From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: Re: [PATCH] KVM: arm64: Skip instruction after emulating write to TCR_EL1
Date: Fri, 28 Jul 2023 17:10:27 +0000 [thread overview]
Message-ID: <ZMP2g29gsg96BshH@linux.dev> (raw)
In-Reply-To: <87h6poqwq1.wl-maz@kernel.org>
On Fri, Jul 28, 2023 at 09:14:14AM +0100, Marc Zyngier wrote:
> On Fri, 28 Jul 2023 01:08:24 +0100,
> Oliver Upton <oliver.upton@linux.dev> wrote:
> >
> > Whelp, this is embarrassing. Since commit 082fdfd13841 ("KVM: arm64:
> > Prevent guests from enabling HA/HD on Ampere1") KVM traps writes to
> > TCR_EL1 on AmpereOne to work around an erratum in the unadvertised
> > HAFDBS implementation, preventing the guest from enabling the feature.
> > Unfortunately, I failed virtualization 101 when working on that change,
> > and forgot to advance PC after instruction emulation.
> >
> > Do the right thing and skip the MSR instruction after emulating the
> > write.
> >
> > Fixes: 082fdfd13841 ("KVM: arm64: Prevent guests from enabling HA/HD on Ampere1")
> > Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
>
> Oh hum... I think it is high time for a new PR to Paolo!
Definitely, now let's sweep this mess under the rug :)
> Acked-by: Marc Zyngier <maz@kernel.org>
Appreciated!
--
Thanks,
Oliver
next prev parent reply other threads:[~2023-07-28 17:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 0:08 [PATCH] KVM: arm64: Skip instruction after emulating write to TCR_EL1 Oliver Upton
2023-07-28 8:14 ` Marc Zyngier
2023-07-28 17:10 ` Oliver Upton [this message]
2023-07-28 17:11 ` Oliver Upton
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