KVM PCI device assignment

My coworker is setting up KVM PCI device assignment to get around a problem he had with assigning more than four drives per server. Normally we'd just use clustered LVM and assign drives directly from the SAN by editing that VMs XML file contained in /etc/libvirt/qemu/ . However, this is the first time we've needed more than four drives per VM and KVM will only allow 4 drives per server since we're limited to a single disk controller.

Update: Turns out this was not a good idea since the VM would monopolize the device on the physical machine; e.g. the VM would get an HBA to the SAN.

Update 2: Using NPIV seems to be the right thing for this.