iommufd/selftest: Add set_dev_pasid in mock iommu

JIRA: https://issues.redhat.com/browse/RHEL-114131
Upstream-Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit 9eb5920
Author: Yi Liu <yi.l.liu@intel.com>
Date: Fri Mar 21 10:19:37 2025 -0700

    iommufd/selftest: Add set_dev_pasid in mock iommu

    The callback is needed to make pasid_attach/detach path complete for mock
    device. A nop is enough for set_dev_pasid.

    A MOCK_FLAGS_DEVICE_PASID is added to indicate a pasid-capable mock device
    for the pasid test cases. Other test cases will still create a non-pasid
    mock device. While the mock iommu always pretends to be pasid-capable.

    Link: https://patch.msgid.link/r/20250321171940.7213-16-yi.l.liu@intel.com
    Reviewed-by: Kevin Tian <kevin.tian@intel.com>
    Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
    Signed-off-by: Yi Liu <yi.l.liu@intel.com>
    Tested-by: Nicolin Chen <nicolinc@nvidia.com>
    Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

(cherry picked from commit 9eb5920)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>

Author: snits

drivers/iommu/iommufd/iommufd_test.h

@@ -49,6 +49,7 @@ enum {
 enum {
 	MOCK_FLAGS_DEVICE_NO_DIRTY = 1 << 0,
 	MOCK_FLAGS_DEVICE_HUGE_IOVA = 1 << 1,
+	MOCK_FLAGS_DEVICE_PASID = 1 << 2,
 };
 
 enum {
@@ -154,6 +155,9 @@ struct iommu_test_cmd {
 };
 #define IOMMU_TEST_CMD _IO(IOMMUFD_TYPE, IOMMUFD_CMD_BASE + 32)
 
+/* Mock device/iommu PASID width */
+#define MOCK_PASID_WIDTH 20
+
 /* Mock structs for IOMMU_DEVICE_GET_HW_INFO ioctl */
 #define IOMMU_HW_INFO_TYPE_SELFTEST	0xfeedbeef
 #define IOMMU_HW_INFO_SELFTEST_REGVAL	0xdeadbeef

drivers/iommu/iommufd/selftest.c

@@ -223,8 +223,16 @@ static int mock_domain_nop_attach(struct iommu_domain *domain,
 	return 0;
 }
 
+static int mock_domain_set_dev_pasid_nop(struct iommu_domain *domain,
+					 struct device *dev, ioasid_t pasid,
+					 struct iommu_domain *old)
+{
+	return 0;
+}
+
 static const struct iommu_domain_ops mock_blocking_ops = {
 	.attach_dev = mock_domain_nop_attach,
+	.set_dev_pasid = mock_domain_set_dev_pasid_nop
 };
 
 static struct iommu_domain mock_blocking_domain = {
@@ -366,7 +374,7 @@ mock_domain_alloc_nested(struct device *dev, struct iommu_domain *parent,
 	struct mock_iommu_domain_nested *mock_nested;
 	struct mock_iommu_domain *mock_parent;
 
-	if (flags)
+	if (flags & ~IOMMU_HWPT_ALLOC_PASID)
 		return ERR_PTR(-EOPNOTSUPP);
 	if (!parent || parent->ops != mock_ops.default_domain_ops)
 		return ERR_PTR(-EINVAL);
@@ -388,7 +396,8 @@ mock_domain_alloc_paging_flags(struct device *dev, u32 flags,
 {
 	bool has_dirty_flag = flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
 	const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
-				 IOMMU_HWPT_ALLOC_NEST_PARENT;
+				 IOMMU_HWPT_ALLOC_NEST_PARENT |
+				 IOMMU_HWPT_ALLOC_PASID;
 	struct mock_dev *mdev = to_mock_dev(dev);
 	bool no_dirty_ops = mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY;
 	struct mock_iommu_domain *mock;
@@ -608,7 +617,7 @@ mock_viommu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
 	struct mock_viommu *mock_viommu = to_mock_viommu(viommu);
 	struct mock_iommu_domain_nested *mock_nested;
 
-	if (flags)
+	if (flags & ~IOMMU_HWPT_ALLOC_PASID)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	mock_nested = __mock_domain_alloc_nested(user_data);
@@ -743,6 +752,7 @@ static const struct iommu_ops mock_ops = {
 			.map_pages = mock_domain_map_pages,
 			.unmap_pages = mock_domain_unmap_pages,
 			.iova_to_phys = mock_domain_iova_to_phys,
+			.set_dev_pasid = mock_domain_set_dev_pasid_nop,
 		},
 };
 
@@ -803,6 +813,7 @@ static struct iommu_domain_ops domain_nested_ops = {
 	.free = mock_domain_free_nested,
 	.attach_dev = mock_domain_nop_attach,
 	.cache_invalidate_user = mock_domain_cache_invalidate_user,
+	.set_dev_pasid = mock_domain_set_dev_pasid_nop,
 };
 
 static inline struct iommufd_hw_pagetable *
@@ -862,11 +873,17 @@ static void mock_dev_release(struct device *dev)
 
 static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 {
+	struct property_entry prop[] = {
+		PROPERTY_ENTRY_U32("pasid-num-bits", 0),
+		{},
+	};
+	const u32 valid_flags = MOCK_FLAGS_DEVICE_NO_DIRTY |
+				MOCK_FLAGS_DEVICE_HUGE_IOVA |
+				MOCK_FLAGS_DEVICE_PASID;
 	struct mock_dev *mdev;
 	int rc, i;
 
-	if (dev_flags &
-	    ~(MOCK_FLAGS_DEVICE_NO_DIRTY | MOCK_FLAGS_DEVICE_HUGE_IOVA))
+	if (dev_flags & ~valid_flags)
 		return ERR_PTR(-EINVAL);
 
 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
@@ -890,6 +907,15 @@ static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 	if (rc)
 		goto err_put;
 
+	if (dev_flags & MOCK_FLAGS_DEVICE_PASID)
+		prop[0] = PROPERTY_ENTRY_U32("pasid-num-bits", MOCK_PASID_WIDTH);
+
+	rc = device_create_managed_software_node(&mdev->dev, prop, NULL);
+	if (rc) {
+		dev_err(&mdev->dev, "add pasid-num-bits property failed, rc: %d", rc);
+		goto err_put;
+	}
+
 	rc = device_add(&mdev->dev);
 	if (rc)
 		goto err_put;
@@ -1778,6 +1804,7 @@ int __init iommufd_test_init(void)
 	init_completion(&mock_iommu.complete);
 
 	mock_iommu_iopf_queue = iopf_queue_alloc("mock-iopfq");
+	mock_iommu.iommu_dev.max_pasids = (1 << MOCK_PASID_WIDTH);
 
 	return 0;