Messages in this thread | | | Date | Tue, 15 Mar 2022 11:33:22 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v2 3/8] iommu/vt-d: Implement device_pasid domain attach ops |
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On Mon, Mar 14, 2022 at 10:07:07PM -0700, Jacob Pan wrote: > + /* > + * Each domain could have multiple devices attached with shared or per > + * device PASIDs. At the domain level, we keep track of unique PASIDs and > + * device user count. > + * E.g. If a domain has two devices attached, device A has PASID 0, 1; > + * device B has PASID 0, 2. Then the domain would have PASID 0, 1, 2. > + */
A 2d array of xarray's seems like a poor data structure for this task.
AFACIT this wants to store a list of (device, pasid) tuples, so a simple linked list, 1d xarray vector or a red black tree seems more appropriate..
> + if (entry) { > + pinfo = entry; > + } else { > + pinfo = kzalloc(sizeof(*pinfo), GFP_ATOMIC); > + if (!pinfo) > + return -ENOMEM; > + pinfo->pasid = pasid; > + /* Store the new PASID info in the per domain array */ > + ret = xa_err(__xa_store(&dmar_domain->pasids, pasid, pinfo, > + GFP_ATOMIC)); > + if (ret) > + goto xa_store_err; > + } > + /* Store PASID in per device-domain array, this is for tracking devTLB */ > + ret = xa_err(xa_store(&info->pasids, pasid, pinfo, GFP_ATOMIC)); > + if (ret) > + goto xa_store_err; > + > + atomic_inc(&pinfo->users); > + xa_unlock(&dmar_domain->pasids); > + > + return 0; > + > +xa_store_err: > + xa_unlock(&dmar_domain->pasids); > + spin_lock_irqsave(&iommu->lock, flags); > + intel_pasid_tear_down_entry(iommu, dev, pasid, false); > + spin_unlock_irqrestore(&iommu->lock, flags); > + > + if (!atomic_read(&pinfo->users)) { > + __xa_erase(&dmar_domain->pasids, pasid);
This isn't locked right
Jason
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