Re: [PATCH v13 22/35] KVM: Allow arch code to track number of memslot address spaces per VM

From: Paolo Bonzini
Date: Mon Oct 30 2023 - 13:35:13 EST


On 10/27/23 20:22, Sean Christopherson wrote:
Let x86 track the number of address spaces on a per-VM basis so that KVM
can disallow SMM memslots for confidential VMs. Confidentials VMs are
fundamentally incompatible with emulating SMM, which as the name suggests
requires being able to read and write guest memory and register state.

Disallowing SMM will simplify support for guest private memory, as KVM
will not need to worry about tracking memory attributes for multiple
address spaces (SMM is the only "non-default" address space across all
architectures).

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>