Add the domain_alloc_paging callback for domain allocation using the
iommu_paging_domain_alloc() interface.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241021085125.192333-2-baolu.lu@linux.intel.com
---
 drivers/iommu/intel/iommu.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index e860bc9439a2..0d2237b55b6b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4592,6 +4592,19 @@ static struct iommu_domain identity_domain = {
 	},
 };
 
+static struct iommu_domain *intel_iommu_domain_alloc_paging(struct device *dev)
+{
+	struct dmar_domain *dmar_domain;
+	bool first_stage;
+
+	first_stage = first_level_by_default(0);
+	dmar_domain = paging_domain_alloc(dev, first_stage);
+	if (IS_ERR(dmar_domain))
+		return ERR_CAST(dmar_domain);
+
+	return &dmar_domain->domain;
+}
+
 const struct iommu_ops intel_iommu_ops = {
 	.blocked_domain		= &blocking_domain,
 	.release_domain		= &blocking_domain,
@@ -4601,6 +4614,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.domain_alloc		= intel_iommu_domain_alloc,
 	.domain_alloc_user	= intel_iommu_domain_alloc_user,
 	.domain_alloc_sva	= intel_svm_domain_alloc,
+	.domain_alloc_paging	= intel_iommu_domain_alloc_paging,
 	.probe_device		= intel_iommu_probe_device,
 	.release_device		= intel_iommu_release_device,
 	.get_resv_regions	= intel_iommu_get_resv_regions,
-- 
2.43.0