Re: [RFC v2] KVM: x86: Support KVM VMs sharing SEV context

[Steve Rutherford]

On Thu, Apr 8, 2021 at 10:43 AM James Bottomley <jejb@xxxxxxxxxxxxx> wrote:
>
> On Fri, 2021-04-02 at 16:20 +0200, Paolo Bonzini wrote:
> > On 02/04/21 13:58, Ashish Kalra wrote:
> > > Hi Nathan,
> > >
> > > Will you be posting a corresponding Qemu patch for this ?
> >
> > Hi Ashish,
> >
> > as far as I know IBM is working on QEMU patches for guest-based
> > migration helpers.
>
> Yes, that's right, we'll take on this part.
>
> > However, it would be nice to collaborate on the low-level (SEC/PEI)
> > firmware patches to detect whether a CPU is part of the primary VM
> > or the mirror.  If Google has any OVMF patches already done for that,
> > it would be great to combine it with IBM's SEV migration code and
> > merge it into upstream OVMF.
>
> We've reached the stage with our prototyping where not having the OVMF
> support is blocking us from working on QEMU.  If we're going to have to
> reinvent the wheel in OVMF because Google is unwilling to publish the
> patches, can you at least give some hints about how you did it?
>
> Thanks,
>
> James

Hey James,
It's not strictly necessary to modify OVMF to make SEV VMs live
migrate. If we were to modify OVMF, we would contribute those changes
upstream.

Thanks,
Steve