Re: [RFC PATCH 00/13] Add support for Mirror VM.

[Dr. David Alan Gilbert]

* Paolo Bonzini (pbonzini@redhat.com) wrote:
> On 16/08/21 17:13, Ashish Kalra wrote:
> > > > I think that once the mirror VM starts booting and running the UEFI
> > > > code, it might be only during the PEI or DXE phase where it will
> > > > start actually running the MH code, so mirror VM probably still need
> > > > to handles KVM_EXIT_IO when SEC phase does I/O, I can see PIC
> > > > accesses and Debug Agent initialization stuff in SEC startup code.
> > > That may be a design of the migration helper code that you were working
> > > with, but it's not necessary.
> > > 
> > Actually my comments are about a more generic MH code.
> 
> I don't think that would be a good idea; designing QEMU's migration helper
> interface to be as constrained as possible is a good thing.  The migration
> helper is extremely security sensitive code, so it should not expose itself
> to the attack surface of the whole of QEMU.

It's also odd in that it's provided by the guest and acting on behalf of
the migration code; that's an unusually trusting relationship.

Dave

> Paolo
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK