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Message-ID: <3882aec9-c221-f431-c0f7-a764ca947655@linux.intel.com>
Date:   Fri, 11 Aug 2023 09:23:55 +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>,
        iommu@lists.linux.dev, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 04/12] iommu: Replace device fault handler with
 iommu_queue_iopf()
Content-Language: en-US
To:     Jason Gunthorpe <jgg@ziepe.ca>
References: <20230727054837.147050-1-baolu.lu@linux.intel.com>
 <20230727054837.147050-5-baolu.lu@linux.intel.com>
 <ZNUq2IcvjEkwQewc@ziepe.ca>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <ZNUq2IcvjEkwQewc@ziepe.ca>
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On 2023/8/11 2:22, Jason Gunthorpe wrote:
> On Thu, Jul 27, 2023 at 01:48:29PM +0800, Lu Baolu wrote:
>> The individual iommu drivers report iommu faults by calling
>> iommu_report_device_fault(), where a pre-registered device fault handler
>> is called to route the fault to another fault handler installed on the
>> corresponding iommu domain.
>>
>> The pre-registered device fault handler is static and won't be dynamic
>> as the fault handler is eventually per iommu domain. Replace calling
>> device fault handler with iommu_queue_iopf().
>>
>> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>
>> ---
>>   drivers/iommu/iommu.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index 4352a149a935..00309f66153b 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -1381,7 +1381,7 @@ int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt)
>>   		mutex_unlock(&fparam->lock);
>>   	}
>>   
>> -	ret = fparam->handler(&evt->fault, fparam->data);
>> +	ret = iommu_queue_iopf(&evt->fault, dev);
>>   	if (ret && evt_pending) {
>>   		mutex_lock(&fparam->lock);
>>   		list_del(&evt_pending->list);
> I don't get it, why not remove fparam->handler/data entirely in this
> patch? There is no user once you do this change?

It needs some cleanups elsewhere, so I put it in a separate patch.

Best regards,
baolu