Re: [libvirt] [PATCH] qemu: sound: Support intel 'hda' model

On 01/11/2011 06:10 AM, Daniel P. Berrange wrote: > On Tue, Jan 11, 2011 at 11:46:14AM +0100, Gerd Hoffmann wrote: >> On 01/10/11 18:19, Cole Robinson wrote: >>> In QEMU, the card itself is a PCI device, but it requires >>> -device hda-output in order to actually get sound to the host. AIUI this >>> is just HDA configuration and does not require stable addressing, so >>> is not presently represented in the XML. >> >> It isn't that simple. There are actually multiple devices involved. >> Each audio codec (yes, there can be multiple of these, up to 15) is >> connected via HDA Link to the pci controller. Each audio codec has >> a codec address (HDA bus property: cad=[0..14]). >> >> So you can specify "-device intel-hda -device hda-duplex -device >> hda-output" and the guest has multiple audio devices. Win7 even >> handles this correctly, whereas alsa uses only the first codec it >> finds (lowest codec address). Not that this buys you much today, >> qemu mixes all channels together before sending them off to the >> hosts sound system, i.e. you don't see a stream per sound card in >> pulseaudio. That might change in the future though. >> > > So 'intel-hda' should really be considered as a controller, > and hda-output' & 'hda-duplex' are the things to be treated > as devices in the guest config. > > This suggests a setup more like the one we did for virtio-serial > where we'd invent a new address type for codecs, and have XML > looking something like > > <controller type='hda' model='ich6'> > <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/> > </controller> > <sound model='hda-output'> > <address type='hda' codec='0'/> > </sound> > <sound model='hda-duplex'> > <address type='hda' codec='1'/> > </sound> > Sounds good, though I think doing <sound model='hda' mic="on|off"/> would be preferable from a UI perspective, since it sounds like that's the only differentiating factor (or maybe use 'duplex' or 'input' etc.). Does that sound okay?