Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v6 08/12] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces | Date | Thu, 12 May 2022 05:44:49 +0000 |
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> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Thursday, May 12, 2022 1:17 PM > > On 2022/5/12 13:01, Tian, Kevin wrote: > >> From: Baolu Lu <baolu.lu@linux.intel.com> > >> Sent: Thursday, May 12, 2022 11:03 AM > >> > >> On 2022/5/11 22:53, Jason Gunthorpe wrote: > >>>>> Also, given the current arrangement it might make sense to have a > >>>>> struct iommu_domain_sva given that no driver is wrappering this in > >>>>> something else. > >>>> Fair enough. How about below wrapper? > >>>> > >>>> +struct iommu_sva_domain { > >>>> + /* > >>>> + * Common iommu domain header,*must* be put at the top > >>>> + * of the structure. > >>>> + */ > >>>> + struct iommu_domain domain; > >>>> + struct mm_struct *mm; > >>>> + struct iommu_sva bond; > >>>> +} > >>>> > >>>> The refcount is wrapped in bond. > >>> I'm still not sure that bond is necessary > >> > >> "bond" is the sva handle that the device drivers get through calling > >> iommu_sva_bind(). > >> > > > > 'bond' was required before because we didn't have a domain to wrap > > the page table at that time. > > > > Now we have a domain and it is 1:1 associated to bond. Probably > > make sense now by just returning the domain as the sva handle > > instead? > > It also includes the device information that the domain has been > attached. So the sva_unbind() looks like this: > > /** > * iommu_sva_unbind_device() - Remove a bond created with > iommu_sva_bind_device > * @handle: the handle returned by iommu_sva_bind_device() > * > * Put reference to a bond between device and address space. The device > should > * not be issuing any more transaction for this PASID. All outstanding page > * requests for this PASID must have been flushed to the IOMMU. > */ > void iommu_sva_unbind_device(struct iommu_sva *handle) > > It's fine to replace the iommu_sva with iommu_sva_domain for sva handle, > if we can include the device in the unbind() interface.
can we just have unbind(domain, device)?
> > Anyway, I'd expect to achieve all these in two steps: > > - sva and iopf refactoring, only iommu internal changes; > - sva interface refactoring, only interface changes. > > Does above work? > > Best regards, > baolu
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