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

[Alexander Graf]

On 14.04.14 14:56, Michael S. Tsirkin wrote:
> 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.

It's quite hard to backport a driver onto installation media :). We 
already have openSUSE isos out there that support virtio and ppc64le.


Alex