spice: add opengl/virgl/dmabuf support

This adds support for dma-buf passing to spice.  This makes virtio-gpu
with 3d acceleration work with spice.

Workflow:
 * virglrenderer renders the guest command stream into a texture.
 * qemu exports the texture as dma-buf and passes on that dma-buf
   to spice-server.
 * spice-server passes the dma-buf to spice-client, using unix
   socket file descriptor passing.
 * spice-client asks the window systems composer to render the
   dma-buf to the screen.

Requires cutting edge spice (server) and spice-gtk (client) builds,
from git master branch.

Also requires libvirt managing your qemu instance, and using
"virt-viewer --attach $guest".  libvirt will connect spice-server and
spice-client using unix sockets instead of tcp sockets then, which
is required for file descriptor passing.

Works for the local case (spice server and client on the same machine)
only.  Supporting remote too is planned (by feeding the dma-bufs into
gpu-assisted video encoder), but not there yet.

gl mode is turned off by default, use "-spice gl=on,$otherargs" to
enable it.

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

4 files changed, 140 insertions, 4 deletions

diff --git a/include/ui/spice-display.h b/include/ui/spice-display.h
index b25328a6ba..48dc8c4990 100644
--- a/include/ui/spice-display.h
+++ b/include/ui/spice-display.h
@@ -24,6 +24,14 @@
 #include "ui/console.h"
 #include "sysemu/sysemu.h"
 
+#if defined(CONFIG_OPENGL_DMABUF)
+# if SPICE_SERVER_VERSION >= 0x000d00 /* release 0.13.0 */
+#  define HAVE_SPICE_GL 1
+#  include "ui/egl-helpers.h"
+#  include "ui/egl-context.h"
+# endif
+#endif
+
 #define NUM_MEMSLOTS 8
 #define MEMSLOT_GENERATION_BITS 8
 #define MEMSLOT_SLOT_BITS 8
@@ -50,6 +58,7 @@ enum {
     QXL_COOKIE_TYPE_IO,
     QXL_COOKIE_TYPE_RENDER_UPDATE_AREA,
     QXL_COOKIE_TYPE_POST_LOAD_MONITORS_CONFIG,
+    QXL_COOKIE_TYPE_GL_DRAW_DONE,
 };
 
 typedef struct QXLCookie {
@@ -104,6 +113,12 @@ struct SimpleSpiceDisplay {
     QEMUCursor *cursor;
     int mouse_x, mouse_y;
     QEMUBH *cursor_bh;
+
+#ifdef HAVE_SPICE_GL
+    /* opengl rendering */
+    QEMUBH *gl_unblock_bh;
+    int dmabuf_fd;
+#endif
 };
 
 struct SimpleSpiceUpdate {
diff --git a/qemu-options.hx b/qemu-options.hx
index 2f0465eeb1..f528405810 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1051,6 +1051,7 @@ DEF("spice", HAS_ARG, QEMU_OPTION_spice,
     "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
     "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
     "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
+    "       [,gl=[on|off]]\n"
     "   enable spice\n"
     "   at least one of {port, tls-port} is mandatory\n",
     QEMU_ARCH_ALL)
@@ -1142,6 +1143,9 @@ Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
 @item seamless-migration=[on|off]
 Enable/disable spice seamless migration. Default is off.
 
+@item gl=[on|off]
+Enable/disable OpenGL context. Default is off.
+
 @end table
 ETEXI
 
diff --git a/ui/spice-core.c b/ui/spice-core.c
index 4dbd99ab19..5abec1721a 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -494,9 +494,14 @@ static QemuOptsList qemu_spice_opts = {
         },{
             .name = "playback-compression",
             .type = QEMU_OPT_BOOL,
-        }, {
+        },{
             .name = "seamless-migration",
             .type = QEMU_OPT_BOOL,
+#ifdef HAVE_SPICE_GL
+        },{
+            .name = "gl",
+            .type = QEMU_OPT_BOOL,
+#endif
         },
         { /* end of list */ }
     },
@@ -819,6 +824,14 @@ void qemu_spice_init(void)
 #if SPICE_SERVER_VERSION >= 0x000c02
     qemu_spice_register_ports();
 #endif
+
+#ifdef HAVE_SPICE_GL
+    if (qemu_opt_get_bool(opts, "gl", 0)) {
+        if (egl_rendernode_init() == 0) {
+            display_opengl = 1;
+        }
+    }
+#endif
 }
 
 int qemu_spice_add_interface(SpiceBaseInstance *sin)
diff --git a/ui/spice-display.c b/ui/spice-display.c
index 4e5c8a2d97..904fb33b14 100644
--- a/ui/spice-display.c
+++ b/ui/spice-display.c
@@ -650,9 +650,23 @@ static void interface_update_area_complete(QXLInstance *sin,
 /* called from spice server thread context only */
 static void interface_async_complete(QXLInstance *sin, uint64_t cookie_token)
 {
-    /* should never be called, used in qxl native mode only */
-    fprintf(stderr, "%s: abort()\n", __func__);
-    abort();
+    QXLCookie *cookie = (QXLCookie *)(uintptr_t)cookie_token;
+
+    switch (cookie->type) {
+#ifdef HAVE_SPICE_GL
+    case QXL_COOKIE_TYPE_GL_DRAW_DONE:
+    {
+        SimpleSpiceDisplay *ssd = container_of(sin, SimpleSpiceDisplay, qxl);
+        qemu_bh_schedule(ssd->gl_unblock_bh);
+        break;
+    }
+#endif
+    default:
+        /* should never be called, used in qxl native mode only */
+        fprintf(stderr, "%s: abort()\n", __func__);
+        abort();
+    }
+    g_free(cookie);
 }
 
