qemu: Generate cmd line for pipewire audio backend

This is mostly straightforward, except for a teensy-weensy detail: usually, there's no system wide daemon running, no system wide available socket that anybody could connect to. PipeWire uses a per user daemon approach instead. But this in turn means, that the socket location floats between various locations and is derived from various environment variables (just like the actual socket name) and thus we must pass the variables to QEMU. Resolves: https://gitlab.com/libvirt/libvirt/-/issues/560 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
2025-03-20 07:59:00 +00:00 · 2023-05-10 12:58:44 +02:00 · 2023-05-10 12:58:44 +02:00 · 10594bb311
commit 10594bb311
parent c472ce024b
8 changed files with 191 additions and 0 deletions
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@ -7833,6 +7833,68 @@ qemuBuildAudioSDLProps(virDomainAudioIOSDL *def,
 }


+static int
+qemuBuildAudioPipewireAudioProps(virDomainAudioIOPipewireAudio *def,
+                                 virJSONValue **props)
+{
+    return virJSONValueObjectAdd(props,
+                                 "S:name", def->name,
+                                 "S:stream-name", def->streamName,
+                                 "p:latency", def->latency,
+                                 NULL);
+}
+
+
+static void
+qemuBuildAudioPipewireAudioEnv(virCommand *cmd,
+                               const char *runtimeDir)
+{
+    const char *envVars[] = { "PIPEWIRE_RUNTIME_DIR", "XDG_RUNTIME_DIR",
+                              "USERPROFILE" };
+    size_t i;
+
+    /* PipeWire needs access to its daemon socket. The socket name is
+     * configurable (core.name in pipewire.conf, or PIPEWIRE_CORE and
+     * PIPEWIRE_REMOTE env vars). If the socket name is not an absolute
+     * path, then the socket is looked for in the following directories
+     * (in order):
+     *
+     * - PIPEWIRE_RUNTIME_DIR
+     * - XDG_RUNTIME_DIR
+     * - USERPROFILE
+     *
+     * This order is defined in get_runtime_dir() from
+     * src/modules/module-protocol-native/local-socket.c from PipeWire's
+     * codebase.
+     *
+     * Now, PIPEWIRE_CORE and/or PIPEWIRE_REMOTE should be passed
+     * whenever present in the environment. But for the other three
+     * (socket location dirs):
+     *
+     * 1) set it to user defined value (@runtimeDir != NULL), or
+     * 2) we can add just the first existing one (basically mimic
+     *    get_runtime_dir() logic; @runtimeDir == NULL).
+     */
+
+    virCommandAddEnvPass(cmd, "PIPEWIRE_CORE");
+    virCommandAddEnvPass(cmd, "PIPEWIRE_REMOTE");
+
+    if (runtimeDir) {
+        virCommandAddEnvPair(cmd, "PIPEWIRE_RUNTIME_DIR", runtimeDir);
+    } else {
+        for (i = 0; i < G_N_ELEMENTS(envVars); i++) {
+            const char *value = getenv(envVars[i]);
+
+            if (!value)
+                continue;
+
+            virCommandAddEnvPair(cmd, envVars[i], value);
+            break;
+        }
+    }
+}
+
+
 static int
 qemuBuildAudioCommandLineArg(virCommand *cmd,
                             virDomainAudioDef *def)
@ -7939,6 +8001,13 @@ qemuBuildAudioCommandLineArg(virCommand *cmd,
        break;

