> From: Alexandre Courbot <[email protected]> > This patch adds session management to the virtio-media driver. > A session is created when the /dev/videoX device is opened, and > destroyed when it is closed. > Opening a session sends VIRTIO_MEDIA_CMD_OPEN to the host, and closing > it sends VIRTIO_MEDIA_CMD_CLOSE. > It adds drivers/media/virtio/session.h and implements the open and > release fops. > Signed-off-by: Alexandre Courbot <[email protected]> > Assisted-by: Antigravity:gemini-3.5-flash > Co-developed-by: Brian Daniels <[email protected]> > Signed-off-by: Brian Daniels <[email protected]>
Tested-by: Dorinda Bassey <[email protected]> On Thu, Aug 13, 2026 at 8:00 PM Brian Daniels <[email protected]> wrote: > > From: Alexandre Courbot <[email protected]> > > This patch adds session management to the virtio-media driver. > A session is created when the /dev/videoX device is opened, and > destroyed when it is closed. > > Opening a session sends VIRTIO_MEDIA_CMD_OPEN to the host, and closing > it sends VIRTIO_MEDIA_CMD_CLOSE. > > It adds drivers/media/virtio/session.h and implements the open and > release fops. > > Signed-off-by: Alexandre Courbot <[email protected]> > Assisted-by: Antigravity:gemini-3.5-flash > Co-developed-by: Brian Daniels <[email protected]> > Signed-off-by: Brian Daniels <[email protected]> > --- > drivers/media/virtio/session.h | 132 +++++ > drivers/media/virtio/virtio_media_driver.c | 604 ++++++++++++++++++++- > 2 files changed, 732 insertions(+), 4 deletions(-) > create mode 100644 drivers/media/virtio/session.h > > diff --git a/drivers/media/virtio/session.h b/drivers/media/virtio/session.h > new file mode 100644 > index 000000000..d523c8171 > --- /dev/null > +++ b/drivers/media/virtio/session.h > @@ -0,0 +1,132 @@ > +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0+ */ > + > +/* > + * Definitions of virtio-media session related structures. > + * > + * Copyright (c) 2024-2026 Google LLC. > + */ > + > +#ifndef __VIRTIO_MEDIA_SESSION_H > +#define __VIRTIO_MEDIA_SESSION_H > + > +#include <linux/scatterlist.h> > +#include <media/v4l2-fh.h> > + > +#include "uapi/linux/virtio_media.h" > + > +#define VIRTIO_MEDIA_LAST_QUEUE (V4L2_BUF_TYPE_META_OUTPUT) > + > +/* > + * Size of the per-session virtio shadow and event buffers. 16K should be > + * enough to contain everything we need. > + */ > +#define VIRTIO_SHADOW_BUF_SIZE 0x4000 > + > +/** > + * struct virtio_media_buffer - Current state of a buffer. > + * @buffer: &struct v4l2_buffer with current information about the buffer. > + * @planes: backing planes array for @buffer. > + * @list: link into the list of buffers pending dequeue. > + */ > +struct virtio_media_buffer { > + struct v4l2_buffer buffer; > + struct v4l2_plane planes[VIDEO_MAX_PLANES]; > + struct list_head list; > +}; > + > +/** > + * struct virtio_media_queue_state - Represents the state of a V4L2 queue. > + * @streaming: Whether the queue is currently streaming. > + * @allocated_bufs: How many buffers are currently allocated. > + * @is_capture_last: set to true when the last buffer has been received on a > + * capture queue, so we can return %-EPIPE on subsequent > + * DQBUF requests. > + * @buffers: Buffer state array of size @allocated_bufs. > + * @queued_bufs: How many buffers are currently queued on the device. > + * @pending_dqbufs: Buffers that are available for being dequeued. > + */ > +struct virtio_media_queue_state { > + bool streaming; > + size_t allocated_bufs; > + bool is_capture_last; > + > + struct virtio_media_buffer *buffers; > + size_t queued_bufs; > + struct list_head pending_dqbufs; > +}; > + > +/** > + * struct virtio_media_session - A session on a virtio_media device. > + * @fh: file handler for the session. > + * @file: