vrend: send max_combined_shader_buffers to guest

This is usedful to accurately communicate the amount of SSBOs supported
to the guest-driver, so we can expose the right amount there.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/virgl_hw.h

@@ -351,6 +351,7 @@ struct virgl_caps_v2 {
         uint32_t max_texture_2d_size;
         uint32_t max_texture_3d_size;
         uint32_t max_texture_cube_size;
+        uint32_t max_combined_shader_buffers;
 };
 
 union virgl_caps {

src/vrend_renderer.c

@@ -8140,6 +8140,8 @@ static void vrend_renderer_fill_caps_v2(int gl_ver, int gles_ver,  union virgl_c
       if (max > PIPE_MAX_SHADER_BUFFERS)
          max = PIPE_MAX_SHADER_BUFFERS;
       caps->v2.max_shader_buffer_frag_compute = max;
+      glGetIntegerv(GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS,
+                    (GLint*)&caps->v2.max_combined_shader_buffers);
    }
 
    if (has_feature(feat_images)) {