[libvirt-users] How can a bridge be optimized?

[Whit Blauvelt]

Hi,

Netperf tells me that a KVM VM using a bridged connection to a system across
the Gigabit LAN sees on average about 1/10th of the bandwidth the host sees.
This is on very lightly loaded hosts, although with multiple low-use VMs.
I've tried adjusting the CPU throttling after seeing that mentioned as a
possible factor in slowing down a bridge, but it has not much if any effect
here. 

Is there a good guide somewhere to what might make a difference with this? 

I recall the kernel recently adding a new alternative for handling VM
interfaces, but can't recall what it was called. Would that be a marked
improvement? Is it supported by libvirt?

Thanks,
Whit