Re: [RFC PATCH 05/10] iommu/vt-d: Setup DMA remapping for mediated devices

[Lu Baolu]

Hi,

On 07/23/2018 12:44 PM, Liu, Yi L wrote:
>> From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx]
>> Sent: Sunday, July 22, 2018 2:09 PM
>>
>> This configures the second level page table when external components request to
>> allocate a domain for a mediated device.
> I think it should be the time when adding a mediate device to the domain.

You are right. Will correct it.

>
>> Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
>> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
>> Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
>> Cc: Liu Yi L <yi.l.liu@xxxxxxxxx>
>> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
>> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>> ---
>>  drivers/iommu/intel-iommu.c | 73
>> ++++++++++++++++++++++++++++++++++++++++-----
>>  1 file changed, 66 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index
>> 57ccfc4..b6e9ea8 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -2569,8 +2569,9 @@ static struct dmar_domain
>> *dmar_insert_one_dev_info(struct intel_iommu *iommu,
>>  	if (dev)
>>  		dev->archdata.iommu = info;
>>
>> -	if (dev && dev_is_pci(dev) && sm_supported(iommu)) {
>> -		bool pass_through;
>> +	if (dev && sm_supported(iommu)) {
>> +		bool pass_through = hw_pass_through &&
>> +				domain_type_is_si(domain);
>>
>>  		ret = intel_pasid_alloc_table(dev);
>>  		if (ret) {
>> @@ -2579,12 +2580,21 @@ static struct dmar_domain
>> *dmar_insert_one_dev_info(struct intel_iommu *iommu,
>>  			return NULL;
>>  		}
>>
>> -		/* Setup the PASID entry for requests without PASID: */
>> -		pass_through = hw_pass_through && domain_type_is_si(domain);
>>  		spin_lock(&iommu->lock);
>> -		intel_pasid_setup_second_level(iommu, domain, dev,
>> -					       PASID_RID2PASID,
>> -					       pass_through);
>> +
>> +		/* Setup the PASID entry for requests without PASID: */
>> +		if (dev_is_pci(dev))
>> +			intel_pasid_setup_second_level(iommu, domain, dev,
>> +						       PASID_RID2PASID,
> can domain->default_pasid be initialized to be PASID_RID2PASID if the domain
> is not a domain used by mediated device?

PASID_RID2PASID is 0 as well.


>
>> +						       pass_through);
>> +		/* Setup the PASID entry for mediated devices: */
>> +		else if (dev_is_mdev(dev))
>> +			intel_pasid_setup_second_level(iommu, domain, dev,
>> +						       domain->default_pasid,
>> +						       false);
>> +		else
>> +			pr_err("Unsupported device %s\n", dev_name(dev));
>> +
>>  		spin_unlock(&iommu->lock);
>>  	}
>>  	spin_unlock_irqrestore(&device_domain_lock, flags); @@ -4937,6 +4947,32
>> @@ static void domain_context_clear(struct intel_iommu *iommu, struct device
>> *dev)
>>  	pci_for_each_dma_alias(to_pci_dev(dev), &domain_context_clear_one_cb,
>> iommu);  }
>>
>> +static void
>> +iommu_flush_ext_iotlb(struct intel_iommu *iommu, u16 did, u32 pasid,
> Per latest VT-d spec, its new name is pasid-based-iotlb. Pls update the naming
> accordingly. :)

Okay.

Best regards,
Lu Baolu

>
> Regards,
> Yi Liu
>
>> +u64 gran) {
>> +	struct qi_desc desc;
>> +
>> +	desc.high = 0;
>> +	desc.low = QI_EIOTLB_PASID(pasid) | QI_EIOTLB_DID(did) |
>> +			QI_EIOTLB_GRAN(gran) | QI_EIOTLB_TYPE;
>> +
>> +	qi_submit_sync(&desc, iommu);
>> +}
>> +
>> +static void iommu_flush_pasid_dev_iotlb(struct intel_iommu *iommu,
>> +					struct device *dev, int sid, int pasid) {
>> +	struct qi_desc desc;
>> +	struct pci_dev *pdev = to_pci_dev(dev);
>> +	int qdep = pci_ats_queue_depth(pdev);
>> +
>> +	desc.low = QI_DEV_EIOTLB_PASID(pasid) | QI_DEV_EIOTLB_SID(sid) |
>> +			QI_DEV_EIOTLB_QDEP(qdep) | QI_DEIOTLB_TYPE;
>> +	desc.high = QI_DEV_EIOTLB_ADDR(-1ULL >> 1) | QI_DEV_EIOTLB_SIZE;
>> +
>> +	qi_submit_sync(&desc, iommu);
>> +}
>> +
>>  static void __dmar_remove_one_dev_info(struct device_domain_info *info)  {
>>  	struct intel_iommu *iommu;
>> @@ -4949,6 +4985,29 @@ static void __dmar_remove_one_dev_info(struct
>> device_domain_info *info)
>>
>>  	iommu = info->iommu;
>>
>> +	if (dev_is_mdev(info->dev)) {
>> +		struct dmar_domain *domain = info->domain;
>> +		int did = domain->iommu_did[iommu->seq_id];
>> +		int sid = info->bus << 8 | info->devfn;
>> +		struct device *dev = info->dev;
>> +
>> +		intel_pasid_clear_entry(dev, domain->default_pasid);
>> +
>> +		/* Flush IOTLB including PASID Cache: */
>> +		iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH);
>> +
>> +		/*
>> +		 * Flush EIOTLB. The only way to flush global mappings within
>> +		 * a PASID is to use QI_GRAN_ALL_ALL.
>> +		 */
>> +		iommu_flush_ext_iotlb(iommu, did, domain->default_pasid,
>> +				      QI_GRAN_ALL_ALL);
>> +
>> +		/* Flush Dev TLB: */
>> +		iommu_flush_pasid_dev_iotlb(iommu, dev_mdev_parent(dev), sid,
>> +					    domain->default_pasid);
>> +	}
>> +
>>  	if (info->dev) {
>>  		iommu_disable_dev_iotlb(info);
>>  		domain_context_clear(iommu, info->dev);
>> --
>> 2.7.4
>