virglrenderer: open rendernode even for EGL_MESA_platform_surfaceless

It is possible to open rendernodes when using EGL_MESA_platform_surfaceless.

v2: fail if user-provided fd fails (@davidriley)

Reviewed-by: David Riley <davidriley@chromium.org>
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/virgl_egl.h

@@ -26,8 +26,9 @@
 
 #include "vrend_renderer.h"
 struct virgl_egl;
+struct virgl_gbm;
 
-struct virgl_egl *virgl_egl_init(int fd, bool surfaceless, bool gles);
+struct virgl_egl *virgl_egl_init(struct virgl_gbm *gbm, bool surfaceless, bool gles);
 
 void virgl_egl_destroy(struct virgl_egl *egl);
 

src/virgl_egl_context.c

@@ -82,7 +82,7 @@ static bool virgl_egl_has_extension_in_string(const char *haystack, const char *
    return false;
 }
 
-struct virgl_egl *virgl_egl_init(int fd, bool surfaceless, bool gles)
+struct virgl_egl *virgl_egl_init(struct virgl_gbm *gbm, bool surfaceless, bool gles)
 {
    static EGLint conf_att[] = {
       EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
@@ -110,28 +110,12 @@ struct virgl_egl *virgl_egl_init(int fd, bool surfaceless, bool gles)
    if (gles)
       conf_att[3] = EGL_OPENGL_ES2_BIT;
 
-   /*
+   if (surfaceless)
-    * The surfaceless flag (specified with VIRGL_RENDERER_USE_SURFACELESS)
-    * takes precedence and will attempt to get a display of type
-    * EGL_PLATFORM_SURFACELESS_MESA.
-    * If surfaceless is not specified, an fd supplied with the get_drm_fd
-    * is used to open a GBM device.
-    * If not provided, /dev/dri rendernodes are scanned and used to open
-    * a GBM device.
-    * If none of the above results in a valid display, a fallback will be
-    * done to use the default display, as long as an fd hasn't been explicitly
-    * provided.
-    */
-
-   if (surfaceless) {
       conf_att[1] = EGL_PBUFFER_BIT;
-      egl->gbm = NULL;
+   else if (!gbm)
-   } else {
-      egl->gbm = virgl_gbm_init(fd);
-      if (!egl->gbm)
       goto fail;
-   }
 
+   egl->gbm = gbm;
    const char *client_extensions = eglQueryString (NULL, EGL_EXTENSIONS);
 
    if (strstr (client_extensions, "EGL_KHR_platform_base")) {
@@ -169,14 +153,9 @@ struct virgl_egl *virgl_egl_init(int fd, bool surfaceless, bool gles)
        * Don't fallback to the default display if the fd provided by (*get_drm_fd)
        * can't be used.
        */
-      if (fd >= 0)
+      if (egl->gbm && egl->gbm->fd < 0)
          goto fail;
 
-      if (egl->gbm) {
-         virgl_gbm_fini(egl->gbm);
-         egl->gbm = NULL;
-      }
-
       egl->egl_display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
       if (!egl->egl_display)
          goto fail;
@@ -246,9 +225,6 @@ struct virgl_egl *virgl_egl_init(int fd, bool surfaceless, bool gles)
    return egl;
 
  fail:
-   if (egl->gbm)
-      virgl_gbm_fini(egl->gbm);
-
    free(egl);
    return NULL;
 }
@@ -259,8 +235,6 @@ void virgl_egl_destroy(struct virgl_egl *egl)
                   EGL_NO_CONTEXT);
    eglDestroyContext(egl->egl_display, egl->egl_ctx);
    eglTerminate(egl->egl_display);
-   if (egl->gbm)
-      virgl_gbm_fini(egl->gbm);
    free(egl);
 }
 

src/virglrenderer.c

@@ -39,8 +39,10 @@
 #include "virglrenderer.h"
 
 #ifdef HAVE_EPOXY_EGL_H
+#include "virgl_gbm.h"
 #include "virgl_egl.h"
-static struct virgl_egl *egl;
+static struct virgl_gbm *gbm = NULL;
+static struct virgl_egl *egl = NULL;
 #endif
 
 #ifdef HAVE_EPOXY_GLX_H
@@ -312,6 +314,10 @@ void virgl_renderer_cleanup(UNUSED void *cookie)
       virgl_egl_destroy(egl);
       egl = NULL;
       use_context = CONTEXT_NONE;
+      if (gbm) {
+         virgl_gbm_fini(gbm);
+         gbm = NULL;
+      }
    }
 #endif
 #ifdef HAVE_EPOXY_GLX_H
@@ -341,10 +347,26 @@ int virgl_renderer_init(void *cookie, int flags, struct virgl_renderer_callbacks
       if (cbs->version >= 2 && cbs->get_drm_fd) {
          fd = cbs->get_drm_fd(cookie);
       }
-      egl = virgl_egl_init(fd, flags & VIRGL_RENDERER_USE_SURFACELESS,
+
+      /*
+       * If the user specifies a preferred DRM fd and we can't use it, fail. If the user doesn't
+       * specify an fd, it's possible to initialize EGL without one.
+       */
+      gbm = virgl_gbm_init(fd);
+      if (fd > 0 && !gbm)
+         return -1;
+
+      egl = virgl_egl_init(gbm, flags & VIRGL_RENDERER_USE_SURFACELESS,
                            flags & VIRGL_RENDERER_USE_GLES);
-      if (!egl)
+      if (!egl) {
+         if (gbm) {
+            virgl_gbm_fini(gbm);
+            gbm = NULL;
+         }
+
          return -1;
+      }
+
       use_context = CONTEXT_EGL;
 #else
       vrend_printf( "EGL is not supported on this platform\n");