ui: Create sync objects and fences only for blobs

Create sync objects and fences only for dmabufs that are blobs. Once a
fence is created (after glFlush) and is signalled,
graphic_hw_gl_flushed() will be called and virtio-gpu cmd processing
will be resumed.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Message-Id: <20210914211837.3229977-4-vivek.kasireddy@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/display/virtio-gpu-udmabuf.c

@@ -185,6 +185,7 @@ static VGPUDMABuf
     dmabuf->buf.stride = fb->stride;
     dmabuf->buf.fourcc = qemu_pixman_to_drm_format(fb->format);
     dmabuf->buf.fd = res->dmabuf_fd;
+    dmabuf->buf.allow_fences = true;
 
     dmabuf->scanout_id = scanout_id;
     QTAILQ_INSERT_HEAD(&g->dmabuf.bufs, dmabuf, next);

include/ui/console.h

@@ -170,6 +170,7 @@ typedef struct QemuDmaBuf {
     bool      y0_top;
     void      *sync;
     int       fence_fd;
+    bool      allow_fences;
 } QemuDmaBuf;
 
 typedef struct DisplayState DisplayState;

include/ui/egl-helpers.h

@@ -19,6 +19,7 @@ typedef struct egl_fb {
     GLuint texture;
     GLuint framebuffer;
     bool delete_texture;
+    QemuDmaBuf *dmabuf;
 } egl_fb;
 
 void egl_fb_destroy(egl_fb *fb);

include/ui/gtk.h

@@ -155,6 +155,7 @@ extern bool gtk_use_gl_area;
 /* ui/gtk.c */
 void gd_update_windowsize(VirtualConsole *vc);
 int gd_monitor_update_interval(GtkWidget *widget);
+void gd_hw_gl_flushed(void *vc);
 
 /* ui/gtk-egl.c */
 void gd_egl_init(VirtualConsole *vc);

ui/gtk-egl.c

@@ -12,6 +12,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/main-loop.h"
 
 #include "trace.h"
 
@@ -94,6 +95,18 @@ void gd_egl_draw(VirtualConsole *vc)
     }
 
     glFlush();
+#ifdef CONFIG_GBM
+    if (vc->gfx.guest_fb.dmabuf) {
+        QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
+
+        egl_dmabuf_create_fence(dmabuf);
+        if (dmabuf->fence_fd > 0) {
+            qemu_set_fd_handler(dmabuf->fence_fd, gd_hw_gl_flushed, NULL, vc);
+            return;
+        }
+        graphic_hw_gl_block(vc->gfx.dcl.con, false);
+    }
+#endif
     graphic_hw_gl_flushed(vc->gfx.dcl.con);
 }
 
@@ -209,6 +222,8 @@ void gd_egl_scanout_dmabuf(DisplayChangeListener *dcl,
                            QemuDmaBuf *dmabuf)
 {
 #ifdef CONFIG_GBM
+    VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
+
     egl_dmabuf_import_texture(dmabuf);
     if (!dmabuf->texture) {
         return;
@@ -217,6 +232,10 @@ void gd_egl_scanout_dmabuf(DisplayChangeListener *dcl,
     gd_egl_scanout_texture(dcl, dmabuf->texture,
                            false, dmabuf->width, dmabuf->height,
                            0, 0, dmabuf->width, dmabuf->height);
+
+    if (dmabuf->allow_fences) {
+        vc->gfx.guest_fb.dmabuf = dmabuf;
+    }
 #endif
 }
 
@@ -281,6 +300,12 @@ void gd_egl_scanout_flush(DisplayChangeListener *dcl,
         egl_fb_blit(&vc->gfx.win_fb, &vc->gfx.guest_fb, !vc->gfx.y0_top);
     }
 
+#ifdef CONFIG_GBM
+    if (vc->gfx.guest_fb.dmabuf) {
+        egl_dmabuf_create_sync(vc->gfx.guest_fb.dmabuf);
+    }
+#endif
+
     eglSwapBuffers(qemu_egl_display, vc->gfx.esurface);
 }
 

ui/gtk-gl-area.c

@@ -8,6 +8,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/main-loop.h"
 
 #include "trace.h"
 
@@ -71,7 +72,25 @@ void gd_gl_area_draw(VirtualConsole *vc)
         surface_gl_render_texture(vc->gfx.gls, vc->gfx.ds);
     }
 
+#ifdef CONFIG_GBM
+    if (vc->gfx.guest_fb.dmabuf) {
+        egl_dmabuf_create_sync(vc->gfx.guest_fb.dmabuf);
+    }
+#endif
+
     glFlush();
+#ifdef CONFIG_GBM
+    if (vc->gfx.guest_fb.dmabuf) {
+        QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
+
+        egl_dmabuf_create_fence(dmabuf);
+        if (dmabuf->fence_fd > 0) {
+            qemu_set_fd_handler(dmabuf->fence_fd, gd_hw_gl_flushed, NULL, vc);
+            return;
+        }
+        graphic_hw_gl_block(vc->gfx.dcl.con, false);
+    }
+#endif
     graphic_hw_gl_flushed(vc->gfx.dcl.con);
 }
 
@@ -213,6 +232,9 @@ void gd_gl_area_scanout_flush(DisplayChangeListener *dcl,
 {
     VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
 
+    if (vc->gfx.guest_fb.dmabuf) {
+        graphic_hw_gl_block(vc->gfx.dcl.con, true);
+    }
     gtk_gl_area_queue_render(GTK_GL_AREA(vc->gfx.drawing_area));
 }
 
@@ -231,6 +253,10 @@ void gd_gl_area_scanout_dmabuf(DisplayChangeListener *dcl,
     gd_gl_area_scanout_texture(dcl, dmabuf->texture,
                                false, dmabuf->width, dmabuf->height,
                                0, 0, dmabuf->width, dmabuf->height);
+
+    if (dmabuf->allow_fences) {
+        vc->gfx.guest_fb.dmabuf = dmabuf;
+    }
 #endif
 }
 

ui/gtk.c

@@ -36,6 +36,7 @@
 #include "qapi/qapi-commands-machine.h"
 #include "qapi/qapi-commands-misc.h"
 #include "qemu/cutils.h"
+#include "qemu/main-loop.h"
 
 #include "ui/console.h"
 #include "ui/gtk.h"
@@ -583,6 +584,18 @@ static void gd_gl_release_dmabuf(DisplayChangeListener *dcl,
 #endif
 }
 
+void gd_hw_gl_flushed(void *vcon)
+{
+    VirtualConsole *vc = vcon;
+    QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
+
+    graphic_hw_gl_block(vc->gfx.dcl.con, false);
+    graphic_hw_gl_flushed(vc->gfx.dcl.con);
+    qemu_set_fd_handler(dmabuf->fence_fd, NULL, NULL, NULL);
+    close(dmabuf->fence_fd);
+    dmabuf->fence_fd = -1;
+}
+
 /** DisplayState Callbacks (opengl version) **/
 
 static const DisplayChangeListenerOps dcl_gl_area_ops = {