tools/testing/selftests/vfio/lib/iommu.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 #include <dirent.h>
 #include <fcntl.h>
 #include <libgen.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>

 #include <linux/limits.h>
 #include <linux/mman.h>
 #include <linux/types.h>
 #include <linux/vfio.h>
 #include <linux/iommufd.h>

 #include "../../../kselftest.h"
 #include <libvfio.h>

 const char *default_iommu_mode = "iommufd";

 /* Reminder: Keep in sync with FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(). */
 static const struct iommu_mode iommu_modes[] = {
 	{
 		.name = "vfio_type1_iommu",
 		.container_path = "/dev/vfio/vfio",
 		.iommu_type = VFIO_TYPE1_IOMMU,
 	},
 	{
 		.name = "vfio_type1v2_iommu",
 		.container_path = "/dev/vfio/vfio",
 		.iommu_type = VFIO_TYPE1v2_IOMMU,
 	},
 	{
 		.name = "iommufd_compat_type1",
 		.container_path = "/dev/iommu",
 		.iommu_type = VFIO_TYPE1_IOMMU,
 	},
 	{
 		.name = "iommufd_compat_type1v2",
 		.container_path = "/dev/iommu",
 		.iommu_type = VFIO_TYPE1v2_IOMMU,
 	},
 	{
 		.name = "iommufd",
 	},
 };

 static const struct iommu_mode *lookup_iommu_mode(const char *iommu_mode)
 {
 	int i;

 	if (!iommu_mode)
 		iommu_mode = default_iommu_mode;

 	for (i = 0; i < ARRAY_SIZE(iommu_modes); i++) {
 		if (strcmp(iommu_mode, iommu_modes[i].name))
 			continue;

 		return &iommu_modes[i];
 	}

 	VFIO_FAIL("Unrecognized IOMMU mode: %s\n", iommu_mode);
 }

 int __iommu_hva2iova(struct iommu *iommu, void *vaddr, iova_t *iova)
 {
 	struct dma_region *region;

 	list_for_each_entry(region, &iommu->dma_regions, link) {
 		if (vaddr < region->vaddr)
 			continue;

 		if (vaddr >= region->vaddr + region->size)
 			continue;

 		if (iova)
 			*iova = region->iova + (vaddr - region->vaddr);

 		return 0;
 	}

 	return -ENOENT;
 }

 iova_t iommu_hva2iova(struct iommu *iommu, void *vaddr)
 {
 	iova_t iova;
 	int ret;

 	ret = __iommu_hva2iova(iommu, vaddr, &iova);
 	VFIO_ASSERT_EQ(ret, 0, "%p is not mapped into the iommu\n", vaddr);

 	return iova;
 }

 static int vfio_iommu_map(struct iommu *iommu, struct dma_region *region)
 {
 	struct vfio_iommu_type1_dma_map args = {
 		.argsz = sizeof(args),
 		.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
 		.vaddr = (u64)region->vaddr,
 		.iova = region->iova,
 		.size = region->size,
 	};

 	if (ioctl(iommu->container_fd, VFIO_IOMMU_MAP_DMA, &args))
 		return -errno;

 	return 0;
 }

 static int iommufd_map(struct iommu *iommu, struct dma_region *region)
 {
 	struct iommu_ioas_map args = {
 		.size = sizeof(args),
 		.flags = IOMMU_IOAS_MAP_READABLE |
 			 IOMMU_IOAS_MAP_WRITEABLE |
 			 IOMMU_IOAS_MAP_FIXED_IOVA,
 		.user_va = (u64)region->vaddr,
 		.iova = region->iova,
 		.length = region->size,
 		.ioas_id = iommu->ioas_id,
 	};

 	if (ioctl(iommu->iommufd, IOMMU_IOAS_MAP, &args))
 		return -errno;

 	return 0;
 }

 int __iommu_map(struct iommu *iommu, struct dma_region *region)
 {
 	int ret;

 	if (iommu->iommufd)
 		ret = iommufd_map(iommu, region);
 	else
 		ret = vfio_iommu_map(iommu, region);

 	if (ret)
 		return ret;

 	list_add(&region->link, &iommu->dma_regions);

 	return 0;
 }

 static int __vfio_iommu_unmap(int fd, u64 iova, u64 size, u32 flags, u64 *unmapped)
 {
 	struct vfio_iommu_type1_dma_unmap args = {
 		.argsz = sizeof(args),
 		.iova = iova,
 		.size = size,
 		.flags = flags,
 	};

 	if (ioctl(fd, VFIO_IOMMU_UNMAP_DMA, &args))
 		return -errno;

 	if (unmapped)
 		*unmapped = args.size;

 	return 0;
 }

 static int vfio_iommu_unmap(struct iommu *iommu, struct dma_region *region,
 			    u64 *unmapped)
 {
 	return __vfio_iommu_unmap(iommu->container_fd, region->iova,
 				  region->size, 0, unmapped);
 }

 static int __iommufd_unmap(int fd, u64 iova, u64 length, u32 ioas_id, u64 *unmapped)
 {
 	struct iommu_ioas_unmap args = {
 		.size = sizeof(args),
 		.iova = iova,
 		.length = length,
 		.ioas_id = ioas_id,
 	};

 	if (ioctl(fd, IOMMU_IOAS_UNMAP, &args))
 		return -errno;

 	if (unmapped)
 		*unmapped = args.length;

 	return 0;
 }

 static int iommufd_unmap(struct iommu *iommu, struct dma_region *region,
 			 u64 *unmapped)
 {
 	return __iommufd_unmap(iommu->iommufd, region->iova, region->size,
 			       iommu->ioas_id, unmapped);
 }

