On Fri, Mar 18, 2022 at 08:01:04PM +0800, Lu Baolu wrote: > On 2022/3/15 19:49, Tian, Kevin wrote: > > > From: Jean-Philippe Brucker<jean-phili...@linaro.org> > > > Sent: Tuesday, March 15, 2022 7:27 PM > > > > > > On Mon, Mar 14, 2022 at 10:07:06PM -0700, Jacob Pan wrote: > > > > From: Lu Baolu<baolu...@linux.intel.com> > > > > > > > > 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...@linux.intel.com> > > > > Signed-off-by: Jacob Pan<jacob.jun....@linux.intel.com> > > > > 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 > > > Isn't that operation "assign a PASID to a domain" instead? In patch 5, > > > the domain is already attached to the device, so set_domain_pasid() might > > > be clearer and to the point. If the IOMMU driver did the allocation we > > > could also avoid patch 1. > > iiuc this API can also work for future SIOV usage where each mdev attached > > to the domain has its own pasid. "assigning a PASID to a domain" sounds > > like going back to the previous aux domain approach which has one PASID > > per domain and that PASID is used on all devices attached to the aux > > domain... > > > > This also works for SVA as far as I can see. The sva_bind essentially is > to attach an SVA domain to the PASID of a device. The sva_bind/unbind > ops could be removed with these two new callbacks.
As we talked before I would like to see 'sva bind' go away and be replaced with: domain = alloc_sva_iommu_domain(device, current) attach_dev_pasid_domain(domain, device, pasid) Which composes better with everything else. SVA is just a special kind of iommu_domain Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu