[PATCH 6/6] iommu/vt-d: Add domain_alloc_user op

[Yi Liu <yi.l.liu@intel.com>]

This adds the domain_alloc_user op implementation. It supports allocating
domains to be used as parent under nested translation.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/intel/iommu.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 5db283c17e0d..491bcde1ff96 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4074,6 +4074,25 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 	return NULL;
 }
 
+static struct iommu_domain *
+intel_iommu_domain_alloc_user(struct device *dev, u32 flags)
+{
+	struct iommu_domain *domain;
+	struct intel_iommu *iommu;
+
+	iommu = device_to_iommu(dev, NULL, NULL);
+	if (!iommu)
+		return ERR_PTR(-ENODEV);
+
+	if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ecap_nest(iommu->ecap))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	domain = iommu_domain_alloc(dev->bus);
+	if (!domain)
+		domain = ERR_PTR(-ENOMEM);
+	return domain;
+}
+
 static void intel_iommu_domain_free(struct iommu_domain *domain)
 {
 	if (domain != &si_domain->domain && domain != &blocking_domain)
@@ -4807,6 +4826,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.hw_info		= intel_iommu_hw_info,
 	.domain_alloc		= intel_iommu_domain_alloc,
+	.domain_alloc_user	= intel_iommu_domain_alloc_user,
 	.probe_device		= intel_iommu_probe_device,
 	.probe_finalize		= intel_iommu_probe_finalize,
 	.release_device		= intel_iommu_release_device,
-- 
2.34.1