuf->priv = stream;
> > + ret = virtio_video_queue_cmd_buffer(vv, vbuf);
> > + if (ret)
> > + return ret;
> > +
> > + ret = wait_event_timeout(vv->wq, stream->control.is_updated, 5 *
> > HZ); + if (ret == 0) {
> > + v4l2_err(&vv->v4l2_dev, "timed out waiting for
> > get_params\n"); + return -1;
> > + }
> > + return 0;
> > +}
> > +
> > +int virtio_video_cmd_set_control(struct virtio_video *vv, uint32_t
> > stream_id, + uint32_t control, uint32_t
> > value) +{
> > + struct virtio_video_set_control *req_p = NULL;
> > + struct virtio_video_vbuffer *vbuf = NULL;
> > + struct virtio_video_control_val_level *ctrl_l = NULL;
> > + struct virtio_video_control_val_profile *ctrl_p = NULL;
> > + struct virtio_video_control_val_bitrate *ctrl_b = NULL;
> > + size_t size;
> > +
> > + if (!vv || 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 -1;
> > + }
> > +
> > + req_p = virtio_video_alloc_req(vv, &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(vv, vbuf);
> > +}
> > +
> > diff --git a/include/uapi/linux/virtio_ids.h
> > b/include/uapi/linux/virtio_ids.h index 6d5c3b2d4f4d..89dfc94ecaa3 100644
> > --- a/include/uapi/linux/virtio_ids.h
> > +++ b/include/uapi/linux/virtio_ids.h
> > @@ -43,5 +43,7 @@
> >
> > #define VIRTIO_ID_INPUT 18 /* virtio input */
> > #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */
> > #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */
> >
> > +#define VIRTIO_ID_VIDEO_ENC 30 /* virtio video encoder */
> > +#define VIRTIO_ID_VIDEO_DEC 31 /* virtio video decoder */
> >
> > #endif /* _LINUX_VIRTIO_IDS_H */
> >
> > diff --git a/include/uapi/linux/virtio_video.h
> > b/include/uapi/linux/virtio_video.h new file mode 100644
> > index 000000000000..0dd98a2237c6
> > --- /dev/null
> > +++ b/include/uapi/linux/virtio_video.h
> > @@ -0,0 +1,469 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ */
> > +/*
> > + * Virtio Video Device
> > + *
> > + * This header is BSD licensed so anyone can use the definitions
> > + * to implement compatible drivers/servers:
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + * 1. Redistributions of source code must retain the above copyright
> > + * notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + * notice, this list of conditions and the following disclaimer in the
> > + * documentation and/or other materials provided with the
> > distribution.
> > + * 3. Neither the name of IBM nor the names of its contributors
> > + * may be used to endorse or promote products derived from this
> > software + * without specific prior written permission.
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> > + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> > + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
> > + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR
> > + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> > + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
> > + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
> > + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
> > + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
> > + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
> > + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> > + * SUCH DAMAGE.
> > + *
> > + * Copyright (C) 2019 OpenSynergy GmbH.
> > + */
> > +
> > +#ifndef _UAPI_LINUX_VIRTIO_VIDEO_H
> > +#define _UAPI_LINUX_VIRTIO_VIDEO_H
> > +
> > +#include <linux/types.h>
> > +#include <linux/virtio_config.h>
> > +
> > +/*
> > + * Feature bits
> > + */
> > +
> > +/* Guest pages can be used for video buffers. */
> > +#define VIRTIO_VIDEO_F_RESOURCE_GUEST_PAGES 0
> > +/*
> > + * The host can process buffers even if they are non-contiguous memory
> > such as + * scatter-gather lists.