file pointer associated with the session's file handler. > + * @id: session ID used to communicate with the device. > + * @nonblocking_dequeue: whether dequeue should block or not (nonblocking if > + * file opened with O_NONBLOCK). > + * @uses_mplane: whether the queues for this session use the MPLANE API or > not. > + * @cmd: union of session commands ``close``, ``ioctl``, and ``mmap``. A > + * session can have one command currently running. The rest of the > + * commands are handled by &struct virtio_media. > + * @resp: union of responses to session commands ``close``, ``ioctl``, and > + * ``mmap``. A session can wait on one command only. The rest of the > + * responses are handled by &struct virtio_media. > + * @shadow_buf: shadow buffer where data to be added to the descriptor chain > can > + * be staged before being sent to the device. > + * @command_sgs: SG table gathering descriptors for a given command and its > + * response. > + * @queues: state of all the queues for this session. > + * @queues_lock: protects all members for the queues for this session. > + * @dqbuf_wait: waitqueue for dequeued buffers, if ``VIDIOC_DQBUF`` needs to > + * block or when polling. > + * @list: link into the list of sessions for the device. > + */ > +struct virtio_media_session { > + struct v4l2_fh fh; > + struct file *file; > + u32 id; > + bool nonblocking_dequeue; > + bool uses_mplane; > + > + __dma_from_device_group_begin(); > + union { > + struct virtio_media_cmd_close close; > + struct virtio_media_cmd_ioctl ioctl; > + struct virtio_media_cmd_mmap mmap; > + } cmd; > + > + union { > + struct virtio_media_resp_ioctl ioctl; > + struct virtio_media_resp_mmap mmap; > + } resp; > + __dma_from_device_group_end(); > + > + void *shadow_buf; > + > + struct sg_table command_sgs; > + > + struct virtio_media_queue_state queues[VIRTIO_MEDIA_LAST_QUEUE + 1]; > + struct mutex queues_lock; /* protects queues array and states */ > + wait_queue_head_t dqbuf_wait; > + > + struct list_head list; > +}; > + > +static inline struct virtio_media_session *fh_to_session(struct v4l2_fh *fh) > +{ > + return container_of(fh, struct virtio_media_session, fh); > +} > + > +static inline void > +virtio_media_session_fh_add(struct virtio_media_session *session, > + struct file *file) > +{ > + v4l2_fh_add(&session->fh, file); > + session->file = file; > +} > + > +static inline void > +virtio_media_session_fh_del(struct virtio_media_session *session) > +{ > + v4l2_fh_del(&session->fh, session->file); > +} > + > +#endif // __VIRTIO_MEDIA_SESSION_H > diff --git a/drivers/media/virtio/virtio_media_driver.c > b/drivers/media/virtio/virtio_media_driver.c > index 25f2ceaa6..ef8065e34 100644 > --- a/drivers/media/virtio/virtio_media_driver.c > +++ b/drivers/media/virtio/virtio_media_driver.c > @@ -14,25 +14,589 @@ > #include <linux/virtio.h> > #include <linux/virtio_config.h> > #include <linux/virtio_ids.h> > +#include <linux/slab.h> > +#include <linux/scatterlist.h> > +#include <linux/vmalloc.h> > +#include <linux/workqueue.h> > +#include <linux/dma-mapping.h> > > #include <media/v4l2-dev.h> > #include <media/v4l2-device.h> > +#include <media/v4l2-fh.h> > +#include <media/v4l2-event.h> > > #include "uapi/linux/virtio_media.h" > +#include "session.h" > #include "virtio_media.h" > > -static void commandq_callback(struct virtqueue *vq) > +#define VIRTIO_MEDIA_NUM_EVENT_BUFS 16 > + > +/** > + * virtio_media_session_alloc() - Allocate a new session. > + * @vv: virtio-media device the session belongs to. > + * @id: ID of the session. > + * @file: file associated with the session. > + */ > +static struct virtio_media_session * > +virtio_media_session_alloc(struct virtio_media *vv, u32 id, > + struct file *file) > +{ > + struct virtio_media_session *session; > + int i; > + int ret; > + > + session = kzalloc_obj(*session, GFP_KERNEL); > + if (!session) > + goto err_session; > + > + session->shadow_buf = kzalloc(VIRTIO_SHADOW_BUF_SIZE, GFP_KERNEL); > + if (!session->shadow_buf) > + goto err_shadow_buf; > + > + ret = sg_alloc_table(&session->command_sgs, DESC_CHAIN_MAX_LEN, > + GFP_KERNEL); > + if (ret) > + goto err_payload_sgs; > + > + session->id = id; > + session->nonblocking_dequeue = file->f_flags & O_NONBLOCK; > + > + INIT_LIST_HEAD(&session->list); > + v4l2_fh_init(&session->fh, &vv->video_dev); > + virtio_media_session_fh_add(session, file); > + > + for (i = 0; i <= VIRTIO_MEDIA_LAST_QUEUE; i++) > + INIT_LIST_HEAD(&session->queues[i].pending_dqbufs); > + mutex_init(&session->queues_lock); > + > + init_waitqueue_head(&session->dqbuf_wait); > + > + mutex_lock(&vv->sessions_lock); > + list_add_tail(&session->list, &vv->sessions); > + mutex_unlock(&vv->sessions_lock); > + > + return session; > + > +err_payload_sgs: > + kfree(session->shadow_buf); > +err_shadow_buf: > + kfree(session); > +err_session: > + return ERR_PTR(-ENOMEM); > +} > + > +/** > + * virtio_media_session_free() - Free all resources of a session. > + * @vv: virtio-media device the session belongs to. > + * @session: session to destroy. > + * > + * All the resources of @session, as well as the backing memory of @session > + * itself, are freed. > + */ > +static void virtio_media_session_free(struct virtio_media *vv, > + struct virtio_media_session *session) > +{ > + int i; > + > + mutex_lock(&vv->sessions_lock); > + list_del(&session->list); > + mutex_unlock(&vv->sessions_lock); > + > + virtio_media_session_fh_del(session); > + v4l2_fh_exit(&session->fh); > + > + sg_free_table(&session->command_sgs); > + > + for (i = 0; i <= VIRTIO_MEDIA_LAST_QUEUE; i++) > + vfree(session->queues[i].buffers); > + > + kfree(session->shadow_buf); > + kfree(session); > +} > + > +/** > + * virtio_media_session_close() - Close and free a session. > + * @vv: virtio-media device the session belongs to. > + * @session: session to close and destroy. > + * > + * This sends the ``VIRTIO_MEDIA_CMD_CLOSE`` command to the device, and frees > + * all resources used by @session. > + */ > +static int virtio_media_session_close(struct virtio_media *vv, > + struct virtio_media_session *session) > +{ > + struct virtio_media_cmd_close *cmd_close = &session->cmd.close; > + struct scatterlist cmd_sg = {}; > + struct scatterlist *sgs[1] = { &cmd_sg }; > + int ret; > + > + mutex_lock(&vv->vlock); > + > + cmd_close->hdr.cmd = VIRTIO_MEDIA_CMD_CLOSE; > + cmd_close->session_id = session->id; > + > + sg_set_buf(&cmd_sg, cmd_close, sizeof(*cmd_close)); > + sg_mark_end(&cmd_sg); > + > + ret = virtio_media_send_command(vv, sgs, 1, 0, 0, NULL); > + mutex_unlock(&vv->vlock); > + if (ret < 0) > + return ret; > + > + virtio_media_session_free(vv, session); > + > + return 0; > +} > + > +/** > + * virtio_media_find_session() - Look up a session with a given ID. > + * @vv: virtio-media device to lookup the session from. > + * @id: ID of the session to lookup. > + */ > +static struct virtio_media_session * > +virtio_media_find_session(struct virtio_media *vv, u32 id) > +{ > + struct list_head *p; > + struct virtio_media_session *session = NULL; > + > + mutex_lock(&vv->sessions_lock); > + list_for_each(p, &vv->sessions) { > + struct virtio_media_session *s = > + list_entry(p, struct virtio_media_session, list); > + if (s->id == id) { > + session = s; > + break; > + } > + } > + mutex_unlock(&vv->sessions_lock); > + > + return session; > +} > + > +/** > + * struct virtio_media_cmd_callback_param - Callback parameters to the virtio > + * command queue. > + * @vv: virtio-media device in