New guest tools ISO for Linux and FreeBSD. Can you help with the tests?
Actually, on any recent enough Linux system (ie not many years old) , the PV drivers are directly included in the kernel. Unless, maybe, a very specific distro decides that they don't want Xen support in their kernel.
So the tools you install on the VMs are merely an agent to make the VM more cooperative with the hypervisor, but they don't affect performance.
The situation is different on Windows systems where you need to install PV drivers to achieve better performance.