Re: [PATCH v2 2/8] iommu: Add attach/detach_dev_pasid domain ops

[Jason Gunthorpe]

On Fri, Mar 18, 2022 at 07:52:33PM +0800, Lu Baolu wrote:
> On 2022/3/15 13:07, Jacob Pan wrote:
> > From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > 
> > An IOMMU domain represents an address space which can be attached by
> > devices that perform DMA within a domain. However, for platforms with
> > PASID capability the domain attachment needs be handled at device+PASID
> > level. There can be multiple PASIDs within a device and multiple devices
> > attached to a given domain.
> > This patch introduces a new IOMMU op which support device, PASID, and
> > IOMMU domain attachment. The immediate use case is for PASID capable
> > devices to perform DMA under DMA APIs.
> > 
> > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> >   include/linux/iommu.h | 6 ++++++
> >   1 file changed, 6 insertions(+)
> > 
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index 369f05c2a4e2..fde5b933dbe3 100644
> > +++ b/include/linux/iommu.h
> > @@ -227,6 +227,8 @@ struct iommu_iotlb_gather {
> >    * @aux_get_pasid: get the pasid given an aux-domain
> >    * @sva_bind: Bind process address space to device
> >    * @sva_unbind: Unbind process address space from device
> > + * @attach_dev_pasid: attach an iommu domain to a pasid of device
> > + * @detach_dev_pasid: detach an iommu domain from a pasid of device
> >    * @sva_get_pasid: Get PASID associated to a SVA handle
> >    * @page_response: handle page request response
> >    * @cache_invalidate: invalidate translation caches
> > @@ -296,6 +298,10 @@ struct iommu_ops {
> >   	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
> >   				      void *drvdata);
> >   	void (*sva_unbind)(struct iommu_sva *handle);
> > +	int (*attach_dev_pasid)(struct iommu_domain *domain,
> > +				struct device *dev, ioasid_t id);
> > +	void (*detach_dev_pasid)(struct iommu_domain *domain,
> > +				 struct device *dev, ioasid_t id);
> 
> As we have introduced iommu_domain_ops, these callbacks should be part
> of the domain ops.

+1

Jason