Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd implementation from Jason Gunthorpe:
 "iommufd is the user API to control the IOMMU subsystem as it relates
  to managing IO page tables that point at user space memory.

  It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO
  container) which is the VFIO specific interface for a similar idea.

  We see a broad need for extended features, some being highly IOMMU
  device specific:
   - Binding iommu_domain's to PASID/SSID
   - Userspace IO page tables, for ARM, x86 and S390
   - Kernel bypassed invalidation of user page tables
   - Re-use of the KVM page table in the IOMMU
   - Dirty page tracking in the IOMMU
   - Runtime Increase/Decrease of IOPTE size
   - PRI support with faults resolved in userspace

  Many of these HW features exist to support VM use cases - for instance
  the combination of PASID, PRI and Userspace IO Page Tables allows an
  implementation of DMA Shared Virtual Addressing (vSVA) within a guest.
  Dirty tracking enables VM live migration with SRIOV devices and PASID
  support allow creating "scalable IOV" devices, among other things.

  As these features are fundamental to a VM platform they need to be
  uniformly exposed to all the driver families that do DMA into VMs,
  which is currently VFIO and VDPA"

For more background, see the extended explanations in Jason's pull request:

  https://lore.kernel.org/lkml/Y5dzTU8dlmXTbzoJ@nvidia.com/

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (62 commits)
  iommufd: Change the order of MSI setup
  iommufd: Improve a few unclear bits of code
  iommufd: Fix comment typos
  vfio: Move vfio group specific code into group.c
  vfio: Refactor dma APIs for emulated devices
  vfio: Wrap vfio group module init/clean code into helpers
  vfio: Refactor vfio_device open and close
  vfio: Make vfio_device_open() truly device specific
  vfio: Swap order of vfio_device_container_register() and open_device()
  vfio: Set device->group in helper function
  vfio: Create wrappers for group register/unregister
  vfio: Move the sanity check of the group to vfio_create_group()
  vfio: Simplify vfio_create_group()
  iommufd: Allow iommufd to supply /dev/vfio/vfio
  vfio: Make vfio_container optionally compiled
  vfio: Move container related MODULE_ALIAS statements into container.c
  vfio-iommufd: Support iommufd for emulated VFIO devices
  vfio-iommufd: Support iommufd for physical VFIO devices
  vfio-iommufd: Allow iommufd to be used in place of a container fd
  vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()
  ...

7 files changed, 2530 insertions, 0 deletions

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index b4fc124aa0fe..41b649452560 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -27,6 +27,7 @@ TARGETS += ftrace
 TARGETS += futex
 TARGETS += gpio
 TARGETS += intel_pstate
+TARGETS += iommu
 TARGETS += ipc
 TARGETS += ir
 TARGETS += kcmp
diff --git a/tools/testing/selftests/iommu/.gitignore b/tools/testing/selftests/iommu/.gitignore
new file mode 100644
index 000000000000..7d0703049eba
--- /dev/null
+++ b/tools/testing/selftests/iommu/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/iommufd
+/iommufd_fail_nth
diff --git a/tools/testing/selftests/iommu/Makefile b/tools/testing/selftests/iommu/Makefile
new file mode 100644
index 000000000000..7cb74d26f141
--- /dev/null
+++ b/tools/testing/selftests/iommu/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -Wall -O2 -Wno-unused-function
+CFLAGS += -I../../../../include/uapi/
+CFLAGS += -I../../../../include/
+
+CFLAGS += -D_GNU_SOURCE
+
+TEST_GEN_PROGS :=
+TEST_GEN_PROGS += iommufd
+TEST_GEN_PROGS += iommufd_fail_nth
+
+include ../lib.mk
diff --git a/tools/testing/selftests/iommu/config b/tools/testing/selftests/iommu/config
new file mode 100644
index 000000000000..6c4f901d6fed
--- /dev/null
+++ b/tools/testing/selftests/iommu/config
@@ -0,0 +1,2 @@
+CONFIG_IOMMUFD
+CONFIG_IOMMUFD_TEST
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
new file mode 100644
index 000000000000..8aa8a346cf22
--- /dev/null
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -0,0 +1,1654 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES */
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/eventfd.h>
+
+#define __EXPORTED_HEADERS__
+#include <linux/vfio.h>
+
+#include "iommufd_utils.h"
+
+static void *buffer;
+
+static unsigned long PAGE_SIZE;
+static unsigned long HUGEPAGE_SIZE;
+
+#define MOCK_PAGE_SIZE (PAGE_SIZE / 2)
+
+static unsigned long get_huge_page_size(void)
+{
+	char buf[80];
+	int ret;
+	int fd;
+
+	fd = open("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size",
+		  O_RDONLY);
+	if (fd < 0)
+		return 2 * 1024 * 1024;
+
+	ret = read(fd, buf, sizeof(buf));
+	close(fd);
+	if (ret <= 0 || ret == sizeof(buf))
+		return 2 * 1024 * 1024;
+	buf[ret] = 0;
+	return strtoul(buf, NULL, 10);
+}
+
+static __attribute__((constructor)) void setup_sizes(void)
+{
+	void *vrc;
+	int rc;
+
+	PAGE_SIZE = sysconf(_SC_PAGE_SIZE);
+	HUGEPAGE_SIZE = get_huge_page_size();
+
+	BUFFER_SIZE = PAGE_SIZE * 16;
+	rc = posix_memalign(&buffer, HUGEPAGE_SIZE, BUFFER_SIZE);
+	assert(!rc);
+	assert(buffer);
+	assert((uintptr_t)buffer % HUGEPAGE_SIZE == 0);
+	vrc = mmap(buffer, BUFFER_SIZE, PROT_READ | PROT_WRITE,
+		   MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+	assert(vrc == buffer);
+}
+
+FIXTURE(iommufd)
+{
+	int fd;
+};
+
+FIXTURE_SETUP(iommufd)
+{
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+}
+
+FIXTURE_TEARDOWN(iommufd)
+{
+	teardown_iommufd(self->fd, _metadata);
+}
+
+TEST_F(iommufd, simple_close)
+{
+}
+
+TEST_F(iommufd, cmd_fail)
+{
+	struct iommu_destroy cmd = { .size = sizeof(cmd), .id = 0 };
+
+	/* object id is invalid */
+	EXPECT_ERRNO(ENOENT, _test_ioctl_destroy(self->fd, 0));
+	/* Bad pointer */
+	EXPECT_ERRNO(EFAULT, ioctl(self->fd, IOMMU_DESTROY, NULL));
+	/* Unknown ioctl */
+	EXPECT_ERRNO(ENOTTY,
+		     ioctl(self->fd, _IO(IOMMUFD_TYPE, IOMMUFD_CMD_BASE - 1),
+			   &cmd));
+}
+
+TEST_F(iommufd, cmd_length)
+{
+#define TEST_LENGTH(_struct, _ioctl)                                     \
+	{                                                                \
+		struct {                                                 \
+			struct _struct cmd;                              \
+			uint8_t extra;                                   \
+		} cmd = { .cmd = { .size = sizeof(struct _struct) - 1 }, \
+			  .extra = UINT8_MAX };                          \
+		int old_errno;                                           \
+		int rc;                                                  \
+									 \
+		EXPECT_ERRNO(EINVAL, ioctl(self->fd, _ioctl, &cmd));     \
+		cmd.cmd.size = sizeof(struct _struct) + 1;               \
+		EXPECT_ERRNO(E2BIG, ioctl(self->fd, _ioctl, &cmd));      \
+		cmd.cmd.size = sizeof(struct _struct);                   \
+		rc = ioctl(self->fd, _ioctl, &cmd);                      \
+		old_errno = errno;                                       \
+		cmd.cmd.size = sizeof(struct _struct) + 1;               \
+		cmd.extra = 0;                                           \
+		if (rc) {                                                \
+			EXPECT_ERRNO(old_errno,                          \
+				     ioctl(self->fd, _ioctl, &cmd));     \
+		} else {                                                 \
+			ASSERT_EQ(0, ioctl(self->fd, _ioctl, &cmd));     \
+		}                                                        \
+	}
+
+	TEST_LENGTH(iommu_destroy, IOMMU_DESTROY);
+	TEST_LENGTH(iommu_ioas_alloc, IOMMU_IOAS_ALLOC);
+	TEST_LENGTH(iommu_ioas_iova_ranges, IOMMU_IOAS_IOVA_RANGES);
+	TEST_LENGTH(iommu_ioas_allow_iovas, IOMMU_IOAS_ALLOW_IOVAS);
+	TEST_LENGTH(iommu_ioas_map, IOMMU_IOAS_MAP);
+	TEST_LENGTH(iommu_ioas_copy, IOMMU_IOAS_COPY);
+	TEST_LENGTH(iommu_ioas_unmap, IOMMU_IOAS_UNMAP);
+	TEST_LENGTH(iommu_option, IOMMU_OPTION);
+	TEST_LENGTH(iommu_vfio_ioas, IOMMU_VFIO_IOAS);
+#undef TEST_LENGTH
+}
+
+TEST_F(iommufd, cmd_ex_fail)
+{
+	struct {
+		struct iommu_destroy cmd;
+		__u64 future;
+	} cmd = { .cmd = { .size = sizeof(cmd), .id = 0 } };
+
+	/* object id is invalid and command is longer */
+	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_DESTROY, &cmd));
+	/* future area is non-zero */
+	cmd.future = 1;
+	EXPECT_ERRNO(E2BIG, ioctl(self->fd, IOMMU_DESTROY, &cmd));
+	/* Original command "works" */
+	cmd.cmd.size = sizeof(cmd.cmd);
+	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_DESTROY, &cmd));
+	/* Short command fails */
+	cmd.cmd.size = sizeof(cmd.cmd) - 1;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, IOMMU_DESTROY, &cmd));
+}
+
+TEST_F(iommufd, global_options)
+{
+	struct iommu_option cmd = {
+		.size = sizeof(cmd),
+		.option_id = IOMMU_OPTION_RLIMIT_MODE,
+		.op = IOMMU_OPTION_OP_GET,
+		.val64 = 1,
+	};
+
+	cmd.option_id = IOMMU_OPTION_RLIMIT_MODE;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	ASSERT_EQ(0, cmd.val64);
+
+	/* This requires root */
+	cmd.op = IOMMU_OPTION_OP_SET;
+	cmd.val64 = 1;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	cmd.val64 = 2;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	cmd.op = IOMMU_OPTION_OP_GET;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	ASSERT_EQ(1, cmd.val64);
+
+	cmd.op = IOMMU_OPTION_OP_SET;
