Arnd Bergmann wrote: > On Friday 30 July 2010 17:51:52 Shirley Ma wrote: >> On Fri, 2010-07-30 at 16:53 +0800, Xin, Xiaohui wrote: >>>> Since vhost-net already supports macvtap/tun backends, do you think >>>> whether it's better to implement zero copy in macvtap/tun than >>>> inducing a new media passthrough device here? >>>> >>> >>> I'm not sure if there will be more duplicated code in the kernel. >> >> I think it should be less duplicated code in the kernel if we use >> macvtap to support what media passthrough driver here. Since macvtap >> has support virtio_net head and offloading already, the only missing >> func is zero copy. Also QEMU supports macvtap, we just need add a >> zero copy flag in option. > > Yes, I fully agree and that was one of the intended directions for > macvtap to start with. Thank you so much for following up on that, > I've long been planning to work on macvtap zero-copy myself but it's > now lower on my priorities, so it's good to hear that you made > progress on it, even if there are still performance issues. > But zero-copy is a Linux generic feature that can be used by other VMMs as well if the BE service drivers want to incorporate. If we can make mp device VMM-agnostic (it may be not yet in current patch), that will help Linux more. Thx, Eddie-- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html