I'm using Debian SID distro and I have installed the KVM hypervisor from the unstable repositories: Qemu version is 1.7 and libvirt version is 1.2.1. I've migrated a Windows 7 machine from Virtualbox to KVM, but I have some problems with it. I have managed to install all virtio drivers and QXL/spice and all works fine. However, I have a problem with the ich6 sound card - when I select it and try to start the machine, I get an error: unsupported configuration: hda-duplex not supported in this QEMU binary. Also when I add a USB Redirection channel, I get an error: USB redirection is not supported by this version of QEMU. What have I done wrong? I installed the regular version of qemu-kvm and libvirt from the SID repository. I've also set the /dev/kvm to rw-rw-rw- and chowned it to group kvm (without it the machine wouldn't even start). I also had to set cpu-mode to host-passthrough because when I used standard "Copy host CPU configuration" in Virtual Manager and it set SandyBridge, I got a similar error that the CPU configuration is not supported by the QEMU binary.
Thank you for the help.