> > + */
> > +#define VIRTIO_VIDEO_F_RESOURCE_NON_CONTIG 1
> > +
> > +/*
> > + * Image formats
> > + */
> > +
> > +enum virtio_video_format {
> > + /* Raw formats */
> > + VIRTIO_VIDEO_FORMAT_RAW_MIN = 1,
> > + VIRTIO_VIDEO_FORMAT_ARGB8888 = VIRTIO_VIDEO_FORMAT_RAW_MIN,
> > + VIRTIO_VIDEO_FORMAT_BGRA8888,
> > + VIRTIO_VIDEO_FORMAT_NV12, /* 12 Y/CbCr 4:2:0 */
> > + VIRTIO_VIDEO_FORMAT_YUV420, /* 12 YUV 4:2:0 */
> > + VIRTIO_VIDEO_FORMAT_YVU420, /* 12 YVU 4:2:0 */
> > + VIRTIO_VIDEO_FORMAT_RAW_MAX = VIRTIO_VIDEO_FORMAT_YVU420,
> > +
> > + /* Coded formats */
> > + VIRTIO_VIDEO_FORMAT_CODED_MIN = 0x1000,
> > + VIRTIO_VIDEO_FORMAT_MPEG2 =
> > + VIRTIO_VIDEO_FORMAT_CODED_MIN, /* MPEG-2 Part 2 */
> > + VIRTIO_VIDEO_FORMAT_MPEG4, /* MPEG-4 Part 2 */
> > + VIRTIO_VIDEO_FORMAT_H264, /* H.264 */
> > + VIRTIO_VIDEO_FORMAT_HEVC, /* HEVC aka H.265*/
> > + VIRTIO_VIDEO_FORMAT_VP8, /* VP8 */
> > + VIRTIO_VIDEO_FORMAT_VP9, /* VP9 */
> > + VIRTIO_VIDEO_FORMAT_CODED_MAX = VIRTIO_VIDEO_FORMAT_VP9,
> > +};
> > +
> > +enum virtio_video_profile {
> > + /* H.264 */
> > + VIRTIO_VIDEO_PROFILE_H264_MIN = 0x100,
> > + VIRTIO_VIDEO_PROFILE_H264_BASELINE =
> > VIRTIO_VIDEO_PROFILE_H264_MIN,
> > + VIRTIO_VIDEO_PROFILE_H264_MAIN,
> > + VIRTIO_VIDEO_PROFILE_H264_EXTENDED,
> > + VIRTIO_VIDEO_PROFILE_H264_HIGH,
> > + VIRTIO_VIDEO_PROFILE_H264_HIGH10PROFILE,
> > + VIRTIO_VIDEO_PROFILE_H264_HIGH422PROFILE,
> > + VIRTIO_VIDEO_PROFILE_H264_HIGH444PREDICTIVEPROFILE,
> > + VIRTIO_VIDEO_PROFILE_H264_SCALABLEBASELINE,
> > + VIRTIO_VIDEO_PROFILE_H264_SCALABLEHIGH,
> > + VIRTIO_VIDEO_PROFILE_H264_STEREOHIGH,
> > + VIRTIO_VIDEO_PROFILE_H264_MULTIVIEWHIGH,
> > + VIRTIO_VIDEO_PROFILE_H264_MAX =
> > VIRTIO_VIDEO_PROFILE_H264_MULTIVIEWHIGH, +
> > + /* HEVC */
> > + VIRTIO_VIDEO_PROFILE_HEVC_MIN = 0x200,
> > + VIRTIO_VIDEO_PROFILE_HEVC_MAIN = VIRTIO_VIDEO_PROFILE_HEVC_MIN,
> > + VIRTIO_VIDEO_PROFILE_HEVC_MAIN10,
> > + VIRTIO_VIDEO_PROFILE_HEVC_MAIN_STILL_PICTURE,
> > + VIRTIO_VIDEO_PROFILE_HEVC_MAX =
> > + VIRTIO_VIDEO_PROFILE_HEVC_MAIN_STILL_PICTURE,
> > +
> > + /* VP8 */
> > + VIRTIO_VIDEO_PROFILE_VP8_MIN = 0x300,
> > + VIRTIO_VIDEO_PROFILE_VP8_PROFILE0 = VIRTIO_VIDEO_PROFILE_VP8_MIN,
> > + VIRTIO_VIDEO_PROFILE_VP8_PROFILE1,
> > + VIRTIO_VIDEO_PROFILE_VP8_PROFILE2,
> > + VIRTIO_VIDEO_PROFILE_VP8_PROFILE3,
> > + VIRTIO_VIDEO_PROFILE_VP8_MAX = VIRTIO_VIDEO_PROFILE_VP8_PROFILE3,
> > +
> > + /* VP9 */
> > + VIRTIO_VIDEO_PROFILE_VP9_MIN = 0x400,
> > + VIRTIO_VIDEO_PROFILE_VP9_PROFILE0 = VIRTIO_VIDEO_PROFILE_VP9_MIN,
> > + VIRTIO_VIDEO_PROFILE_VP9_PROFILE1,
> > + VIRTIO_VIDEO_PROFILE_VP9_PROFILE2,
> > + VIRTIO_VIDEO_PROFILE_VP9_PROFILE3,
> > + VIRTIO_VIDEO_PROFILE_VP9_MAX = VIRTIO_VIDEO_PROFILE_VP9_PROFILE3,
> > +};
> > +
> > +enum virtio_video_level {
> > + /* H.264 */
> > + VIRTIO_VIDEO_LEVEL_H264_MIN = 0x100,
> > + VIRTIO_VIDEO_LEVEL_H264_1_0 = VIRTIO_VIDEO_LEVEL_H264_MIN,
> > + VIRTIO_VIDEO_LEVEL_H264_1_1,
> > + VIRTIO_VIDEO_LEVEL_H264_1_2,
> > + VIRTIO_VIDEO_LEVEL_H264_1_3,
> > + VIRTIO_VIDEO_LEVEL_H264_2_0,
> > + VIRTIO_VIDEO_LEVEL_H264_2_1,
> > + VIRTIO_VIDEO_LEVEL_H264_2_2,
> > + VIRTIO_VIDEO_LEVEL_H264_3_0,
> > + VIRTIO_VIDEO_LEVEL_H264_3_1,
> > + VIRTIO_VIDEO_LEVEL_H264_3_2,
> > + VIRTIO_VIDEO_LEVEL_H264_4_0,
> > + VIRTIO_VIDEO_LEVEL_H264_4_1,
