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

[Isaku Yamahata]

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