ui: add an optional get_flags callback to GraphicHwOps

Those flags can be used to express different requirements for the
display or other needs.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210204105232.834642-12-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/display/virtio-gpu-base.c

@@ -114,7 +114,25 @@ virtio_gpu_gl_block(void *opaque, bool block)
     }
 }
 
+static int
+virtio_gpu_get_flags(void *opaque)
+{
+    VirtIOGPUBase *g = opaque;
+    int flags = GRAPHIC_FLAGS_NONE;
+
+    if (virtio_gpu_virgl_enabled(g->conf)) {
+        flags |= GRAPHIC_FLAGS_GL;
+    }
+
+    if (virtio_gpu_dmabuf_enabled(g->conf)) {
+        flags |= GRAPHIC_FLAGS_DMABUF;
+    }
+
+    return flags;
+}
+
 static const GraphicHwOps virtio_gpu_ops = {
+    .get_flags = virtio_gpu_get_flags,
     .invalidate = virtio_gpu_invalidate_display,
     .gfx_update = virtio_gpu_update_display,
     .text_update = virtio_gpu_text_update,

hw/display/virtio-vga.c

@@ -68,7 +68,16 @@ static void virtio_vga_base_gl_block(void *opaque, bool block)
     }
 }
 
+static int virtio_vga_base_get_flags(void *opaque)
+{
+    VirtIOVGABase *vvga = opaque;
+    VirtIOGPUBase *g = vvga->vgpu;
+
+    return g->hw_ops->get_flags(g);
+}
+
 static const GraphicHwOps virtio_vga_base_ops = {
+    .get_flags = virtio_vga_base_get_flags,
     .invalidate = virtio_vga_base_invalidate_display,
     .gfx_update = virtio_vga_base_update_display,
     .text_update = virtio_vga_base_text_update,

hw/vfio/display.c

@@ -335,7 +335,13 @@ static void vfio_display_dmabuf_update(void *opaque)
     }
 }
 
+static int vfio_display_get_flags(void *opaque)
+{
+    return GRAPHIC_FLAGS_GL | GRAPHIC_FLAGS_DMABUF;
+}
+
 static const GraphicHwOps vfio_display_dmabuf_ops = {
+    .get_flags  = vfio_display_get_flags,
     .gfx_update = vfio_display_dmabuf_update,
     .ui_info    = vfio_display_edid_ui_info,
 };

include/ui/console.h

@@ -368,7 +368,16 @@ static inline void console_write_ch(console_ch_t *dest, uint32_t ch)
     *dest = ch;
 }
 
+enum {
+    GRAPHIC_FLAGS_NONE     = 0,
+    /* require a console/display with GL callbacks */
+    GRAPHIC_FLAGS_GL       = 1 << 0,
+    /* require a console/display with DMABUF import */
+    GRAPHIC_FLAGS_DMABUF   = 1 << 1,
+};
+
 typedef struct GraphicHwOps {
+    int (*get_flags)(void *opaque); /* optional, default 0 */
     void (*invalidate)(void *opaque);
     void (*gfx_update)(void *opaque);
     bool gfx_update_async; /* if true, calls graphic_hw_update_done() */