Messages in this thread | | | Date | Wed, 30 Mar 2022 16:02:01 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH RFC v2 03/11] iommu/sva: Add iommu_domain type for SVA |
| |
On Tue, Mar 29, 2022 at 01:37:52PM +0800, Lu Baolu wrote: > @@ -95,6 +101,7 @@ struct iommu_domain { > void *handler_token; > struct iommu_domain_geometry geometry; > struct iommu_dma_cookie *iova_cookie; > + struct iommu_sva_cookie *sva_cookie;
Cookie is still the wrong word to use here
> +struct iommu_sva_cookie { > + struct mm_struct *mm; > + ioasid_t pasid; > + refcount_t users;
Really surprised to see a refcount buried inside the iommu_domain..
This design seems inside out, the SVA struct should 'enclose' the domain, not be a pointer inside it.
struct iommu_sva_domain { struct kref_t kref; struct mm_struct *mm; ioasid_t pasid;
/* All the domains that are linked to this */ struct xarray domain_list; };
And then you could have a pointer to that inside the mm_struct instead of just the naked pasid.
> +static __maybe_unused struct iommu_domain *
Why maybe unused?
> +iommu_sva_get_domain(struct device *dev, struct mm_struct *mm) > +{ > + struct iommu_domain *domain; > + ioasid_t pasid = mm->pasid; > + > + if (pasid == INVALID_IOASID) > + return NULL; > + > + domain = xa_load(&sva_domain_array, pasid); > + if (!domain) > + return iommu_sva_alloc_domain(dev, mm); > + iommu_sva_domain_get_user(domain);
This assumes any domain is interchangeable with any device, which is not the iommu model. We need a domain op to check if a device is compatiable with the domain for vfio an iommufd, this should do the same.
It means each mm can have a list of domains associated with it and a new domain is auto-created if the device doesn't work with any of the existing domains.
Jason
| |