qemu: add -display dbus support

By default, libvirt will start a private bus and tell QEMU to connect to it. Instead, a D-Bus "address" to connect to can be specified, or the p2p mode enabled. D-Bus display works best with GL & a rendernode, which can be specified with <gl> child element. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2024-12-23 21:34:54 +03:00 · 2022-05-13 20:38:13 +02:00 · 2022-05-13 20:38:13 +02:00 · bde66322e8
commit bde66322e8
parent 5c1e203a80
7 changed files with 174 additions and 4 deletions
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@ -8556,6 +8556,36 @@ qemuBuildGraphicsEGLHeadlessCommandLine(virQEMUDriverConfig *cfg G_GNUC_UNUSED,
 }


+static int
+qemuBuildGraphicsDBusCommandLine(virCommand *cmd,
+                                 virDomainGraphicsDef *graphics)
+{
+    g_auto(virBuffer) opt = VIR_BUFFER_INITIALIZER;
+
+    virBufferAddLit(&opt, "dbus");
+
+    if (graphics->data.dbus.p2p) {
+        virBufferAddLit(&opt, ",p2p=on");
+    } else {
+        virBufferAddLit(&opt, ",addr=");
+        virQEMUBuildBufferEscapeComma(&opt, graphics->data.dbus.address);
+    }
+    if (graphics->data.dbus.gl != VIR_TRISTATE_BOOL_ABSENT)
+        virBufferAsprintf(&opt, ",gl=%s",
+                          virTristateSwitchTypeToString(graphics->data.dbus.gl));
+    if (graphics->data.dbus.rendernode) {
+        virBufferAddLit(&opt, ",rendernode=");
+        virQEMUBuildBufferEscapeComma(&opt,
+                                      graphics->data.dbus.rendernode);
+    }
+
+    virCommandAddArg(cmd, "-display");
+    virCommandAddArgBuffer(cmd, &opt);
+
+    return 0;
+}
+
+
 static int
 qemuBuildGraphicsCommandLine(virQEMUDriverConfig *cfg,
                             virCommand *cmd,
@ -8591,7 +8621,11 @@ qemuBuildGraphicsCommandLine(virQEMUDriverConfig *cfg,
                                                        graphics) < 0)
                return -1;

+            break;
        case VIR_DOMAIN_GRAPHICS_TYPE_DBUS:
+            if (qemuBuildGraphicsDBusCommandLine(cmd, graphics) < 0)
+                return -1;
+
            break;
        case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
        case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
@ -10147,6 +10181,7 @@ qemuBuildCommandLineValidate(virQEMUDriver *driver,
    int vnc = 0;
    int spice = 0;
    int egl_headless = 0;
+    int dbus = 0;

    if (!driver->privileged) {
        /* If we have no cgroups then we can have no tunings that
@ -10192,6 +10227,8 @@ qemuBuildCommandLineValidate(virQEMUDriver *driver,
            ++egl_headless;
            break;
        case VIR_DOMAIN_GRAPHICS_TYPE_DBUS:
+            ++dbus;
+            break;
        case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
        case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
        case VIR_DOMAIN_GRAPHICS_TYPE_LAST:
@ -10199,10 +10236,10 @@ qemuBuildCommandLineValidate(virQEMUDriver *driver,
        }
    }

-    if (sdl > 1 || vnc > 1 || spice > 1 || egl_headless > 1) {
+    if (sdl > 1 || vnc > 1 || spice > 1 || egl_headless > 1 || dbus > 1) {
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                       _("only 1 graphics device of each type "
-                         "(sdl, vnc, spice, headless) is supported"));
+                         "(sdl, vnc, spice, headless, dbus) is supported"));
        return -1;
    }

--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@ -15718,6 +15718,8 @@ qemuDomainOpenGraphics(virDomainPtr dom,
        protocol = "spice";
        break;
    case VIR_DOMAIN_GRAPHICS_TYPE_DBUS:
+        protocol = "@dbus-display";
+        break;
    case VIR_DOMAIN_GRAPHICS_TYPE_SDL:
    case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
    case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
@ -15787,6 +15789,8 @@ qemuDomainOpenGraphicsFD(virDomainPtr dom,
        protocol = "spice";
        break;
    case VIR_DOMAIN_GRAPHICS_TYPE_DBUS:
+        protocol = "@dbus-display";
+        break;
    case VIR_DOMAIN_GRAPHICS_TYPE_SDL:
    case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
    case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@ -4906,6 +4906,22 @@ qemuProcessGraphicsSetupNetworkAddress(virDomainGraphicsListenDef *glisten,
 }


