Messages in this thread | | | Date | Tue, 24 May 2022 09:12:35 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH v4 3/6] iommu/vt-d: Implement domain ops for attach_dev_pasid |
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Hi Jason,
On Tue, 24 May 2022 10:51:35 -0300, Jason Gunthorpe <jgg@nvidia.com> wrote:
> On Wed, May 18, 2022 at 11:21:17AM -0700, Jacob Pan wrote: > > On VT-d platforms with scalable mode enabled, devices issue DMA requests > > with PASID need to attach PASIDs to given IOMMU domains. The attach > > operation involves the following: > > - Programming the PASID into the device's PASID table > > - Tracking device domain and the PASID relationship > > - Managing IOTLB and device TLB invalidations > > > > This patch add attach_dev_pasid functions to the default domain ops > > which is used by DMA and identity domain types. It could be extended to > > support other domain types whenever necessary. > > > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > > drivers/iommu/intel/iommu.c | 72 +++++++++++++++++++++++++++++++++++-- > > 1 file changed, 70 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > > index 1c2c92b657c7..75615c105fdf 100644 > > +++ b/drivers/iommu/intel/iommu.c > > @@ -1556,12 +1556,18 @@ static void __iommu_flush_dev_iotlb(struct > > device_domain_info *info, u64 addr, unsigned int mask) > > { > > u16 sid, qdep; > > + ioasid_t pasid; > > > > if (!info || !info->ats_enabled) > > return; > > > > sid = info->bus << 8 | info->devfn; > > qdep = info->ats_qdep; > > + pasid = iommu_get_pasid_from_domain(info->dev, > > &info->domain->domain); > > No, a simgple domain can be attached to multiple pasids, all need to > be flushed. > Here is device TLB flush, why would I want to flush PASIDs other than my own device attached?
At one level up, we do have a list of device to be flushed. list_for_each_entry(info, &domain->devices, link) __iommu_flush_dev_iotlb(info, addr, mask);
Note that RID2PASID is not in the pasid_array, its DEVTLB flush also needs special handling in that the device is doing DMA w/o PASID, thus not aware of RID2PASID.
> This whole API isn't suitable. > > Jason
Thanks,
Jacob
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