On Thu, Dec 01, 2022 at 07:30:19PM -0800, Michael Kelley wrote: > Current code always maps the IO-APIC as shared (decrypted) in a > confidential VM. But Hyper-V guest VMs on AMD SEV-SNP with vTOM > enabled use a paravisor running in VMPL0 to emulate the IO-APIC. > In such a case, the IO-APIC must be accessed as private (encrypted). Lemme see I understand this correctly: the paravisor is emulating the IO-APIC in the lower range of the address space, under the vTOM which is accessed encrypted. That's why you need to access it encrypted in the guest. Close? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette