contrib/vhost-user-gpu: add support for sending dmabuf modifiers

virglrenderer recently added virgl_renderer_resource_get_info_ext as a
new api, which gets resource information, including dmabuf modifiers.

We have to support dmabuf modifiers since the driver may choose to
allocate buffers with these modifiers for efficiency, and importing
buffers without modifiers information may result in completely broken
rendering.

Signed-off-by: Erico Nunes <ernunes@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20230714153900.475857-3-ernunes@redhat.com>

1 files changed, 48 insertions, 3 deletions

diff --git a/contrib/vhost-user-gpu/virgl.c b/contrib/vhost-user-gpu/virgl.c
index 211aa110a9..1da6cc1588 100644
--- a/contrib/vhost-user-gpu/virgl.c
+++ b/contrib/vhost-user-gpu/virgl.c
@@ -318,6 +318,37 @@ virgl_resource_detach_backing(VuGpu *g,
     vg_cleanup_mapping_iov(g, res_iovs, num_iovs);
 }
 
+static int
+virgl_get_resource_info_modifiers(uint32_t resource_id,
+                                  struct virgl_renderer_resource_info *info,
+                                  uint64_t *modifiers)
+{
+    int ret;
+#ifdef VIRGL_RENDERER_RESOURCE_INFO_EXT_VERSION
+    struct virgl_renderer_resource_info_ext info_ext;
+    ret = virgl_renderer_resource_get_info_ext(resource_id, &info_ext);
+    if (ret < 0) {
+        return ret;
+    }
+
+    *info = info_ext.base;
+    *modifiers = info_ext.modifiers;
+#else
+    ret = virgl_renderer_resource_get_info(resource_id, info);
+    if (ret < 0) {
+        return ret;
+    }
+
+    /*
+     * Before virgl_renderer_resource_get_info_ext,
+     * getting the modifiers was not possible.
+     */
+    *modifiers = 0;
+#endif
+
+    return 0;
+}
+
 static void
 virgl_cmd_set_scanout(VuGpu *g,
                       struct virtio_gpu_ctrl_command *cmd)
@@ -338,7 +369,9 @@ virgl_cmd_set_scanout(VuGpu *g,
     memset(&info, 0, sizeof(info));
 
     if (ss.resource_id && ss.r.width && ss.r.height) {
-        ret = virgl_renderer_resource_get_info(ss.resource_id, &info);
+        uint64_t modifiers = 0;
+        ret = virgl_get_resource_info_modifiers(ss.resource_id, &info,
+                                                &modifiers);
         if (ret == -1) {
             g_critical("%s: illegal resource specified %d\n",
                        __func__, ss.resource_id);
@@ -354,8 +387,6 @@ virgl_cmd_set_scanout(VuGpu *g,
         }
         assert(fd >= 0);
         VhostUserGpuMsg msg = {
-            .request = VHOST_USER_GPU_DMABUF_SCANOUT,
-            .size = sizeof(VhostUserGpuDMABUFScanout),
             .payload.dmabuf_scanout.scanout_id = ss.scanout_id,
             .payload.dmabuf_scanout.x =  ss.r.x,
             .payload.dmabuf_scanout.y =  ss.r.y,
@@ -367,6 +398,20 @@ virgl_cmd_set_scanout(VuGpu *g,
             .payload.dmabuf_scanout.fd_flags = info.flags,
             .payload.dmabuf_scanout.fd_drm_fourcc = info.drm_fourcc
         };
+
+        if (g->use_modifiers) {
+            /*
+             * The mesage uses all the fields set in dmabuf_scanout plus
+             * modifiers which is appended after VhostUserGpuDMABUFScanout.
+             */
+            msg.request = VHOST_USER_GPU_DMABUF_SCANOUT2;
+            msg.size = sizeof(VhostUserGpuDMABUFScanout2);
+            msg.payload.dmabuf_scanout2.modifier = modifiers;
+        } else {
+            msg.request = VHOST_USER_GPU_DMABUF_SCANOUT;
+            msg.size = sizeof(VhostUserGpuDMABUFScanout);
+        }
+
         vg_send_msg(g, &msg, fd);
         close(fd);
     } else {