[PATCH v6 3/3] iommu/vt-d: Add iotlb flush for nested domain

[Yi Liu <yi.l.liu@intel.com>]

This implements the .cache_invalidate_user() callback to support iotlb
flush for nested domain.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/intel/nested.c | 54 ++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 19538fb616db..ef8fe53c33ef 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -73,9 +73,63 @@ static void intel_nested_domain_free(struct iommu_domain *domain)
 	kfree(to_dmar_domain(domain));
 }
 
+static void domain_flush_iotlb_psi(struct dmar_domain *domain,
+				   u64 addr, unsigned long npages)
+{
+	struct iommu_domain_info *info;
+	unsigned long i;
+
+	xa_for_each(&domain->iommu_array, i, info)
+		iommu_flush_iotlb_psi(info->iommu, domain,
+				      addr >> VTD_PAGE_SHIFT, npages, 1, 0);
+}
+
+static int intel_nested_cache_invalidate_user(struct iommu_domain *domain,
+					      struct iommu_user_data_array *array,
+					      u32 *cerror_idx)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct iommu_hwpt_vtd_s1_invalidate inv_info;
+	u32 index;
+	int ret;
+
+	/* REVISIT:
+	 * VT-d has defined ITE, ICE, IQE for invalidation failure per hardware,
+	 * but no error code yet, so just set the error code to be 0.
+	 */
+	*cerror_idx = 0;
+
+	for (index = 0; index < array->entry_num; index++) {
+		ret = iommu_copy_struct_from_user_array(&inv_info, array,
+							IOMMU_HWPT_DATA_VTD_S1,
+							index, __reserved);
+		if (ret) {
+			pr_err_ratelimited("Failed to fetch invalidation request\n");
+			break;
+		}
+
+		if (inv_info.__reserved || (inv_info.flags & ~IOMMU_VTD_INV_FLAGS_LEAF) ||
+		    !IS_ALIGNED(inv_info.addr, VTD_PAGE_SIZE)) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (inv_info.addr == 0 && inv_info.npages == -1)
+			intel_flush_iotlb_all(domain);
+		else
+			domain_flush_iotlb_psi(dmar_domain,
+					       inv_info.addr, inv_info.npages);
+	}
+
+	array->entry_num = index;
+
+	return ret;
+}
+
 static const struct iommu_domain_ops intel_nested_domain_ops = {
 	.attach_dev		= intel_nested_attach_dev,
 	.free			= intel_nested_domain_free,
+	.cache_invalidate_user	= intel_nested_cache_invalidate_user,
 };
 
 struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *s2_domain,
-- 
2.34.1