Re: [libvirt] [PATCH] qemu: Allow using regular audio backends with VNC

On 05/24/2010 10:14 AM, Daniel P. Berrange wrote: > On Thu, May 20, 2010 at 12:04:04PM -0400, Cole Robinson wrote: >> Currently all host audio backends are disabled if a VM is using VNC, in >> favor of the QEMU VNC audio extension. Unfortunately no released VNC >> client supports this extension, so users have no way of getting audio >> to work if using VNC. >> >> Add a new config option in qemu.conf which allows changing libvirt's >> behavior, but keep the default intact. >> >> Signed-off-by: Cole Robinson <crobinso(a)redhat.com&gt; >> --- >> src/qemu/qemu.conf | 10 ++++++++++ >> src/qemu/qemu_conf.c | 17 ++++++++++++----- >> src/qemu/qemu_conf.h | 2 ++ >> 3 files changed, 24 insertions(+), 5 deletions(-) >> >> diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf >> index 3da332f..fec946d 100644 >> --- a/src/qemu/qemu.conf >> +++ b/src/qemu/qemu.conf >> @@ -168,3 +168,13 @@ >> # be assigned to guests. >> # >> # relaxed_acs_check = 1 >> + >> + >> +# QEMU implements anextension for providing audio over a VNC connection, >> +# though if your VNC client does not support it, your only chance for getting >> +# sound output is through regular audio backends. By default, libvirt will >> +# disable all QEMU sound backends if using VNC, since they can cause >> +# permissions issues. Enabling this option will make libvirtd honor the >> +# QEMU_AUDIO_DRV environment variable when using VNC. >> +# >> +# vnc_enable_audio_backend = 0 > > I think this would be better named as 'vnc_allow_host_audio' > since its not toggling VNC audio, just whether it is allowed > to use the host audio drivers. > Okay, I'll change and resend. > NB, even with this toggled things are unlikely to magically > 'just work'. If QEMU is running as 'qemu' user ID, that user > won't have any permissions to use /dev/snd/* devices. And > if running as 'root' then pulseaudio won't autospawn so will > need to be run manually. > Right. Currently getting sound to work in Fedora is a big pain, and there have been quite a few user complaints. I'm going to write up a 'known bug' page, documenting a workaround of qemu.conf user/group = $USER to fix the issue, but this patch will still need to be backported.