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Message-ID: <6334aaf3-ed7c-4ded-827d-423b861a0b28@linux.intel.com>
Date:   Wed, 13 Dec 2023 10:14:00 +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>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Nicolin Chen <nicolinc@nvidia.com>,
        Yi Liu <yi.l.liu@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Longfang Liu <liulongfang@huawei.com>,
        Yan Zhao <yan.y.zhao@intel.com>, iommu@lists.linux.dev,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 12/12] iommu: Use refcount for fault data access
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To:     Jason Gunthorpe <jgg@ziepe.ca>
References: <20231207064308.313316-1-baolu.lu@linux.intel.com>
 <20231207064308.313316-13-baolu.lu@linux.intel.com>
 <20231211152456.GB1489931@ziepe.ca>
 <416b6639-8904-4b31-973c-d5522e2731d8@linux.intel.com>
 <20231212151447.GC3013885@ziepe.ca>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20231212151447.GC3013885@ziepe.ca>
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On 12/12/23 11:14 PM, Jason Gunthorpe wrote:
> On Tue, Dec 12, 2023 at 01:17:47PM +0800, Baolu Lu wrote:
>> On 12/11/23 11:24 PM, Jason Gunthorpe wrote:
>>> Also iopf_queue_remove_device() is messed up - it returns an error
>>> code but nothing ever does anything with it ???? Remove functions like
>>> this should never fail.
>> Yes, agreed.
>>
>>> Removal should be like I explained earlier:
>>>    - Disable new PRI reception
>> This could be done by
>>
>> 	rcu_assign_pointer(param->fault_param, NULL);
>>
>> ?
> Not without a synchronize_rcu
> 
> disable new PRI reception should be done by the driver - it should
> turn off PRI generation in the IOMMU HW and flush any HW PRI queues.

Yeah! Get you now.

Best regards,
baolu