From 10aaad0edc7ff827f91583cd537b6f11b77e6e79 Mon Sep 17 00:00:00 2001
From: Qiang Yu <yuq825@gmail.com>
Date: Thu, 27 Mar 2025 10:58:47 +0800
Subject: [PATCH] ui/dbus: change dbus ScanoutDMABUF interface
MIME-Version: 1.0
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To handle multi plane.

v3:
  * rename interface
  * add x/y/backing_width/backing_height arg

v2:
  * use new dmabuf API and check length

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Message-ID: <20250327025848.46962-6-yuq825@gmail.com>
[ Fix style ]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 ui/dbus-display1.xml |  45 +++++++++++++++++
 ui/dbus-listener.c   | 114 ++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 152 insertions(+), 7 deletions(-)

diff --git a/ui/dbus-display1.xml b/ui/dbus-display1.xml
index 72deefa455..4a41a7e0f3 100644
--- a/ui/dbus-display1.xml
+++ b/ui/dbus-display1.xml
@@ -614,6 +614,51 @@
     </method>
   </interface>
 
+  <!--
+      org.qemu.Display1.Listener.Unix.ScanoutDMABUF2:
+
+      This optional client-side interface can complement
+      org.qemu.Display1.Listener on ``/org/qemu/Display1/Listener`` for
+      Unix-specific DMABUF scanout setup which support multi plane.
+  -->
+  <?if $(env.HOST_OS) != windows?>
+  <interface name="org.qemu.Display1.Listener.Unix.ScanoutDMABUF2">
+    <!--
+        ScanoutDMABUF2:
+        @dmabuf: DMABUF file descriptor of each plane.
+        @x: display x offset, in pixels
+        @y: display y offset, in pixels
+        @width: display width, in pixels.
+        @height: display height, in pixels.
+        @offset: offset of each plane, in bytes.
+        @stride: stride of each plane, in bytes.
+        @num_planes: plane number.
+        @fourcc: DMABUF fourcc.
+        @backing_width: backing framebuffer width, in pixels
+        @backing_height: backing framebuffer height, in pixels
+        @modifier: DMABUF modifier.
+        @y0_top: whether Y position 0 is the top or not.
+
+        Resize and update the display content with DMABUF.
+    -->
+    <method name="ScanoutDMABUF2">
+      <arg type="ah" name="dmabuf" direction="in"/>
+      <arg type="u" name="x" direction="in"/>
+      <arg type="u" name="y" direction="in"/>
+      <arg type="u" name="width" direction="in"/>
+      <arg type="u" name="height" direction="in"/>
+      <arg type="au" name="offset" direction="in"/>
+      <arg type="au" name="stride" direction="in"/>
+      <arg type="u" name="num_planes" direction="in"/>
+      <arg type="u" name="fourcc" direction="in"/>
+      <arg type="u" name="backing_width" direction="in"/>
+      <arg type="u" name="backing_height" direction="in"/>
+      <arg type="t" name="modifier" direction="in"/>
+      <arg type="b" name="y0_top" direction="in"/>
+    </method>
+  </interface>
+  <?endif?>
+
   <!--
       org.qemu.Display1.Clipboard:
 
diff --git a/ui/dbus-listener.c b/ui/dbus-listener.c
index 90147972cd..42875b8eed 100644
--- a/ui/dbus-listener.c
+++ b/ui/dbus-listener.c
@@ -85,6 +85,7 @@ struct _DBusDisplayListener {
 #endif
 #else /* !WIN32 */
     QemuDBusDisplay1ListenerUnixMap *map_proxy;
+    QemuDBusDisplay1ListenerUnixScanoutDMABUF2 *scanout_dmabuf_v2_proxy;
 #endif
 
     guint dbus_filter;
@@ -288,10 +289,9 @@ static void dbus_call_update_gl(DisplayChangeListener *dcl,
 }
 