 static void interface_set_client_capabilities(QXLInstance *sin,
@@ -779,6 +793,89 @@ static const DisplayChangeListenerOps display_listener_ops = {
     .dpy_cursor_define    = display_mouse_define,
 };
 
+#ifdef HAVE_SPICE_GL
+
+static void qemu_spice_gl_block(SimpleSpiceDisplay *ssd, bool block)
+{
+    graphic_hw_gl_block(ssd->dcl.con, block);
+}
+
+static void qemu_spice_gl_unblock_bh(void *opaque)
+{
+    SimpleSpiceDisplay *ssd = opaque;
+
+    qemu_spice_gl_block(ssd, false);
+}
+
+static QEMUGLContext qemu_spice_gl_create_context(DisplayChangeListener *dcl,
+                                                  QEMUGLParams *params)
+{
+    eglMakeCurrent(qemu_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE,
+                   qemu_egl_rn_ctx);
+    return qemu_egl_create_context(dcl, params);
+}
+
+static void qemu_spice_gl_scanout(DisplayChangeListener *dcl,
+                                  uint32_t tex_id,
+                                  bool y_0_top,
+                                  uint32_t x, uint32_t y,
+                                  uint32_t w, uint32_t h)
+{
+    SimpleSpiceDisplay *ssd = container_of(dcl, SimpleSpiceDisplay, dcl);
+    EGLint stride = 0, fourcc = 0;
+    int fd = -1;
+
+    if (tex_id) {
+        fd = egl_get_fd_for_texture(tex_id, &stride, &fourcc);
+        if (fd < 0) {
+            fprintf(stderr, "%s: failed to get fd for texture\n", __func__);
+            return;
+        }
+    }
+    dprint(0, "%s: %dx%d (stride %d, fourcc 0x%x)\n", __func__,
+           w, h, stride, fourcc);
+
+    assert(!tex_id || fd >= 0);
+
+    /* note: spice server will close the fd */
+    spice_qxl_gl_scanout(&ssd->qxl, fd,
+                         surface_width(ssd->ds),
+                         surface_height(ssd->ds),
+                         stride, fourcc, y_0_top);
+}
+
+static void qemu_spice_gl_update(DisplayChangeListener *dcl,
+                                 uint32_t x, uint32_t y, uint32_t w, uint32_t h)
+{
+    SimpleSpiceDisplay *ssd = container_of(dcl, SimpleSpiceDisplay, dcl);
+    uint64_t cookie;
+
+    dprint(1, "%s\n", __func__);
+    qemu_spice_gl_block(ssd, true);
+    cookie = (uintptr_t)qxl_cookie_new(QXL_COOKIE_TYPE_GL_DRAW_DONE, 0);
+    spice_qxl_gl_draw_async(&ssd->qxl, x, y, w, h, cookie);
+}
+
+static const DisplayChangeListenerOps display_listener_gl_ops = {
+    .dpy_name             = "spice-egl",
+    .dpy_gfx_update       = display_update,
+    .dpy_gfx_switch       = display_switch,
+    .dpy_gfx_check_format = qemu_pixman_check_format,
+    .dpy_refresh          = display_refresh,
+    .dpy_mouse_set        = display_mouse_set,
+    .dpy_cursor_define    = display_mouse_define,
+
+    .dpy_gl_ctx_create       = qemu_spice_gl_create_context,
+    .dpy_gl_ctx_destroy      = qemu_egl_destroy_context,
+    .dpy_gl_ctx_make_current = qemu_egl_make_context_current,
+    .dpy_gl_ctx_get_current  = qemu_egl_get_current_context,
+
+    .dpy_gl_scanout          = qemu_spice_gl_scanout,
+    .dpy_gl_update           = qemu_spice_gl_update,
+};
+
+#endif /* HAVE_SPICE_GL */
+
 static void qemu_spice_display_init_one(QemuConsole *con)
 {
     SimpleSpiceDisplay *ssd = g_new0(SimpleSpiceDisplay, 1);
@@ -786,6 +883,13 @@ static void qemu_spice_display_init_one(QemuConsole *con)
     qemu_spice_display_init_common(ssd);
 
     ssd->dcl.ops = &display_listener_ops;
+#ifdef HAVE_SPICE_GL
+    if (display_opengl) {
+        ssd->dcl.ops = &display_listener_gl_ops;
+        ssd->dmabuf_fd = -1;
+        ssd->gl_unblock_bh = qemu_bh_new(qemu_spice_gl_unblock_bh, ssd);
+    }
+#endif
     ssd->dcl.con = con;
 
     ssd->qxl.base.sif = &dpy_interface.base;