Re: [kvm-unit-tests PATCH v1 1/4] arm64: split its-trigger test into KVM and TCG variants

Marc Zyngier
2021-04-28T14:36:13Z

On Wed, 28 Apr 2021 15:00:15 +0100,
Alexandru Elisei <alexandru.elisei@arm.com> wrote:
>
> I interpret that as that an INVALL guarantees that a change is
> visible, but it the change can become visible even without the
> INVALL.

Yes. Expecting the LPI to be delivered or not in the absence of an
invalidate when its configuration has been altered is wrong. The
architecture doesn't guarantee anything of the sort.

> The test relies on the fact that changes to the LPI tables are not
> visible *under KVM* until the INVALL command, but that's not
> necessarily the case on real hardware. To match the spec, I think
> the test "dev2/eventid=20 still does not trigger any LPI" should be
> removed and the stats reset should take place before the
> configuration for LPI 8195 is set to the default.

If that's what the test expects (I haven't tried to investigate), it
should be dropped completely, rather than trying to sidestep it for
TCG.

Thanks,

M.

--
Without deviation from the norm, progress is not possible.