Description:
I found the default qemu audio driver seems oss. I have to add environment variables "export QEMU_AUDIO_DRV=alsa" to make it work.The key is I usually run virtual machine with virt-manager, it has virtual network. I google it and found similar problem on Gentoo forum: http://forums.gentoo.org/viewtopic-t-920554-start-0.html. By the way, display use SDL.

Additional info:
* package version(s) 1.4.0-2
* config and/or log files etc. Output:
[gkj@JG-Arch ~]$ bash qemu
oss: Could not initialize ADC
oss: Failed to open `/dev/dsp'
oss: Reason: No such file or directory
oss: Could not initialize ADC
oss: Failed to open `/dev/dsp'
oss: Reason: No such file or directory
audio: Failed to create voice `ac97.pi'
oss: Could not initialize DAC
oss: Failed to open `/dev/dsp'
oss: Reason: No such file or directory
oss: Could not initialize DAC
oss: Failed to open `/dev/dsp'
oss: Reason: No such file or directory
audio: Failed to create voice `ac97.po'
......

Steps to reproduce:
use bash file, content like this:
#!/bin/sh

#export QEMU_AUDIO_DRV=alsa

qemu-system-i386 -enable-kvm -usbdevice tablet -m 512 -vga vmware -soundhw ac97 -boot order=c -drive file=/home/VM/WinXP.img,if=virtio -net nic,model=virtio