+	cmd.val64 = 0;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	cmd.op = IOMMU_OPTION_OP_GET;
+	cmd.option_id = IOMMU_OPTION_HUGE_PAGES;
+	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	cmd.op = IOMMU_OPTION_OP_SET;
+	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_OPTION, &cmd));
+}
+
+FIXTURE(iommufd_ioas)
+{
+	int fd;
+	uint32_t ioas_id;
+	uint32_t domain_id;
+	uint64_t base_iova;
+};
+
+FIXTURE_VARIANT(iommufd_ioas)
+{
+	unsigned int mock_domains;
+	unsigned int memory_limit;
+};
+
+FIXTURE_SETUP(iommufd_ioas)
+{
+	unsigned int i;
+
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+	test_ioctl_ioas_alloc(&self->ioas_id);
+
+	if (!variant->memory_limit) {
+		test_ioctl_set_default_memory_limit();
+	} else {
+		test_ioctl_set_temp_memory_limit(variant->memory_limit);
+	}
+
+	for (i = 0; i != variant->mock_domains; i++) {
+		test_cmd_mock_domain(self->ioas_id, NULL, &self->domain_id);
+		self->base_iova = MOCK_APERTURE_START;
+	}
+}
+
+FIXTURE_TEARDOWN(iommufd_ioas)
+{
+	test_ioctl_set_default_memory_limit();
+	teardown_iommufd(self->fd, _metadata);
+}
+
+FIXTURE_VARIANT_ADD(iommufd_ioas, no_domain)
+{
+};
+
+FIXTURE_VARIANT_ADD(iommufd_ioas, mock_domain)
+{
+	.mock_domains = 1,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_ioas, two_mock_domain)
+{
+	.mock_domains = 2,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_ioas, mock_domain_limit)
+{
+	.mock_domains = 1,
+	.memory_limit = 16,
+};
+
+TEST_F(iommufd_ioas, ioas_auto_destroy)
+{
+}
+
+TEST_F(iommufd_ioas, ioas_destroy)
+{
+	if (self->domain_id) {
+		/* IOAS cannot be freed while a domain is on it */
+		EXPECT_ERRNO(EBUSY,
+			     _test_ioctl_destroy(self->fd, self->ioas_id));
+	} else {
+		/* Can allocate and manually free an IOAS table */
+		test_ioctl_destroy(self->ioas_id);
+	}
+}
+
+TEST_F(iommufd_ioas, ioas_area_destroy)
+{
+	/* Adding an area does not change ability to destroy */
+	test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE, self->base_iova);
+	if (self->domain_id)
+		EXPECT_ERRNO(EBUSY,
+			     _test_ioctl_destroy(self->fd, self->ioas_id));
+	else
+		test_ioctl_destroy(self->ioas_id);
+}
+
+TEST_F(iommufd_ioas, ioas_area_auto_destroy)
+{
+	int i;
+
+	/* Can allocate and automatically free an IOAS table with many areas */
+	for (i = 0; i != 10; i++) {
+		test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE,
+					  self->base_iova + i * PAGE_SIZE);
+	}
+}
+
+TEST_F(iommufd_ioas, area)
+{
+	int i;
+
+	/* Unmap fails if nothing is mapped */
+	for (i = 0; i != 10; i++)
+		test_err_ioctl_ioas_unmap(ENOENT, i * PAGE_SIZE, PAGE_SIZE);
+
+	/* Unmap works */
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE,
+					  self->base_iova + i * PAGE_SIZE);
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_unmap(self->base_iova + i * PAGE_SIZE,
+				      PAGE_SIZE);
+
+	/* Split fails */
+	test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE * 2,
+				  self->base_iova + 16 * PAGE_SIZE);
+	test_err_ioctl_ioas_unmap(ENOENT, self->base_iova + 16 * PAGE_SIZE,
+				  PAGE_SIZE);
+	test_err_ioctl_ioas_unmap(ENOENT, self->base_iova + 17 * PAGE_SIZE,
+				  PAGE_SIZE);
+
+	/* Over map fails */
+	test_err_ioctl_ioas_map_fixed(EEXIST, buffer, PAGE_SIZE * 2,
+				      self->base_iova + 16 * PAGE_SIZE);
+	test_err_ioctl_ioas_map_fixed(EEXIST, buffer, PAGE_SIZE,
+				      self->base_iova + 16 * PAGE_SIZE);
+	test_err_ioctl_ioas_map_fixed(EEXIST, buffer, PAGE_SIZE,
+				      self->base_iova + 17 * PAGE_SIZE);
+	test_err_ioctl_ioas_map_fixed(EEXIST, buffer, PAGE_SIZE * 2,
+				      self->base_iova + 15 * PAGE_SIZE);
+	test_err_ioctl_ioas_map_fixed(EEXIST, buffer, PAGE_SIZE * 3,
+				      self->base_iova + 15 * PAGE_SIZE);
+
+	/* unmap all works */
+	test_ioctl_ioas_unmap(0, UINT64_MAX);
+
+	/* Unmap all succeeds on an empty IOAS */
+	test_ioctl_ioas_unmap(0, UINT64_MAX);
+}
+
+TEST_F(iommufd_ioas, unmap_fully_contained_areas)
+{
+	uint64_t unmap_len;
+	int i;
+
+	/* Give no_domain some space to rewind base_iova */
+	self->base_iova += 4 * PAGE_SIZE;
+
+	for (i = 0; i != 4; i++)
+		test_ioctl_ioas_map_fixed(buffer, 8 * PAGE_SIZE,
+					  self->base_iova + i * 16 * PAGE_SIZE);
+
+	/* Unmap not fully contained area doesn't work */
+	test_err_ioctl_ioas_unmap(ENOENT, self->base_iova - 4 * PAGE_SIZE,
+				  8 * PAGE_SIZE);
+	test_err_ioctl_ioas_unmap(ENOENT,
+				  self->base_iova + 3 * 16 * PAGE_SIZE +
+					  8 * PAGE_SIZE - 4 * PAGE_SIZE,
+				  8 * PAGE_SIZE);
+
+	/* Unmap fully contained areas works */
+	ASSERT_EQ(0, _test_ioctl_ioas_unmap(self->fd, self->ioas_id,
+					    self->base_iova - 4 * PAGE_SIZE,
+					    3 * 16 * PAGE_SIZE + 8 * PAGE_SIZE +
+						    4 * PAGE_SIZE,
+					    &unmap_len));
+	ASSERT_EQ(32 * PAGE_SIZE, unmap_len);
+}
+
+TEST_F(iommufd_ioas, area_auto_iova)
+{
+	struct iommu_test_cmd test_cmd = {
+		.size = sizeof(test_cmd),
+		.op = IOMMU_TEST_OP_ADD_RESERVED,
+		.id = self->ioas_id,
+		.add_reserved = { .start = PAGE_SIZE * 4,
+				  .length = PAGE_SIZE * 100 },
+	};
+	struct iommu_iova_range ranges[1] = {};
+	struct iommu_ioas_allow_iovas allow_cmd = {
+		.size = sizeof(allow_cmd),
+		.ioas_id = self->ioas_id,
+		.num_iovas = 1,
+		.allowed_iovas = (uintptr_t)ranges,
+	};
+	__u64 iovas[10];
+	int i;
+
+	/* Simple 4k pages */
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_map(buffer, PAGE_SIZE, &iovas[i]);
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_unmap(iovas[i], PAGE_SIZE);
+
+	/* Kernel automatically aligns IOVAs properly */
+	for (i = 0; i != 10; i++) {
+		size_t length = PAGE_SIZE * (i + 1);
+
+		if (self->domain_id) {
+			test_ioctl_ioas_map(buffer, length, &iovas[i]);
+		} else {
+			test_ioctl_ioas_map((void *)(1UL << 31), length,
+					    &iovas[i]);
+		}
+		EXPECT_EQ(0, iovas[i] % (1UL << (ffs(length) - 1)));
+	}
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_unmap(iovas[i], PAGE_SIZE * (i + 1));
+
+	/* Avoids a reserved region */
+	ASSERT_EQ(0,
+		  ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ADD_RESERVED),
+			&test_cmd));
+	for (i = 0; i != 10; i++) {
+		size_t length = PAGE_SIZE * (i + 1);
+
+		test_ioctl_ioas_map(buffer, length, &iovas[i]);
+		EXPECT_EQ(0, iovas[i] % (1UL << (ffs(length) - 1)));
+		EXPECT_EQ(false,
+			  iovas[i] > test_cmd.add_reserved.start &&
+				  iovas[i] <
+					  test_cmd.add_reserved.start +
+						  test_cmd.add_reserved.length);
+	}
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_unmap(iovas[i], PAGE_SIZE * (i + 1));
+
+	/* Allowed region intersects with a reserved region */
+	ranges[0].start = PAGE_SIZE;
+	ranges[0].last = PAGE_SIZE * 600;
+	EXPECT_ERRNO(EADDRINUSE,
+		     ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd));
+
+	/* Allocate from an allowed region */
+	if (self->domain_id) {
+		ranges[0].start = MOCK_APERTURE_START + PAGE_SIZE;
+		ranges[0].last = MOCK_APERTURE_START + PAGE_SIZE * 600 - 1;
+	} else {
+		ranges[0].start = PAGE_SIZE * 200;
+		ranges[0].last = PAGE_SIZE * 600 - 1;
+	}
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd));
+	for (i = 0; i != 10; i++) {
+		size_t length = PAGE_SIZE * (i + 1);
+
+		test_ioctl_ioas_map(buffer, length, &iovas[i]);
+		EXPECT_EQ(0, iovas[i] % (1UL << (ffs(length) - 1)));
+		EXPECT_EQ(true, iovas[i] >= ranges[0].start);
+		EXPECT_EQ(true, iovas[i] <= ranges[0].last);
+		EXPECT_EQ(true, iovas[i] + length > ranges[0].start);
+		EXPECT_EQ(true, iovas[i] + length <= ranges[0].last + 1);
+	}
+	for (i = 0; i != 10; i++)
+		test_ioctl_ioas_unmap(iovas[i], PAGE_SIZE * (i + 1));
+}
+
+TEST_F(iommufd_ioas, area_allowed)
+{
+	struct iommu_test_cmd test_cmd = {
+		.size = sizeof(test_cmd),
+		.op = IOMMU_TEST_OP_ADD_RESERVED,
+		.id = self->ioas_id,
+		.add_reserved = { .start = PAGE_SIZE * 4,
+				  .length = PAGE_SIZE * 100 },
+	};
+	struct iommu_iova_range ranges[1] = {};
+	struct iommu_ioas_allow_iovas allow_cmd = {
+		.size = sizeof(allow_cmd),
+		.ioas_id = self->ioas_id,
+		.num_iovas = 1,
+		.allowed_iovas = (uintptr_t)ranges,
+	};
+
+	/* Reserved intersects an allowed */
+	allow_cmd.num_iovas = 1;
+	ranges[0].start = self->base_iova;
+	ranges[0].last = ranges[0].start + PAGE_SIZE * 600;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd));
+	test_cmd.add_reserved.start = ranges[0].start + PAGE_SIZE;
+	test_cmd.add_reserved.length = PAGE_SIZE;
+	EXPECT_ERRNO(EADDRINUSE,
+		     ioctl(self->fd,
+			   _IOMMU_TEST_CMD(IOMMU_TEST_OP_ADD_RESERVED),
+			   &test_cmd));
+	allow_cmd.num_iovas = 0;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd));
+
+	/* Allowed intersects a reserved */
+	ASSERT_EQ(0,
+		  ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ADD_RESERVED),
+			&test_cmd));
+	allow_cmd.num_iovas = 1;
+	ranges[0].start = self->base_iova;
+	ranges[0].last = ranges[0].start + PAGE_SIZE * 600;
+	EXPECT_ERRNO(EADDRINUSE,
+		     ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd));
+}
+
+TEST_F(iommufd_ioas, copy_area)
+{
+	struct iommu_ioas_copy copy_cmd = {
+		.size = sizeof(copy_cmd),
+		.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
+		.dst_ioas_id = self->ioas_id,
+		.src_ioas_id = self->ioas_id,
+		.length = PAGE_SIZE,
+	};
+
+	test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE, self->base_iova);
+
+	/* Copy inside a single IOAS */
+	copy_cmd.src_iova = self->base_iova;
