Re: [PATCH v4 2/2] drm/virtio: add edid support

From: Daniel Vetter
Date: Tue Oct 30 2018 - 05:38:11 EST


On Tue, Oct 30, 2018 at 07:32:06AM +0100, Gerd Hoffmann wrote:
> linux guest driver implementation of the VIRTIO_GPU_F_EDID feature.
>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>

Like with bochs, I think drm_do_get_edid() here is overkill and fairly
pointless.
-Daniel

> ---
> drivers/gpu/drm/virtio/virtgpu_drv.h | 3 ++
> drivers/gpu/drm/virtio/virtgpu_display.c | 12 ++++++
> drivers/gpu/drm/virtio/virtgpu_drv.c | 1 +
> drivers/gpu/drm/virtio/virtgpu_kms.c | 8 ++++
> drivers/gpu/drm/virtio/virtgpu_vq.c | 67 ++++++++++++++++++++++++++++++++
> 5 files changed, 91 insertions(+)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
> index d29f0c7c76..852078419d 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> @@ -114,6 +114,7 @@ struct virtio_gpu_output {
> struct drm_encoder enc;
> struct virtio_gpu_display_one info;
> struct virtio_gpu_update_cursor cursor;
> + struct edid *edid;
> int cur_x;
> int cur_y;
> bool enabled;
> @@ -204,6 +205,7 @@ struct virtio_gpu_device {
> spinlock_t ctx_id_idr_lock;
>
> bool has_virgl_3d;
> + bool has_edid;
>
> struct work_struct config_changed_work;
>
> @@ -298,6 +300,7 @@ int virtio_gpu_cmd_get_capset_info(struct virtio_gpu_device *vgdev, int idx);
> int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev,
> int idx, int version,
> struct virtio_gpu_drv_cap_cache **cache_p);
> +int virtio_gpu_cmd_get_edids(struct virtio_gpu_device *vgdev);
> void virtio_gpu_cmd_context_create(struct virtio_gpu_device *vgdev, uint32_t id,
> uint32_t nlen, const char *name);
> void virtio_gpu_cmd_context_destroy(struct virtio_gpu_device *vgdev,
> diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
> index 8f8fed471e..b5580b11a0 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_display.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_display.c
> @@ -169,6 +169,12 @@ static int virtio_gpu_conn_get_modes(struct drm_connector *connector)
> struct drm_display_mode *mode = NULL;
> int count, width, height;
>
> + if (output->edid) {
> + count = drm_add_edid_modes(connector, output->edid);
> + if (count)
> + return count;
> + }
> +
> width = le32_to_cpu(output->info.r.width);
> height = le32_to_cpu(output->info.r.height);
> count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX);
> @@ -287,6 +293,8 @@ static int vgdev_output_init(struct virtio_gpu_device *vgdev, int index)
> drm_connector_init(dev, connector, &virtio_gpu_connector_funcs,
> DRM_MODE_CONNECTOR_VIRTUAL);
> drm_connector_helper_add(connector, &virtio_gpu_conn_helper_funcs);
> + if (vgdev->has_edid)
> + drm_connector_attach_edid_property(connector);
>
> drm_encoder_init(dev, encoder, &virtio_gpu_enc_funcs,
> DRM_MODE_ENCODER_VIRTUAL, NULL);
> @@ -378,6 +386,10 @@ int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev)
>
> void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev)
> {
> + int i;
> +
> + for (i = 0 ; i < vgdev->num_scanouts; ++i)
> + kfree(vgdev->outputs[i].edid);
> virtio_gpu_fbdev_fini(vgdev);
> drm_mode_config_cleanup(vgdev->ddev);
> }
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
> index d9287c144f..f7f32a885a 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> @@ -80,6 +80,7 @@ static unsigned int features[] = {
> */
> VIRTIO_GPU_F_VIRGL,
> #endif
> + VIRTIO_GPU_F_EDID,
> };
> static struct virtio_driver virtio_gpu_driver = {
> .feature_table = features,
> diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
> index 65060c0852..f6cbbb27e4 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_kms.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
> @@ -44,6 +44,8 @@ static void virtio_gpu_config_changed_work_func(struct work_struct *work)
