iommu/vt-d: Add domain_alloc_user op

Add the domain_alloc_user() op implementation. It supports allocating domains to be used as parent under nested translation. Unlike other drivers VT-D uses only a single page table format so it only needs to check if the HW can support nesting. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Yi Liu <[email protected]> Reviewed-by: Lu Baolu <[email protected]> Reviewed-by: Kevin Tian <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>
sedwards · Oct 10, 2023 · c97d1b2 · c97d1b2
1 parent 4086636
commit c97d1b2
Showing 1 changed file with 28 additions and 0 deletions.
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
@@ -4074,6 +4074,33 @@ 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;
+
+	if (flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	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_alloc_user op needs to fully initialize a domain
+	 * before return, so uses iommu_domain_alloc() here for
+	 * simple.
+	 */
+	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 +4834,7 @@ 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,