> > + VIRTIO_VIDEO_LEVEL_H264_4_2,
> > + VIRTIO_VIDEO_LEVEL_H264_5_0,
> > + VIRTIO_VIDEO_LEVEL_H264_5_1,
> > + VIRTIO_VIDEO_LEVEL_H264_MAX = VIRTIO_VIDEO_LEVEL_H264_5_1,
> > +};
> > +
> > +/*
> > + * Config
> > + */
> > +
> > +struct virtio_video_config {
> > + __le32 version;
> > + __le32 max_caps_length;
> > + __le32 max_resp_length;
> > +};
> > +
> > +/*
> > + * Commands
> > + */
> > +
> > +enum virtio_video_cmd_type {
> > + /* Command */
> > + VIRTIO_VIDEO_CMD_QUERY_CAPABILITY = 0x0100,
> > + VIRTIO_VIDEO_CMD_STREAM_CREATE,
> > + VIRTIO_VIDEO_CMD_STREAM_DESTROY,
> > + VIRTIO_VIDEO_CMD_STREAM_DRAIN,
> > + VIRTIO_VIDEO_CMD_RESOURCE_CREATE,
> > + VIRTIO_VIDEO_CMD_RESOURCE_QUEUE,
> > + VIRTIO_VIDEO_CMD_RESOURCE_DESTROY_ALL,
> > + VIRTIO_VIDEO_CMD_QUEUE_CLEAR,
> > + VIRTIO_VIDEO_CMD_GET_PARAMS,
> > + VIRTIO_VIDEO_CMD_SET_PARAMS,
> > + VIRTIO_VIDEO_CMD_QUERY_CONTROL,
> > + VIRTIO_VIDEO_CMD_GET_CONTROL,
> > + VIRTIO_VIDEO_CMD_SET_CONTROL,
> > +
> > + /* Response */
> > + VIRTIO_VIDEO_RESP_OK_NODATA = 0x0200,
> > + VIRTIO_VIDEO_RESP_OK_QUERY_CAPABILITY,
> > + VIRTIO_VIDEO_RESP_OK_RESOURCE_QUEUE,
> > + VIRTIO_VIDEO_RESP_OK_GET_PARAMS,
> > + VIRTIO_VIDEO_RESP_OK_QUERY_CONTROL,
> > + VIRTIO_VIDEO_RESP_OK_GET_CONTROL,
> > +
> > + VIRTIO_VIDEO_RESP_ERR_INVALID_OPERATION = 0x0300,
> > + VIRTIO_VIDEO_RESP_ERR_OUT_OF_MEMORY,
> > + VIRTIO_VIDEO_RESP_ERR_INVALID_STREAM_ID,
> > + VIRTIO_VIDEO_RESP_ERR_INVALID_RESOURCE_ID,
> > + VIRTIO_VIDEO_RESP_ERR_INVALID_PARAMETER,
> > + VIRTIO_VIDEO_RESP_ERR_UNSUPPORTED_CONTROL,
> > +};
> > +
> > +struct virtio_video_cmd_hdr {
> > + __le32 type; /* One of enum virtio_video_cmd_type */
> > + __le32 stream_id;
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_QUERY_CAPABILITY */
> > +enum virtio_video_queue_type {
> > + VIRTIO_VIDEO_QUEUE_TYPE_INPUT = 0x100,
> > + VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT,
> > +};
> > +
> > +struct virtio_video_query_capability {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __u8 padding[4];
> > +};
> > +
> > +enum virtio_video_planes_layout_flag {
> > + VIRTIO_VIDEO_PLANES_LAYOUT_SINGLE_BUFFER = 1 << 0,
> > + VIRTIO_VIDEO_PLANES_LAYOUT_PER_PLANE = 1 << 1,
> > +};
> > +
> > +struct virtio_video_format_range {
> > + __le32 min;
> > + __le32 max;
> > + __le32 step;
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_format_frame {
> > + struct virtio_video_format_range width;
> > + struct virtio_video_format_range height;
> > + __le32 num_rates;
> > + __u8 padding[4];
> > + /* Followed by struct virtio_video_format_range frame_rates[] */
> > +};
> > +
> > +struct virtio_video_format_desc {
> > + __le64 mask;
> > + __le32 format; /* One of VIRTIO_VIDEO_FORMAT_* types */
> > + __le32 planes_layout; /* Bitmask with VIRTIO_VIDEO_PLANES_LAYOUT_*
> > */ + __le32 plane_align;
> > + __le32 num_frames;
> > + /* Followed by struct virtio_video_format_frame frames[] */
> > +};
> > +
> > +struct virtio_video_query_capability_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 num_descs;
> > + __u8 padding[4];
> > + /* Followed by struct virtio_video_format_desc descs[] */
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_STREAM_CREATE */
> > +enum virtio_video_mem_type {
> > + VIRTIO_VIDEO_MEM_TYPE_GUEST_PAGES,
