Re: [PATCH 0/4] KVM: arm/arm64: Fix locking issues

From: Paolo Bonzini <pbonzini@redhat.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Andre Przywara <andre.przywara@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	Eric Auger <eric.auger@redhat.com>,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Subject: Re: [PATCH 0/4] KVM: arm/arm64: Fix locking issues
Date: Tue, 15 May 2018 14:05:38 +0200	[thread overview]
Message-ID: <e33bdec4-97d9-fcc1-da1f-2c6d87b2c56d@redhat.com> (raw)
In-Reply-To: <b8aae9d6-1413-157d-52c2-e06511975e11@arm.com>

On 15/05/2018 13:54, Marc Zyngier wrote:
> On 15/05/18 12:35, Paolo Bonzini wrote:
>> On 15/05/2018 12:26, Christoffer Dall wrote:
>>> On Fri, May 11, 2018 at 03:20:11PM +0100, Andre Przywara wrote:
>>>> Jan recently reported lockdep complaints regarding various locks in our
>>>> VGIC emulation [1][2].
>>>> This boiled down to two separate issues:
>>>> - When promoting the vgic_irq->irq_lock to require IRQs being disabled,
>>>>   we forgot to amend some instances of this lock on the way. Also this
>>>>   needs to be applied to dependent locks as well. The first two patches
>>>>   fix that. The patch split is designed to simplify backporting.
>>>>   Those patches have been posted before, I am resending them as part
>>>>   of this series.
>>>> - Calling kvm_read_guest() requires us to be inside an SRCU critical
>>>>   section. On some architectures we are always in it when handling VCPU
>>>>   exits, but on ARM we need to lock it individually. Patches 3 and 4
>>>>   fix that, the split is again made to ease backporting.
>>>>   Each of the hunks fix an indiviual commit, but I refrained from
>>>>   splitting this down into eight patches just to put proper Fixes: tags
>>>>   on it. Eventually those commits are part of one out of two series, I put
>>>>   the respective kernel release version as a tag to the Cc: stable line.
>>>>
>>>> I couldn't reproduce the full lockdep splat on my setup, but at least
>>>> could show one instance and prove that these patches fixes that.
>>>>
>>>>
>>> For the series:
>>>
>>> Acked-by: Christoffer Dall <christoffer.dall@arm.com>
>>
>> Shall I put the patches on their route to Linus?
> If you're about to send something, yes please (saves me having to send
> you a pull request). In that case, please add my

Yes, I do - and I was keeping my eyes on this series anyway.

Thanks,

Paolo

> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
> 
> to the whole series.
> 
> Thanks,
> 
> 	M.
> 