Re: [PATCH v5 0/4] KVM: arm64: Errata management for VM Live migration

[Sebastian Ott <sebott@redhat.com>]

On Tue, 4 Feb 2025, Marc Zyngier wrote:
> On Tue, 04 Feb 2025 16:45:38 +0000,
> Sebastian Ott <sebott@redhat.com> wrote:
>>
>> Hey,
>>
>> On Fri, 24 Jan 2025, Shameer Kolothum wrote:
>>> On ARM64 platforms most of the errata workarounds are based on CPU
>>> MIDR/REVIDR values and a number of these workarounds need to be
>>> implemented by the Guest kernel as well. This creates a problem when
>>> Guest needs to be migrated to a platform that differs in these
>>> MIDR/REVIDR values even if the VMM can come up with a common minimum
>>> feature list for the Guest using the recently introduced "Writable
>>> ID registers" support.
>>
>> Currently MIDR/REVIDR are still RO and guest access is not trapped - so
>> even with the errata management patches in place the guest state would
>> change and a migration (between hosts that differ in these regs) would
>> not be possible. Are there any plans to allow to actually change these?
>
> Sure thing. We only need a victim! :)

;-) Nice. I'll hack smth up then.

Sebastian