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From: Marc Zyngier <maz@kernel.org>
To: l00313349 <liting8@huawei.com>
Cc: <linux-arm-kernel@lists.infradead.org>, <kvmarm@lists.linux.dev>,
	<oliver.upton@linux.dev>, <james.morse@arm.com>,
	<suzuki.poulose@arm.com>, <yuzenghui@huawei.com>,
	<catalin.marinas@arm.com>, <will@kernel.org>,
	<zhengchuan@huawei.com>, <xiexiangyou@huawei.com>
Subject: Re: [PATCH] KVM: arm64: fix MPIDR to vcpu index cache to support vcpu change at runtime
Date: Wed, 29 Nov 2023 19:18:42 +0000	[thread overview]
Message-ID: <87il5k8j1p.wl-maz@kernel.org> (raw)
In-Reply-To: <20231128135402.1943-1-liting8@huawei.com>

On Tue, 28 Nov 2023 13:54:02 +0000,
l00313349 <liting8@huawei.com> wrote:
> 
> From: Ting Li <liting8@huawei.com>
> 
> Consider vcpu change at runtime, for example online_vcpus is 8,
> but only start 2 vcpu threads, MPIDR to vcpu index 0 may be overwrited
> and vm hangs. When start other vcpu threads, cache will be outdated
> and always get mismatch.

If userspace creates two vcpus with the same vcpu_id, and therefore
the same MPIDR value, that's userspace's problem. Don't do that.

Why should we do anything else?

	M.

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

  reply	other threads:[~2023-11-29 19:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-28 13:54 [PATCH] KVM: arm64: fix MPIDR to vcpu index cache to support vcpu change at runtime l00313349
2023-11-29 19:18 ` Marc Zyngier [this message]
2023-12-01 10:48   ` liting (Q)
2023-12-01 12:15     ` Marc Zyngier

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