Subject: vhost net on 10ge with x2apic

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 29 Dec 2009 16:07:43 +0200

Got hold of some 10Ge cards and did some light benchmarking of kvm networking
with and without vhost net accelerator, while enabling x2apic emulation.
I've put a summary of results here:
http://www.linux-kvm.org/page/VhostNet#Performance

Main conclusions: vhost net improves latency (a lot) and bandwidth/cpu
utilization (less).  With x2apic and a recent guest, virtio userspace
has decent bandwidth but high latency and cpu utilization.  vhost net
bandwidth can get very close to native bandwidth (95%).
We still have work to do tuning virtio guest drivers.

-- 
MST