Re: [RFC PATCH 1/3] kvm: x86: Rename KVM_DEBUGREG_RELOAD to KVM_DEBUGREG_NEED_RELOAD

From: Paolo Bonzini
Date: Sat Apr 25 2020 - 15:16:32 EST


On 25/04/20 18:54, Nadav Amit wrote:
>> I wonder if KVM_DEBUGREG_RELOAD is needed at all. It should be easy to
>> write selftests for it, using the testcase in commit message
>> 172b2386ed16 and the information in commit ae561edeb421.
> I must be missing something, since I did not follow this thread and other
> KVM changes very closely.
>
> Yet, for the record, I added KVM_DEBUGREG_RELOAD due to real experienced
> issues that I had while running Intelâs fuzzing tests on KVM: IIRC, the DRs
> were not reloaded after an INIT event that clears them.

Indeed, but the code has changed since then and I'm not sure it is still
needed.

> Personally, I would prefer that a test for that, if added, would be added
> to KVM-unit-tests, based on Liranâs INIT test. This would allow to confirm
> bare-metal behaves as the VM.

Yes, that would be good as well of course.

Paolo