> > +};
> > +
> > +struct virtio_video_stream_create {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 in_mem_type; /* One of VIRTIO_VIDEO_MEM_TYPE_* types */
> > + __le32 out_mem_type; /* One of VIRTIO_VIDEO_MEM_TYPE_* types */
> > + __le32 coded_format; /* One of VIRTIO_VIDEO_FORMAT_* types */
> > + __u8 padding[4];
> > + __u8 tag[64];
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_STREAM_DESTROY */
> > +struct virtio_video_stream_destroy {
> > + struct virtio_video_cmd_hdr hdr;
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_STREAM_DRAIN */
> > +struct virtio_video_stream_drain {
> > + struct virtio_video_cmd_hdr hdr;
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_RESOURCE_CREATE */
> > +struct virtio_video_mem_entry {
> > + __le64 addr;
> > + __le32 length;
> > + __u8 padding[4];
> > +};
> > +
> > +#define VIRTIO_VIDEO_MAX_PLANES 8
> > +
> > +struct virtio_video_resource_create {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __le32 resource_id;
> > + __le32 planes_layout;
> > + __le32 num_planes;
> > + __le32 plane_offsets[VIRTIO_VIDEO_MAX_PLANES];
> > + __le32 num_entries[VIRTIO_VIDEO_MAX_PLANES];
> > + /* Followed by struct virtio_video_mem_entry entries[] */
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_RESOURCE_QUEUE */
> > +struct virtio_video_resource_queue {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __le32 resource_id;
> > + __le64 timestamp;
> > + __le32 num_data_sizes;
> > + __le32 data_sizes[VIRTIO_VIDEO_MAX_PLANES];
> > + __u8 padding[4];
> > +};
> > +
> > +enum virtio_video_buffer_flag {
> > + VIRTIO_VIDEO_BUFFER_FLAG_ERR = 0x0001,
> > + VIRTIO_VIDEO_BUFFER_FLAG_EOS = 0x0002,
> > +
> > + /* Encoder only */
> > + VIRTIO_VIDEO_BUFFER_FLAG_IFRAME = 0x0004,
> > + VIRTIO_VIDEO_BUFFER_FLAG_PFRAME = 0x0008,
> > + VIRTIO_VIDEO_BUFFER_FLAG_BFRAME = 0x0010,
> > +};
> > +
> > +struct virtio_video_resource_queue_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le64 timestamp;
> > + __le32 flags; /* One of VIRTIO_VIDEO_BUFFER_FLAG_* flags */
> > + __le32 size; /* Encoded size */
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_RESOURCE_DESTROY_ALL */
> > +struct virtio_video_resource_destroy_all {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __u8 padding[4];
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_QUEUE_CLEAR */
> > +struct virtio_video_queue_clear {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __u8 padding[4];
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_GET_PARAMS */
> > +struct virtio_video_plane_format {
> > + __le32 plane_size;
> > + __le32 stride;
> > +};
> > +
> > +struct virtio_video_crop {
> > + __le32 left;
> > + __le32 top;
> > + __le32 width;
> > + __le32 height;
> > +};
> > +
> > +struct virtio_video_params {
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __le32 format; /* One of VIRTIO_VIDEO_FORMAT_* types */
> > + __le32 frame_width;
> > + __le32 frame_height;
> > + __le32 min_buffers;
> > + __le32 max_buffers;
> > + struct virtio_video_crop crop;
> > + __le32 frame_rate;
> > + __le32 num_planes;
> > + struct virtio_video_plane_format
> > plane_formats[VIRTIO_VIDEO_MAX_PLANES]; +};
> > +
> > +struct virtio_video_get_params {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 queue_type; /* One of VIRTIO_VIDEO_QUEUE_TYPE_* types */
