Re: [PATCH v4 11/13] iommu/vt-d: Add set_dev_pasid callback for nested domain

[Baolu Lu <baolu.lu@linux.intel.com>]

On 11/4/24 21:18, Yi Liu wrote:
> From: Lu Baolu <baolu.lu@linux.intel.com>
> 
> Add intel_nested_set_dev_pasid() to set a nested type domain to a PASID
> of a device.
> 

Co-developed-by: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Co-developed-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>

And convert the patch author to you.

> ---
>   drivers/iommu/intel/iommu.c  |  2 +-
>   drivers/iommu/intel/iommu.h  |  7 ++++++
>   drivers/iommu/intel/nested.c | 43 ++++++++++++++++++++++++++++++++++++
>   drivers/iommu/intel/pasid.h  | 11 +++++++++
>   4 files changed, 62 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 7e82b3a4bba7..7f1ca3c342a3 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -1944,7 +1944,7 @@ static int domain_setup_first_level(struct intel_iommu *iommu,
>   					     flags);
>   }
>   
> -static bool dev_is_real_dma_subdevice(struct device *dev)
> +bool dev_is_real_dma_subdevice(struct device *dev)

How about making this a static inline in the header?

>   {
>   	return dev && dev_is_pci(dev) &&
>   	       pci_real_dma_dev(to_pci_dev(dev)) != to_pci_dev(dev);
> diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
> index 8e7ffb421ac4..55478d7b64cf 100644
> --- a/drivers/iommu/intel/iommu.h
> +++ b/drivers/iommu/intel/iommu.h
> @@ -818,6 +818,11 @@ domain_id_iommu(struct dmar_domain *domain, struct intel_iommu *iommu)
>   	return info->did;
>   }
>   
> +static inline int domain_type_is_nested(struct dmar_domain *domain)
> +{
> +	return domain->domain.type == IOMMU_DOMAIN_NESTED;
> +}

Why do you need this?

> +
>   /*
>    * 0: readable
>    * 1: writable
> @@ -1225,6 +1230,8 @@ void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
>    */
>   #define QI_OPT_WAIT_DRAIN		BIT(0)
>   
> +bool dev_is_real_dma_subdevice(struct device *dev);
> +
>   int domain_attach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu);
>   void domain_detach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu);
>   void device_block_translation(struct device *dev);
> diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
> index 3ce3c4fd210e..890087f3509f 100644
> --- a/drivers/iommu/intel/nested.c
> +++ b/drivers/iommu/intel/nested.c
> @@ -130,8 +130,51 @@ static int intel_nested_cache_invalidate_user(struct iommu_domain *domain,
>   	return ret;
>   }
>   
> +static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
> +				      struct device *dev, ioasid_t pasid,
> +				      struct iommu_domain *old)
> +{
> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct intel_iommu *iommu = info->iommu;
> +	struct dev_pasid_info *dev_pasid;
> +	int ret;
> +
> +	/* No SVA domain replacement usage so far */
> +	if (old && old->type == IOMMU_DOMAIN_SVA)
> +		return -EOPNOTSUPP;

No need for this check from driver's point of view. If there is really a
need, it should go to the iommu core.

> +
> +	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
 > +		return -EOPNOTSUPP;> +
> +	if (context_copied(iommu, info->bus, info->devfn))
> +		return -EBUSY;
> +
> +	ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain,
> +					   dev);
> +	if (ret)
> +		return ret;
> +
> +	dev_pasid = domain_add_dev_pasid(domain, dev, pasid);
> +	if (IS_ERR(dev_pasid))
> +		return PTR_ERR(dev_pasid);
> +
> +	ret = domain_setup_nested(iommu, dmar_domain, dev, pasid, old);
> +	if (ret)
> +		goto out_remove_dev_pasid;
> +
> +	domain_remove_dev_pasid(old, dev, pasid);
> +
> +	return 0;
> +
> +out_remove_dev_pasid:
> +	domain_remove_dev_pasid(domain, dev, pasid);
> +	return ret;
> +}
> +
>   static const struct iommu_domain_ops intel_nested_domain_ops = {
>   	.attach_dev		= intel_nested_attach_dev,
> +	.set_dev_pasid		= intel_nested_set_dev_pasid,
>   	.free			= intel_nested_domain_free,
>   	.cache_invalidate_user	= intel_nested_cache_invalidate_user,
>   };
> diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
> index a3b5945a1812..31a4e7c01853 100644
> --- a/drivers/iommu/intel/pasid.h
> +++ b/drivers/iommu/intel/pasid.h
> @@ -335,6 +335,17 @@ static inline int domain_setup_passthrough(struct intel_iommu *iommu,
>   	return intel_pasid_setup_pass_through(iommu, dev, pasid);
>   }
>   
> +static inline int domain_setup_nested(struct intel_iommu *iommu,
> +				      struct dmar_domain *domain,
> +				      struct device *dev, ioasid_t pasid,
> +				      struct iommu_domain *old)
> +{
> +	if (old)
> +		return intel_pasid_replace_nested(iommu, dev,
> +						  pasid, domain);
> +	return intel_pasid_setup_nested(iommu, dev, pasid, domain);
> +}
> +
>   void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
>   				 struct device *dev, u32 pasid,
>   				 bool fault_ignore);

Others look good to me.

--
baolu