[PATCH v2 5/7] iommu/vt-d: Create unique domain ops for each stage

[Jason Gunthorpe <jgg@nvidia.com>]

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.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/intel/cache.c  |  5 ++--
 drivers/iommu/intel/iommu.c  | 58 +++++++++++++++++++++++++-----------
 drivers/iommu/intel/iommu.h  |  2 ++
 drivers/iommu/intel/nested.c |  3 +-
 drivers/iommu/intel/svm.c    |  1 -
 5 files changed, 47 insertions(+), 22 deletions(-)

diff --git a/drivers/iommu/intel/cache.c b/drivers/iommu/intel/cache.c
index fc35cba5914532..29b8af6487512c 100644
--- a/drivers/iommu/intel/cache.c
+++ b/drivers/iommu/intel/cache.c
@@ -371,7 +371,7 @@ static void cache_tag_flush_iotlb(struct dmar_domain *domain, struct cache_tag *
 	struct intel_iommu *iommu = tag->iommu;
 	u64 type = DMA_TLB_PSI_FLUSH;
 
-	if (domain->use_first_level) {
+	if (domain->domain.ops == &intel_fs_paging_domain_ops) {
 		qi_batch_add_piotlb(iommu, tag->domain_id, tag->pasid, addr,
 				    pages, ih, domain->qi_batch);
 		return;
@@ -546,7 +546,8 @@ void cache_tag_flush_range_np(struct dmar_domain *domain, unsigned long start,
 			qi_batch_flush_descs(iommu, domain->qi_batch);
 		iommu = tag->iommu;
 
-		if (!cap_caching_mode(iommu->cap) || domain->use_first_level) {
+		if (!cap_caching_mode(iommu->cap) ||
+		    domain->domain.ops == &intel_fs_paging_domain_ops) {
 			iommu_flush_write_buffer(iommu);
 			continue;
 		}
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 243e77d5a06aac..7a5c794e488614 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(domain->domain.ops != &intel_ss_paging_domain_ops))
+		return -EINVAL;
+
 	pr_debug("Set context mapping for %02x:%02x.%d\n",
 		bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
 
@@ -1800,12 +1803,14 @@ 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 (domain->domain.ops == &intel_fs_paging_domain_ops)
 		ret = domain_setup_first_level(iommu, domain, dev,
 					       IOMMU_NO_PASID, NULL);
-	else
+	else if (domain->domain.ops == &intel_ss_paging_domain_ops)
 		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;
@@ -3274,7 +3279,6 @@ 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);
@@ -3332,6 +3336,8 @@ 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;
 }
 
@@ -3360,6 +3366,7 @@ 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)
@@ -4081,12 +4088,15 @@ 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 (domain->ops == &intel_fs_paging_domain_ops)
 		ret = domain_setup_first_level(iommu, dmar_domain,
 					       dev, pasid, old);
-	else
+	else if (domain->ops == &intel_ss_paging_domain_ops)
 		ret = domain_setup_second_level(iommu, dmar_domain,
 						dev, pasid, old);
+	else if (WARN_ON(true))
+		ret = -EINVAL;
+
 	if (ret)
 		goto out_unwind_iopf;
 
@@ -4361,6 +4371,32 @@ 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,
@@ -4379,18 +4415,6 @@ 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)
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index ca6843973d4393..9b9e5fde4a3062 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1375,6 +1375,8 @@ struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
 					 u8 devfn, int alloc);
 
 extern const struct iommu_ops intel_iommu_ops;
+extern const struct iommu_domain_ops intel_fs_paging_domain_ops;
+extern const struct iommu_domain_ops intel_ss_paging_domain_ops;
 
 #ifdef CONFIG_INTEL_IOMMU
 extern int intel_iommu_sm;
diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index fc312f649f9ef0..d976d6b6188d3f 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -216,7 +216,7 @@ intel_iommu_domain_alloc_nested(struct device *dev, struct iommu_domain *parent,
 	/* Must be nested domain */
 	if (user_data->type != IOMMU_HWPT_DATA_VTD_S1)
 		return ERR_PTR(-EOPNOTSUPP);
-	if (parent->ops != intel_iommu_ops.default_domain_ops ||
+	if (parent->ops != &intel_ss_paging_domain_ops ||
 	    !s2_domain->nested_parent)
 		return ERR_PTR(-EINVAL);
 
@@ -229,7 +229,6 @@ intel_iommu_domain_alloc_nested(struct device *dev, struct iommu_domain *parent,
 	if (!domain)
 		return ERR_PTR(-ENOMEM);
 
-	domain->use_first_level = true;
 	domain->s2_domain = s2_domain;
 	domain->s1_cfg = vtd;
 	domain->domain.ops = &intel_nested_domain_ops;
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 8c0bed36c58777..e147f71f91b722 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -214,7 +214,6 @@ struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	domain->domain.ops = &intel_svm_domain_ops;
-	domain->use_first_level = true;
 	INIT_LIST_HEAD(&domain->dev_pasids);
 	INIT_LIST_HEAD(&domain->cache_tags);
 	spin_lock_init(&domain->cache_lock);
-- 
2.43.0