Bug 658359

Summary:	Could not hear the sound in guest which connected by VNC
Product:	Red Hat Enterprise Linux 5	Reporter:	Golita Yue <gyue>
Component:	kvm	Assignee:	Gerd Hoffmann <kraxel>
Status:	CLOSED WONTFIX	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	low
Version:	5.6	CC:	mkenneth, qzhou, virt-maint
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-01-14 12:28:28 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	580948

Description Golita Yue 2010-11-30 06:08:01 UTC

Description of problem:
Could not hear sound in guest which use VNC to connect.
but can hear the sound when connect the guest via spice.
Use the same driver in above two conditions, QEMU_AUDIO_DRV=alsa

Version-Release number of selected component (if applicable):
kvm-83-217.el5
kernel 2.6.18-233.el5

How reproducible:
100%

Steps to Reproduce:
1. run QEMU_AUDIO_DRV=alsa
2. start guest with 
/usr/libexec/qemu-kvm -m 2G -smp 2 -uuid `uuidgen` -monitor stdio -boot c -drive file=/home/winxp-32.raw,if=ide,bus=0,unit=0,boot=on,format=raw,cache=none -net nic,macaddr=54:52:00:73:b5:90,model=rtl8139,vlan=0 -net tap,vlan=0,script=/etc/qemu-ifup -usb -vnc :2 -soundhw ac97
3. to hear the sound from guest
  
Actual results:
Could not hear sound in guest
The message display in monitor:
interface_audio_init: 
line_in_init: 
line_out_init: freq 44100 channels 2 format AUD_FMT_S16 HOST_ENDIANNESS

Expected results:
can hear the sound in guest

Additional info:
Can hear the sound in guest which use spice to connect.
/usr/libexec/qemu-kvm -m 2G -smp 2 -uuid `uuidgen` -monitor stdio -boot c -drive file=/home/winxp-32.raw,if=ide,bus=0,unit=0,boot=on,format=raw,cache=none -net nic,macaddr=54:52:00:73:b5:90,model=rtl8139,vlan=0 -net tap,vlan=0,script=/etc/qemu-ifup -usb -spice disable-ticketing,port=5930 -qxl 1 -soundhw ac97

Comment 2 RHEL Program Management 2011-01-11 20:28:28 UTC

This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated in the
current release, Red Hat is unfortunately unable to address this
request at this time. Red Hat invites you to ask your support
representative to propose this request, if appropriate and relevant,
in the next release of Red Hat Enterprise Linux.

Comment 3 RHEL Program Management 2011-01-11 22:57:02 UTC

This request was erroneously denied for the current release of
Red Hat Enterprise Linux.  The error has been fixed and this
request has been re-proposed for the current release.

Comment 4 Gerd Hoffmann 2011-01-14 12:28:28 UTC

QEMU_AUDIO_DRV=alsa is broken, bug in the spice patches, spice (in rhel5) grabs the audio output unconditionally and QEMU_AUDIO_DRV=<anything> has no effect at all.

Fixing this would *not* make the sound play on the vnc client machine, but on the host where the VM is running, which is probably not the desired effect.

Fixing this also has the risk of adding regressions because alsa devices can't be shared and thus two VMs trying to play sound could conflict with each other.

Beside that this is not a supported configuration.