[PATCH v8 6/8] iommu/vt-d: Set the nested domain to a device

Yi Liu
2023-10-26T04:43:30Z

This adds the helper for setting the nested domain to a device hence
enable nested domain usage on Intel VT-d.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/intel/nested.c | 54 ++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 56bb205fca06..b560ab76e126 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -12,8 +12,61 @@
#define pr_fmt(fmt) "DMAR: " fmt

#include <linux/iommu.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>

#include "iommu.h"
+#include "pasid.h"
+
+static int intel_nested_attach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_iommu *iommu = info->iommu;
+ unsigned long flags;
+ int ret = 0;
+
+ if (info->domain)
+ device_block_translation(dev);
+
+ if (iommu->agaw < dmar_domain->s2_domain->agaw) {
+ dev_err_ratelimited(dev, "Adjusted guest address width not compatible\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Stage-1 domain cannot work alone, it is nested on a s2_domain.
+ * The s2_domain will be used in nested translation, hence needs
+ * to ensure the s2_domain is compatible with this IOMMU.
+ */
+ ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain, dev);
+ if (ret) {
+ dev_err_ratelimited(dev, "s2 domain is not compatible\n");
+ return ret;
+ }
+
+ ret = domain_attach_iommu(dmar_domain, iommu);
+ if (ret) {
+ dev_err_ratelimited(dev, "Failed to attach domain to iommu\n");
+ return ret;
+ }
+
+ ret = intel_pasid_setup_nested(iommu, dev,
+ IOMMU_NO_PASID, dmar_domain);
+ if (ret) {
+ domain_detach_iommu(dmar_domain, iommu);
+ dev_err_ratelimited(dev, "Failed to setup pasid entry\n");
+ return ret;
+ }
+
+ info->domain = dmar_domain;
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_add(&info->link, &dmar_domain->devices);
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+
+ return 0;
+}

static void intel_nested_domain_free(struct iommu_domain *domain)
{
@@ -21,6 +74,7 @@ static void intel_nested_domain_free(struct iommu_domain *domain)
}

static const struct iommu_domain_ops intel_nested_domain_ops = {
+ .attach_dev = intel_nested_attach_dev,
.free = intel_nested_domain_free,
};

--
2.34.1