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

From: Gerd Hoffmann
Date: Tue Oct 30 2018 - 02:32:14 EST


linux guest driver implementation of the VIRTIO_GPU_F_EDID feature.

Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
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