+	copy_cmd.dst_iova = self->base_iova + PAGE_SIZE;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_COPY, &copy_cmd));
+
+	/* Copy between IOAS's */
+	copy_cmd.src_iova = self->base_iova;
+	copy_cmd.dst_iova = 0;
+	test_ioctl_ioas_alloc(&copy_cmd.dst_ioas_id);
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_COPY, &copy_cmd));
+}
+
+TEST_F(iommufd_ioas, iova_ranges)
+{
+	struct iommu_test_cmd test_cmd = {
+		.size = sizeof(test_cmd),
+		.op = IOMMU_TEST_OP_ADD_RESERVED,
+		.id = self->ioas_id,
+		.add_reserved = { .start = PAGE_SIZE, .length = PAGE_SIZE },
+	};
+	struct iommu_iova_range *ranges = buffer;
+	struct iommu_ioas_iova_ranges ranges_cmd = {
+		.size = sizeof(ranges_cmd),
+		.ioas_id = self->ioas_id,
+		.num_iovas = BUFFER_SIZE / sizeof(*ranges),
+		.allowed_iovas = (uintptr_t)ranges,
+	};
+
+	/* Range can be read */
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES, &ranges_cmd));
+	EXPECT_EQ(1, ranges_cmd.num_iovas);
+	if (!self->domain_id) {
+		EXPECT_EQ(0, ranges[0].start);
+		EXPECT_EQ(SIZE_MAX, ranges[0].last);
+		EXPECT_EQ(1, ranges_cmd.out_iova_alignment);
+	} else {
+		EXPECT_EQ(MOCK_APERTURE_START, ranges[0].start);
+		EXPECT_EQ(MOCK_APERTURE_LAST, ranges[0].last);
+		EXPECT_EQ(MOCK_PAGE_SIZE, ranges_cmd.out_iova_alignment);
+	}
+
+	/* Buffer too small */
+	memset(ranges, 0, BUFFER_SIZE);
+	ranges_cmd.num_iovas = 0;
+	EXPECT_ERRNO(EMSGSIZE,
+		     ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES, &ranges_cmd));
+	EXPECT_EQ(1, ranges_cmd.num_iovas);
+	EXPECT_EQ(0, ranges[0].start);
+	EXPECT_EQ(0, ranges[0].last);
+
+	/* 2 ranges */
+	ASSERT_EQ(0,
+		  ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ADD_RESERVED),
+			&test_cmd));
+	ranges_cmd.num_iovas = BUFFER_SIZE / sizeof(*ranges);
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES, &ranges_cmd));
+	if (!self->domain_id) {
+		EXPECT_EQ(2, ranges_cmd.num_iovas);
+		EXPECT_EQ(0, ranges[0].start);
+		EXPECT_EQ(PAGE_SIZE - 1, ranges[0].last);
+		EXPECT_EQ(PAGE_SIZE * 2, ranges[1].start);
+		EXPECT_EQ(SIZE_MAX, ranges[1].last);
+	} else {
+		EXPECT_EQ(1, ranges_cmd.num_iovas);
+		EXPECT_EQ(MOCK_APERTURE_START, ranges[0].start);
+		EXPECT_EQ(MOCK_APERTURE_LAST, ranges[0].last);
+	}
+
+	/* Buffer too small */
+	memset(ranges, 0, BUFFER_SIZE);
+	ranges_cmd.num_iovas = 1;
+	if (!self->domain_id) {
+		EXPECT_ERRNO(EMSGSIZE, ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES,
+					     &ranges_cmd));
+		EXPECT_EQ(2, ranges_cmd.num_iovas);
+		EXPECT_EQ(0, ranges[0].start);
+		EXPECT_EQ(PAGE_SIZE - 1, ranges[0].last);
+	} else {
+		ASSERT_EQ(0,
+			  ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES, &ranges_cmd));
+		EXPECT_EQ(1, ranges_cmd.num_iovas);
+		EXPECT_EQ(MOCK_APERTURE_START, ranges[0].start);
+		EXPECT_EQ(MOCK_APERTURE_LAST, ranges[0].last);
+	}
+	EXPECT_EQ(0, ranges[1].start);
+	EXPECT_EQ(0, ranges[1].last);
+}
+
+TEST_F(iommufd_ioas, access_pin)
+{
+	struct iommu_test_cmd access_cmd = {
+		.size = sizeof(access_cmd),
+		.op = IOMMU_TEST_OP_ACCESS_PAGES,
+		.access_pages = { .iova = MOCK_APERTURE_START,
+				  .length = BUFFER_SIZE,
+				  .uptr = (uintptr_t)buffer },
+	};
+	struct iommu_test_cmd check_map_cmd = {
+		.size = sizeof(check_map_cmd),
+		.op = IOMMU_TEST_OP_MD_CHECK_MAP,
+		.check_map = { .iova = MOCK_APERTURE_START,
+			       .length = BUFFER_SIZE,
+			       .uptr = (uintptr_t)buffer },
+	};
+	uint32_t access_pages_id;
+	unsigned int npages;
+
+	test_cmd_create_access(self->ioas_id, &access_cmd.id,
+			       MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES);
+
+	for (npages = 1; npages < BUFFER_SIZE / PAGE_SIZE; npages++) {
+		uint32_t mock_device_id;
+		uint32_t mock_hwpt_id;
+
+		access_cmd.access_pages.length = npages * PAGE_SIZE;
+
+		/* Single map/unmap */
+		test_ioctl_ioas_map_fixed(buffer, BUFFER_SIZE,
+					  MOCK_APERTURE_START);
+		ASSERT_EQ(0, ioctl(self->fd,
+				   _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+				   &access_cmd));
+		test_cmd_destroy_access_pages(
+			access_cmd.id,
+			access_cmd.access_pages.out_access_pages_id);
+
+		/* Double user */
+		ASSERT_EQ(0, ioctl(self->fd,
+				   _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+				   &access_cmd));
+		access_pages_id = access_cmd.access_pages.out_access_pages_id;
+		ASSERT_EQ(0, ioctl(self->fd,
+				   _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+				   &access_cmd));
+		test_cmd_destroy_access_pages(
+			access_cmd.id,
+			access_cmd.access_pages.out_access_pages_id);
+		test_cmd_destroy_access_pages(access_cmd.id, access_pages_id);
+
+		/* Add/remove a domain with a user */
+		ASSERT_EQ(0, ioctl(self->fd,
+				   _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+				   &access_cmd));
+		test_cmd_mock_domain(self->ioas_id, &mock_device_id,
+				     &mock_hwpt_id);
+		check_map_cmd.id = mock_hwpt_id;
+		ASSERT_EQ(0, ioctl(self->fd,
+				   _IOMMU_TEST_CMD(IOMMU_TEST_OP_MD_CHECK_MAP),
+				   &check_map_cmd));
+
+		test_ioctl_destroy(mock_device_id);
+		test_ioctl_destroy(mock_hwpt_id);
+		test_cmd_destroy_access_pages(
+			access_cmd.id,
+			access_cmd.access_pages.out_access_pages_id);
+
+		test_ioctl_ioas_unmap(MOCK_APERTURE_START, BUFFER_SIZE);
+	}
+	test_cmd_destroy_access(access_cmd.id);
+}
+
+TEST_F(iommufd_ioas, access_pin_unmap)
+{
+	struct iommu_test_cmd access_pages_cmd = {
+		.size = sizeof(access_pages_cmd),
+		.op = IOMMU_TEST_OP_ACCESS_PAGES,
+		.access_pages = { .iova = MOCK_APERTURE_START,
+				  .length = BUFFER_SIZE,
+				  .uptr = (uintptr_t)buffer },
+	};
+
+	test_cmd_create_access(self->ioas_id, &access_pages_cmd.id,
+			       MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES);
+	test_ioctl_ioas_map_fixed(buffer, BUFFER_SIZE, MOCK_APERTURE_START);
+	ASSERT_EQ(0,
+		  ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+			&access_pages_cmd));
+
+	/* Trigger the unmap op */
+	test_ioctl_ioas_unmap(MOCK_APERTURE_START, BUFFER_SIZE);
+
+	/* kernel removed the item for us */
+	test_err_destroy_access_pages(
+		ENOENT, access_pages_cmd.id,
+		access_pages_cmd.access_pages.out_access_pages_id);
+}
+
+static void check_access_rw(struct __test_metadata *_metadata, int fd,
+			    unsigned int access_id, uint64_t iova,
+			    unsigned int def_flags)
+{
+	uint16_t tmp[32];
+	struct iommu_test_cmd access_cmd = {
+		.size = sizeof(access_cmd),
+		.op = IOMMU_TEST_OP_ACCESS_RW,
+		.id = access_id,
+		.access_rw = { .uptr = (uintptr_t)tmp },
+	};
+	uint16_t *buffer16 = buffer;
+	unsigned int i;
+	void *tmp2;
+
+	for (i = 0; i != BUFFER_SIZE / sizeof(*buffer16); i++)
+		buffer16[i] = rand();
+
+	for (access_cmd.access_rw.iova = iova + PAGE_SIZE - 50;
+	     access_cmd.access_rw.iova < iova + PAGE_SIZE + 50;
+	     access_cmd.access_rw.iova++) {
+		for (access_cmd.access_rw.length = 1;
+		     access_cmd.access_rw.length < sizeof(tmp);
+		     access_cmd.access_rw.length++) {
+			access_cmd.access_rw.flags = def_flags;
+			ASSERT_EQ(0, ioctl(fd,
+					   _IOMMU_TEST_CMD(
+						   IOMMU_TEST_OP_ACCESS_RW),
+					   &access_cmd));
+			ASSERT_EQ(0,
+				  memcmp(buffer + (access_cmd.access_rw.iova -
+						   iova),
+					 tmp, access_cmd.access_rw.length));
+
+			for (i = 0; i != ARRAY_SIZE(tmp); i++)
+				tmp[i] = rand();
+			access_cmd.access_rw.flags = def_flags |
+						     MOCK_ACCESS_RW_WRITE;
+			ASSERT_EQ(0, ioctl(fd,
+					   _IOMMU_TEST_CMD(
+						   IOMMU_TEST_OP_ACCESS_RW),
+					   &access_cmd));
+			ASSERT_EQ(0,
+				  memcmp(buffer + (access_cmd.access_rw.iova -
+						   iova),
+					 tmp, access_cmd.access_rw.length));
+		}
+	}
+
+	/* Multi-page test */
+	tmp2 = malloc(BUFFER_SIZE);
+	ASSERT_NE(NULL, tmp2);
+	access_cmd.access_rw.iova = iova;
+	access_cmd.access_rw.length = BUFFER_SIZE;
+	access_cmd.access_rw.flags = def_flags;
+	access_cmd.access_rw.uptr = (uintptr_t)tmp2;
+	ASSERT_EQ(0, ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			   &access_cmd));
+	ASSERT_EQ(0, memcmp(buffer, tmp2, access_cmd.access_rw.length));
+	free(tmp2);
+}
+
+TEST_F(iommufd_ioas, access_rw)
+{
+	__u32 access_id;
+	__u64 iova;
+
+	test_cmd_create_access(self->ioas_id, &access_id, 0);
+	test_ioctl_ioas_map(buffer, BUFFER_SIZE, &iova);
+	check_access_rw(_metadata, self->fd, access_id, iova, 0);
+	check_access_rw(_metadata, self->fd, access_id, iova,
+			MOCK_ACCESS_RW_SLOW_PATH);
+	test_ioctl_ioas_unmap(iova, BUFFER_SIZE);
+	test_cmd_destroy_access(access_id);
+}
+
+TEST_F(iommufd_ioas, access_rw_unaligned)
+{
+	__u32 access_id;
+	__u64 iova;
+
+	test_cmd_create_access(self->ioas_id, &access_id, 0);
+
+	/* Unaligned pages */
+	iova = self->base_iova + MOCK_PAGE_SIZE;
+	test_ioctl_ioas_map_fixed(buffer, BUFFER_SIZE, iova);
+	check_access_rw(_metadata, self->fd, access_id, iova, 0);
+	test_ioctl_ioas_unmap(iova, BUFFER_SIZE);
+	test_cmd_destroy_access(access_id);
+}
+
+TEST_F(iommufd_ioas, fork_gone)
+{
+	__u32 access_id;
+	pid_t child;
+
+	test_cmd_create_access(self->ioas_id, &access_id, 0);
+
+	/* Create a mapping with a different mm */
+	child = fork();
+	if (!child) {
+		test_ioctl_ioas_map_fixed(buffer, BUFFER_SIZE,
+					  MOCK_APERTURE_START);
+		exit(0);
+	}
+	ASSERT_NE(-1, child);
+	ASSERT_EQ(child, waitpid(child, NULL, 0));
+
+	if (self->domain_id) {
+		/*
+		 * If a domain already existed then everything was pinned within
+		 * the fork, so this copies from one domain to another.
