Messages in this thread | | | Date | Thu, 2 Apr 2009 16:52:53 +0800 | From | Herbert Xu <> | Subject | Re: [RFC PATCH 00/17] virtual-bus |
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Avi Kivity <avi@redhat.com> wrote: > > virtio is already non-kvm-specific (lguest uses it) and non-pci-specific > (s390 uses it).
I think Greg's work shows that putting the backend in the kernel can dramatically reduce the cost of a single guest->host transaction. I'm sure the same thing would work for virtio too.
> If you have a good exit mitigation scheme you can cut exits by a factor > of 100; so the userspace exit costs are cut by the same factor. If you > have good copyless networking APIs you can cut the cost of copies to > zero (well, to the cost of get_user_pages_fast(), but a kernel solution > needs that too).
Given the choice of having to mitigate or not having the problem in the first place, guess what I would prefer :)
Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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