use. > + * @done: flag to be switched once the command is completed. > + * @resp_len: length of the received response from the command. Only valid > + * after @done flag has switched to %true. > + */ > +struct virtio_media_cmd_callback_param { > + struct virtio_media *vv; > + bool done; > + size_t resp_len; > +}; > + > +/** > + * commandq_callback() - Callback for the command queue. > + * @queue: command virtqueue. > + * > + * This just wakes up the thread that was waiting on the command to complete. > + */ > +static void commandq_callback(struct virtqueue *queue) > +{ > + unsigned int len; > + struct virtio_media_cmd_callback_param *param; > + > +process_bufs: > + while ((param = virtqueue_get_buf(queue, &len))) { > + param->done = true; > + param->resp_len = len; > + wake_up(¶m->vv->wq); > + } > + > + if (!virtqueue_enable_cb(queue)) { > + virtqueue_disable_cb(queue); > + goto process_bufs; > + } > +} > + > +/** > + * virtio_media_kick_command() - send a command to the commandq. > + * @vv: virtio-media device in use. > + * @sgs: descriptor chain to send. > + * @out_sgs: number of device-readable descriptors in @sgs. > + * @in_sgs: number of device-writable descriptors in @sgs. > + * @resp_len: output parameter. Upon success, contains the size of the > response > + * in bytes. > + */ > +static int virtio_media_kick_command(struct virtio_media *vv, > + struct scatterlist **sgs, > + const size_t out_sgs, const size_t > in_sgs, > + size_t *resp_len) > +{ > + struct virtio_media_cmd_callback_param cb_param = { > + .vv = vv, > + .done = false, > + .resp_len = 0, > + }; > + struct virtio_media_resp_header *resp_header; > + int ret = virtqueue_add_sgs(vv->commandq, sgs, out_sgs, in_sgs, > + &cb_param, GFP_ATOMIC); > + if (ret) { > + v4l2_err(&vv->v4l2_dev, > + "failed to add sgs to command virtqueue\n"); > + return ret; > + } > + > + if (!virtqueue_kick(vv->commandq)) { > + v4l2_err(&vv->v4l2_dev, "failed to kick command virtqueue\n"); > + return -EINVAL; > + } > + > + /* Wait for the response. */ > + ret = wait_event_timeout(vv->wq, cb_param.done, 5 * HZ); > + if (ret == 0) { > + v4l2_err(&vv->v4l2_dev, > + "timed out waiting for response to command\n"); > + return -ETIMEDOUT; > + } > + > + if (resp_len) > + *resp_len = cb_param.resp_len; > + > + if (in_sgs > 0) { > + /* > + * If we expect a response, make sure we have at least a > + * response header - anything shorter is invalid. > + */ > + if (cb_param.resp_len < sizeof(*resp_header)) { > + v4l2_err(&vv->v4l2_dev, > + "received response header is too short\n"); > + return -EINVAL; > + } > + > + resp_header = sg_virt(sgs[out_sgs]); > + if (resp_header->status) > + /* Host returns a positive error code. */ > + return -resp_header->status; > + } > + > + return 0; > +} > + > +/** > + * virtio_media_send_command() - Send a command to the device and wait for > its > + * response. > + * @vv: virtio-media device in use. > + * @sgs: descriptor chain to send. > + * @out_sgs: number of device-readable descriptors in @sgs. > + * @in_sgs: number of device-writable descriptors in @sgs. > + * @minimum_resp_len: minimum length of the response expected by the caller > + * when the command is successful. Anything shorter than > + * that will result in %-EINVAL being returned. > + * @resp_len: output parameter. Upon success, contains the size of the > response > + * in bytes. > + */ > +int virtio_media_send_command(struct virtio_media *vv, struct scatterlist > **sgs, > + const size_t out_sgs, const size_t in_sgs, > + size_t minimum_resp_len, size_t *resp_len) > +{ > + size_t local_resp_len = resp_len ? *resp_len : 0; > + int ret = virtio_media_kick_command(vv, sgs, out_sgs, in_sgs, > + &local_resp_len); > + if (resp_len) > + *resp_len = local_resp_len; > + > + /* > + * If the host could not process the command, there is no valid > + * response. > + */ > + if (ret < 0) > + return ret; > + > + /* Make sure the host wrote a complete reply. */ > + if (local_resp_len < minimum_resp_len) { > + v4l2_err(&vv->v4l2_dev, > + "received response is too short: received %zu, > expected at least %zu\n", > + local_resp_len, minimum_resp_len); > + return -EINVAL; > + } > + > + return 0; > +} > + > +/** > + * virtio_media_send_event_buffer() - Sends an event buffer to the host so it > + * can return it with an event. > + * @vv: virtio-media device in use. > + * @event_buffer: pointer to the event buffer to send to the device. > + */ > +static int virtio_media_send_event_buffer(struct virtio_media *vv, > + void *event_buffer) > +{ > + struct scatterlist *sgs[1], vresp; > + int ret; > + > + sg_init_one(&vresp, event_buffer, VIRTIO_MEDIA_EVENT_MAX_SIZE); > + sgs[0] = &vresp; > + > + ret = virtqueue_add_sgs(vv->eventq, sgs, 0, 1, event_buffer, > + GFP_ATOMIC); > + if (ret) { > + v4l2_err(&vv->v4l2_dev, > + "failed to add sgs to event virtqueue\n"); > + return ret; > + } > + > + if (!virtqueue_kick(vv->eventq)) { > + v4l2_err(&vv->v4l2_dev, "failed to kick event virtqueue\n"); > + return -EINVAL; > + } > + > + return 0; > +} > + > +/** > + * eventq_callback() - Callback for the event queue. > + * @queue: event virtqueue. > + * > + * This just schedules for event work to be run. > + */ > +static void eventq_callback(struct virtqueue *queue) > +{ > + struct virtio_media *vv = queue->vdev->priv; > + > + schedule_work(&vv->eventq_work); > +} > + > +/** > + * virtio_media_process_dqbuf_event() - Process a dequeued event for a > session. > + * @vv: virtio-media device in use. > + * @session: session the event is addressed to. > + * @dqbuf_evt: the dequeued event to process. > + * > + * Invalid events are ignored with an error log. > + */ > +static void > +virtio_media_process_dqbuf_event(struct virtio_media *vv, > + struct virtio_media_session *session, > + struct virtio_media_event_dqbuf *dqbuf_evt) > +{ > + struct virtio_media_buffer *dqbuf; > + const enum v4l2_buf_type queue_type = dqbuf_evt->buffer.type; > + struct virtio_media_queue_state *queue; > + typeof(dqbuf->buffer.m) buffer_m; > + typeof(dqbuf->buffer.m.planes[0].m) plane_m; > + int i; > + > + if (queue_type >= ARRAY_SIZE(session->queues)) { > + v4l2_err(&vv->v4l2_dev, > + "unmanaged queue %d passed to dqbuf event", > + dqbuf_evt->buffer.type); > + return; > + } > + queue = &session->queues[queue_type]; > + > + if (dqbuf_evt->buffer.index >= queue->allocated_bufs) { > + v4l2_err(&vv->v4l2_dev, > + "invalid buffer ID %d for queue %d in dqbuf event", > + dqbuf_evt->buffer.index, dqbuf_evt->buffer.type); > + return; > + } > + > + dqbuf = &queue->buffers[dqbuf_evt->buffer.index]; > + > + /* > + * Preserve the 'm' union that was passed to us during QBUF so > userspace > + * gets back the information it submitted. > + */ > + buffer_m = dqbuf->buffer.m; > + memcpy(&dqbuf->buffer, &dqbuf_evt->buffer, sizeof(dqbuf->buffer)); > + dqbuf->buffer.m = buffer_m; > + if (V4L2_TYPE_IS_MULTIPLANAR(dqbuf->buffer.type)) { > + if (dqbuf->buffer.length > VIDEO_MAX_PLANES) { > + v4l2_err(&vv->v4l2_dev, > + "invalid number of planes received from host > for a multiplanar buffer\n"); > + return; > + } > + for (i = 0; i < dqbuf->buffer.length; i++) { > + plane_m = dqbuf->planes[i].m; > + memcpy(&dqbuf->planes[i], &dqbuf_evt->planes[i], > + sizeof(struct v4l2_plane)); > + dqbuf->planes[i].m = plane_m; > + } > + } > + > + /* Set the DONE flag as the buffer is waiting to be dequeued. */ > + dqbuf->buffer.flags |= V4L2_BUF_FLAG_DONE; > + > + mutex_lock(&session->queues_lock); > + list_add_tail(&dqbuf->list, &queue->pending_dqbufs); > + queue->queued_bufs -= 1; > + mutex_unlock(&session->queues_lock); > + > + wake_up(&session->dqbuf_wait); > +} > + > +/** > + * virtio_media_process_events() - Process all pending events on a device. > + * @vv: device whose pending events we want to process. > + * > + * Retrieves all pending events on @vv's event queue and dispatches them to > + * their corresponding session. > + * > + * Invalid events are ignored with an error log. > + */ > +void virtio_media_process_events(struct virtio_media *vv) > +{ > + struct virtio_media_event_error *error_evt; > + struct virtio_media_event_dqbuf *dqbuf_evt; > + struct virtio_media_event_event *event_evt; > + struct virtio_media_session *session; > + struct virtio_media_event_header *evt; > + unsigned int len; > + > + mutex_lock(&vv->events_lock); > + > +process_bufs: > + while ((evt = virtqueue_get_buf(vv->eventq, &len))) { > + /* Make sure we received enough data */ > + if (len < sizeof(*evt)) { > + v4l2_err(&vv->v4l2_dev, > + "event is too short: got %u, expected at > least %zu\n", > + len, sizeof(*evt)); > + goto end_of_event; > + } > + > + session = virtio_media_find_session(vv, evt->session_id); > + if (!session) { > + v4l2_err(&vv->v4l2_dev, "cannot find session %d\n", > + evt->session_id); > + goto end_of_event; > + } > + > + switch (evt->event) { > + case VIRTIO_MEDIA_EVT_ERROR: > + if (len < sizeof(*error_evt)) { > + v4l2_err(&vv->v4l2_dev, > + "error event is too short: got %u, > expected %zu\n", > + len, sizeof(*error_evt)); > + break; > + } > + error_evt = (struct virtio_media_event_error *)evt; > + v4l2_err(&vv->v4l2_dev, > + "received error %d for session %d", > + error_evt->errno, error_evt->hdr.session_id); > + virtio_media_session_close(vv, session); > + break; > + > + /* > + * Dequeued buffer: put it into the right queue so user-space > + * can dequeue it. > + */ > + case VIRTIO_MEDIA_EVT_DQBUF: > + if (len < sizeof(*dqbuf_evt)) { > + v4l2_err(&vv->v4l2_dev, > + "dqbuf event is too short: got %u, > expected %zu\n", > + len, sizeof(*dqbuf_evt)); > + break; > + } > + dqbuf_evt = (struct virtio_media_event_dqbuf *)evt; > + virtio_media_process_dqbuf_event(vv, session, > + dqbuf_evt); > + break; > + > + case VIRTIO_MEDIA_EVT_EVENT: > + if (len < sizeof(*event_evt)) { > + v4l2_err(&vv->v4l2_dev, > + "session event is too short: got %u > expected %zu\n", > + len, sizeof(*event_evt)); > + break; > + } > + > + event_evt = (struct virtio_media_event_event *)evt; > + v4l2_event_queue_fh(&session->fh, &event_evt->event); > + break; > + > + default: > + v4l2_err(&vv->v4l2_dev, "unknown event type %d\n", > + evt->event); > + break; > + } > + > +end_of_event: > + virtio_media_send_event_buffer(vv, evt); > + } > + > + if (!virtqueue_enable_cb(vv->eventq)) { > + virtqueue_disable_cb(vv->eventq); > + goto process_bufs; > + } > + > + mutex_unlock(&vv->events_lock); > +} > + > +static void virtio_media_event_work(struct work_struct *work) > { > + struct virtio_media *vv = > + container_of(work, struct virtio_media, eventq_work); > + > + virtio_media_process_events(vv); > +} > + > +/** > + * virtio_media_device_open() - Create a new session from an opened file. > + * @file: opened file for the session. > + */ > +static int virtio_media_device_open(struct file *file) > +{ > + struct video_device *video_dev = video_devdata(file); > + struct virtio_media *vv = to_virtio_media(video_dev); > + struct virtio_media_cmd_open *cmd_open = &vv->cmd.open; > + struct virtio_media_resp_open *resp_open = &vv->resp.open; > + struct scatterlist cmd_sg = {}, resp_sg = {}; > + struct scatterlist *sgs[2] = { &cmd_sg, &resp_sg }; > + struct virtio_media_session *session; > + u32 session_id; > + int