Re: [PATCH RFC 06/11] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces

Lu Baolu
2022-03-21T11:02:34Z

On 2022/3/21 16:04, Tian, Kevin wrote:
>> From: Lu Baolu <baolu.lu@linux.intel.com>
>> Sent: Sunday, March 20, 2022 2:40 PM
>> +struct iommu_sva *
>> +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void
>> *drvdata)
>> +{
>> + int ret = -EINVAL;
>> + struct iommu_sva *handle;
>> + struct iommu_domain *domain;
>> +
>> + handle = kzalloc(sizeof(*handle), GFP_KERNEL);
>> + if (!handle)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + ret = iommu_sva_alloc_pasid(mm, 1, (1U << dev->iommu->pasid_bits)
>> - 1);
>> + if (ret)
>> + goto out;
>> +
>> + domain = iommu_sva_domain_alloc(dev);
>> + if (!domain) {
>> + ret = -ENOMEM;
>> + goto out;
>> + }
>> + domain->sva_cookie = mm;
>
> one domain can be attached by multiple devices, so this should not be
> a blind alloc.

Indeed. Perhaps we could associate the SVA domain with the mm->pasid and
add a user counter inside the domain.

Best regards,
baolu