Open Stack

On Tue, Jun 4, 2019 at 5:53 PM Dr. David Alan Gilbert
<dgilbert at redhat.com> wrote:
>
> * Tao Peng (bergwolf at hyper.sh) wrote:
> > On Tue, Jun 4, 2019 at 7:18 AM Mahalingam, Ganesh
> > <ganesh.mahalingam at intel.com> wrote:
> > >
> > > Peng, Stefan,
> > > While working on enabling virtio-fs on Kata there was a small confusion on whether virtio-fs can work with VM Templating. With the current setup of kata, VM templating and virtio-fs are mutually exclusive (VM templating is enabled in qemu-lite and virtio-fs currently only with NEMU), but they will converge very soon.
> > >
> > > An open question we had was, would they both work with each other given that VM templating turns off memory sharing for all VMs other than the first one and virtio-fs expects guest memory be shared & file-backed for all VMs.
> > Hi Stefan,
> >
> > What happens if we specify share=on and share=off for different memory
> > file backends? Can virtio-fs only pick up the shared one?
>
> All vhost-user devices (including virtio-fs) need the share=on - because
> that's the only way that the vhost-user process sees the writes done
> by qemu or the guest.  I think we need it for all of RAM.
>
Hmm, vm templating needs the initial ram to be mapped private so that
it can be shared safely across multiple VM instances. It does conflict
with vhost-user requirement that guest memory can be accessed by a
different process.

Ganesh, how about we just marking vm templating and vhost-user
conflict with each other?

Cheers,
Tao
-- 
Into something rich and strange.