+static int
+qemuProcessGraphicsSetupDBus(virQEMUDriver *driver,
+                             virDomainGraphicsDef *graphics,
+                             virDomainObj *vm)
+{
+    if (graphics->type != VIR_DOMAIN_GRAPHICS_TYPE_DBUS)
+        return 0;
+
+    if (!graphics->data.dbus.p2p && !graphics->data.dbus.address) {
+        graphics->data.dbus.address = qemuDBusGetAddress(driver, vm);
+    }
+
+    return 0;
+}
+
+
 static int
 qemuProcessGraphicsSetupListen(virQEMUDriver *driver,
                               virDomainGraphicsDef *graphics,
@ -4997,16 +5013,29 @@ qemuProcessGraphicsSetupRenderNode(virDomainGraphicsDef *graphics,
        return 0;

    /* Don't bother picking a DRM node if QEMU doesn't support it. */
-    if (graphics->type == VIR_DOMAIN_GRAPHICS_TYPE_SPICE) {
+    switch (graphics->type) {
+    case VIR_DOMAIN_GRAPHICS_TYPE_SPICE:
        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_SPICE_RENDERNODE))
            return 0;

        rendernode = &graphics->data.spice.rendernode;
-    } else {
+        break;
+    case VIR_DOMAIN_GRAPHICS_TYPE_EGL_HEADLESS:
        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_EGL_HEADLESS_RENDERNODE))
            return 0;

        rendernode = &graphics->data.egl_headless.rendernode;
+        break;
+    case VIR_DOMAIN_GRAPHICS_TYPE_DBUS:
+        rendernode = &graphics->data.dbus.rendernode;
+        break;
+    case VIR_DOMAIN_GRAPHICS_TYPE_SDL:
+    case VIR_DOMAIN_GRAPHICS_TYPE_VNC:
+    case VIR_DOMAIN_GRAPHICS_TYPE_RDP:
+    case VIR_DOMAIN_GRAPHICS_TYPE_DESKTOP:
+    case VIR_DOMAIN_GRAPHICS_TYPE_LAST:
+        virReportEnumRangeError(virDomainGraphicsType, graphics->type);
+        break;
    }

    if (!(*rendernode = virHostGetDRMRenderNode()))
@ -5034,6 +5063,9 @@ qemuProcessSetupGraphics(virQEMUDriver *driver,

        if (qemuProcessGraphicsSetupListen(driver, graphics, vm) < 0)
            return -1;
+
+        if (qemuProcessGraphicsSetupDBus(driver, graphics, vm) < 0)
+            return -1;
    }

    if (allocate) {
--- a/tests/qemuxml2argvdata/graphics-dbus-address.args
+++ b/tests/qemuxml2argvdata/graphics-dbus-address.args
@ -0,0 +1,30 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-i386 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
+-machine pc,usb=off,dump-guest-core=off \
+-accel tcg \
+-m 214 \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-usb \
+-display dbus,addr=unix:path=/tmp/foo,gl=on,rendernode=/dev/dri/foo \
+-device cirrus-vga,id=video0,bus=pci.0,addr=0x2 \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/graphics-dbus-p2p.args
+++ b/tests/qemuxml2argvdata/graphics-dbus-p2p.args
@ -0,0 +1,30 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-i386 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
+-machine pc,usb=off,dump-guest-core=off \
+-accel tcg \
+-m 214 \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-usb \
+-display dbus,p2p=on \
+-device cirrus-vga,id=video0,bus=pci.0,addr=0x2 \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/graphics-dbus.args
+++ b/tests/qemuxml2argvdata/graphics-dbus.args
@ -0,0 +1,30 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-i386 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
+-machine pc,usb=off,dump-guest-core=off \
+-accel tcg \
+-m 214 \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-usb \
+-display dbus,addr=unix:path=/bad-test-used-env-xdg-runtime-dir/libvirt/qemu/run/dbus/-1-QEMUGuest1-dbus.sock \
+-device cirrus-vga,id=video0,bus=pci.0,addr=0x2 \
+-msg timestamp=on
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@ -1531,6 +1531,13 @@ mymain(void)
    DO_TEST_CAPS_LATEST_PARSE_ERROR("graphics-spice-invalid-egl-headless");
    DO_TEST_CAPS_LATEST("graphics-spice-gl-auto-rendernode");

+    DO_TEST("graphics-dbus",
+            QEMU_CAPS_DEVICE_CIRRUS_VGA, QEMU_CAPS_DISPLAY_DBUS);
+    DO_TEST("graphics-dbus-address",
+            QEMU_CAPS_DEVICE_CIRRUS_VGA, QEMU_CAPS_DISPLAY_DBUS);
+    DO_TEST("graphics-dbus-p2p",
+            QEMU_CAPS_DEVICE_CIRRUS_VGA, QEMU_CAPS_DISPLAY_DBUS);
+
    DO_TEST_NOCAPS("input-usbmouse");
    DO_TEST_NOCAPS("input-usbtablet");
    DO_TEST_NOCAPS("misc-acpi");