Re: [PATCH 2/3] Documentation: KVM: add virtual CPU errata documentation

From: Jim Mattson
Date: Wed Mar 23 2022 - 13:00:16 EST


On Tue, Mar 22, 2022 at 4:07 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> Add a file to document all the different ways in which the virtual CPU
> emulation is imperfect. Include an example to show how to document
> such errata.
This is fantastic. Thank you. Along these lines, I wonder if we should
come up with a mechanism a la IA32_ARCH_CAPABILITIES (or AMD's OSVW
MSRs) for declaring fixed errata.

For example, today, KVM ignores the guest-only and host-only bits in
PerfEvtSel MSRs, but I can't imagine we're going to do that forever.

Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>