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. This could
also benefit a vIOMMU use case where only single vIOMMU is exposed, hence
no RHSA will be present but device numa domain can be correct.
Cc: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Kevin Tian <kevin.t...@intel.com>
Cc: Ashok Raj <ashok....@intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 37 +++++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
Change log:
v1->v2:
- Add a comment as suggested by Kevin.
https://lore.kernel.org/linux-iommu/mwhpr11mb1645e6d6bd1efdfa139aa37c8c...@mwhpr11mb1645.namprd11.prod.outlook.com/
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 7f844d1c8cd9..69d5a87188f4 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -698,12 +698,47 @@ 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,
@@ -5096,8 +5131,6 @@ 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 =
--
2.17.1