+		 */
+		test_cmd_mock_domain(self->ioas_id, NULL, NULL);
+		check_access_rw(_metadata, self->fd, access_id,
+				MOCK_APERTURE_START, 0);
+
+	} else {
+		/*
+		 * Otherwise we need to actually pin pages which can't happen
+		 * since the fork is gone.
+		 */
+		test_err_mock_domain(EFAULT, self->ioas_id, NULL, NULL);
+	}
+
+	test_cmd_destroy_access(access_id);
+}
+
+TEST_F(iommufd_ioas, fork_present)
+{
+	__u32 access_id;
+	int pipefds[2];
+	uint64_t tmp;
+	pid_t child;
+	int efd;
+
+	test_cmd_create_access(self->ioas_id, &access_id, 0);
+
+	ASSERT_EQ(0, pipe2(pipefds, O_CLOEXEC));
+	efd = eventfd(0, EFD_CLOEXEC);
+	ASSERT_NE(-1, efd);
+
+	/* Create a mapping with a different mm */
+	child = fork();
+	if (!child) {
+		__u64 iova;
+		uint64_t one = 1;
+
+		close(pipefds[1]);
+		test_ioctl_ioas_map_fixed(buffer, BUFFER_SIZE,
+					  MOCK_APERTURE_START);
+		if (write(efd, &one, sizeof(one)) != sizeof(one))
+			exit(100);
+		if (read(pipefds[0], &iova, 1) != 1)
+			exit(100);
+		exit(0);
+	}
+	close(pipefds[0]);
+	ASSERT_NE(-1, child);
+	ASSERT_EQ(8, read(efd, &tmp, sizeof(tmp)));
+
+	/* Read pages from the remote process */
+	test_cmd_mock_domain(self->ioas_id, NULL, NULL);
+	check_access_rw(_metadata, self->fd, access_id, MOCK_APERTURE_START, 0);
+
+	ASSERT_EQ(0, close(pipefds[1]));
+	ASSERT_EQ(child, waitpid(child, NULL, 0));
+
+	test_cmd_destroy_access(access_id);
+}
+
+TEST_F(iommufd_ioas, ioas_option_huge_pages)
+{
+	struct iommu_option cmd = {
+		.size = sizeof(cmd),
+		.option_id = IOMMU_OPTION_HUGE_PAGES,
+		.op = IOMMU_OPTION_OP_GET,
+		.val64 = 3,
+		.object_id = self->ioas_id,
+	};
+
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	ASSERT_EQ(1, cmd.val64);
+
+	cmd.op = IOMMU_OPTION_OP_SET;
+	cmd.val64 = 0;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	cmd.op = IOMMU_OPTION_OP_GET;
+	cmd.val64 = 3;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	ASSERT_EQ(0, cmd.val64);
+
+	cmd.op = IOMMU_OPTION_OP_SET;
+	cmd.val64 = 2;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	cmd.op = IOMMU_OPTION_OP_SET;
+	cmd.val64 = 1;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+}
+
+TEST_F(iommufd_ioas, ioas_iova_alloc)
+{
+	unsigned int length;
+	__u64 iova;
+
+	for (length = 1; length != PAGE_SIZE * 2; length++) {
+		if (variant->mock_domains && (length % MOCK_PAGE_SIZE)) {
+			test_err_ioctl_ioas_map(EINVAL, buffer, length, &iova);
+		} else {
+			test_ioctl_ioas_map(buffer, length, &iova);
+			test_ioctl_ioas_unmap(iova, length);
+		}
+	}
+}
+
+TEST_F(iommufd_ioas, ioas_align_change)
+{
+	struct iommu_option cmd = {
+		.size = sizeof(cmd),
+		.option_id = IOMMU_OPTION_HUGE_PAGES,
+		.op = IOMMU_OPTION_OP_SET,
+		.object_id = self->ioas_id,
+		/* 0 means everything must be aligned to PAGE_SIZE */
+		.val64 = 0,
+	};
+
+	/*
+	 * We cannot upgrade the alignment using OPTION_HUGE_PAGES when a domain
+	 * and map are present.
+	 */
+	if (variant->mock_domains)
+		return;
+
+	/*
+	 * We can upgrade to PAGE_SIZE alignment when things are aligned right
+	 */
+	test_ioctl_ioas_map_fixed(buffer, PAGE_SIZE, MOCK_APERTURE_START);
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	/* Misalignment is rejected at map time */
+	test_err_ioctl_ioas_map_fixed(EINVAL, buffer + MOCK_PAGE_SIZE,
+				      PAGE_SIZE,
+				      MOCK_APERTURE_START + PAGE_SIZE);
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	/* Reduce alignment */
+	cmd.val64 = 1;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	/* Confirm misalignment is rejected during alignment upgrade */
+	test_ioctl_ioas_map_fixed(buffer + MOCK_PAGE_SIZE, PAGE_SIZE,
+				  MOCK_APERTURE_START + PAGE_SIZE);
+	cmd.val64 = 0;
+	EXPECT_ERRNO(EADDRINUSE, ioctl(self->fd, IOMMU_OPTION, &cmd));
+
+	test_ioctl_ioas_unmap(MOCK_APERTURE_START + PAGE_SIZE, PAGE_SIZE);
+	test_ioctl_ioas_unmap(MOCK_APERTURE_START, PAGE_SIZE);
+}
+
+TEST_F(iommufd_ioas, copy_sweep)
+{
+	struct iommu_ioas_copy copy_cmd = {
+		.size = sizeof(copy_cmd),
+		.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
+		.src_ioas_id = self->ioas_id,
+		.dst_iova = MOCK_APERTURE_START,
+		.length = MOCK_PAGE_SIZE,
+	};
+	unsigned int dst_ioas_id;
+	uint64_t last_iova;
+	uint64_t iova;
+
+	test_ioctl_ioas_alloc(&dst_ioas_id);
+	copy_cmd.dst_ioas_id = dst_ioas_id;
+
+	if (variant->mock_domains)
+		last_iova = MOCK_APERTURE_START + BUFFER_SIZE - 1;
+	else
+		last_iova = MOCK_APERTURE_START + BUFFER_SIZE - 2;
+
+	test_ioctl_ioas_map_fixed(buffer, last_iova - MOCK_APERTURE_START + 1,
+				  MOCK_APERTURE_START);
+
+	for (iova = MOCK_APERTURE_START - PAGE_SIZE; iova <= last_iova;
+	     iova += 511) {
+		copy_cmd.src_iova = iova;
+		if (iova < MOCK_APERTURE_START ||
+		    iova + copy_cmd.length - 1 > last_iova) {
+			EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_IOAS_COPY,
+						   &copy_cmd));
+		} else {
+			ASSERT_EQ(0,
+				  ioctl(self->fd, IOMMU_IOAS_COPY, &copy_cmd));
+			test_ioctl_ioas_unmap_id(dst_ioas_id, copy_cmd.dst_iova,
+						 copy_cmd.length);
+		}
+	}
+
+	test_ioctl_destroy(dst_ioas_id);
+}
+
+FIXTURE(iommufd_mock_domain)
+{
+	int fd;
+	uint32_t ioas_id;
+	uint32_t domain_id;
+	uint32_t domain_ids[2];
+	int mmap_flags;
+	size_t mmap_buf_size;
+};
+
+FIXTURE_VARIANT(iommufd_mock_domain)
+{
+	unsigned int mock_domains;
+	bool hugepages;
+};
+
+FIXTURE_SETUP(iommufd_mock_domain)
+{
+	unsigned int i;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+	test_ioctl_ioas_alloc(&self->ioas_id);
+
+	ASSERT_GE(ARRAY_SIZE(self->domain_ids), variant->mock_domains);
+
+	for (i = 0; i != variant->mock_domains; i++)
+		test_cmd_mock_domain(self->ioas_id, NULL, &self->domain_ids[i]);
+	self->domain_id = self->domain_ids[0];
+
+	self->mmap_flags = MAP_SHARED | MAP_ANONYMOUS;
+	self->mmap_buf_size = PAGE_SIZE * 8;
+	if (variant->hugepages) {
+		/*
+		 * MAP_POPULATE will cause the kernel to fail mmap if THPs are
+		 * not available.
+		 */
+		self->mmap_flags |= MAP_HUGETLB | MAP_POPULATE;
+		self->mmap_buf_size = HUGEPAGE_SIZE * 2;
+	}
+}
+
+FIXTURE_TEARDOWN(iommufd_mock_domain)
+{
+	teardown_iommufd(self->fd, _metadata);
+}
+
+FIXTURE_VARIANT_ADD(iommufd_mock_domain, one_domain)
+{
+	.mock_domains = 1,
+	.hugepages = false,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_mock_domain, two_domains)
+{
+	.mock_domains = 2,
+	.hugepages = false,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_mock_domain, one_domain_hugepage)
+{
+	.mock_domains = 1,
+	.hugepages = true,
+};
+
+FIXTURE_VARIANT_ADD(iommufd_mock_domain, two_domains_hugepage)
+{
+	.mock_domains = 2,
+	.hugepages = true,
+};
+
+/* Have the kernel check that the user pages made it to the iommu_domain */
+#define check_mock_iova(_ptr, _iova, _length)                                \
+	({                                                                   \
+		struct iommu_test_cmd check_map_cmd = {                      \
+			.size = sizeof(check_map_cmd),                       \
+			.op = IOMMU_TEST_OP_MD_CHECK_MAP,                    \
+			.id = self->domain_id,                               \
+			.check_map = { .iova = _iova,                        \
+				       .length = _length,                    \
+				       .uptr = (uintptr_t)(_ptr) },          \
+		};                                                           \
+		ASSERT_EQ(0,                                                 \
+			  ioctl(self->fd,                                    \
+				_IOMMU_TEST_CMD(IOMMU_TEST_OP_MD_CHECK_MAP), \
+				&check_map_cmd));                            \
+		if (self->domain_ids[1]) {                                   \
+			check_map_cmd.id = self->domain_ids[1];              \
+			ASSERT_EQ(0,                                         \
+				  ioctl(self->fd,                            \
+					_IOMMU_TEST_CMD(                     \
+						IOMMU_TEST_OP_MD_CHECK_MAP), \
+					&check_map_cmd));                    \
+		}                                                            \
+	})
+
+TEST_F(iommufd_mock_domain, basic)
+{
+	size_t buf_size = self->mmap_buf_size;
+	uint8_t *buf;
+	__u64 iova;
+
+	/* Simple one page map */
+	test_ioctl_ioas_map(buffer, PAGE_SIZE, &iova);
+	check_mock_iova(buffer, iova, PAGE_SIZE);
+
+	buf = mmap(0, buf_size, PROT_READ | PROT_WRITE, self->mmap_flags, -1,
+		   0);
+	ASSERT_NE(MAP_FAILED, buf);
+
+	/* EFAULT half way through mapping */
+	ASSERT_EQ(0, munmap(buf + buf_size / 2, buf_size / 2));
+	test_err_ioctl_ioas_map(EFAULT, buf, buf_size, &iova);
+
+	/* EFAULT on first page */
+	ASSERT_EQ(0, munmap(buf, buf_size / 2));
+	test_err_ioctl_ioas_map(EFAULT, buf, buf_size, &iova);
+}
+
+TEST_F(iommufd_mock_domain, ro_unshare)
+{
+	uint8_t *buf;
+	__u64 iova;
+	int fd;
+
+	fd = open("/proc/self/exe", O_RDONLY);
+	ASSERT_NE(-1, fd);
+
+	buf = mmap(0, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+	ASSERT_NE(MAP_FAILED, buf);
+	close(fd);
+
+	/*
+	 * There have been lots of changes to the "unshare" mechanism in
+	 * get_user_pages(), make sure it works right. The write to the page
+	 * after we map it for reading should not change the assigned PFN.
