virtio-gpu-virgl: teach it to get the QEMU EGL display

virgl offers a few features that require to have access to the
underlying EGLDisplay. This is the case for the D3D texture sharing support.

The API callback is merged for virgl 1.0:
https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/1113

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230606115658.677673-18-marcandre.lureau@redhat.com>

hw/display/virtio-gpu-virgl.c

@@ -18,9 +18,17 @@
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/virtio-gpu.h"
 
+#include "ui/egl-helpers.h"
+
 #include <virglrenderer.h>
 
-static struct virgl_renderer_callbacks virtio_gpu_3d_cbs;
+#if VIRGL_RENDERER_CALLBACKS_VERSION >= 4
+static void *
+virgl_get_egl_display(G_GNUC_UNUSED void *cookie)
+{
+    return qemu_egl_display;
+}
+#endif
 
 static void virgl_cmd_create_resource_2d(VirtIOGPU *g,
                                          struct virtio_gpu_ctrl_command *cmd)
@@ -608,6 +616,13 @@ int virtio_gpu_virgl_init(VirtIOGPU *g)
 {
     int ret;
 
+#if VIRGL_RENDERER_CALLBACKS_VERSION >= 4
+    if (qemu_egl_display) {
+        virtio_gpu_3d_cbs.version = 4;
+        virtio_gpu_3d_cbs.get_egl_display = virgl_get_egl_display;
+    }
+#endif
+
     ret = virgl_renderer_init(g, 0, &virtio_gpu_3d_cbs);
     if (ret != 0) {
         error_report("virgl could not be initialized: %d", ret);