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Subject: Re: [PATCH] irqchip/gic-v4.1: Properly lock VPEs when doing a
 directLPI invalidation
To:     Marc Zyngier <maz@kernel.org>
CC:     <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Kunkun Jiang <jiangkunkun@huawei.com>,
        <wanghaibin.wang@huawei.com>
References: <20230617073242.3199746-1-maz@kernel.org>
From:   Zenghui Yu <yuzenghui@huawei.com>
Message-ID: <b665e102-eba9-cd4f-5b4e-ccbd77444233@huawei.com>
Date:   Thu, 29 Jun 2023 22:52:24 +0800
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Hi Marc,

On 2023/6/17 15:32, Marc Zyngier wrote:
> We normally rely on the irq_to_cpuid_[un]lock() primitives to make
> sure nothing will change col->idx while performing a LPI invalidation.

"change col_idx while performing a vLPI invalidation"?

> However, these primitives do not cover VPE doorbells, and we have
> some open-coded locking for that. Unfortunately, this locking is
> pretty bogus.
> 
> Instead, extend the above primitives to cover VPE doorbells and
> convert the whole thing to it.
> 
> Fixes: f3a059219bc7 ("irqchip/gic-v4.1: Ensure mutual exclusion between vPE affinity change and RD access")
> Reported-by: Kunkun Jiang <jiangkunkun@huawei.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Zenghui Yu <yuzenghui@huawei.com>
> Cc: wanghaibin.wang@huawei.com

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

Nit: I think the Subject header can be changed to 'irqchip/gic-v4' as
the bug it fixes only affects GICv4 HW. v4.1 is unaffected.

Thanks,
Zenghui