[PATCH v6 5/5] img/app: Run PipeWire and WirePlumber in the VMs

[Demi Marie Obenour <demiobenour@gmail.com>]

WirePlumber is completely overkill as a session manager here, and
ideally a trivial session manager would be used instead.  PipeWire is
configured to listen on the PulseAudio socket, so PulseAudio
compatibility works.  pw-record and pw-play both work, and if PulseAudio
is installed paplay and parecord also work.  This does install a lot of
unnecessary files into the VMs, which will hopefully be removed
later as part of a debloating effort.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
 img/app/Makefile                              |  18 +-
 img/app/default.nix                           |   3 +
 img/app/etc/mdev.conf                         |   1 +
 img/app/etc/pipewire/pipewire.conf            | 199 ++++++++++++++++++
 .../etc/s6-rc/app/dependencies.d/wireplumber  |   0
 .../etc/s6-rc/pipewire/dependencies.d/dbus    |   0
 img/app/etc/s6-rc/pipewire/notification-fd    |   1 +
 .../s6-rc/pipewire/notification-fd.license    |   2 +
 img/app/etc/s6-rc/pipewire/run                |  23 ++
 img/app/etc/s6-rc/pipewire/type               |   1 +
 img/app/etc/s6-rc/pipewire/type.license       |   2 +
 .../etc/s6-rc/wireplumber/dependencies.d/dbus |   0
 .../s6-rc/wireplumber/dependencies.d/pipewire |   0
 img/app/etc/s6-rc/wireplumber/run             |   4 +
 img/app/etc/s6-rc/wireplumber/type            |   1 +
 img/app/etc/s6-rc/wireplumber/type.license    |   2 +
 .../wireplumber.conf.d/99_spectrum.conf       |  39 ++++
 17 files changed, 293 insertions(+), 3 deletions(-)
 create mode 100644 img/app/etc/pipewire/pipewire.conf
 create mode 100644 img/app/etc/s6-rc/app/dependencies.d/wireplumber
 create mode 100644 img/app/etc/s6-rc/pipewire/dependencies.d/dbus
 create mode 100644 img/app/etc/s6-rc/pipewire/notification-fd
 create mode 100644 img/app/etc/s6-rc/pipewire/notification-fd.license
 create mode 100644 img/app/etc/s6-rc/pipewire/run
 create mode 100644 img/app/etc/s6-rc/pipewire/type
 create mode 100644 img/app/etc/s6-rc/pipewire/type.license
 create mode 100644 img/app/etc/s6-rc/wireplumber/dependencies.d/dbus
 create mode 100644 img/app/etc/s6-rc/wireplumber/dependencies.d/pipewire
 create mode 100644 img/app/etc/s6-rc/wireplumber/run
 create mode 100644 img/app/etc/s6-rc/wireplumber/type
 create mode 100644 img/app/etc/s6-rc/wireplumber/type.license
 create mode 100644 img/app/etc/wireplumber/wireplumber.conf.d/99_spectrum.conf

diff --git a/img/app/Makefile b/img/app/Makefile
index 4b4d64f81d99a01eebe777f3737fef813ebb6d3f..69bc9afc0756b0628ddc1fe53913a75b45b3213b 100644
--- a/img/app/Makefile
+++ b/img/app/Makefile
@@ -53,7 +53,10 @@ VM_FILES = \
 	etc/s6-linux-init/scripts/rc.init \
 	etc/s6-linux-init/scripts/rc.shutdown \
 	etc/s6-linux-init/scripts/rc.shutdown.final \
-	etc/xdg/xdg-desktop-portal/portals.conf
+	etc/xdg/xdg-desktop-portal/portals.conf \
+	etc/pipewire/pipewire.conf \
+	etc/wireplumber/wireplumber.conf.d/99_spectrum.conf
+
 VM_DIRS = dev run proc sys tmp \
 	etc/s6-linux-init/run-image/service \
 	etc/s6-linux-init/run-image/user \
@@ -85,6 +88,7 @@ build/rootfs.erofs: ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(VM_FILES) $(V