> virtio_cread(vgdev->vdev, struct virtio_gpu_config,
> events_read, &events_read);
> if (events_read & VIRTIO_GPU_EVENT_DISPLAY) {
> + if (vgdev->has_edid)
> + virtio_gpu_cmd_get_edids(vgdev);
> virtio_gpu_cmd_get_display_info(vgdev);
> drm_helper_hpd_irq_event(vgdev->ddev);
> events_clear |= VIRTIO_GPU_EVENT_DISPLAY;
> @@ -174,6 +176,10 @@ int virtio_gpu_driver_load(struct drm_device *dev, unsigned long flags)
> #else
> DRM_INFO("virgl 3d acceleration not supported by guest\n");
> #endif
> + if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_EDID)) {
> + vgdev->has_edid = true;
> + DRM_INFO("EDID support available.\n");
> + }
>
> ret = virtio_find_vqs(vgdev->vdev, 2, vqs, callbacks, names, NULL);
> if (ret) {
> @@ -219,6 +225,8 @@ int virtio_gpu_driver_load(struct drm_device *dev, unsigned long flags)
>
> if (num_capsets)
> virtio_gpu_get_capsets(vgdev, num_capsets);
> + if (vgdev->has_edid)
> + virtio_gpu_cmd_get_edids(vgdev);
> virtio_gpu_cmd_get_display_info(vgdev);
> wait_event_timeout(vgdev->resp_wq, !vgdev->display_info_pending,
> 5 * HZ);
> diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
> index 4e2e037aed..dd149a59c7 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_vq.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
> @@ -604,6 +604,45 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev,
> wake_up(&vgdev->resp_wq);
> }
>
> +static int virtio_get_edid_block(void *data, u8 *buf,
> + unsigned int block, size_t len)
> +{
> + struct virtio_gpu_resp_edid *resp = data;
> + size_t start = block * EDID_LENGTH;
> +
> + if (start + len > le32_to_cpu(resp->size))
> + return -1;
> + memcpy(buf, resp->edid + start, len);
> + return 0;
> +}
> +
> +static void virtio_gpu_cmd_get_edid_cb(struct virtio_gpu_device *vgdev,
> + struct virtio_gpu_vbuffer *vbuf)
> +{
> + struct virtio_gpu_cmd_get_edid *cmd =
> + (struct virtio_gpu_cmd_get_edid *)vbuf->buf;
> + struct virtio_gpu_resp_edid *resp =
> + (struct virtio_gpu_resp_edid *)vbuf->resp_buf;
> + uint32_t scanout = le32_to_cpu(cmd->scanout);
> + struct virtio_gpu_output *output;
> + struct edid *new_edid, *old_edid;
> +
> + if (scanout >= vgdev->num_scanouts)
> + return;
> + output = vgdev->outputs + scanout;
> +
> + new_edid = drm_do_get_edid(&output->conn, virtio_get_edid_block, resp);
> +
> + spin_lock(&vgdev->display_info_lock);
> + old_edid = output->edid;
> + output->edid = new_edid;
> + drm_connector_update_edid_property(&output->conn, output->edid);
> + spin_unlock(&vgdev->display_info_lock);
> +
> + kfree(old_edid);
> + wake_up(&vgdev->resp_wq);
> +}
> +
> int virtio_gpu_cmd_get_display_info(struct virtio_gpu_device *vgdev)
> {
> struct virtio_gpu_ctrl_hdr *cmd_p;
> @@ -706,6 +745,34 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev,
> return 0;
> }
>
> +int virtio_gpu_cmd_get_edids(struct virtio_gpu_device *vgdev)
> +{
> + struct virtio_gpu_cmd_get_edid *cmd_p;
> + struct virtio_gpu_vbuffer *vbuf;
> + void *resp_buf;
> + int scanout;
> +
> + if (WARN_ON(!vgdev->has_edid))
> + return -EINVAL;
> +
> + for (scanout = 0; scanout < vgdev->num_scanouts; scanout++) {
> + resp_buf = kzalloc(sizeof(struct virtio_gpu_resp_edid),
> + GFP_KERNEL);
> + if (!resp_buf)
> + return -ENOMEM;
> +
> + cmd_p = virtio_gpu_alloc_cmd_resp
> + (vgdev, &virtio_gpu_cmd_get_edid_cb, &vbuf,
> + sizeof(*cmd_p), sizeof(struct virtio_gpu_resp_edid),
> + resp_buf);
> + cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_GET_EDID);
> + cmd_p->scanout = cpu_to_le32(scanout);
> + virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
> + }
> +
> + return 0;
> +}
> +
> void virtio_gpu_cmd_context_create(struct virtio_gpu_device *vgdev, uint32_t id,
> uint32_t nlen, const char *name)
> {
> --
> 2.9.3
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch