Filesystem passthrough functionality in Centos 6.2?

I have a CentOS 6.3 machine currently running 2 virtualized CentOS 6.2 machines via KVM/QEMU/Libvirt. I'm trying to setup filesystem passthrough between the guests and the host. However the option is grayed out in the Virtualization Manager with the message "Not supported for this hypervisor/libvirt combination".

And in addition if I attempt to set it up using

virsh edit [VM name]

The VM throws an error on boot along the lines of "passthrough not supported by QEMU" (Sorry I don't have the exact error right now. I don't have access to the machine, will update next time I'm in front of it).

I can't seem to find a lot of information on this issue. Is there a compatibility issue between CentOS and filesystem passthrough?

Thanks.

Strange I was trying to do the same thing today as well. I don't think it's currently supported in the version of KVM that's included with CentOS 6.x.

% rpm -aq|grep kvm
qemu-kvm-0.12.1.2-2.295.el6_3.8.x86_64

I think this is the error you're referring to:

error is: Not supported for this hypervisor/libvirt combination (CentOS 6.3)

According to the libvirt documentation for the Domain XML format, filesystem is a supported command taking passthrough as an accessmode: http://libvirt.org/formatdomain.html#elementsFilesystems

These links were helpful:

• KVM-QEMU Filesystem passthrough
• http://wiki.qemu.org/Documentation/9psetup
• http://www.linux-kvm.org/page/9p_virtio