contrib/vhost-user-gpu: implement get_edid feature

Implement the virtio-gpu feature in contrib/vhost-user-gpu, which was
unsupported until now.
In this implementation, the feature is enabled inconditionally to avoid
creating another optional config argument.
Similarly to get_display_info, vhost-user-gpu sends a message back to
the frontend to have access to all the display information. In the
case of get_edid, it also needs to pass which scanout we should
retrieve the edid for.

The VHOST_USER_GPU_PROTOCOL_F_EDID protocol feature is required if the
frontend sets the VIRTIO_GPU_F_EDID virtio-gpu feature. If the frontend
sets the virtio-gpu feature but does not support the protocol feature,
the backend will abort with an error.

Signed-off-by: Erico Nunes <ernunes@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230626164708.1163239-4-ernunes@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/contrib/vhost-user-gpu/vugpu.h b/contrib/vhost-user-gpu/vugpu.h
index e2864bba68..f0f2069c47 100644
--- a/contrib/vhost-user-gpu/vugpu.h
+++ b/contrib/vhost-user-gpu/vugpu.h
@@ -36,6 +36,7 @@ typedef enum VhostUserGpuRequest {
     VHOST_USER_GPU_UPDATE,
     VHOST_USER_GPU_DMABUF_SCANOUT,
     VHOST_USER_GPU_DMABUF_UPDATE,
+    VHOST_USER_GPU_GET_EDID,
 } VhostUserGpuRequest;
 
 typedef struct VhostUserGpuDisplayInfoReply {
@@ -83,6 +84,10 @@ typedef struct VhostUserGpuDMABUFScanout {
     int fd_drm_fourcc;
 } QEMU_PACKED VhostUserGpuDMABUFScanout;
 
+typedef struct VhostUserGpuEdidRequest {
+    uint32_t scanout_id;
+} QEMU_PACKED VhostUserGpuEdidRequest;
+
 typedef struct VhostUserGpuMsg {
     uint32_t request; /* VhostUserGpuRequest */
     uint32_t flags;
@@ -93,6 +98,8 @@ typedef struct VhostUserGpuMsg {
         VhostUserGpuScanout scanout;
         VhostUserGpuUpdate update;
         VhostUserGpuDMABUFScanout dmabuf_scanout;
+        VhostUserGpuEdidRequest edid_req;
+        struct virtio_gpu_resp_edid resp_edid;
         struct virtio_gpu_resp_display_info display_info;
         uint64_t u64;
     } payload;
@@ -104,6 +111,8 @@ static VhostUserGpuMsg m __attribute__ ((unused));
 
 #define VHOST_USER_GPU_MSG_FLAG_REPLY 0x4
 
+#define VHOST_USER_GPU_PROTOCOL_F_EDID 0
+
 struct virtio_gpu_scanout {
     uint32_t width, height;
     int x, y;
@@ -122,6 +131,7 @@ typedef struct VuGpu {
 
     bool virgl;
     bool virgl_inited;
+    bool edid_inited;
     uint32_t inflight;
 
     struct virtio_gpu_scanout scanout[VIRTIO_GPU_MAX_SCANOUTS];
@@ -171,6 +181,7 @@ int     vg_create_mapping_iov(VuGpu *g,
                               struct iovec **iov);
 void    vg_cleanup_mapping_iov(VuGpu *g, struct iovec *iov, uint32_t count);
 void    vg_get_display_info(VuGpu *vg, struct virtio_gpu_ctrl_command *cmd);
+void    vg_get_edid(VuGpu *vg, struct virtio_gpu_ctrl_command *cmd);
 
 void    vg_wait_ok(VuGpu *g);