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Message-ID: <c69320f8-c906-549f-0fbd-ef4c9b665f25@linux.intel.com>
Date:   Tue, 23 Aug 2022 14:26:19 +0800
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Cc:     baolu.lu@linux.intel.com, Joerg Roedel <joro@8bytes.org>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Kevin Tian <kevin.tian@intel.com>, yi.l.liu@intel.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] iommu/vt-d: Fix possible recursive lock in
 iommu_flush_dev_iotlb()
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To:     iommu@lists.linux.dev
References: <20220817025650.3253959-1-baolu.lu@linux.intel.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20220817025650.3253959-1-baolu.lu@linux.intel.com>
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On 2022/8/17 10:56, Lu Baolu wrote:
> The per domain spinlock is acquired in iommu_flush_dev_iotlb(), which
> is possbile to be called in the interrupt context. For instance,
> 
>    <IRQ>
>    iommu_flush_dev_iotlb
>    iommu_flush_iotlb_psi
>    intel_iommu_tlb_sync
>    iommu_iotlb_sync
>    __iommu_dma_unmap
>    ? nvme_unmap_data
>    nvme_unmap_data
>    nvme_pci_complete_rq
>    nvme_irq
>    __handle_irq_event_percpu
>    handle_irq_event_percpu
>    handle_irq_event
>    handle_edge_irq
>    __common_interrupt
>    common_interrupt
> 
> This coverts the spin_lock/unlock() into the irq save/restore varieties
> to avoid the possible recursive locking issues.
> 
> Fixes: ffd5869d93530 ("iommu/vt-d: Replace spin_lock_irqsave() with spin_lock()")
> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>

This patch has been queued:

https://lore.kernel.org/linux-iommu/20220823061557.1631056-1-baolu.lu@linux.intel.com/

Best regards,
baolu