 VM_S6_RC_FILES = \
 	etc/s6-rc/app/dependencies.d/dbus \
 	etc/s6-rc/app/dependencies.d/wayland-proxy-virtwl \
+	etc/s6-rc/app/dependencies.d/wireplumber \
 	etc/s6-rc/app/run \
 	etc/s6-rc/app/type \
 	etc/s6-rc/dbus/notification-fd \
@@ -98,9 +102,16 @@ VM_S6_RC_FILES = \
 	etc/s6-rc/mdevd/type \
 	etc/s6-rc/ok-all/contents \
 	etc/s6-rc/ok-all/type \
+	etc/s6-rc/pipewire/notification-fd \
+	etc/s6-rc/pipewire/run \
+	etc/s6-rc/pipewire/type \
 	etc/s6-rc/wayland-proxy-virtwl/notification-fd \
 	etc/s6-rc/wayland-proxy-virtwl/run \
-	etc/s6-rc/wayland-proxy-virtwl/type
+	etc/s6-rc/wayland-proxy-virtwl/type \
+	etc/s6-rc/wireplumber/dependencies.d/dbus \
+	etc/s6-rc/wireplumber/dependencies.d/pipewire \
+	etc/s6-rc/wireplumber/run \
+	etc/s6-rc/wireplumber/type
 
 build/etc/s6-rc: $(VM_S6_RC_FILES)
 	mkdir -p $$(dirname $@)
@@ -137,7 +148,7 @@ start-virtiofsd: scripts/start-virtiofsd.elb
 .PHONY: start-virtiofsd
 
 run-qemu: $(imgdir)/appvm/blk/root.img start-vhost-user-net start-virtiofsd
-	@../../scripts/run-qemu.sh -m 256 -cpu host -kernel $(KERNEL) -vga none \
+	@../../scripts/run-qemu.sh -m 256 -kernel $(KERNEL) -vga none \
 	    -drive file=$(imgdir)/appvm/blk/root.img,if=virtio,format=raw,readonly=on \
 	    -append "root=PARTLABEL=root nokaslr" \
 	    -gdb unix:build/gdb.sock,server,nowait \
@@ -147,6 +158,7 @@ run-qemu: $(imgdir)/appvm/blk/root.img start-vhost-user-net start-virtiofsd
 	    -chardev socket,id=virtiofsd,path=build/virtiofsd.sock \
 	    -device vhost-user-fs-pci,chardev=virtiofsd,tag=virtiofs0 \
 	    -device virtio-gpu-rutabaga-pci,cross-domain=on,hostmem=8G \
+	    -audio driver=pipewire,model=virtio \
 	    -object memory-backend-memfd,id=mem,size=256M,share=on \
 	    -numa node,memdev=mem \
 	    -device vhost-vsock-pci,guest-cid=3 \
diff --git a/img/app/default.nix b/img/app/default.nix
index 740643ac41f6473cdb6f6b0fd1f5f47f4493240d..d3eed1f0accdc8968d1ba5bdec74ab597789082f 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -48,6 +48,9 @@ let
       pkgs.xwayland
       pkgs.xdg-desktop-portal
       pkgs.xdg-desktop-portal-gtk
+      # Depends on pulseaudio libs
+      pkgs.pipewire
+      pkgs.wireplumber
     ];
   })).fhsenv;
 in
diff --git a/img/app/etc/mdev.conf b/img/app/etc/mdev.conf
index f2101e1f683c49808358b25520080c59ed2afa8e..0e4a1a088522c05da9e0ce15fe135c40d6cf3064 100644
--- a/img/app/etc/mdev.conf
+++ b/img/app/etc/mdev.conf
@@ -5,3 +5,4 @@
 $INTERFACE=.* 0:0 660 ! +/etc/mdev/iface
 $MODALIAS=virtio:d0000001Av.* 0:0 660 ! +/etc/mdev/virtiofs
 dri/card0 0:0 660 +background { /etc/mdev/listen card0 }
+snd/controlC0 0:0 660 +background { /etc/mdev/listen controlC0 }
diff --git a/img/app/etc/pipewire/pipewire.conf b/img/app/etc/pipewire/pipewire.conf
new file mode 100644
index 0000000000000000000000000000000000000000..e5a413a409f46e7fe176102bbd6780db14f85dba
--- /dev/null
+++ b/img/app/etc/pipewire/pipewire.conf
@@ -0,0 +1,199 @@
+# SPDX-License-Identifier: MIT
+
+# Copyright © 2018 Wim Taymans
+# Copyright © 2025 Demi Marie Obenour
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+
+# This file is based on the upstream default configuration.  This can be
+# found in upstream GitLab or in any distro with a recent version of PipeWire.
