[PATCH v7 6/8] iommu/vt-d: Set the nested domain to a device

[Yi Liu]

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....@linux.intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
Signed-off-by: Yi Liu <yi.l....@intel.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 859c60bead05..d9197dd72748 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