Hi, > > 23:16 GuestPhysAddrSize Maximum guest physical address size in bits. > > This number applies only to guests using nested > > paging. When this field is zero, refer to the > > PhysAddrSize field for the maximum guest > > physical address size. See “Secure Virtual > > Machine” in APM Volume 2.
> I believe the main purpose of GuestPhysAddrSize was for software use (for > nested virtualization) and that the hardware itself has always returned zero > for that value. So you should be able to use that field. Adding @Paolo for > his thoughts. Posted patches for kernel https://lore.kernel.org/kvm/20240301101410.356007-1-kra...@redhat.com/ and qemu https://lore.kernel.org/kvm/20240301101713.356759-1-kra...@redhat.com/ (sorry forgot to Cc you). Reviewers mentioned this is meant for nested guests, i.e. (if I understand this correctly) the l0 hypervisor can use that to tell the l1 hypervisor what the l2 guest phys-bits should be. Is this nested virtualization use documented somewhere? Tried to search for GuestPhysAddrSize or Fn8000_0008_EAX in APM Volume 2, found nothing. Is there any case where the phys-bits limits for an l1 guest and l2 guest would be different? thanks & take care, Gerd -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#116313): https://edk2.groups.io/g/devel/message/116313 Mute This Topic: https://groups.io/mt/104510523/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
