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From:   Yi Liu <yi.l.liu@intel.com>
To:     joro@8bytes.org, alex.williamson@redhat.com, jgg@nvidia.com,
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Subject: [PATCH v2 6/6] iommu/vt-d: Add domain_alloc_user op
Date:   Thu, 28 Sep 2023 00:15:28 -0700
Message-Id: <20230928071528.26258-7-yi.l.liu@intel.com>
In-Reply-To: <20230928071528.26258-1-yi.l.liu@intel.com>
References: <20230928071528.26258-1-yi.l.liu@intel.com>
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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 | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 5db283c17e0d..017aed5813d8 100644
--- 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,
-- 
2.34.1