From: Marc Zyngier <maz@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Reiji Watanabe <reijiw@google.com>,
Oliver Upton <oliver.upton@linux.dev>,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
kvmarm@lists.linux.dev, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Ricardo Koller <ricarkol@google.com>,
Jing Zhang <jingzhangos@google.com>,
Raghavendra Rao Anata <rananta@google.com>,
Shaoqin Huang <shahuang@redhat.com>,
Rob Herring <robh@kernel.org>
Subject: Re: [PATCH v2 2/2] KVM: arm64: PMU: Don't overwrite PMUSERENR with vcpu loaded
Date: Wed, 12 Apr 2023 11:22:29 +0100 [thread overview]
Message-ID: <86v8i1l7ru.wl-maz@kernel.org> (raw)
In-Reply-To: <ZDZ3xbSePtOD3CSX@FVFF77S0Q05N>
On Wed, 12 Apr 2023 10:20:05 +0100,
Mark Rutland <mark.rutland@arm.com> wrote:
>
> On Tue, Apr 11, 2023 at 10:14:10PM -0700, Reiji Watanabe wrote:
> > Uh, right, interrupts are not masked during those windows...
> >
> > What I am currently considering on this would be disabling
> > IRQs while manipulating the register, and introducing a new flag
> > to indicate whether the PMUSERENR for the guest EL0 is loaded,
> > and having kvm_set_pmuserenr() check the new flag.
> >
> > The code would be something like below (local_irq_save/local_irq_restore
> > needs to be excluded for NVHE though).
It shouldn't need to be excluded. It should be fairly harmless, unless
I'm missing something really obvious?
> >
> > What do you think ?
>
> I'm happy with that; it doesn't change the arm_pmu side of the interface and it
> looks good from a functional perspective.
>
> I'll have to leave it to Marc and Oliver to say whether they're happy with the
> KVM side.
This looks OK to me. My only ask would be to have a small comment in
the __{de}activate_traps_common() functions to say what this protects
against, because I'll page it out within minutes.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-04-12 10:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-08 3:47 [PATCH v2 0/2] KVM: arm64: PMU: Correct the handling of PMUSERENR_EL0 Reiji Watanabe
2023-04-08 3:47 ` [PATCH v2 1/2] KVM: arm64: PMU: Restore the host's PMUSERENR_EL0 Reiji Watanabe
2023-04-08 3:47 ` [PATCH v2 2/2] KVM: arm64: PMU: Don't overwrite PMUSERENR with vcpu loaded Reiji Watanabe
2023-04-11 9:33 ` Mark Rutland
2023-04-12 5:14 ` Reiji Watanabe
2023-04-12 9:20 ` Mark Rutland
2023-04-12 10:22 ` Marc Zyngier [this message]
2023-04-13 0:07 ` Reiji Watanabe
2023-04-13 8:56 ` Marc Zyngier
2023-04-15 3:11 ` Reiji Watanabe
2023-04-08 9:04 ` [PATCH v2 0/2] KVM: arm64: PMU: Correct the handling of PMUSERENR_EL0 Marc Zyngier
2023-04-11 11:24 ` Will Deacon
2023-04-12 10:29 ` Marc Zyngier
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=86v8i1l7ru.wl-maz@kernel.org \
--to=maz@kernel.org \
--cc=alexandru.elisei@arm.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=jingzhangos@google.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=oliver.upton@linux.dev \
--cc=pbonzini@redhat.com \
--cc=rananta@google.com \
--cc=reijiw@google.com \
--cc=ricarkol@google.com \
--cc=robh@kernel.org \
--cc=shahuang@redhat.com \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
--cc=yuzenghui@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).