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_get_params_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > + struct virtio_video_params params;
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_SET_PARAMS */
> > +struct virtio_video_set_params {
> > + struct virtio_video_cmd_hdr hdr;
> > + struct virtio_video_params params;
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_QUERY_CONTROL */
> > +enum virtio_video_control_type {
> > + VIRTIO_VIDEO_CONTROL_BITRATE = 1,
> > + VIRTIO_VIDEO_CONTROL_PROFILE,
> > + VIRTIO_VIDEO_CONTROL_LEVEL,
> > +};
> > +
> > +struct virtio_video_query_control_profile {
> > + __le32 format; /* One of VIRTIO_VIDEO_FORMAT_* */
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_query_control_level {
> > + __le32 format; /* One of VIRTIO_VIDEO_FORMAT_* */
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_query_control {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 control; /* One of VIRTIO_VIDEO_CONTROL_* types */
> > + __u8 padding[4];
> > + /*
> > + * Followed by a value of struct virtio_video_query_control_*
> > + * in accordance with the value of control.
> > + */
> > +};
> > +
> > +struct virtio_video_query_control_resp_profile {
> > + __le32 num;
> > + __u8 padding[4];
> > + /* Followed by an array le32 profiles[] */
> > +};
> > +
> > +struct virtio_video_query_control_resp_level {
> > + __le32 num;
> > + __u8 padding[4];
> > + /* Followed by an array le32 level[] */
> > +};
> > +
> > +struct virtio_video_query_control_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > + /* Followed by one of struct virtio_video_query_control_resp_* */
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_GET_CONTROL */
> > +struct virtio_video_get_control {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 control; /* One of VIRTIO_VIDEO_CONTROL_* types */
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_control_val_bitrate {
> > + __le32 bitrate;
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_control_val_profile {
> > + __le32 profile;
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_control_val_level {
> > + __le32 level;
> > + __u8 padding[4];
> > +};
> > +
> > +struct virtio_video_get_control_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > + /* Followed by one of struct virtio_video_control_val_* */
> > +};
> > +
> > +/* VIRTIO_VIDEO_CMD_SET_CONTROL */
> > +struct virtio_video_set_control {
> > + struct virtio_video_cmd_hdr hdr;
> > + __le32 control; /* One of VIRTIO_VIDEO_CONTROL_* types */
> > + __u8 padding[4];
> > + /* Followed by one of struct virtio_video_control_val_* */
> > +};
> > +
> > +struct virtio_video_set_control_resp {
> > + struct virtio_video_cmd_hdr hdr;
> > +};
> > +
> > +/*
> > + * Events
> > + */
> > +
> > +enum virtio_video_event_type {
> > + /* For all devices */
> > + VIRTIO_VIDEO_EVENT_ERROR = 0x0100,
> > +
> > + /* For decoder only */
> > + VIRTIO_VIDEO_EVENT_DECODER_RESOLUTION_CHANGED = 0x0200,
> > +};
> > +
> > +struct virtio_video_event {
> > + __le32 event_type; /* One of VIRTIO_VIDEO_EVENT_* types */
> > + __le32 stream_id;
> > +};
> > +
> > +#endif /* _UAPI_LINUX_VIRTIO_VIDEO_H */
> >
> > --
> > 2.25.0