iommu/vt-d: Use device numa domain if RHSA is missing

If there are multiple NUMA domains but the RHSA is missing in ACPI/DMAR
table, we could default to the device NUMA domain as fall back.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20200904010303.2961-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20200922060843.31546-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index f8177c59d229a65957dccb598a5d0cf16731054c..077b69ff680bc30944b328747f7a46956013b91c 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -700,12 +700,47 @@ static int domain_update_iommu_superpage(struct dmar_domain *domain,
        return fls(mask);
 }
 
+static int domain_update_device_node(struct dmar_domain *domain)
+{
+       struct device_domain_info *info;
+       int nid = NUMA_NO_NODE;
+
+       assert_spin_locked(&device_domain_lock);
+
+       if (list_empty(&domain->devices))
+               return NUMA_NO_NODE;
+
+       list_for_each_entry(info, &domain->devices, link) {
+               if (!info->dev)
+                       continue;
+
+               /*
+                * There could possibly be multiple device numa nodes as devices
+                * within the same domain may sit behind different IOMMUs. There
+                * isn't perfect answer in such situation, so we select first
+                * come first served policy.
+                */
+               nid = dev_to_node(info->dev);
+               if (nid != NUMA_NO_NODE)
+                       break;
+       }
+
+       return nid;
+}
+
 /* Some capabilities may be different across iommus */
 static void domain_update_iommu_cap(struct dmar_domain *domain)
 {
        domain_update_iommu_coherency(domain);
        domain->iommu_snooping = domain_update_iommu_snooping(NULL);
        domain->iommu_superpage = domain_update_iommu_superpage(domain, NULL);
+
+       /*
+        * If RHSA is missing, we should default to the device numa domain
+        * as fall back.
+        */
+       if (domain->nid == NUMA_NO_NODE)
+               domain->nid = domain_update_device_node(domain);
 }
 
 struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
@@ -5085,8 +5120,6 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
                if (type == IOMMU_DOMAIN_DMA)
                        intel_init_iova_domain(dmar_domain);
 
-               domain_update_iommu_cap(dmar_domain);
-
                domain = &dmar_domain->domain;
                domain->geometry.aperture_start = 0;
                domain->geometry.aperture_end   =