    case VIR_DOMAIN_AUDIO_TYPE_PIPEWIRE:
+        if (qemuBuildAudioPipewireAudioProps(&def->backend.pipewire.input, &in) < 0 ||
+            qemuBuildAudioPipewireAudioProps(&def->backend.pipewire.output, &out) < 0)
+            return -1;
+
+        qemuBuildAudioPipewireAudioEnv(cmd, def->backend.pipewire.runtimeDir);
+        break;
+
    case VIR_DOMAIN_AUDIO_TYPE_LAST:
    default:
        virReportEnumRangeError(virDomainAudioType, def->type);
--- a/tests/qemuxml2argvdata/audio-many-backends.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/audio-many-backends.x86_64-latest.args
@ -6,6 +6,7 @@ LOGNAME=test \
 XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
 XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
 XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+PIPEWIRE_RUNTIME_DIR=/run/user/1000 \
 /usr/bin/qemu-system-x86_64 \
 -name guest=QEMUGuest1,debug-threads=on \
 -S \
@ -32,6 +33,7 @@ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
 -audiodev '{"id":"audio1","driver":"none"}' \
 -audiodev '{"id":"audio2","driver":"alsa"}' \
 -audiodev '{"id":"audio3","driver":"pa"}' \
+-audiodev '{"id":"audio4","driver":"pipewire"}' \
 -vnc 127.0.0.1:0,audiodev=audio2 \
 -device '{"driver":"cirrus-vga","id":"video0","bus":"pci.0","addr":"0x2"}' \
 -device '{"driver":"AC97","id":"sound0","audiodev":"audio1","bus":"pci.0","addr":"0x3"}' \
--- a/tests/qemuxml2argvdata/audio-many-backends.xml
+++ b/tests/qemuxml2argvdata/audio-many-backends.xml
@ -51,6 +51,7 @@
    <audio id='1' type='none'/>
    <audio id='2' type='alsa'/>
    <audio id='3' type='pulseaudio'/>
+    <audio id='4' type='pipewire'/>
    <video>
      <model type='cirrus' vram='16384' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
--- a/tests/qemuxml2argvdata/audio-pipewire-best.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/audio-pipewire-best.x86_64-latest.args
@ -0,0 +1,36 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+PIPEWIRE_RUNTIME_DIR=/run/user/1000 \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-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 \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"host_cdrom","filename":"/dev/cdrom","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":true,"driver":"raw","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-cd","bus":"ide.1","unit":0,"drive":"libvirt-1-format","id":"ide0-1-0","bootindex":1}' \
+-audiodev '{"id":"audio1","driver":"pipewire","timer-period":50,"in":{"mixing-engine":true,"fixed-settings":true,"voices":1,"buffer-length":200,"frequency":44100,"channels":2,"format":"s16","name":"fish"},"out":{"mixing-engine":true,"fixed-settings":true,"voices":2,"buffer-length":200,"frequency":22050,"channels":4,"format":"f32","name":"fish"}}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/audio-pipewire-full.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/audio-pipewire-full.x86_64-latest.args
@ -0,0 +1,36 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+PIPEWIRE_RUNTIME_DIR=/run/user/1000 \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-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 \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"host_cdrom","filename":"/dev/cdrom","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":true,"driver":"raw","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-cd","bus":"ide.1","unit":0,"drive":"libvirt-1-format","id":"ide0-1-0","bootindex":1}' \
+-audiodev '{"id":"audio1","driver":"pipewire","timer-period":50,"in":{"mixing-engine":true,"fixed-settings":true,"voices":1,"buffer-length":100,"frequency":44100,"channels":2,"format":"s16","name":"fish","stream-name":"food","latency":100},"out":{"mixing-engine":true,"fixed-settings":true,"voices":2,"buffer-length":200,"frequency":22050,"channels":4,"format":"f32","name":"fish","stream-name":"food","latency":200}}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/audio-pipewire-minimal.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/audio-pipewire-minimal.x86_64-latest.args
@ -0,0 +1,36 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+PIPEWIRE_RUNTIME_DIR=/run/user/1000 \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-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 \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"host_cdrom","filename":"/dev/cdrom","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":true,"driver":"raw","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-cd","bus":"ide.1","unit":0,"drive":"libvirt-1-format","id":"ide0-1-0","bootindex":1}' \
+-audiodev '{"id":"audio1","driver":"pipewire"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@ -869,6 +869,9 @@ mymain(void)
    g_unsetenv("DYLD_FORCE_FLAT_NAMESPACE");
    g_unsetenv("QEMU_AUDIO_DRV");
    g_unsetenv("SDL_AUDIODRIVER");
+    g_unsetenv("PIPEWIRE_CORE");
+    g_unsetenv("PIPEWIRE_REMOTE");
+    g_unsetenv("PIPEWIRE_RUNTIME_DIR");

    DO_TEST_CAPS_LATEST("minimal");
    DO_TEST_CAPS_LATEST_PARSE_ERROR("minimal-no-memory");
@ -909,6 +912,9 @@ mymain(void)
    DO_TEST_CAPS_LATEST("audio-jack-minimal");
    DO_TEST_CAPS_LATEST("audio-oss-minimal");
    DO_TEST_CAPS_LATEST("audio-pulseaudio-minimal");
+    g_setenv("PIPEWIRE_RUNTIME_DIR", "/run/user/1000", TRUE);
+    DO_TEST_CAPS_LATEST("audio-pipewire-minimal");
+    g_unsetenv("PIPEWIRE_RUNTIME_DIR");
    DO_TEST_CAPS_LATEST("audio-sdl-minimal");
    DO_TEST_CAPS_LATEST("audio-spice-minimal");
    DO_TEST_CAPS_LATEST("audio-file-minimal");
@ -918,6 +924,7 @@ mymain(void)
    DO_TEST_CAPS_LATEST("audio-coreaudio-best");
    DO_TEST_CAPS_LATEST("audio-oss-best");
    DO_TEST_CAPS_LATEST("audio-pulseaudio-best");
+    DO_TEST_CAPS_LATEST("audio-pipewire-best");
    DO_TEST_CAPS_LATEST("audio-sdl-best");
    DO_TEST_CAPS_LATEST("audio-spice-best");
    DO_TEST_CAPS_LATEST("audio-file-best");
@ -928,11 +935,14 @@ mymain(void)
    DO_TEST_CAPS_LATEST("audio-jack-full");
    DO_TEST_CAPS_LATEST("audio-oss-full");
    DO_TEST_CAPS_LATEST("audio-pulseaudio-full");
+    DO_TEST_CAPS_LATEST("audio-pipewire-full");
    DO_TEST_CAPS_LATEST("audio-sdl-full");
    DO_TEST_CAPS_LATEST("audio-spice-full");
    DO_TEST_CAPS_LATEST("audio-file-full");

+    g_setenv("PIPEWIRE_RUNTIME_DIR", "/run/user/1000", TRUE);
    DO_TEST_CAPS_LATEST("audio-many-backends");
+    g_unsetenv("PIPEWIRE_RUNTIME_DIR");

    /* Validate auto-creation of <audio> for legacy compat */
    g_setenv("QEMU_AUDIO_DRV", "sdl", TRUE);
--- a/tests/qemuxml2xmloutdata/audio-many-backends.x86_64-latest.xml
+++ b/tests/qemuxml2xmloutdata/audio-many-backends.x86_64-latest.xml
@ -51,6 +51,7 @@
    <audio id='1' type='none'/>
    <audio id='2' type='alsa'/>
    <audio id='3' type='pulseaudio'/>
+    <audio id='4' type='pipewire'/>
    <video>
      <model type='cirrus' vram='16384' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>