[PATCH 2/3] qemu: Generate cmd line for pipewire audio backend

Michal Privoznik mprivozn at redhat.com
Thu May 11 12:14:51 UTC 2023 

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.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_command.c                       | 61 +++++++++++++++++++
 .../audio-many-backends.x86_64-latest.args    |  2 +
 .../qemuxml2argvdata/audio-many-backends.xml  |  1 +
 .../audio-pipewire-best.x86_64-latest.args    | 36 +++++++++++
 .../audio-pipewire-full.x86_64-latest.args    | 36 +++++++++++
 .../audio-pipewire-minimal.x86_64-latest.args | 36 +++++++++++
 tests/qemuxml2argvtest.c                      | 12 ++++
 7 files changed, 184 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/audio-pipewire-best.x86_64-latest.args
 create mode 100644 tests/qemuxml2argvdata/audio-pipewire-full.x86_64-latest.args
 create mode 100644 tests/qemuxml2argvdata/audio-pipewire-minimal.x86_64-latest.args

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3a08cac870..b31f4db6b1 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -7783,6 +7783,60 @@ 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 *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), we can add just the first existing one
+     * (basically mimic get_runtime_dir() logic).
+     */
+
+    virCommandAddEnvPass(cmd, "PIPEWIRE_CORE");
+    virCommandAddEnvPass(cmd, "PIPEWIRE_REMOTE");
+
+    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)
@@ -7889,6 +7943,13 @@ 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);
+        break;
+
     case VIR_DOMAIN_AUDIO_TYPE_LAST:
     default:
         virReportEnumRangeError(virDomainAudioType, def->type);
diff --git a/tests/qemuxml2argvdata/audio-many-backends.x86_64-latest.args b/tests/qemuxml2argvdata/audio-many-backends.x86_64-latest.args
index 9caf591daf..13dd55054e 100644
--- 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 \
+XDG_RUNTIME_DIR=/bad-test-used-env-xdg-runtime-dir \
 /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"}' \
diff --git a/tests/qemuxml2argvdata/audio-many-backends.xml b/tests/qemuxml2argvdata/audio-many-backends.xml
index c681784526..1659723f91 100644
--- 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'/>
diff --git a/tests/qemuxml2argvdata/audio-pipewire-best.x86_64-latest.args b/tests/qemuxml2argvdata/audio-pipewire-best.x86_64-latest.args
new file mode 100644
index 0000000000..2e8635c1b0
--- /dev/null
+++ 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 214 \
+-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
diff --git a/tests/qemuxml2argvdata/audio-pipewire-full.x86_64-latest.args b/tests/qemuxml2argvdata/audio-pipewire-full.x86_64-latest.args
new file mode 100644
index 0000000000..caed694823
--- /dev/null
+++ 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 214 \
+-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","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
diff --git a/tests/qemuxml2argvdata/audio-pipewire-minimal.x86_64-latest.args b/tests/qemuxml2argvdata/audio-pipewire-minimal.x86_64-latest.args
new file mode 100644
index 0000000000..2e76997d58
--- /dev/null
+++ 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 214 \
+-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
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 3100078b54..f29597a19f 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -926,6 +926,9 @@ 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_NOCAPS("minimal");
     DO_TEST_PARSE_ERROR_NOCAPS("minimal-no-memory");
@@ -967,6 +970,9 @@ 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");
@@ -976,6 +982,9 @@ mymain(void)
     DO_TEST_CAPS_LATEST("audio-coreaudio-best");
     DO_TEST_CAPS_LATEST("audio-oss-best");
     DO_TEST_CAPS_LATEST("audio-pulseaudio-best");
+    g_setenv("PIPEWIRE_RUNTIME_DIR", "/run/user/1000", TRUE);
+    DO_TEST_CAPS_LATEST("audio-pipewire-best");
+    g_unsetenv("PIPEWIRE_RUNTIME_DIR");
     DO_TEST_CAPS_LATEST("audio-sdl-best");
     DO_TEST_CAPS_LATEST("audio-spice-best");
     DO_TEST_CAPS_LATEST("audio-file-best");
@@ -986,6 +995,9 @@ mymain(void)
     DO_TEST_CAPS_LATEST("audio-jack-full");
     DO_TEST_CAPS_LATEST("audio-oss-full");
     DO_TEST_CAPS_LATEST("audio-pulseaudio-full");
+    g_setenv("PIPEWIRE_RUNTIME_DIR", "/run/user/1000", TRUE);
+    DO_TEST_CAPS_LATEST("audio-pipewire-full");
+    g_unsetenv("PIPEWIRE_RUNTIME_DIR");
     DO_TEST_CAPS_LATEST("audio-sdl-full");
     DO_TEST_CAPS_LATEST("audio-spice-full");
     DO_TEST_CAPS_LATEST("audio-file-full");
-- 
2.39.3

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