Re: vhost net: performance with ping benchmark

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Aug 25, 2009 at 08:08:05AM -0500, Anthony Liguori wrote:
> Michael S. Tsirkin wrote:
>>> My preference is ring proxying.  Not we'll need ring proxying (or at  
>>> least event proxying) for non-MSI guests.
>>>     
>>
>> Exactly, that's what I meant earlier. That's enough, isn't it, Anthony?
>>   
>
> It is if we have a working implementation that demonstrates the
> userspace interface is sufficient.

The idea is trivial enough to be sure the interface is sufficient:
we point kernel at used buffer at address X, and
copy stuff from there to guest buffer, then signal guest.
I'll post a code snippet to show how it's done if you like.

> Once it goes into the upstream
> kernel, we need to have backwards compatibility code in QEMU forever
> to  support that kernel version.

Don't worry: kernel needs to handle old userspace as well, and neither I
nor Rusty want to have a compatibility mess in kernel.

> Regards,
>
> Anthony Liguori