Re: [Qemu-devel] [PATCH v7 1/8] virtio: endian-ambivalent targets using legacy virtio

[Michael S. Tsirkin]

On Mon, Apr 14, 2014 at 02:49:31PM +0200, Alexander Graf wrote:
> 
> On 14.04.14 14:46, Michael S. Tsirkin wrote:
> >On Mon, Apr 14, 2014 at 02:40:04PM +0200, Alexander Graf wrote:
> >>On 14.04.14 14:37, Michael S. Tsirkin wrote:
> >>>On Mon, Apr 14, 2014 at 02:29:20PM +0200, Alexander Graf wrote:
> >>>>On 14.04.14 14:24, Michael S. Tsirkin wrote:
> >>>>
> >>>This will have to be measured and proved by whoever's proposing the
> >>>patch, not by reviewers.  Platforms such as AMD which don't do
> >>>prediction well would be especially interesting to test on.
> >>Sure, Greg, can you do that? I'm sure Michael has test cases
> >>available he can give you to measure performance on this.
> >>
> >>Speaking of which, how does all of this work with vhost?
> >>
> >>
> >>Alex
> >I think that's missing.
> >As a first step, we need to disable vhost when
> >host/guest endian-ness do not match.
> >
> >We could also add cross-endian support to vhost.
> >
> >Or just wait a couple more months for virtio 1.0 which is fixed
> >endian-ness.
> 
> That won't help for current ppc64le guests, so I suppose we will
> need cross-endian vhost.
> 
> 
> Alex

It's kernel level work anyway.
Just backport a new driver. Seems less work for more benefit.

-- 
MST