Date:   Mon, 23 Jan 2023 11:23:50 +0000
Message-ID: <86cz75mr3t.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Shanker Donthineni <sdonthineni@nvidia.com>
Cc:     James Morse <james.morse@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-kernel@vger.kernel.org, Vikram Sethi <vsethi@nvidia.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Ard Biesheuvel <ardb@kernel.org>
Subject: Re: [PATCH] KVM: arm64: vgic: Fix soft lockup during VM teardown
In-Reply-To: <c0fccfce-17f8-e25c-ca21-41ce1ffd54dd@nvidia.com>
References: <20230118022348.4137094-1-sdonthineni@nvidia.com>
        <863588njmt.wl-maz@kernel.org>
        <28061ceb-a7ce-0aca-a97d-8227dcfe6800@nvidia.com>
        <87bkmvdmna.wl-maz@kernel.org>
        <2e0c971a-0199-ff0d-c13c-d007d9f03122@nvidia.com>
        <86wn5imxm9.wl-maz@kernel.org>
        <b3bf3a46-410b-a756-dfd9-ee74d5dc31e0@nvidia.com>
        <86r0vpmn5q.wl-maz@kernel.org>
        <c0fccfce-17f8-e25c-ca21-41ce1ffd54dd@nvidia.com>
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On Sat, 21 Jan 2023 15:35:48 +0000,
Shanker Donthineni <sdonthineni@nvidia.com> wrote:
> 
> 
> 
> On 1/20/23 06:00, Marc Zyngier wrote:
> > What I am asking agin is: is there any overlap between any vgic ioctl
> > and the teardown of the VM? Do you ever see kvm_vm_release() being
> > called before kvm_device_release()?
> > 
> > Because that's the overlap I've been talking all along.
> 
> I've not observed overlap of kvm_vm_release() with ioctls
> kvm_device_ioctl(), kvm_vcpu_ioctl() and kvm_vm_ioctl() for
> 3hrs. Test created hundreds of VMs and teardowns.

OK, that's reassuring. Thanks for looking into this.

	M.

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