iommu/vt-d: Create unique domain ops for each stage

Use the domain ops pointer to tell what kind of domain it is instead of
the internal use_first_level indication. This also protects against
wrongly using a SVA/nested/IDENTITY/BLOCKED domain type in places they
should not be.

The only remaining uses of use_first_level outside the paging domain are in
paging_domain_compatible() and intel_iommu_enforce_cache_coherency().

Thus, remove the useless sets of use_first_level in
intel_svm_domain_alloc() and intel_iommu_domain_alloc_nested(). None of
the unique ops for these domain types ever reference it on their call
chains.

Add a WARN_ON() check in domain_context_mapping_one() as it only works
with second stage.

This is preparation for iommupt which will have different ops for each of
the stages.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v3-dbbe6f7e7ae3+124ffe-vtd_prep_jgg@nvidia.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250714045028.958850-8-baolu.lu@linux.intel.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 42 insertions, 18 deletions

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 553f0e32be9a..940d1c6c2248 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1462,6 +1462,9 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 	struct context_entry *context;
 	int ret;
 
+	if (WARN_ON(!intel_domain_is_ss_paging(domain)))
+		return -EINVAL;
+
 	pr_debug("Set context mapping for %02x:%02x.%d\n",
 		bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
 
@@ -1780,7 +1783,7 @@ static int domain_setup_first_level(struct intel_iommu *iommu,
 static bool domain_need_iotlb_sync_map(struct dmar_domain *domain,
 				       struct intel_iommu *iommu)
 {
-	if (cap_caching_mode(iommu->cap) && !domain->use_first_level)
+	if (cap_caching_mode(iommu->cap) && intel_domain_is_ss_paging(domain))
 		return true;
 
 	if (rwbf_quirk || cap_rwbf(iommu->cap))
@@ -1812,12 +1815,14 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
 
 	if (!sm_supported(iommu))
 		ret = domain_context_mapping(domain, dev);
-	else if (domain->use_first_level)
+	else if (intel_domain_is_fs_paging(domain))
 		ret = domain_setup_first_level(iommu, domain, dev,
 					       IOMMU_NO_PASID, NULL);
-	else
+	else if (intel_domain_is_ss_paging(domain))
 		ret = domain_setup_second_level(iommu, domain, dev,
 						IOMMU_NO_PASID, NULL);
+	else if (WARN_ON(true))
+		ret = -EINVAL;
 
 	if (ret)
 		goto out_block_translation;
@@ -3288,7 +3293,6 @@ static struct dmar_domain *paging_domain_alloc(struct device *dev, bool first_st
 	domain->use_first_level = first_stage;
 
 	domain->domain.type = IOMMU_DOMAIN_UNMANAGED;
-	domain->domain.ops = intel_iommu_ops.default_domain_ops;
 
 	/* calculate the address width */
 	addr_width = agaw_to_width(iommu->agaw);
@@ -3346,6 +3350,8 @@ intel_iommu_domain_alloc_first_stage(struct device *dev,
 	dmar_domain = paging_domain_alloc(dev, true);
 	if (IS_ERR(dmar_domain))
 		return ERR_CAST(dmar_domain);
+
+	dmar_domain->domain.ops = &intel_fs_paging_domain_ops;
 	return &dmar_domain->domain;
 }
 
@@ -3374,6 +3380,7 @@ intel_iommu_domain_alloc_second_stage(struct device *dev,
 	if (IS_ERR(dmar_domain))
 		return ERR_CAST(dmar_domain);
 
+	dmar_domain->domain.ops = &intel_ss_paging_domain_ops;
 	dmar_domain->nested_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
 
 	if (flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING)
@@ -4098,12 +4105,15 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
 	if (ret)
 		goto out_remove_dev_pasid;
 
-	if (dmar_domain->use_first_level)
+	if (intel_domain_is_fs_paging(dmar_domain))
 		ret = domain_setup_first_level(iommu, dmar_domain,
 					       dev, pasid, old);
-	else
+	else if (intel_domain_is_ss_paging(dmar_domain))
 		ret = domain_setup_second_level(iommu, dmar_domain,
 						dev, pasid, old);
+	else if (WARN_ON(true))
+		ret = -EINVAL;
+
 	if (ret)
 		goto out_unwind_iopf;
 
@@ -4378,6 +4388,32 @@ static struct iommu_domain identity_domain = {
 	},
 };
 
+const struct iommu_domain_ops intel_fs_paging_domain_ops = {
+	.attach_dev = intel_iommu_attach_device,
+	.set_dev_pasid = intel_iommu_set_dev_pasid,
+	.map_pages = intel_iommu_map_pages,
+	.unmap_pages = intel_iommu_unmap_pages,
+	.iotlb_sync_map = intel_iommu_iotlb_sync_map,
+	.flush_iotlb_all = intel_flush_iotlb_all,
+	.iotlb_sync = intel_iommu_tlb_sync,
+	.iova_to_phys = intel_iommu_iova_to_phys,
+	.free = intel_iommu_domain_free,
+	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
+};
+
+const struct iommu_domain_ops intel_ss_paging_domain_ops = {
+	.attach_dev = intel_iommu_attach_device,
+	.set_dev_pasid = intel_iommu_set_dev_pasid,
+	.map_pages = intel_iommu_map_pages,
+	.unmap_pages = intel_iommu_unmap_pages,
+	.iotlb_sync_map = intel_iommu_iotlb_sync_map,
+	.flush_iotlb_all = intel_flush_iotlb_all,
+	.iotlb_sync = intel_iommu_tlb_sync,
+	.iova_to_phys = intel_iommu_iova_to_phys,
+	.free = intel_iommu_domain_free,
+	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
+};
+
 const struct iommu_ops intel_iommu_ops = {
 	.blocked_domain		= &blocking_domain,
 	.release_domain		= &blocking_domain,
@@ -4396,18 +4432,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.def_domain_type	= device_def_domain_type,
 	.pgsize_bitmap		= SZ_4K,
 	.page_response		= intel_iommu_page_response,
-	.default_domain_ops = &(const struct iommu_domain_ops) {
-		.attach_dev		= intel_iommu_attach_device,
-		.set_dev_pasid		= intel_iommu_set_dev_pasid,
-		.map_pages		= intel_iommu_map_pages,
-		.unmap_pages		= intel_iommu_unmap_pages,
-		.iotlb_sync_map		= intel_iommu_iotlb_sync_map,
-		.flush_iotlb_all        = intel_flush_iotlb_all,
-		.iotlb_sync		= intel_iommu_tlb_sync,
-		.iova_to_phys		= intel_iommu_iova_to_phys,
-		.free			= intel_iommu_domain_free,
-		.enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
-	}
 };
 
 static void quirk_iommu_igfx(struct pci_dev *dev)