+# The following changes have been made:
+#
+# - Conditions that have known values in Spectrum VMs are omitted.
+# - Modules for hardware devices Spectrum VMs don't have are not loaded.
+# - The PulseAudio emulation server is loaded.
+# - Settings for VMs are applied unconditionally.
+# - Most comments in the upstream files have been removed.
+# - Device nodes for virtio-sound devices have been added.
+# - Integration with udev and logind is removed.
+context.properties = {
+    # Upstream defaults.
+    link.max-buffers = 16
+    core.daemon = true
+    core.name   = pipewire-0
+    # Account for running in a VM
+    default.clock.min-quantum = 1024
+}
+
+# Upstream defaults, with support for AVB, V4L2, libcamera
+# bluez, Vulkan, JACK, and video conversion omitted.
+context.spa-libs = {
+    audio.convert.* = audioconvert/libspa-audioconvert
+    api.alsa.*      = alsa/libspa-alsa
+    support.*       = support/libspa-support
+}
+
+context.modules = [
+    # Upstream defaults
+    { name = libpipewire-module-rt
+        args = { nice.level = -11, rt.prio = 88 }
+    }
+    { name = libpipewire-module-protocol-native  }
+    { name = libpipewire-module-metadata }
+    { name = libpipewire-module-spa-device-factory }
+    { name = libpipewire-module-spa-node-factory }
+    { name = libpipewire-module-client-node }
+    { name = libpipewire-module-access }
+    { name = libpipewire-module-client-device }
+    { name = libpipewire-module-portal }
+    { name = libpipewire-module-adapter }
+    { name = libpipewire-module-link-factory }
+    { name = libpipewire-module-session-manager }
+
+    # Load the PulseAudio server into PipeWire.
+    # This avoids needing a separate pipewire-pulse
+    # process.  The args are those used when running
+    # in a VM.
+    { name = libpipewire-module-protocol-pulse
+        args = {
+            server.address = [ "unix:native" ]
+            pulse.min.quantum = 1024/48000
+        }
+    }
+]
+
+context.objects = [
+    # Upstream defaults
+    { factory = spa-node-factory
+        args = {
+            factory.name    = support.node.driver
+            node.name       = Dummy-Driver
+            node.group      = pipewire.dummy
+            node.sync-group = sync.dummy
+            priority.driver = 200000
+        }
+    }
+    { factory = spa-node-factory
+        args = {
+            factory.name    = support.node.driver
+            node.name       = Freewheel-Driver
+            priority.driver = 190000
+            node.group      = pipewire.freewheel
+            node.sync-group = sync.dummy
+            node.freewheel  = true
+        }
+    }
+
+    # Spectrum doesn't use udev, so device nodes must be created statically.
+    # Creating them with pw-cli works as long as pw-cli is running, but
+    # the nodes are destroyed when pw-cli exits.
