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Subject: Re: [PATCH v6 08/15] iommu: Pass domain to sva_unbind_gpasid()
To:     Alex Williamson <alex.williamson@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>
Cc:     baolu.lu@linux.intel.com, joro@8bytes.org, kevin.tian@intel.com,
        jacob.jun.pan@linux.intel.com, ashok.raj@intel.com,
        jun.j.tian@intel.com, yi.y.sun@intel.com, jean-philippe@linaro.org,
        peterx@redhat.com, hao.wu@intel.com, stefanha@gmail.com,
        iommu@lists.linux-foundation.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1595917664-33276-1-git-send-email-yi.l.liu@intel.com>
 <1595917664-33276-9-git-send-email-yi.l.liu@intel.com>
 <20200820150619.5dc1ec7a@x1.home>
From:   Auger Eric <eric.auger@redhat.com>
Message-ID: <7db3f15c-09e3-6a52-352a-c9a499895922@redhat.com>
Date:   Fri, 21 Aug 2020 15:09:29 +0200
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Hi,

On 8/20/20 11:06 PM, Alex Williamson wrote:
> On Mon, 27 Jul 2020 23:27:37 -0700
> Liu Yi L <yi.l.liu@intel.com> wrote:
> 
>> From: Yi Sun <yi.y.sun@intel.com>
>>
>> Current interface is good enough for SVA virtualization on an assigned
>> physical PCI device, but when it comes to mediated devices, a physical
>> device may attached with multiple aux-domains. Also, for guest unbind,
> 
> s/may/may be/
> 
>> the PASID to be unbind should be allocated to the VM. This check requires
>> to know the ioasid_set which is associated with the domain.
>>
>> So this interface needs to pass in domain info. Then the iommu driver is
>> able to know which domain will be used for the 2nd stage translation of
>> the nesting mode and also be able to do PASID ownership check. This patch
>> passes @domain per the above reason. Also, the prototype of &pasid is
>> changed frnt" to "u32" as the below link.
> 
> s/frnt"/from an "int"/
>  
>> https://lore.kernel.org/kvm/27ac7880-bdd3-2891-139e-b4a7cd18420b@redhat.com/
> 
> This is really confusing, the link is to Eric's comment asking that the
> conversion from (at the time) int to ioasid_t be included in the commit
> log.  The text here implies that it's pointing to some sort of
> justification for the change, which it isn't.  It just notes that it
> happened, not why it happened, with a mostly irrelevant link.
> 
>> Cc: Kevin Tian <kevin.tian@intel.com>
>> CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
>> Cc: Alex Williamson <alex.williamson@redhat.com>
>> Cc: Eric Auger <eric.auger@redhat.com>
>> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
>> Cc: Joerg Roedel <joro@8bytes.org>
>> Cc: Lu Baolu <baolu.lu@linux.intel.com>
>> Reviewed-by: Eric Auger <eric.auger@redhat.com>
>> Signed-off-by: Yi Sun <yi.y.sun@intel.com>
>> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
>> ---
>> v5 -> v6:
>> *) use "u32" prototype for @pasid.
>> *) add review-by from Eric Auger.
> 
> I'd probably hold off on adding Eric's R-b given the additional change
> in this version FWIW.  Thanks,

Yep I did not notice that change given the R-b was applied ;-)

Thanks

Eric
> 
> Alex
>  
>> v2 -> v3:
>> *) pass in domain info only
>> *) use u32 for pasid instead of int type
>>
>> v1 -> v2:
>> *) added in v2.
>> ---
>>  drivers/iommu/intel/svm.c   | 3 ++-
>>  drivers/iommu/iommu.c       | 2 +-
>>  include/linux/intel-iommu.h | 3 ++-
>>  include/linux/iommu.h       | 3 ++-
>>  4 files changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
>> index c27d16a..c85b8d5 100644
>> --- a/drivers/iommu/intel/svm.c
>> +++ b/drivers/iommu/intel/svm.c
>> @@ -436,7 +436,8 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
>>  	return ret;
>>  }
>>  
>> -int intel_svm_unbind_gpasid(struct device *dev, int pasid)
>> +int intel_svm_unbind_gpasid(struct iommu_domain *domain,
>> +			    struct device *dev, u32 pasid)
>>  {
>>  	struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
>>  	struct intel_svm_dev *sdev;
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index 1ce2a61..bee79d7 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -2145,7 +2145,7 @@ int iommu_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev,
>>  	if (unlikely(!domain->ops->sva_unbind_gpasid))
>>  		return -ENODEV;
>>  
>> -	return domain->ops->sva_unbind_gpasid(dev, data->hpasid);
>> +	return domain->ops->sva_unbind_gpasid(domain, dev, data->hpasid);
>>  }
>>  EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid);
>>  
>> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
>> index 0d0ab32..f98146b 100644
>> --- a/include/linux/intel-iommu.h
>> +++ b/include/linux/intel-iommu.h
>> @@ -738,7 +738,8 @@ extern int intel_svm_enable_prq(struct intel_iommu *iommu);
>>  extern int intel_svm_finish_prq(struct intel_iommu *iommu);
>>  int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
>>  			  struct iommu_gpasid_bind_data *data);
>> -int intel_svm_unbind_gpasid(struct device *dev, int pasid);
>> +int intel_svm_unbind_gpasid(struct iommu_domain *domain,
>> +			    struct device *dev, u32 pasid);
>>  struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm,
>>  				 void *drvdata);
>>  void intel_svm_unbind(struct iommu_sva *handle);
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index b1ff702..80467fc 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -303,7 +303,8 @@ struct iommu_ops {
>>  	int (*sva_bind_gpasid)(struct iommu_domain *domain,
>>  			struct device *dev, struct iommu_gpasid_bind_data *data);
>>  
>> -	int (*sva_unbind_gpasid)(struct device *dev, int pasid);
>> +	int (*sva_unbind_gpasid)(struct iommu_domain *domain,
>> +				 struct device *dev, u32 pasid);
>>  
>>  	int (*def_domain_type)(struct device *dev);
>>  
>