+	 */
+	ASSERT_EQ(0,
+		  _test_ioctl_ioas_map(self->fd, self->ioas_id, buf, PAGE_SIZE,
+				       &iova, IOMMU_IOAS_MAP_READABLE));
+	check_mock_iova(buf, iova, PAGE_SIZE);
+	memset(buf, 1, PAGE_SIZE);
+	check_mock_iova(buf, iova, PAGE_SIZE);
+	ASSERT_EQ(0, munmap(buf, PAGE_SIZE));
+}
+
+TEST_F(iommufd_mock_domain, all_aligns)
+{
+	size_t test_step = variant->hugepages ? (self->mmap_buf_size / 16) :
+						MOCK_PAGE_SIZE;
+	size_t buf_size = self->mmap_buf_size;
+	unsigned int start;
+	unsigned int end;
+	uint8_t *buf;
+
+	buf = mmap(0, buf_size, PROT_READ | PROT_WRITE, self->mmap_flags, -1,
+		   0);
+	ASSERT_NE(MAP_FAILED, buf);
+	check_refs(buf, buf_size, 0);
+
+	/*
+	 * Map every combination of page size and alignment within a big region,
+	 * less for hugepage case as it takes so long to finish.
+	 */
+	for (start = 0; start < buf_size; start += test_step) {
+		if (variant->hugepages)
+			end = buf_size;
+		else
+			end = start + MOCK_PAGE_SIZE;
+		for (; end < buf_size; end += MOCK_PAGE_SIZE) {
+			size_t length = end - start;
+			__u64 iova;
+
+			test_ioctl_ioas_map(buf + start, length, &iova);
+			check_mock_iova(buf + start, iova, length);
+			check_refs(buf + start / PAGE_SIZE * PAGE_SIZE,
+				   end / PAGE_SIZE * PAGE_SIZE -
+					   start / PAGE_SIZE * PAGE_SIZE,
+				   1);
+
+			test_ioctl_ioas_unmap(iova, length);
+		}
+	}
+	check_refs(buf, buf_size, 0);
+	ASSERT_EQ(0, munmap(buf, buf_size));
+}
+
+TEST_F(iommufd_mock_domain, all_aligns_copy)
+{
+	size_t test_step = variant->hugepages ? self->mmap_buf_size / 16 :
+						MOCK_PAGE_SIZE;
+	size_t buf_size = self->mmap_buf_size;
+	unsigned int start;
+	unsigned int end;
+	uint8_t *buf;
+
+	buf = mmap(0, buf_size, PROT_READ | PROT_WRITE, self->mmap_flags, -1,
+		   0);
+	ASSERT_NE(MAP_FAILED, buf);
+	check_refs(buf, buf_size, 0);
+
+	/*
+	 * Map every combination of page size and alignment within a big region,
+	 * less for hugepage case as it takes so long to finish.
+	 */
+	for (start = 0; start < buf_size; start += test_step) {
+		if (variant->hugepages)
+			end = buf_size;
+		else
+			end = start + MOCK_PAGE_SIZE;
+		for (; end < buf_size; end += MOCK_PAGE_SIZE) {
+			size_t length = end - start;
+			unsigned int old_id;
+			uint32_t mock_device_id;
+			__u64 iova;
+
+			test_ioctl_ioas_map(buf + start, length, &iova);
+
+			/* Add and destroy a domain while the area exists */
+			old_id = self->domain_ids[1];
+			test_cmd_mock_domain(self->ioas_id, &mock_device_id,
+					     &self->domain_ids[1]);
+
+			check_mock_iova(buf + start, iova, length);
+			check_refs(buf + start / PAGE_SIZE * PAGE_SIZE,
+				   end / PAGE_SIZE * PAGE_SIZE -
+					   start / PAGE_SIZE * PAGE_SIZE,
+				   1);
+
+			test_ioctl_destroy(mock_device_id);
+			test_ioctl_destroy(self->domain_ids[1]);
+			self->domain_ids[1] = old_id;
+
+			test_ioctl_ioas_unmap(iova, length);
+		}
+	}
+	check_refs(buf, buf_size, 0);
+	ASSERT_EQ(0, munmap(buf, buf_size));
+}
+
+TEST_F(iommufd_mock_domain, user_copy)
+{
+	struct iommu_test_cmd access_cmd = {
+		.size = sizeof(access_cmd),
+		.op = IOMMU_TEST_OP_ACCESS_PAGES,
+		.access_pages = { .length = BUFFER_SIZE,
+				  .uptr = (uintptr_t)buffer },
+	};
+	struct iommu_ioas_copy copy_cmd = {
+		.size = sizeof(copy_cmd),
+		.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
+		.dst_ioas_id = self->ioas_id,
+		.dst_iova = MOCK_APERTURE_START,
+		.length = BUFFER_SIZE,
+	};
+	unsigned int ioas_id;
+
+	/* Pin the pages in an IOAS with no domains then copy to an IOAS with domains */
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_ioctl_ioas_map_id(ioas_id, buffer, BUFFER_SIZE,
+			       &copy_cmd.src_iova);
+
+	test_cmd_create_access(ioas_id, &access_cmd.id,
+			       MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES);
+
+	access_cmd.access_pages.iova = copy_cmd.src_iova;
+	ASSERT_EQ(0,
+		  ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_PAGES),
+			&access_cmd));
+	copy_cmd.src_ioas_id = ioas_id;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_IOAS_COPY, &copy_cmd));
+	check_mock_iova(buffer, MOCK_APERTURE_START, BUFFER_SIZE);
+
+	test_cmd_destroy_access_pages(
+		access_cmd.id, access_cmd.access_pages.out_access_pages_id);
+	test_cmd_destroy_access(access_cmd.id) test_ioctl_destroy(ioas_id);
+
+	test_ioctl_destroy(ioas_id);
+}
+
+/* VFIO compatibility IOCTLs */
+
+TEST_F(iommufd, simple_ioctls)
+{
+	ASSERT_EQ(VFIO_API_VERSION, ioctl(self->fd, VFIO_GET_API_VERSION));
+	ASSERT_EQ(1, ioctl(self->fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU));
+}
+
+TEST_F(iommufd, unmap_cmd)
+{
+	struct vfio_iommu_type1_dma_unmap unmap_cmd = {
+		.iova = MOCK_APERTURE_START,
+		.size = PAGE_SIZE,
+	};
+
+	unmap_cmd.argsz = 1;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+
+	unmap_cmd.argsz = sizeof(unmap_cmd);
+	unmap_cmd.flags = 1 << 31;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+
+	unmap_cmd.flags = 0;
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+}
+
+TEST_F(iommufd, map_cmd)
+{
+	struct vfio_iommu_type1_dma_map map_cmd = {
+		.iova = MOCK_APERTURE_START,
+		.size = PAGE_SIZE,
+		.vaddr = (__u64)buffer,
+	};
+
+	map_cmd.argsz = 1;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+
+	map_cmd.argsz = sizeof(map_cmd);
+	map_cmd.flags = 1 << 31;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+
+	/* Requires a domain to be attached */
+	map_cmd.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+}
+
+TEST_F(iommufd, info_cmd)
+{
+	struct vfio_iommu_type1_info info_cmd = {};
+
+	/* Invalid argsz */
+	info_cmd.argsz = 1;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_GET_INFO, &info_cmd));
+
+	info_cmd.argsz = sizeof(info_cmd);
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, VFIO_IOMMU_GET_INFO, &info_cmd));
+}
+
+TEST_F(iommufd, set_iommu_cmd)
+{
+	/* Requires a domain to be attached */
+	EXPECT_ERRNO(ENODEV,
+		     ioctl(self->fd, VFIO_SET_IOMMU, VFIO_TYPE1v2_IOMMU));
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU));
+}
+
+TEST_F(iommufd, vfio_ioas)
+{
+	struct iommu_vfio_ioas vfio_ioas_cmd = {
+		.size = sizeof(vfio_ioas_cmd),
+		.op = IOMMU_VFIO_IOAS_GET,
+	};
+	__u32 ioas_id;
+
+	/* ENODEV if there is no compat ioas */
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+
+	/* Invalid id for set */
+	vfio_ioas_cmd.op = IOMMU_VFIO_IOAS_SET;
+	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+
+	/* Valid id for set*/
+	test_ioctl_ioas_alloc(&ioas_id);
+	vfio_ioas_cmd.ioas_id = ioas_id;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+
+	/* Same id comes back from get */
+	vfio_ioas_cmd.op = IOMMU_VFIO_IOAS_GET;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+	ASSERT_EQ(ioas_id, vfio_ioas_cmd.ioas_id);
+
+	/* Clear works */
+	vfio_ioas_cmd.op = IOMMU_VFIO_IOAS_CLEAR;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+	vfio_ioas_cmd.op = IOMMU_VFIO_IOAS_GET;
+	EXPECT_ERRNO(ENODEV, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+}
+
+FIXTURE(vfio_compat_mock_domain)
+{
+	int fd;
+	uint32_t ioas_id;
+};
+
+FIXTURE_VARIANT(vfio_compat_mock_domain)
+{
+	unsigned int version;
+};
+
+FIXTURE_SETUP(vfio_compat_mock_domain)
+{
+	struct iommu_vfio_ioas vfio_ioas_cmd = {
+		.size = sizeof(vfio_ioas_cmd),
+		.op = IOMMU_VFIO_IOAS_SET,
+	};
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+
+	/* Create what VFIO would consider a group */
+	test_ioctl_ioas_alloc(&self->ioas_id);
+	test_cmd_mock_domain(self->ioas_id, NULL, NULL);
+
+	/* Attach it to the vfio compat */
+	vfio_ioas_cmd.ioas_id = self->ioas_id;
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_VFIO_IOAS, &vfio_ioas_cmd));
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_SET_IOMMU, variant->version));
+}
+
+FIXTURE_TEARDOWN(vfio_compat_mock_domain)
+{
+	teardown_iommufd(self->fd, _metadata);
+}
+
+FIXTURE_VARIANT_ADD(vfio_compat_mock_domain, Ver1v2)
+{
+	.version = VFIO_TYPE1v2_IOMMU,
+};
+
+FIXTURE_VARIANT_ADD(vfio_compat_mock_domain, Ver1v0)
+{
+	.version = VFIO_TYPE1_IOMMU,
+};
+
+TEST_F(vfio_compat_mock_domain, simple_close)
+{
+}
+
+TEST_F(vfio_compat_mock_domain, option_huge_pages)
+{
+	struct iommu_option cmd = {
+		.size = sizeof(cmd),
+		.option_id = IOMMU_OPTION_HUGE_PAGES,
+		.op = IOMMU_OPTION_OP_GET,
+		.val64 = 3,
+		.object_id = self->ioas_id,
+	};
+
+	ASSERT_EQ(0, ioctl(self->fd, IOMMU_OPTION, &cmd));
+	if (variant->version == VFIO_TYPE1_IOMMU) {
+		ASSERT_EQ(0, cmd.val64);
+	} else {
+		ASSERT_EQ(1, cmd.val64);
+	}
+}
+
+/*
+ * Execute an ioctl command stored in buffer and check that the result does not
+ * overflow memory.
