[PATCH v9 0/2] Sound support in Spectrum VMs

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

Patch 1 creates directories that PipeWire, WirePlumber, and applications
need early in boot to avoid ordering problems.  Patch 2 adds working
(and tested) support for audio in the VM via PipeWire.  This only works
when running in a VM, as Spectrum OS has no sound on the host yet.
---
Changes since v8:
- Add longer explanation for the priority.driver and priority.session
  values.
- Give credit to George Kiagiadakis.
- Fix spelling errors in comments.

Changes since v7:
- Give the capture node a higher priority.session than the playback
  node, so WirePlumber links recording applications to the capture node
  instead of the monitor of the playback node.
- Give the capture node a higher priority.driver than the playback node,
  so PipeWire has the capture node drive the graph.  This is better
  because capture xruns lead to permanently corrupted data, whereas
  playback xruns do not.
- Re-enable monitor node creation in WirePlumber.

Changes since v6:
- Add missing S-o-b to directory creation patch.
- Add comments explaining why each directory needs to be created.
- Fix spelling errors in commit messages.
- Sort lines in Makefile.
- Don't disable support.settings as a comment in wireplumber.conf says
  to not do that.  Instead, tell WirePlumber to not create monitor
  nodes.  This is a workaround for WirePlumber bug 829.
- Don't remove "-cpu host" from make run-qemu's QEMU command line.  This
  was needed for local testing with KVM disabled but should not have
  been submitted upstream.  Hardware with KVM support should be used
  instead.

Changes since v5:

- Move changes to startup scripts into a single patch.
- Remove "directories" service in favor of creating the directories from
  rc.init.
- Use VM_DIRS to create /run/user and /run/wait.
- Create /run/user and /run/wait on the host as well, using the same
  mechanism as for the VM (though with a different variable name in the
  makefile).
- Use a drop-in configuration file for WirePlumber instead of overriding
  wireplumber.conf.  This should be more robust to future WirePlumber
  changes.

Demi Marie Obenour (2):
  img/app: Create needed directories in early boot
  img/app: Run PipeWire and WirePlumber in the VMs

 img/app/Makefile                              |  16 +-
 img/app/default.nix                           |   3 +
 img/app/etc/mdev.conf                         |   1 +
 img/app/etc/pipewire/pipewire.conf            | 229 ++++++++++++++++++
 img/app/etc/s6-linux-init/scripts/rc.init     |  13 +
 .../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 +
 img/app/etc/s6-rc/wayland-proxy-virtwl/run    |  10 -
 .../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       |  42 ++++
 19 files changed, 338 insertions(+), 12 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


base-commit: 560fd878ba1bbd8df0fe28488e72948f28940948
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)