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Date:   Thu, 13 Jul 2023 11:43:55 +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>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Nicolin Chen <nicolinc@nvidia.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 9/9] iommu: Use fault cookie to store iopf_param
To:     "Tian, Kevin" <kevin.tian@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
References: <20230711010642.19707-1-baolu.lu@linux.intel.com>
 <20230711010642.19707-10-baolu.lu@linux.intel.com>
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 <e26db44c-ec72-085d-13ee-597237ba2134@linux.intel.com>
 <BN9PR11MB527640E6FBD5271E8AF9D59B8C37A@BN9PR11MB5276.namprd11.prod.outlook.com>
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From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <BN9PR11MB527640E6FBD5271E8AF9D59B8C37A@BN9PR11MB5276.namprd11.prod.outlook.com>
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On 2023/7/13 11:24, Tian, Kevin wrote:
>> From: Baolu Lu <baolu.lu@linux.intel.com>
>> Sent: Wednesday, July 12, 2023 11:13 AM
>>
>> On 2023/7/12 6:02, Jacob Pan wrote:
>>> On Tue, 11 Jul 2023 09:06:42 +0800, Lu Baolu<baolu.lu@linux.intel.com>
>>> wrote:
>>>
>>>> @@ -158,7 +158,7 @@ int iommu_queue_iopf(struct iommu_fault *fault,
>>>> struct device *dev)
>>>>    	 * As long as we're holding param->lock, the queue can't be
>>>> unlinked
>>>>    	 * from the device and therefore cannot disappear.
>>>>    	 */
>>>> -	iopf_param = param->iopf_param;
>>>> +	iopf_param = iommu_get_device_fault_cookie(dev, 0);
>>> I am not sure I understand how does it know the cookie type is iopf_param
>>> for PASID 0?
>>>
>>> Between IOPF and IOMMUFD use of the cookie, cookie types are different,
>>> right?
>>>
>>
>> The fault cookie is managed by the code that delivers or handles the
>> faults. The sva and IOMMUFD paths are exclusive.
>>
> 
> what about siov? A siov-capable device can support sva and iommufd
> simultaneously.

For siov case, the pasid should be global. RID and each pasid are still
exclusive, so I don't see any problem. Did I overlook anything?

Best regards,
baolu