lkml.org 
[lkml]   [2008]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 0/16 v6] PCI: Linux kernel SR-IOV support
From
Date
Anthony Liguori <anthony@codemonkey.ws> writes:
>
> What we would rather do in KVM, is have the VFs appear in the host as
> standard network devices. We would then like to back our existing PV
> driver to this VF directly bypassing the host networking stack. A key
> feature here is being able to fill the VF's receive queue with guest
> memory instead of host kernel memory so that you can get zero-copy
> receive traffic. This will perform just as well as doing passthrough
> (at least) and avoid all that ugliness of dealing with SR-IOV in the
> guest.

But you shift a lot of ugliness into the host network stack again.
Not sure that is a good trade off.

Also it would always require context switches and I believe one
of the reasons for the PV/VF model is very low latency IO and having
heavyweight switches to the host and back would be against that.

-Andi

--
ak@linux.intel.com


\
 
 \ /
  Last update: 2008-11-07 16:19    [W:0.225 / U:1.684 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site