From: Marc Zyngier <maz@kernel.org>
To: "Peng Fan (OSS)" <peng.fan@oss.nxp.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Oliver Upton <oupton@kernel.org>,
Fuad Tabba <fuad.tabba@linux.dev>,
Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Mark Rutland <mark.rutland@arm.com>,
"Ivan T. Ivanov" <iivanov@suse.de>,
Francesco Dolcini <francesco@dolcini.it>,
Frank Li <frank.li@nxp.com>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev,
imx@lists.linux.dev, Peng Fan <peng.fan@nxp.com>
Subject: Re: [PATCH v2] arm64: errata: Add NXP iMX8QM workaround for A53 cache coherency issue
Date: Thu, 30 Jul 2026 15:32:30 +0100 [thread overview]
Message-ID: <86ecgkczup.wl-maz@kernel.org> (raw)
In-Reply-To: <20260730-imx8qm-cache-coherency-v2-1-5651aeb1af16@nxp.com>
On Thu, 30 Jul 2026 14:53:02 +0100,
"Peng Fan (OSS)" <peng.fan@oss.nxp.com> wrote:
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 9a6c72a18672..734ccd7ec056 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -3032,6 +3032,11 @@ static __init int kvm_arm_init(void)
>
> in_hyp_mode = is_kernel_in_hyp_mode();
>
> + if (cpus_have_final_cap(ARM64_WORKAROUND_NXP_ERR050104)) {
> + kvm_info("KVM not supported on NXP iMX8QM (ERR050104)\n");
> + return -ENODEV;
> + }
> +
> if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
> cpus_have_final_cap(ARM64_WORKAROUND_1508412))
> kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
I really dislike this sort of hacks in the KVM code.
Instead, please find a way to set 'kvm_mode' to KVM_MODE_NONE from
your erratum handler, and KVM will gracefully disable itself, as if
that was passed on the command line.
It shouldn't be too hard to do.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
prev parent reply other threads:[~2026-07-30 14:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-30 13:53 [PATCH v2] arm64: errata: Add NXP iMX8QM workaround for A53 cache coherency issue Peng Fan (OSS)
2026-07-30 14:11 ` sashiko-bot
2026-07-30 14:32 ` Marc Zyngier [this message]
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