ret; > + > + mutex_lock(&vv->vlock); > + > + sg_set_buf(&cmd_sg, cmd_open, sizeof(*cmd_open)); > + sg_mark_end(&cmd_sg); > + > + sg_set_buf(&resp_sg, resp_open, sizeof(*resp_open)); > + sg_mark_end(&resp_sg); > + > + cmd_open->hdr.cmd = VIRTIO_MEDIA_CMD_OPEN; > + ret = virtio_media_send_command(vv, sgs, 1, 1, sizeof(*resp_open), > + NULL); > + session_id = resp_open->session_id; > + mutex_unlock(&vv->vlock); > + if (ret < 0) > + return ret; > + > + session = virtio_media_session_alloc(vv, session_id, file); > + if (IS_ERR(session)) > + return PTR_ERR(session); > + > + file->private_data = &session->fh; > + > + return 0; > } > > -static void eventq_callback(struct virtqueue *vq) > +/** > + * virtio_media_device_close() - Close a previously opened session. > + * @file: file of the session to close. > + * > + * This sends the ``VIRTIO_MEDIA_CMD_CLOSE`` command to the device, and > closes > + * the session on the driver side. > + */ > +static int virtio_media_device_close(struct file *file) > { > + struct video_device *video_dev = video_devdata(file); > + struct virtio_media *vv = to_virtio_media(video_dev); > + struct virtio_media_session *session = > + fh_to_session(file->private_data); > + > + return virtio_media_session_close(vv, session); > } > > static const struct v4l2_file_operations virtio_media_fops = { > .owner = THIS_MODULE, > - .open = v4l2_fh_open, > - .release = v4l2_fh_release, > + .open = virtio_media_device_open, > + .release = virtio_media_device_close, > }; > > static int virtio_media_probe(struct virtio_device *virtio_dev) > @@ -51,12 +615,23 @@ static int virtio_media_probe(struct virtio_device > *virtio_dev) > }; > struct virtio_media *vv; > struct video_device *vd; > + int i; > int ret; > > vv = devm_kzalloc(dev, sizeof(*vv), GFP_KERNEL); > if (!vv) > return -ENOMEM; > > + const size_t virtio_media_event_aligned_size = > + ALIGN(VIRTIO_MEDIA_EVENT_MAX_SIZE, dma_get_cache_alignment()); > + > + vv->event_buffer = devm_kzalloc(dev, > + virtio_media_event_aligned_size * > + VIRTIO_MEDIA_NUM_EVENT_BUFS, > + GFP_KERNEL); > + if (!vv->event_buffer) > + return -ENOMEM; > + > INIT_LIST_HEAD(&vv->sessions); > mutex_init(&vv->sessions_lock); > mutex_init(&vv->events_lock); > @@ -77,6 +652,7 @@ static int virtio_media_probe(struct virtio_device > *virtio_dev) > > vv->commandq = vqs[0]; > vv->eventq = vqs[1]; > + INIT_WORK(&vv->eventq_work, virtio_media_event_work); > > vd = &vv->video_dev; > vd->v4l2_dev = &vv->v4l2_dev; > @@ -100,10 +676,21 @@ static int virtio_media_probe(struct virtio_device > *virtio_dev) > if (ret) > goto err_register_device; > > + for (i = 0; i < VIRTIO_MEDIA_NUM_EVENT_BUFS; i++) { > + void *ebuf = vv->event_buffer + > + virtio_media_event_aligned_size * i; > + > + ret = virtio_media_send_event_buffer(vv, ebuf); > + if (ret) > + goto err_send_event_buffer; > + } > + > virtio_device_ready(virtio_dev); > > return 0; > > +err_send_event_buffer: > + video_unregister_device(&vv->video_dev); > err_register_device: > virtio_dev->config->del_vqs(virtio_dev); > err_find_vqs: > @@ -114,11 +701,20 @@ static int virtio_media_probe(struct virtio_device > *virtio_dev) > static void virtio_media_remove(struct virtio_device *virtio_dev) > { > struct virtio_media *vv = virtio_dev->priv; > + struct list_head *p, *n; > > + cancel_work_sync(&vv->eventq_work); > virtio_reset_device(virtio_dev); > v4l2_device_unregister(&vv->v4l2_dev); > virtio_dev->config->del_vqs(virtio_dev); > video_unregister_device(&vv->video_dev); > + > + list_for_each_safe(p, n, &vv->sessions) { > + struct virtio_media_session *s = > + list_entry(p, struct virtio_media_session, list); > + > + virtio_media_session_free(vv, s); > + } > } > > static struct virtio_device_id id_table[] = { > -- > 2.55.0.737.g08866a6d13-goog >
