Re: kvm smm mode support?

Gerd Hoffmann
2014-04-28T13:49:36Z

On Sa, 2014-04-26 at 13:02 +0200, Paolo Bonzini wrote:
> Il 26/04/2014 11:40, Paolo Bonzini ha scritto:
> > Il 25/04/2014 09:39, Gerd Hoffmann ha scritto:
> >> Anyone has plans to add smm support to kvm?
> >
> > No plans, but it should be a Simple Matter Of Programming...
>
> Well, we need:
>
> - an extra ioctl to inject an SMI (can be modeled after KVM_NMI)
>
> - an extra user exit triggered when SMM is entered or left
>
> - an extra ioctl (or a GET/SET_ONE_REG implementation) to read/write
> whether we are in SMM, used to determine whether the #UD produced by RSM
> should be forwarded to the guest or trigger emulation.

OVMF probably wants set aside some ram which can't be accessed by the
OS, for secure boot emulation which is actually secure. Guess we'll
just go map/unmap some slot in the smm enter/leave vmexits? Or there
are better ways to do it?

cheers,
Gerd