On Sun, 27 Mar 2011 09:52:54 +0200, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > Though IIRC, qemu's virtio barfs if the first descriptor isn't just the > > hdr (barf...). > > Maybe we can try fixing this before adding more flags, > then e.g. publish used flag can be resued to also > tell us layout is flexible. Or just add a feature flag for that. We should probably do this at some stage, yes. > > > 2. I didn't have time to work on virtio2 ideas presented > > > at the kvm forum yet, any takers? > > > > I didn't even attend. > > Hmm, right. But what was presented there was discussed on list as well: > a single R/W descriptor ring with valid bit instead of 2 rings > + a descriptor array. I'll be happy when we reach the point that the extra cacheline is hurting us :) Then we should do direct descriptors w/ a cookie as the value to hand back when finished. That seems to be close to optimal. > I agree absolutely that not all lessons has been learned, > playing with different ring layouts would make at least > an interesting paper IMO. Yes, I'd like to see the results... Thanks, Rusty. -- 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
