Re: [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory

From: Isaku Yamahata
Date: Mon Aug 22 2022 - 21:25:53 EST


On Wed, Aug 17, 2022 at 10:27:19AM -0500,
Michael Roth <michael.roth@xxxxxxx> wrote:

> > I think the best approach is to turn KVM_TDX_INIT_MEM_REGION into a generic
> > vCPU-scoped ioctl() that allows userspace to pre-map guest memory. Supporting
> > initializing guest private memory with a source page can be implemented via a
> > flag. That also gives KVM line of sight to in-place "conversion", e.g. another
> > flag could be added to say that the dest is also the source.
>
> So is this proposed ioctl only intended to handle the initial encrypted
> payload, and the KVM_MEMORY_ENCRYPT_{REG,UNREG}_REGION ioctls would
> still be used for conversions post-boot?

Yes. It is called before running any vcpu. At run time (after running vcpus),
KVM_MEMORY_ENCRYPT_{REG,UNREG}_REGION is used.
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>