On Thu, Mar 23, 2023 at 05:11:26PM +0100, Jeremi Piotrowski wrote: > That same interface is exposed by physical hardware+firmware to the underlying > Hyper-V. Let me see if I understand it correctly: Hyper-V *baremetal* is using the same ASPT spec to to talk to the *physical* PSP device? Is that ASPT interface to talk to the PSP used by the L0 hypervisor? Or does the L0 HV have a normal driver, similar to the Linux one, without the functionality this ASPT spec provides? > So it wasn't a matter of Microsoft architects coming up with a > guest-host interface but rather exposing the virtual hardware in the same > way as on a physical server. So if you want to expose the same interface to the L1 guest, why isn't Hyper-V emulating an ACPI device just like any other functionality? Why does it need to reach into the interrupt handling internals? I'd expect that the L0 HV would emulate a PSP device, the L1 would simply load the Linux PSP device driver and everything should just work. What's the point of that alternate access at all? But I might still be missing something... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette