Add a caps to advertise fake fp64 support

Signed-off-by: Elie Tournier <elie.tournier@collabora.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/virgl_hw.h

@@ -240,6 +240,7 @@ enum virgl_formats {
 #define VIRGL_CAP_QBO                  (1 << 16)
 #define VIRGL_CAP_TRANSFER             (1 << 17)
 #define VIRGL_CAP_FBO_MIXED_COLOR_FORMATS  (1 << 18)
+#define VIRGL_CAP_FAKE_FP64            (1 << 19)
 
 /* virgl bind flags - these are compatible with mesa 10.5 gallium.
  * but are fixed, no other should be passed to virgl either.

src/vrend_renderer.c

@@ -8632,6 +8632,10 @@ static void vrend_renderer_fill_caps_v2(int gl_ver, int gles_ver,  union virgl_c
 
    if (vrend_check_fremabuffer_mixed_color_attachements())
       caps->v2.capability_bits |= VIRGL_CAP_FBO_MIXED_COLOR_FORMATS;
+
+   /* We want to expose ARB_gpu_shader_fp64 when running on top of ES */
+   if (vrend_state.use_gles)
+      caps->v2.capability_bits |= VIRGL_CAP_FAKE_FP64;
 }
 
 void vrend_renderer_fill_caps(uint32_t set, UNUSED uint32_t version,