linux-kernel - Re: [PATCH v2 2/4] KVM: arm64: Don't WARN from __pkvm_host_share

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Message-ID: <Z74e17vBiJAgViHQ@google.com>
Date: Tue, 25 Feb 2025 19:49:43 +0000
From: Quentin Perret <qperret@...gle.com>
To: Marc Zyngier <maz@...nel.org>
Cc: Oliver Upton <oliver.upton@...ux.dev>, Joey Gouly <joey.gouly@....com>,
	Suzuki K Poulose <suzuki.poulose@....com>,
	Zenghui Yu <yuzenghui@...wei.com>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will@...nel.org>, linux-arm-kernel@...ts.infradead.org,
	kvmarm@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/4] KVM: arm64: Don't WARN from
 __pkvm_host_share_guest()

On Tuesday 25 Feb 2025 at 18:02:02 (+0000), Marc Zyngier wrote:
> On Tue, 25 Feb 2025 01:53:25 +0000,
> Quentin Perret <qperret@...gle.com> wrote:
> > 
> > We currently WARN() if the host attempts to share a page that is not in
> > an acceptable state with a guest. This isn't strictly necessary and
> > makes testing much harder, so drop the WARN and fix the error code.
> 
> Are you really fixing the error code? You still seem to return a
> -EPERM. I guess this was never reachable thanks to WARN() being a
> panic with pKVM?

Exactly, this is really poor wording in the commit message. 'Fix the
error code' in this case was intended to mean 'make sure to return the
error code properly instead outright crashing the device'.

Happy to send out a v3 with a better commit message.

Thanks!
Quentin