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Subject: Re: [RESPIN PATCH] irqchip/gic-v4.1:Fix VSYNC referencing an unmapped
 VPE
To: Nianyao Tang <tangnianyao@huawei.com>
CC: <maz@kernel.org>, <tglx@linutronix.de>,
	<linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
	<guoyang2@huawei.com>, <wangwudi@hisilicon.com>
References: <20240406022737.3898763-1-tangnianyao@huawei.com>
From: Zenghui Yu <yuzenghui@huawei.com>
Message-ID: <7eaf81b4-80b3-2728-0588-ecad6c137848@huawei.com>
Date: Sun, 7 Apr 2024 11:40:39 +0800
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On 2024/4/6 10:27, Nianyao Tang wrote:
> As per the GICv4.1 spec (Arm IHI 0069H, 5.3.19):
> 
> "A VMAPP with {V, Alloc}=={0, x} is self-synchronizing, This means the
> ITS command queue does not show the command as consumed until all of
> its effects are completed."
> 
> Furthermore, VSYNC is allowed to deliver an SError when referencing a
> non existent VPE.
> 
> By these definitions, a VMAPP followed by a VSYNC is a bug, as the
> later references a VPE that has been unmapped by the former.
> 
> Fix it by eliding the VSYNC in this scenario.
> 
> Fixes: 64edfaa9a234 ("irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP")
> 
> Signed-off-by: Nianyao Tang <tangnianyao@huawei.com>
> Reviewed-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>

Thanks.