+    { factory = adapter
+        args = {
+            alsa.card              = 0,
+            alsa.card_name         = "VirtIO SoundCard"
+            alsa.device            = 0
+            alsa.driver_name       = "virtio_snd"
+            alsa.id                = "SoundCard"
+            alsa.long_card_name    = "VirtIO SoundCard at pci/0000:00:01.0/virtio0"
+            alsa.name              = "VirtIO SoundCard"
+            alsa.subdevice         = 0
+            alsa.subdevice_name    = "subdevice #0"
+            api.alsa.card.longname = "VirtIO SoundCard at pci/0000:00:01.0/virtio0"
+            api.alsa.card.name     = "VirtIO SoundCard"
+            api.alsa.headroom      = 0
+            api.alsa.path          = "hw:0,0,0"
+            api.alsa.pcm.card      = 0,
+            api.alsa.pcm.stream    = "playback"
+            audio.allowed-rates    = [ ]
+            audio.channels         = 2
+            audio.format           = "S32"
+            audio.position         = "FL,FR"
+            audio.rate             = 48000
+            factory.name           = "api.alsa.pcm.sink"
+            media.class            = "Audio/Sink"
+            node.name              = "alsa_output.pci-0000_00_01.0.analog-stereo"
+            node.suspend-on-idle   = true
+        }
+    }
+    { factory = adapter
+        args = {
+            alsa.card              = 0,
+            alsa.card_name         = "VirtIO SoundCard"
+            alsa.device            = 0
+            alsa.driver_name       = "virtio_snd"
+            alsa.id                = "SoundCard"
+            alsa.long_card_name    = "VirtIO SoundCard at pci/0000:00:01.0/virtio0"
+            alsa.name              = "VirtIO SoundCard"
+            alsa.subdevice         = 0
+            alsa.subdevice_name    = "subdevice #0"
+            api.alsa.card.longname = "VirtIO SoundCard at pci/0000:00:01.0/virtio0"
+            api.alsa.card.name     = "VirtIO SoundCard"
+            api.alsa.headroom      = 0
+            api.alsa.path          = "hw:0,0,0"
+            api.alsa.pcm.card      = 0,
+            api.alsa.pcm.stream    = "capture"
+            audio.allowed-rates    = [ ]
+            audio.channels         = 2
+            audio.format           = "S32"
+            audio.position         = "FL,FR"
+            audio.rate             = 48000
+            factory.name           = "api.alsa.pcm.source"
+            media.class            = "Audio/Source"
+            node.name              = "alsa_input.pci-0000_00_01.0.analog-stereo"
+            node.suspend-on-idle   = true
+        }
+    }
+]
+
+# Load the modules that are in the default config *except*
+# for ones whose job is to maintain state.
+pulse.cmd = [
+    { cmd = "load-module" args = "module-always-sink" flags = [ ] }
+    { cmd = "load-module" args = "module-device-manager" flags = [ ] }
+]
+
+# More default stuff.
+pulse.rules = [
+    {
+        matches = [
+             { application.process.binary = "teams" }
+             { application.process.binary = "teams-insiders" }
+             { application.process.binary = "teams-for-linux" }
+             { application.process.binary = "skypeforlinux" }
+        ]
+        actions = { quirks = [ force-s16-info ] }
+    }
+    {
+        matches = [ { application.process.binary = "firefox" } ]
+        actions = { quirks = [ remove-capture-dont-move ] }
+    }
+    {
+        matches = [ { application.name = "~speech-dispatcher.*" } ]
+        actions = {
+            update-props = {
+                pulse.min.req          = 512/48000
+                pulse.min.quantum      = 512/48000
+                pulse.idle.timeout     = 5
+            }
+        }
+    }
+]
+
+context.exec = []
diff --git a/img/app/etc/s6-rc/app/dependencies.d/wireplumber b/img/app/etc/s6-rc/app/dependencies.d/wireplumber
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/img/app/etc/s6-rc/pipewire/dependencies.d/dbus b/img/app/etc/s6-rc/pipewire/dependencies.d/dbus
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/img/app/etc/s6-rc/pipewire/notification-fd b/img/app/etc/s6-rc/pipewire/notification-fd
new file mode 100644
index 0000000000000000000000000000000000000000..7ed6ff82de6bcc2a78243fc9c54d3ef5ac14da69
--- /dev/null
+++ b/img/app/etc/s6-rc/pipewire/notification-fd
@@ -0,0 +1 @@
+5
diff --git a/img/app/etc/s6-rc/pipewire/notification-fd.license b/img/app/etc/s6-rc/pipewire/notification-fd.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/img/app/etc/s6-rc/pipewire/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/img/app/etc/s6-rc/pipewire/run b/img/app/etc/s6-rc/pipewire/run
new file mode 100644
index 0000000000000000000000000000000000000000..c5cf090fb4779e0f3ede1782ada5c95ce5b25702
--- /dev/null
+++ b/img/app/etc/s6-rc/pipewire/run
@@ -0,0 +1,23 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2023-2024 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+s6-ipcserver-socketbinder -B /run/user/0/pipewire-0
+fdmove -c 3 0
+
+s6-ipcserver-socketbinder -B /run/user/0/pipewire-0-manager
+fdmove -c 4 0
+
+redirfd -r 0 /dev/null
+
+# Wait for sound devices to be available
+if { /etc/mdev/wait controlC0 }
+
+# Notify readiness.
