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Subject: Re: [RFC PATCH v4 01/39] KVM: arm64: Make lock_all_vcpus() available
 to the rest of KVM
To:     Alexandru Elisei <alexandru.elisei@arm.com>, maz@kernel.org,
        james.morse@arm.com, linux-arm-kernel@lists.infradead.org,
        kvmarm@lists.cs.columbia.edu, will@kernel.org,
        linux-kernel@vger.kernel.org
References: <20210825161815.266051-1-alexandru.elisei@arm.com>
 <20210825161815.266051-2-alexandru.elisei@arm.com>
From:   Suzuki K Poulose <suzuki.poulose@arm.com>
Message-ID: <ed657df4-7242-2c77-cfaf-b0dc1eb5c210@arm.com>
Date:   Wed, 22 Sep 2021 11:39:54 +0100
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On 25/08/2021 17:17, Alexandru Elisei wrote:
> The VGIC code uses the lock_all_vcpus() function to make sure no VCPUs are
> run while it fiddles with the global VGIC state. Move the declaration of
> lock_all_vcpus() and the corresponding unlock function into asm/kvm_host.h
> where it can be reused by other parts of KVM/arm64 and rename the functions
> to kvm_{lock,unlock}_all_vcpus() to make them more generic.
> 
> Because the scope of the code potentially using the functions has
> increased, add a lockdep check that the kvm->lock is held by the caller.
> Holding the lock is necessary because otherwise userspace would be able to
> create new VCPUs and run them while the existing VCPUs are locked.
> 
> No functional change intended.
> 
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>


LGTM,

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>