 #ifdef CONFIG_GBM
-static void dbus_scanout_dmabuf(DisplayChangeListener *dcl,
-                                QemuDmaBuf *dmabuf)
+static void dbus_scanout_dmabuf_v1(DBusDisplayListener *ddl,
+                                   QemuDmaBuf *dmabuf)
 {
-    DBusDisplayListener *ddl = container_of(dcl, DBusDisplayListener, dcl);
     g_autoptr(GError) err = NULL;
     g_autoptr(GUnixFDList) fd_list = NULL;
     int fd;
@@ -322,6 +322,87 @@ static void dbus_scanout_dmabuf(DisplayChangeListener *dcl,
         y0_top, G_DBUS_CALL_FLAGS_NONE,
         -1, fd_list, NULL, NULL, NULL);
 }
+
+static void dbus_scanout_dmabuf_v2(DBusDisplayListener *ddl,
+                                   QemuDmaBuf *dmabuf)
+{
+    g_autoptr(GError) err = NULL;
+    g_autoptr(GUnixFDList) fd_list = NULL;
+    int i, fd_index[DMABUF_MAX_PLANES], num_fds;
+    uint32_t x, y, width, height, fourcc, backing_width, backing_height;
+    GVariant *fd, *offset, *stride, *fd_handles[DMABUF_MAX_PLANES];
+    uint64_t modifier;
+    bool y0_top;
+    int nfds, noffsets, nstrides;
+    const int *fds = qemu_dmabuf_get_fds(dmabuf, &nfds);
+    const uint32_t *offsets = qemu_dmabuf_get_offsets(dmabuf, &noffsets);
+    const uint32_t *strides = qemu_dmabuf_get_strides(dmabuf, &nstrides);
+    uint32_t num_planes = qemu_dmabuf_get_num_planes(dmabuf);
+
+    assert(nfds >= num_planes);
+    assert(noffsets >= num_planes);
+    assert(nstrides >= num_planes);
+
+    fd_list = g_unix_fd_list_new();
+
+    for (num_fds = 0; num_fds < num_planes; num_fds++) {
+        int plane_fd = fds[num_fds];
+
+        if (plane_fd < 0) {
+            break;
+        }
+
+        fd_index[num_fds] = g_unix_fd_list_append(fd_list, plane_fd, &err);
+        if (fd_index[num_fds] < 0) {
+            error_report("Failed to setup dmabuf fdlist: %s", err->message);
+            return;
+        }
+    }
+
+    ddl_discard_display_messages(ddl);
+
+    x = qemu_dmabuf_get_x(dmabuf);
+    y = qemu_dmabuf_get_y(dmabuf);
+    width = qemu_dmabuf_get_width(dmabuf);
+    height = qemu_dmabuf_get_height(dmabuf);
+    fourcc = qemu_dmabuf_get_fourcc(dmabuf);
+    backing_width = qemu_dmabuf_get_backing_width(dmabuf);
+    backing_height = qemu_dmabuf_get_backing_height(dmabuf);
+    modifier = qemu_dmabuf_get_modifier(dmabuf);
+    y0_top = qemu_dmabuf_get_y0_top(dmabuf);
+
+    offset = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
+                                       offsets, num_planes, sizeof(uint32_t));
+    stride = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
+                                       strides, num_planes, sizeof(uint32_t));
+
+    for (i = 0; i < num_fds; i++) {
+        fd_handles[i] = g_variant_new_handle(fd_index[i]);
+    }
+    fd = g_variant_new_array(G_VARIANT_TYPE_HANDLE, fd_handles, num_fds);
+
+    qemu_dbus_display1_listener_unix_scanout_dmabuf2_call_scanout_dmabuf2(
+        ddl->scanout_dmabuf_v2_proxy, fd, x, y, width, height, offset, stride,
+        num_planes, fourcc, backing_width, backing_height, modifier, y0_top,
+        G_DBUS_CALL_FLAGS_NONE, -1, fd_list, NULL, NULL, NULL);
+}
+
+static void dbus_scanout_dmabuf(DisplayChangeListener *dcl,
+                                QemuDmaBuf *dmabuf)
+{
+    DBusDisplayListener *ddl = container_of(dcl, DBusDisplayListener, dcl);
+
+    if (ddl->scanout_dmabuf_v2_proxy) {
+        dbus_scanout_dmabuf_v2(ddl, dmabuf);
+    } else {
+        if (qemu_dmabuf_get_num_planes(dmabuf) > 1) {
+            g_debug("org.qemu.Display1.Listener.ScanoutDMABUF "
+                    "does not support mutli plane");
+            return;
+        }
+        dbus_scanout_dmabuf_v1(ddl, dmabuf);
+    }
+}
 #endif /* GBM */
 #endif /* OPENGL */
 
@@ -514,10 +595,6 @@ static void dbus_scanout_texture(DisplayChangeListener *dcl,
         error_report("%s: failed to export dmabuf for texture", __func__);
         return;
     }
-    if (num_planes > 1) {
-        error_report("%s: does not support multi-plane dmabuf", __func__);
-        return;
-    }
     dmabuf = qemu_dmabuf_new(w, h, offset, stride, x, y, backing_width,
                              backing_height, fourcc, modifier, fd, num_planes,
                              false, backing_y_0_top);
@@ -886,6 +963,8 @@ dbus_display_listener_dispose(GObject *object)
 #ifdef CONFIG_OPENGL
     egl_fb_destroy(&ddl->fb);
 #endif
+#else /* !WIN32 */
+    g_clear_object(&ddl->scanout_dmabuf_v2_proxy);
 #endif
 
     G_OBJECT_CLASS(dbus_display_listener_parent_class)->dispose(object);
@@ -1074,6 +1153,26 @@ dbus_display_listener_setup_shared_map(DBusDisplayListener *ddl)
 #endif
 }
 
+static void dbus_display_listener_setup_scanout_dmabuf_v2(DBusDisplayListener *ddl)
+{
+#ifndef WIN32
+    g_autoptr(GError) err = NULL;
+
+    if (!dbus_display_listener_implements(
+            ddl, "org.qemu.Display1.Listener.Unix.ScanoutDMABUF2")) {
+        return;
+    }
+    ddl->scanout_dmabuf_v2_proxy =
+        qemu_dbus_display1_listener_unix_scanout_dmabuf2_proxy_new_sync(
+            ddl->conn, G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START, NULL,
+            "/org/qemu/Display1/Listener", NULL, &err);
+    if (!ddl->scanout_dmabuf_v2_proxy) {
+        g_debug("Failed to setup Unix scanout dmabuf v2 proxy: %s", err->message);
+        return;
+    }
+#endif
+}
+
 static GDBusMessage *
 dbus_filter(GDBusConnection *connection,
             GDBusMessage    *message,
@@ -1162,6 +1261,7 @@ dbus_display_listener_new(const char *bus_name,
     dbus_display_listener_setup_shared_map(ddl);
     trace_dbus_can_share_map(ddl->can_share_map);
     dbus_display_listener_setup_d3d11(ddl);
+    dbus_display_listener_setup_scanout_dmabuf_v2(ddl);
 
     con = qemu_console_lookup_by_index(dbus_display_console_get_index(console));
     assert(con);
-- 
2.39.5