egl: Allow software rendering for vgem/virtio_gpu in platform_device
Then user could explicitly choose the underlying device for software
rendering when both vgem/virtio_vga are there.
Signed-off-by: Lepton Wu <lepton@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5830>
diff --git a/src/egl/drivers/dri2/platform_device.c b/src/egl/drivers/dri2/platform_device.c
index 3aac62f..7c12b47 100644
--- a/src/egl/drivers/dri2/platform_device.c
+++ b/src/egl/drivers/dri2/platform_device.c
@@ -41,6 +41,7 @@
#include "egl_dri2.h"
#include "loader.h"
+#include "util/debug.h"
static __DRIimage*
device_alloc_image(struct dri2_egl_display *dri2_dpy,
@@ -252,8 +253,9 @@
device_probe_device(_EGLDisplay *disp)
{
struct dri2_egl_display *dri2_dpy = disp->DriverData;
+ bool request_software = env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
- if (disp->Options.ForceSoftware)
+ if (request_software)
_eglLog(_EGL_WARNING, "Not allowed to force software rendering when "
"API explicitly selects a hardware device.");
dri2_dpy->fd = device_get_fd(disp, disp->Device);
@@ -264,6 +266,18 @@
if (!dri2_dpy->driver_name)
goto err_name;
+ /* When doing software rendering, some times user still want to explicitly
+ * choose the render node device since cross node import doesn't work between
+ * vgem/virtio_gpu yet. It would be nice to have a new EXTENSION for this.
+ * For now, just fallback to kms_swrast. */
+ if (disp->Options.ForceSoftware && !request_software &&
+ (strcmp(dri2_dpy->driver_name, "vgem") == 0 ||
+ strcmp(dri2_dpy->driver_name, "virtio_gpu") == 0)) {
+ free(dri2_dpy->driver_name);
+ _eglLog(_EGL_WARNING, "NEEDS EXTENSION: falling back to kms_swrast");
+ dri2_dpy->driver_name = strdup("kms_swrast");
+ }
+
if (!dri2_load_driver_dri3(disp))
goto err_load;