Re: [PATCH 2/3] 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. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- 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 \