+if { fdmove 1 5 echo }
+fdclose 5
+
+export LISTEN_FDS 2
+getpid LISTEN_PID
+pipewire
diff --git a/img/app/etc/s6-rc/pipewire/type b/img/app/etc/s6-rc/pipewire/type
new file mode 100644
index 0000000000000000000000000000000000000000..5883cff0cd1514b2836f4ffa39fdac769a5213cb
--- /dev/null
+++ b/img/app/etc/s6-rc/pipewire/type
@@ -0,0 +1 @@
+longrun
diff --git a/img/app/etc/s6-rc/pipewire/type.license b/img/app/etc/s6-rc/pipewire/type.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/img/app/etc/s6-rc/pipewire/type.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/img/app/etc/s6-rc/wireplumber/dependencies.d/dbus b/img/app/etc/s6-rc/wireplumber/dependencies.d/dbus
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/img/app/etc/s6-rc/wireplumber/dependencies.d/pipewire b/img/app/etc/s6-rc/wireplumber/dependencies.d/pipewire
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/img/app/etc/s6-rc/wireplumber/run b/img/app/etc/s6-rc/wireplumber/run
new file mode 100644
index 0000000000000000000000000000000000000000..d58f1971c7387c896256a91ad0c92386a02fd9e2
--- /dev/null
+++ b/img/app/etc/s6-rc/wireplumber/run
@@ -0,0 +1,4 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+wireplumber --profile spectrum
diff --git a/img/app/etc/s6-rc/wireplumber/type b/img/app/etc/s6-rc/wireplumber/type
new file mode 100644
index 0000000000000000000000000000000000000000..5883cff0cd1514b2836f4ffa39fdac769a5213cb
--- /dev/null
+++ b/img/app/etc/s6-rc/wireplumber/type
@@ -0,0 +1 @@
+longrun
diff --git a/img/app/etc/s6-rc/wireplumber/type.license b/img/app/etc/s6-rc/wireplumber/type.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/img/app/etc/s6-rc/wireplumber/type.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/img/app/etc/wireplumber/wireplumber.conf.d/99_spectrum.conf b/img/app/etc/wireplumber/wireplumber.conf.d/99_spectrum.conf
new file mode 100644
index 0000000000000000000000000000000000000000..ff2f464395aaf7c8f0a739b0f01552c4ee987740
--- /dev/null
+++ b/img/app/etc/wireplumber/wireplumber.conf.d/99_spectrum.conf
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: MIT
+
+# Copyright © 2019-2021 Collabora Ltd.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+
+# Disable various stuff Spectrum doesn't need and which causes errors.
+wireplumber.profiles = {
+  spectrum = {
+    inherits = [ main-embedded ]
+    hardware.video-capture = disabled
+    hardware.bluetooth = disabled
+    support.settings = disabled
+    check.no-media-session = disabled
+    policy.standard = required
+  }
+}
+
+# Default to 100% sink volume.  The host will adjust this as needed.
+wireplumber.settings = {
+  device.routes.default-sink-volume = 1.0
+}
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)