+ */
+static bool is_filled(const void *buf, uint8_t c, size_t len)
+{
+	const uint8_t *cbuf = buf;
+
+	for (; len; cbuf++, len--)
+		if (*cbuf != c)
+			return false;
+	return true;
+}
+
+#define ioctl_check_buf(fd, cmd)                                         \
+	({                                                               \
+		size_t _cmd_len = *(__u32 *)buffer;                      \
+									 \
+		memset(buffer + _cmd_len, 0xAA, BUFFER_SIZE - _cmd_len); \
+		ASSERT_EQ(0, ioctl(fd, cmd, buffer));                    \
+		ASSERT_EQ(true, is_filled(buffer + _cmd_len, 0xAA,       \
+					  BUFFER_SIZE - _cmd_len));      \
+	})
+
+static void check_vfio_info_cap_chain(struct __test_metadata *_metadata,
+				      struct vfio_iommu_type1_info *info_cmd)
+{
+	const struct vfio_info_cap_header *cap;
+
+	ASSERT_GE(info_cmd->argsz, info_cmd->cap_offset + sizeof(*cap));
+	cap = buffer + info_cmd->cap_offset;
+	while (true) {
+		size_t cap_size;
+
+		if (cap->next)
+			cap_size = (buffer + cap->next) - (void *)cap;
+		else
+			cap_size = (buffer + info_cmd->argsz) - (void *)cap;
+
+		switch (cap->id) {
+		case VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE: {
+			struct vfio_iommu_type1_info_cap_iova_range *data =
+				(void *)cap;
+
+			ASSERT_EQ(1, data->header.version);
+			ASSERT_EQ(1, data->nr_iovas);
+			EXPECT_EQ(MOCK_APERTURE_START,
+				  data->iova_ranges[0].start);
+			EXPECT_EQ(MOCK_APERTURE_LAST, data->iova_ranges[0].end);
+			break;
+		}
+		case VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL: {
+			struct vfio_iommu_type1_info_dma_avail *data =
+				(void *)cap;
+
+			ASSERT_EQ(1, data->header.version);
+			ASSERT_EQ(sizeof(*data), cap_size);
+			break;
+		}
+		default:
+			ASSERT_EQ(false, true);
+			break;
+		}
+		if (!cap->next)
+			break;
+
+		ASSERT_GE(info_cmd->argsz, cap->next + sizeof(*cap));
+		ASSERT_GE(buffer + cap->next, (void *)cap);
+		cap = buffer + cap->next;
+	}
+}
+
+TEST_F(vfio_compat_mock_domain, get_info)
+{
+	struct vfio_iommu_type1_info *info_cmd = buffer;
+	unsigned int i;
+	size_t caplen;
+
+	/* Pre-cap ABI */
+	*info_cmd = (struct vfio_iommu_type1_info){
+		.argsz = offsetof(struct vfio_iommu_type1_info, cap_offset),
+	};
+	ioctl_check_buf(self->fd, VFIO_IOMMU_GET_INFO);
+	ASSERT_NE(0, info_cmd->iova_pgsizes);
+	ASSERT_EQ(VFIO_IOMMU_INFO_PGSIZES | VFIO_IOMMU_INFO_CAPS,
+		  info_cmd->flags);
+
+	/* Read the cap chain size */
+	*info_cmd = (struct vfio_iommu_type1_info){
+		.argsz = sizeof(*info_cmd),
+	};
+	ioctl_check_buf(self->fd, VFIO_IOMMU_GET_INFO);
+	ASSERT_NE(0, info_cmd->iova_pgsizes);
+	ASSERT_EQ(VFIO_IOMMU_INFO_PGSIZES | VFIO_IOMMU_INFO_CAPS,
+		  info_cmd->flags);
+	ASSERT_EQ(0, info_cmd->cap_offset);
+	ASSERT_LT(sizeof(*info_cmd), info_cmd->argsz);
+
+	/* Read the caps, kernel should never create a corrupted caps */
+	caplen = info_cmd->argsz;
+	for (i = sizeof(*info_cmd); i < caplen; i++) {
+		*info_cmd = (struct vfio_iommu_type1_info){
+			.argsz = i,
+		};
+		ioctl_check_buf(self->fd, VFIO_IOMMU_GET_INFO);
+		ASSERT_EQ(VFIO_IOMMU_INFO_PGSIZES | VFIO_IOMMU_INFO_CAPS,
+			  info_cmd->flags);
+		if (!info_cmd->cap_offset)
+			continue;
+		check_vfio_info_cap_chain(_metadata, info_cmd);
+	}
+}
+
+static void shuffle_array(unsigned long *array, size_t nelms)
+{
+	unsigned int i;
+
+	/* Shuffle */
+	for (i = 0; i != nelms; i++) {
+		unsigned long tmp = array[i];
+		unsigned int other = rand() % (nelms - i);
+
+		array[i] = array[other];
+		array[other] = tmp;
+	}
+}
+
+TEST_F(vfio_compat_mock_domain, map)
+{
+	struct vfio_iommu_type1_dma_map map_cmd = {
+		.argsz = sizeof(map_cmd),
+		.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
+		.vaddr = (uintptr_t)buffer,
+		.size = BUFFER_SIZE,
+		.iova = MOCK_APERTURE_START,
+	};
+	struct vfio_iommu_type1_dma_unmap unmap_cmd = {
+		.argsz = sizeof(unmap_cmd),
+		.size = BUFFER_SIZE,
+		.iova = MOCK_APERTURE_START,
+	};
+	unsigned long pages_iova[BUFFER_SIZE / PAGE_SIZE];
+	unsigned int i;
+
+	/* Simple map/unmap */
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+	ASSERT_EQ(BUFFER_SIZE, unmap_cmd.size);
+
+	/* UNMAP_FLAG_ALL requres 0 iova/size */
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+	unmap_cmd.flags = VFIO_DMA_UNMAP_FLAG_ALL;
+	EXPECT_ERRNO(EINVAL, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+
+	unmap_cmd.iova = 0;
+	unmap_cmd.size = 0;
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+	ASSERT_EQ(BUFFER_SIZE, unmap_cmd.size);
+
+	/* Small pages */
+	for (i = 0; i != ARRAY_SIZE(pages_iova); i++) {
+		map_cmd.iova = pages_iova[i] =
+			MOCK_APERTURE_START + i * PAGE_SIZE;
+		map_cmd.vaddr = (uintptr_t)buffer + i * PAGE_SIZE;
+		map_cmd.size = PAGE_SIZE;
+		ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+	}
+	shuffle_array(pages_iova, ARRAY_SIZE(pages_iova));
+
+	unmap_cmd.flags = 0;
+	unmap_cmd.size = PAGE_SIZE;
+	for (i = 0; i != ARRAY_SIZE(pages_iova); i++) {
+		unmap_cmd.iova = pages_iova[i];
+		ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
+	}
+}
+
+TEST_F(vfio_compat_mock_domain, huge_map)
+{
+	size_t buf_size = HUGEPAGE_SIZE * 2;
+	struct vfio_iommu_type1_dma_map map_cmd = {
+		.argsz = sizeof(map_cmd),
+		.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
+		.size = buf_size,
+		.iova = MOCK_APERTURE_START,
+	};
+	struct vfio_iommu_type1_dma_unmap unmap_cmd = {
+		.argsz = sizeof(unmap_cmd),
+	};
+	unsigned long pages_iova[16];
+	unsigned int i;
+	void *buf;
+
+	/* Test huge pages and splitting */
+	buf = mmap(0, buf_size, PROT_READ | PROT_WRITE,
+		   MAP_SHARED | MAP_ANONYMOUS | MAP_HUGETLB | MAP_POPULATE, -1,
+		   0);
+	ASSERT_NE(MAP_FAILED, buf);
+	map_cmd.vaddr = (uintptr_t)buf;
+	ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
+
+	unmap_cmd.size = buf_size / ARRAY_SIZE(pages_iova);
+	for (i = 0; i != ARRAY_SIZE(pages_iova); i++)
+		pages_iova[i] = MOCK_APERTURE_START + (i * unmap_cmd.size);
+	shuffle_array(pages_iova, ARRAY_SIZE(pages_iova));
+
+	/* type1 mode can cut up larger mappings, type1v2 always fails */
+	for (i = 0; i != ARRAY_SIZE(pages_iova); i++) {
+		unmap_cmd.iova = pages_iova[i];
+		unmap_cmd.size = buf_size / ARRAY_SIZE(pages_iova);
+		if (variant->version == VFIO_TYPE1_IOMMU) {
+			ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA,
+					   &unmap_cmd));
+		} else {
+			EXPECT_ERRNO(ENOENT,
+				     ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA,
+					   &unmap_cmd));
+		}
+	}
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c
new file mode 100644
index 000000000000..9713111b820d
--- /dev/null
+++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c
@@ -0,0 +1,580 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
+ *
+ * These tests are "kernel integrity" tests. They are looking for kernel
+ * WARN/OOPS/kasn/etc splats triggered by kernel sanitizers & debugging
+ * features. It does not attempt to verify that the system calls are doing what
+ * they are supposed to do.
+ *
+ * The basic philosophy is to run a sequence of calls that will succeed and then
+ * sweep every failure injection point on that call chain to look for
+ * interesting things in error handling.
+ *
+ * This test is best run with:
+ *  echo 1 > /proc/sys/kernel/panic_on_warn
+ * If something is actually going wrong.
+ */
+#include <fcntl.h>
+#include <dirent.h>
+
+#define __EXPORTED_HEADERS__
+#include <linux/vfio.h>
+
+#include "iommufd_utils.h"
+
+static bool have_fault_injection;
+
+static int writeat(int dfd, const char *fn, const char *val)
+{
+	size_t val_len = strlen(val);
+	ssize_t res;
+	int fd;
+
+	fd = openat(dfd, fn, O_WRONLY);
+	if (fd == -1)
+		return -1;
+	res = write(fd, val, val_len);
+	assert(res == val_len);
+	close(fd);
+	return 0;
+}
+
+static __attribute__((constructor)) void setup_buffer(void)
+{
+	BUFFER_SIZE = 2*1024*1024;
+
+	buffer = mmap(0, BUFFER_SIZE, PROT_READ | PROT_WRITE,
+		      MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+}
+
+/*
+ * This sets up fail_injection in a way that is useful for this test.
+ * It does not attempt to restore things back to how they were.
+ */
+static __attribute__((constructor)) void setup_fault_injection(void)
+{
+	DIR *debugfs = opendir("/sys/kernel/debug/");
+	struct dirent *dent;
+
+	if (!debugfs)
+		return;
+
+	/* Allow any allocation call to be fault injected */
+	if (writeat(dirfd(debugfs), "failslab/ignore-gfp-wait", "N"))
+		return;
+	writeat(dirfd(debugfs), "fail_page_alloc/ignore-gfp-wait", "N");
+	writeat(dirfd(debugfs), "fail_page_alloc/ignore-gfp-highmem", "N");
+
+	while ((dent = readdir(debugfs))) {
+		char fn[300];
+
+		if (strncmp(dent->d_name, "fail", 4) != 0)
+			continue;
+
+		/* We are looking for kernel splats, quiet down the log */
+		snprintf(fn, sizeof(fn), "%s/verbose", dent->d_name);
+		writeat(dirfd(debugfs), fn, "0");
+	}
+	closedir(debugfs);
+	have_fault_injection = true;
+}
+
+struct fail_nth_state {
+	int proc_fd;
+	unsigned int iteration;
+};
+
+static void fail_nth_first(struct __test_metadata *_metadata,
+			   struct fail_nth_state *nth_state)
+{
+	char buf[300];
+
+	snprintf(buf, sizeof(buf), "/proc/self/task/%u/fail-nth", getpid());
+	nth_state->proc_fd = open(buf, O_RDWR);
+	ASSERT_NE(-1, nth_state->proc_fd);
+}
+
+static bool fail_nth_next(struct __test_metadata *_metadata,
+			  struct fail_nth_state *nth_state,
+			  int test_result)
+{
+	static const char disable_nth[] = "0";
+	char buf[300];
+
+	/*
+	 * This is just an arbitrary limit based on the current kernel
+	 * situation. Changes in the kernel can dramtically change the number of
+	 * required fault injection sites, so if this hits it doesn't
+	 * necessarily mean a test failure, just that the limit has to be made
+	 * bigger.
+	 */
+	ASSERT_GT(400, nth_state->iteration);
+	if (nth_state->iteration != 0) {
+		ssize_t res;
+		ssize_t res2;
+
+		buf[0] = 0;
+		/*
+		 * Annoyingly disabling the nth can also fail. This means
+		 * the test passed without triggering failure
+		 */
+		res = pread(nth_state->proc_fd, buf, sizeof(buf), 0);
+		if (res == -1 && errno == EFAULT) {
+			buf[0] = '1';
+			buf[1] = '\n';
+			res = 2;
+		}
+
+		res2 = pwrite(nth_state->proc_fd, disable_nth,
+			      ARRAY_SIZE(disable_nth) - 1, 0);
+		if (res2 == -1 && errno == EFAULT) {
+			res2 = pwrite(nth_state->proc_fd, disable_nth,
+				      ARRAY_SIZE(disable_nth) - 1, 0);
+			buf[0] = '1';
+			buf[1] = '\n';
+		}
+		ASSERT_EQ(ARRAY_SIZE(disable_nth) - 1, res2);
+
+		/* printf("  nth %u result=%d nth=%u\n", nth_state->iteration,
+		       test_result, atoi(buf)); */
+		fflush(stdout);
+		ASSERT_LT(1, res);
+		if (res != 2 || buf[0] != '0' || buf[1] != '\n')
+			return false;
+	} else {
+		/* printf("  nth %u result=%d\n", nth_state->iteration,
+		       test_result); */
+	}
+	nth_state->iteration++;
+	return true;
+}
+
+/*
+ * This is called during the test to start failure injection. It allows the test
+ * to do some setup that has already been swept and thus reduce the required
+ * iterations.
+ */
+void __fail_nth_enable(struct __test_metadata *_metadata,
+		       struct fail_nth_state *nth_state)
+{
+	char buf[300];
+	size_t len;
+
+	if (!nth_state->iteration)
+		return;
+
+	len = snprintf(buf, sizeof(buf), "%u", nth_state->iteration);
+	ASSERT_EQ(len, pwrite(nth_state->proc_fd, buf, len, 0));
+}
+#define fail_nth_enable() __fail_nth_enable(_metadata, _nth_state)
+
+#define TEST_FAIL_NTH(fixture_name, name)                                           \
+	static int test_nth_##name(struct __test_metadata *_metadata,               \
+				   FIXTURE_DATA(fixture_name) *self,                \
+				   const FIXTURE_VARIANT(fixture_name)              \
+					   *variant,                                \
+				   struct fail_nth_state *_nth_state);              \
+	TEST_F(fixture_name, name)                                                  \
+	{                                                                           \
+		struct fail_nth_state nth_state = {};                               \
+		int test_result = 0;                                                \
+										    \
+		if (!have_fault_injection)                                          \
+			SKIP(return,                                                \
+				   "fault injection is not enabled in the kernel"); \
+		fail_nth_first(_metadata, &nth_state);                              \
+		ASSERT_EQ(0, test_nth_##name(_metadata, self, variant,              \
+					     &nth_state));                          \
+		while (fail_nth_next(_metadata, &nth_state, test_result)) {         \
+			fixture_name##_teardown(_metadata, self, variant);          \
+			fixture_name##_setup(_metadata, self, variant);             \
+			test_result = test_nth_##name(_metadata, self,              \
+						      variant, &nth_state);         \
+		};                                                                  \
+		ASSERT_EQ(0, test_result);                                          \
+	}                                                                           \
+	static int test_nth_##name(                                                 \
+		struct __test_metadata __attribute__((unused)) *_metadata,          \
+		FIXTURE_DATA(fixture_name) __attribute__((unused)) *self,           \
+		const FIXTURE_VARIANT(fixture_name) __attribute__((unused))         \
+			*variant,                                                   \
+		struct fail_nth_state *_nth_state)
+
+FIXTURE(basic_fail_nth)
+{
+	int fd;
+	uint32_t access_id;
+};
+
+FIXTURE_SETUP(basic_fail_nth)
+{
+	self->fd = -1;
+	self->access_id = 0;
+}
+
+FIXTURE_TEARDOWN(basic_fail_nth)
+{
+	int rc;
+
+	if (self->access_id) {
+		/* The access FD holds the iommufd open until it closes */
+		rc = _test_cmd_destroy_access(self->access_id);
+		assert(rc == 0);
+	}
+	teardown_iommufd(self->fd, _metadata);
+}
+
+/* Cover ioas.c */
+TEST_FAIL_NTH(basic_fail_nth, basic)
+{
+	struct iommu_iova_range ranges[10];
+	uint32_t ioas_id;
+	__u64 iova;
+
+	fail_nth_enable();
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	{
+		struct iommu_ioas_iova_ranges ranges_cmd = {
+			.size = sizeof(ranges_cmd),
+			.num_iovas = ARRAY_SIZE(ranges),
+			.ioas_id = ioas_id,
+			.allowed_iovas = (uintptr_t)ranges,
+		};
+		if (ioctl(self->fd, IOMMU_IOAS_IOVA_RANGES, &ranges_cmd))
+			return -1;
+	}
+
+	{
+		struct iommu_ioas_allow_iovas allow_cmd = {
+			.size = sizeof(allow_cmd),
+			.ioas_id = ioas_id,
+			.num_iovas = 1,
+			.allowed_iovas = (uintptr_t)ranges,
+		};
+
+		ranges[0].start = 16*1024;
+		ranges[0].last = BUFFER_SIZE + 16 * 1024 * 600 - 1;
+		if (ioctl(self->fd, IOMMU_IOAS_ALLOW_IOVAS, &allow_cmd))
+			return -1;
+	}
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, BUFFER_SIZE, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	{
+		struct iommu_ioas_copy copy_cmd = {
+			.size = sizeof(copy_cmd),
+			.flags = IOMMU_IOAS_MAP_WRITEABLE |
+				 IOMMU_IOAS_MAP_READABLE,
+			.dst_ioas_id = ioas_id,
+			.src_ioas_id = ioas_id,
+			.src_iova = iova,
+			.length = sizeof(ranges),
+		};
+
+		if (ioctl(self->fd, IOMMU_IOAS_COPY, &copy_cmd))
+			return -1;
+	}
+
+	if (_test_ioctl_ioas_unmap(self->fd, ioas_id, iova, BUFFER_SIZE,
+				   NULL))
+		return -1;
+	/* Failure path of no IOVA to unmap */
+	_test_ioctl_ioas_unmap(self->fd, ioas_id, iova, BUFFER_SIZE, NULL);
+	return 0;
+}
+
+/* iopt_area_fill_domains() and iopt_area_fill_domain() */
+TEST_FAIL_NTH(basic_fail_nth, map_domain)
+{
+	uint32_t ioas_id;
+	__u32 device_id;
+	__u32 hwpt_id;
+	__u64 iova;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	if (_test_ioctl_set_temp_memory_limit(self->fd, 32))
+		return -1;
+
+	fail_nth_enable();
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
+		return -1;
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, 262144, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	if (_test_ioctl_destroy(self->fd, device_id))
+		return -1;
+	if (_test_ioctl_destroy(self->fd, hwpt_id))
+		return -1;
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
+		return -1;
+	return 0;
+}
+
+TEST_FAIL_NTH(basic_fail_nth, map_two_domains)
+{
+	uint32_t ioas_id;
+	__u32 device_id2;
+	__u32 device_id;
+	__u32 hwpt_id2;
+	__u32 hwpt_id;
+	__u64 iova;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	if (_test_ioctl_set_temp_memory_limit(self->fd, 32))
+		return -1;
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
+		return -1;
+
+	fail_nth_enable();
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id2, &hwpt_id2))
+		return -1;
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, 262144, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	if (_test_ioctl_destroy(self->fd, device_id))
+		return -1;
+	if (_test_ioctl_destroy(self->fd, hwpt_id))
+		return -1;
+
+	if (_test_ioctl_destroy(self->fd, device_id2))
+		return -1;
+	if (_test_ioctl_destroy(self->fd, hwpt_id2))
+		return -1;
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
+		return -1;
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id2, &hwpt_id2))
+		return -1;
+	return 0;
+}
+
+TEST_FAIL_NTH(basic_fail_nth, access_rw)
+{
+	uint64_t tmp_big[4096];
+	uint32_t ioas_id;
+	uint16_t tmp[32];
+	__u64 iova;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	if (_test_ioctl_set_temp_memory_limit(self->fd, 32))
+		return -1;
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, 262144, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	fail_nth_enable();
+
+	if (_test_cmd_create_access(self->fd, ioas_id, &self->access_id, 0))
+		return -1;
+
+	{
+		struct iommu_test_cmd access_cmd = {
+			.size = sizeof(access_cmd),
+			.op = IOMMU_TEST_OP_ACCESS_RW,
+			.id = self->access_id,
+			.access_rw = { .iova = iova,
+				       .length = sizeof(tmp),
+				       .uptr = (uintptr_t)tmp },
+		};
+
+		// READ
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+
+		access_cmd.access_rw.flags = MOCK_ACCESS_RW_WRITE;
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+
+		access_cmd.access_rw.flags = MOCK_ACCESS_RW_SLOW_PATH;
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+		access_cmd.access_rw.flags = MOCK_ACCESS_RW_SLOW_PATH |
+					     MOCK_ACCESS_RW_WRITE;
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+	}
+
+	{
+		struct iommu_test_cmd access_cmd = {
+			.size = sizeof(access_cmd),
+			.op = IOMMU_TEST_OP_ACCESS_RW,
+			.id = self->access_id,
+			.access_rw = { .iova = iova,
+				       .flags = MOCK_ACCESS_RW_SLOW_PATH,
+				       .length = sizeof(tmp_big),
+				       .uptr = (uintptr_t)tmp_big },
+		};
+
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+	}
+	if (_test_cmd_destroy_access(self->access_id))
+		return -1;
+	self->access_id = 0;
+	return 0;
+}
+
+/* pages.c access functions */
+TEST_FAIL_NTH(basic_fail_nth, access_pin)
+{
+	uint32_t access_pages_id;
+	uint32_t ioas_id;
+	__u64 iova;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	if (_test_ioctl_set_temp_memory_limit(self->fd, 32))
+		return -1;
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, BUFFER_SIZE, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	if (_test_cmd_create_access(self->fd, ioas_id, &self->access_id,
+				    MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES))
+		return -1;
+
+	fail_nth_enable();
+
+	{
+		struct iommu_test_cmd access_cmd = {
+			.size = sizeof(access_cmd),
+			.op = IOMMU_TEST_OP_ACCESS_PAGES,
+			.id = self->access_id,
+			.access_pages = { .iova = iova,
+					  .length = BUFFER_SIZE,
+					  .uptr = (uintptr_t)buffer },
+		};
+
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+		access_pages_id = access_cmd.access_pages.out_access_pages_id;
+	}
+
+	if (_test_cmd_destroy_access_pages(self->fd, self->access_id,
+					   access_pages_id))
+		return -1;
+
+	if (_test_cmd_destroy_access(self->access_id))
+		return -1;
+	self->access_id = 0;
+	return 0;
+}
+
+/* iopt_pages_fill_xarray() */
+TEST_FAIL_NTH(basic_fail_nth, access_pin_domain)
+{
+	uint32_t access_pages_id;
+	uint32_t ioas_id;
+	__u32 device_id;
+	__u32 hwpt_id;
+	__u64 iova;
+
+	self->fd = open("/dev/iommu", O_RDWR);
+	if (self->fd == -1)
+		return -1;
+
+	if (_test_ioctl_ioas_alloc(self->fd, &ioas_id))
+		return -1;
+
+	if (_test_ioctl_set_temp_memory_limit(self->fd, 32))
+		return -1;
+
+	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
+		return -1;
+
+	if (_test_ioctl_ioas_map(self->fd, ioas_id, buffer, BUFFER_SIZE, &iova,
+				 IOMMU_IOAS_MAP_WRITEABLE |
+					 IOMMU_IOAS_MAP_READABLE))
+		return -1;
+
+	if (_test_cmd_create_access(self->fd, ioas_id, &self->access_id,
+				    MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES))
+		return -1;
+
+	fail_nth_enable();
+
+	{
+		struct iommu_test_cmd access_cmd = {
+			.size = sizeof(access_cmd),
+			.op = IOMMU_TEST_OP_ACCESS_PAGES,
+			.id = self->access_id,
+			.access_pages = { .iova = iova,
+					  .length = BUFFER_SIZE,
+					  .uptr = (uintptr_t)buffer },
+		};
+
+		if (ioctl(self->fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_ACCESS_RW),
+			  &access_cmd))
+			return -1;
+		access_pages_id = access_cmd.access_pages.out_access_pages_id;
+	}
+
+	if (_test_cmd_destroy_access_pages(self->fd, self->access_id,
+					   access_pages_id))
+		return -1;
+
+	if (_test_cmd_destroy_access(self->access_id))
+		return -1;
+	self->access_id = 0;
+
+	if (_test_ioctl_destroy(self->fd, device_id))
+		return -1;
+	if (_test_ioctl_destroy(self->fd, hwpt_id))
+		return -1;
+	return 0;
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
new file mode 100644
index 000000000000..0d1f46369c2a
--- /dev/null
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -0,0 +1,278 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES */
+#ifndef __SELFTEST_IOMMUFD_UTILS
+#define __SELFTEST_IOMMUFD_UTILS
+
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/fcntl.h>
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <assert.h>
+
+#include "../kselftest_harness.h"
+#include "../../../../drivers/iommu/iommufd/iommufd_test.h"
+
+/* Hack to make assertions more readable */
+#define _IOMMU_TEST_CMD(x) IOMMU_TEST_CMD
+
+static void *buffer;
+static unsigned long BUFFER_SIZE;
+
+/*
+ * Have the kernel check the refcount on pages. I don't know why a freshly
+ * mmap'd anon non-compound page starts out with a ref of 3
+ */
+#define check_refs(_ptr, _length, _refs)                                      \
+	({                                                                    \
+		struct iommu_test_cmd test_cmd = {                            \
+			.size = sizeof(test_cmd),                             \
+			.op = IOMMU_TEST_OP_MD_CHECK_REFS,                    \
+			.check_refs = { .length = _length,                    \
+					.uptr = (uintptr_t)(_ptr),            \
+					.refs = _refs },                      \
+		};                                                            \
+		ASSERT_EQ(0,                                                  \
+			  ioctl(self->fd,                                     \
+				_IOMMU_TEST_CMD(IOMMU_TEST_OP_MD_CHECK_REFS), \
+				&test_cmd));                                  \
+	})
+
+static int _test_cmd_mock_domain(int fd, unsigned int ioas_id, __u32 *device_id,
+				 __u32 *hwpt_id)
+{
+	struct iommu_test_cmd cmd = {
+		.size = sizeof(cmd),
+		.op = IOMMU_TEST_OP_MOCK_DOMAIN,
+		.id = ioas_id,
+		.mock_domain = {},
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_TEST_CMD, &cmd);
+	if (ret)
+		return ret;
+	if (device_id)
+		*device_id = cmd.mock_domain.out_device_id;
+	assert(cmd.id != 0);
+	if (hwpt_id)
+		*hwpt_id = cmd.mock_domain.out_hwpt_id;
+	return 0;
+}
+#define test_cmd_mock_domain(ioas_id, device_id, hwpt_id)                \
+	ASSERT_EQ(0, _test_cmd_mock_domain(self->fd, ioas_id, device_id, \
+					   hwpt_id))
+#define test_err_mock_domain(_errno, ioas_id, device_id, hwpt_id)     \
+	EXPECT_ERRNO(_errno, _test_cmd_mock_domain(self->fd, ioas_id, \
+						   device_id, hwpt_id))
+
+static int _test_cmd_create_access(int fd, unsigned int ioas_id,
+				   __u32 *access_id, unsigned int flags)
+{
+	struct iommu_test_cmd cmd = {
+		.size = sizeof(cmd),
+		.op = IOMMU_TEST_OP_CREATE_ACCESS,
+		.id = ioas_id,
+		.create_access = { .flags = flags },
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_TEST_CMD, &cmd);
+	if (ret)
+		return ret;
+	*access_id = cmd.create_access.out_access_fd;
+	return 0;
+}
+#define test_cmd_create_access(ioas_id, access_id, flags)                  \
+	ASSERT_EQ(0, _test_cmd_create_access(self->fd, ioas_id, access_id, \
+					     flags))
+
+static int _test_cmd_destroy_access(unsigned int access_id)
+{
+	return close(access_id);
+}
+#define test_cmd_destroy_access(access_id) \
+	ASSERT_EQ(0, _test_cmd_destroy_access(access_id))
+
+static int _test_cmd_destroy_access_pages(int fd, unsigned int access_id,
+					  unsigned int access_pages_id)
+{
+	struct iommu_test_cmd cmd = {
+		.size = sizeof(cmd),
+		.op = IOMMU_TEST_OP_DESTROY_ACCESS_PAGES,
+		.id = access_id,
+		.destroy_access_pages = { .access_pages_id = access_pages_id },
+	};
+	return ioctl(fd, IOMMU_TEST_CMD, &cmd);
+}
+#define test_cmd_destroy_access_pages(access_id, access_pages_id)        \
+	ASSERT_EQ(0, _test_cmd_destroy_access_pages(self->fd, access_id, \
+						    access_pages_id))
+#define test_err_destroy_access_pages(_errno, access_id, access_pages_id) \
+	EXPECT_ERRNO(_errno, _test_cmd_destroy_access_pages(              \
+				     self->fd, access_id, access_pages_id))
+
+static int _test_ioctl_destroy(int fd, unsigned int id)
+{
+	struct iommu_destroy cmd = {
+		.size = sizeof(cmd),
+		.id = id,
+	};
+	return ioctl(fd, IOMMU_DESTROY, &cmd);
+}
+#define test_ioctl_destroy(id) ASSERT_EQ(0, _test_ioctl_destroy(self->fd, id))
+
+static int _test_ioctl_ioas_alloc(int fd, __u32 *id)
+{
+	struct iommu_ioas_alloc cmd = {
+		.size = sizeof(cmd),
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_IOAS_ALLOC, &cmd);
+	if (ret)
+		return ret;
+	*id = cmd.out_ioas_id;
+	return 0;
+}
+#define test_ioctl_ioas_alloc(id)                                   \
+	({                                                          \
+		ASSERT_EQ(0, _test_ioctl_ioas_alloc(self->fd, id)); \
+		ASSERT_NE(0, *(id));                                \
+	})
+
+static int _test_ioctl_ioas_map(int fd, unsigned int ioas_id, void *buffer,
+				size_t length, __u64 *iova, unsigned int flags)
+{
+	struct iommu_ioas_map cmd = {
+		.size = sizeof(cmd),
+		.flags = flags,
+		.ioas_id = ioas_id,
+		.user_va = (uintptr_t)buffer,
+		.length = length,
+	};
+	int ret;
+
+	if (flags & IOMMU_IOAS_MAP_FIXED_IOVA)
+		cmd.iova = *iova;
+
+	ret = ioctl(fd, IOMMU_IOAS_MAP, &cmd);
+	*iova = cmd.iova;
+	return ret;
+}
+#define test_ioctl_ioas_map(buffer, length, iova_p)                        \
+	ASSERT_EQ(0, _test_ioctl_ioas_map(self->fd, self->ioas_id, buffer, \
+					  length, iova_p,                  \
+					  IOMMU_IOAS_MAP_WRITEABLE |       \
+						  IOMMU_IOAS_MAP_READABLE))
+
+#define test_err_ioctl_ioas_map(_errno, buffer, length, iova_p)            \
+	EXPECT_ERRNO(_errno,                                               \
+		     _test_ioctl_ioas_map(self->fd, self->ioas_id, buffer, \
+					  length, iova_p,                  \
+					  IOMMU_IOAS_MAP_WRITEABLE |       \
+						  IOMMU_IOAS_MAP_READABLE))
+
+#define test_ioctl_ioas_map_id(ioas_id, buffer, length, iova_p)              \
+	ASSERT_EQ(0, _test_ioctl_ioas_map(self->fd, ioas_id, buffer, length, \
+					  iova_p,                            \
+					  IOMMU_IOAS_MAP_WRITEABLE |         \
+						  IOMMU_IOAS_MAP_READABLE))
+
+#define test_ioctl_ioas_map_fixed(buffer, length, iova)                       \
+	({                                                                    \
+		__u64 __iova = iova;                                          \
+		ASSERT_EQ(0, _test_ioctl_ioas_map(                            \
+				     self->fd, self->ioas_id, buffer, length, \
+				     &__iova,                                 \
+				     IOMMU_IOAS_MAP_FIXED_IOVA |              \
+					     IOMMU_IOAS_MAP_WRITEABLE |       \
+					     IOMMU_IOAS_MAP_READABLE));       \
+	})
+
+#define test_err_ioctl_ioas_map_fixed(_errno, buffer, length, iova)           \
+	({                                                                    \
+		__u64 __iova = iova;                                          \
+		EXPECT_ERRNO(_errno,                                          \
+			     _test_ioctl_ioas_map(                            \
+				     self->fd, self->ioas_id, buffer, length, \
+				     &__iova,                                 \
+				     IOMMU_IOAS_MAP_FIXED_IOVA |              \
+					     IOMMU_IOAS_MAP_WRITEABLE |       \
+					     IOMMU_IOAS_MAP_READABLE));       \
+	})
+
+static int _test_ioctl_ioas_unmap(int fd, unsigned int ioas_id, uint64_t iova,
+				  size_t length, uint64_t *out_len)
+{
+	struct iommu_ioas_unmap cmd = {
+		.size = sizeof(cmd),
+		.ioas_id = ioas_id,
+		.iova = iova,
+		.length = length,
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_IOAS_UNMAP, &cmd);
+	if (out_len)
+		*out_len = cmd.length;
+	return ret;
+}
+#define test_ioctl_ioas_unmap(iova, length)                                \
+	ASSERT_EQ(0, _test_ioctl_ioas_unmap(self->fd, self->ioas_id, iova, \
+					    length, NULL))
+
+#define test_ioctl_ioas_unmap_id(ioas_id, iova, length)                      \
+	ASSERT_EQ(0, _test_ioctl_ioas_unmap(self->fd, ioas_id, iova, length, \
+					    NULL))
+
+#define test_err_ioctl_ioas_unmap(_errno, iova, length)                      \
+	EXPECT_ERRNO(_errno, _test_ioctl_ioas_unmap(self->fd, self->ioas_id, \
+						    iova, length, NULL))
+
+static int _test_ioctl_set_temp_memory_limit(int fd, unsigned int limit)
+{
+	struct iommu_test_cmd memlimit_cmd = {
+		.size = sizeof(memlimit_cmd),
+		.op = IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT,
+		.memory_limit = { .limit = limit },
+	};
+
+	return ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT),
+		     &memlimit_cmd);
+}
+
+#define test_ioctl_set_temp_memory_limit(limit) \
+	ASSERT_EQ(0, _test_ioctl_set_temp_memory_limit(self->fd, limit))
+
+#define test_ioctl_set_default_memory_limit() \
+	test_ioctl_set_temp_memory_limit(65536)
+
+static void teardown_iommufd(int fd, struct __test_metadata *_metadata)
+{
+	struct iommu_test_cmd test_cmd = {
+		.size = sizeof(test_cmd),
+		.op = IOMMU_TEST_OP_MD_CHECK_REFS,
+		.check_refs = { .length = BUFFER_SIZE,
+				.uptr = (uintptr_t)buffer },
+	};
+
+	if (fd == -1)
+		return;
+
+	EXPECT_EQ(0, close(fd));
+
+	fd = open("/dev/iommu", O_RDWR);
+	EXPECT_NE(-1, fd);
+	EXPECT_EQ(0, ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_MD_CHECK_REFS),
+			   &test_cmd));
+	EXPECT_EQ(0, close(fd));
+}
+
+#define EXPECT_ERRNO(expected_errno, cmd)         \
+	({                                        \
+		ASSERT_EQ(-1, cmd);               \
+		EXPECT_EQ(expected_errno, errno); \
+	})
+
+#endif