 int __iommu_unmap(struct iommu *iommu, struct dma_region *region, u64 *unmapped)
 {
 	int ret;

 	if (iommu->iommufd)
 		ret = iommufd_unmap(iommu, region, unmapped);
 	else
 		ret = vfio_iommu_unmap(iommu, region, unmapped);

 	if (ret)
 		return ret;

 	list_del_init(&region->link);

 	return 0;
 }

 int __iommu_unmap_all(struct iommu *iommu, u64 *unmapped)
 {
 	int ret;
 	struct dma_region *curr, *next;

 	if (iommu->iommufd)
 		ret = __iommufd_unmap(iommu->iommufd, 0, UINT64_MAX,
 				      iommu->ioas_id, unmapped);
 	else
 		ret = __vfio_iommu_unmap(iommu->container_fd, 0, 0,
 					 VFIO_DMA_UNMAP_FLAG_ALL, unmapped);

 	if (ret)
 		return ret;

 	list_for_each_entry_safe(curr, next, &iommu->dma_regions, link)
 		list_del_init(&curr->link);

 	return 0;
 }

 static struct vfio_info_cap_header *next_cap_hdr(void *buf, u32 bufsz,
 						 u32 *cap_offset)
 {
 	struct vfio_info_cap_header *hdr;

 	if (!*cap_offset)
 		return NULL;

 	VFIO_ASSERT_LT(*cap_offset, bufsz);
 	VFIO_ASSERT_GE(bufsz - *cap_offset, sizeof(*hdr));

 	hdr = (struct vfio_info_cap_header *)((u8 *)buf + *cap_offset);
 	*cap_offset = hdr->next;

 	return hdr;
 }

 static struct vfio_info_cap_header *vfio_iommu_info_cap_hdr(struct vfio_iommu_type1_info *info,
 							    u16 cap_id)
 {
 	struct vfio_info_cap_header *hdr;
 	u32 cap_offset = info->cap_offset;
 	u32 max_depth;
 	u32 depth = 0;

 	if (!(info->flags & VFIO_IOMMU_INFO_CAPS))
 		return NULL;

 	if (cap_offset)
 		VFIO_ASSERT_GE(cap_offset, sizeof(*info));

 	max_depth = (info->argsz - sizeof(*info)) / sizeof(*hdr);

 	while ((hdr = next_cap_hdr(info, info->argsz, &cap_offset))) {
 		depth++;
 		VFIO_ASSERT_LE(depth, max_depth, "Capability chain contains a cycle\n");

 		if (hdr->id == cap_id)
 			return hdr;
 	}

 	return NULL;
 }

 /* Return buffer including capability chain, if present. Free with free() */
 static struct vfio_iommu_type1_info *vfio_iommu_get_info(int container_fd)
 {
 	struct vfio_iommu_type1_info *info;

 	info = malloc(sizeof(*info));
 	VFIO_ASSERT_NOT_NULL(info);

 	*info = (struct vfio_iommu_type1_info) {
 		.argsz = sizeof(*info),
 	};

 	ioctl_assert(container_fd, VFIO_IOMMU_GET_INFO, info);
 	VFIO_ASSERT_GE(info->argsz, sizeof(*info));

 	info = realloc(info, info->argsz);
 	VFIO_ASSERT_NOT_NULL(info);

 	ioctl_assert(container_fd, VFIO_IOMMU_GET_INFO, info);
 	VFIO_ASSERT_GE(info->argsz, sizeof(*info));

 	return info;
 }

 /*
  * Return iova ranges for the device's container. Normalize vfio_iommu_type1 to
  * report iommufd's iommu_iova_range. Free with free().
  */
 static struct iommu_iova_range *vfio_iommu_iova_ranges(struct iommu *iommu,
 						       u32 *nranges)
 {
 	struct vfio_iommu_type1_info_cap_iova_range *cap_range;
 	struct vfio_iommu_type1_info *info;
 	struct vfio_info_cap_header *hdr;
 	struct iommu_iova_range *ranges = NULL;

 	info = vfio_iommu_get_info(iommu->container_fd);
 	hdr = vfio_iommu_info_cap_hdr(info, VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);
 	VFIO_ASSERT_NOT_NULL(hdr);

 	cap_range = container_of(hdr, struct vfio_iommu_type1_info_cap_iova_range, header);
 	VFIO_ASSERT_GT(cap_range->nr_iovas, 0);

 	ranges = calloc(cap_range->nr_iovas, sizeof(*ranges));
 	VFIO_ASSERT_NOT_NULL(ranges);

 	for (u32 i = 0; i < cap_range->nr_iovas; i++) {
 		ranges[i] = (struct iommu_iova_range){
 			.start = cap_range->iova_ranges[i].start,
 			.last = cap_range->iova_ranges[i].end,
 		};
 	}

 	*nranges = cap_range->nr_iovas;

 	free(info);
 	return ranges;
 }

 /* Return iova ranges of the device's IOAS. Free with free() */
 static struct iommu_iova_range *iommufd_iova_ranges(struct iommu *iommu,
 						    u32 *nranges)
 {
 	struct iommu_iova_range *ranges;
 	int ret;

 	struct iommu_ioas_iova_ranges query = {
 		.size = sizeof(query),
 		.ioas_id = iommu->ioas_id,
 	};

 	ret = ioctl(iommu->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);
 	VFIO_ASSERT_EQ(ret, -1);
 	VFIO_ASSERT_EQ(errno, EMSGSIZE);
 	VFIO_ASSERT_GT(query.num_iovas, 0);

 	ranges = calloc(query.num_iovas, sizeof(*ranges));
 	VFIO_ASSERT_NOT_NULL(ranges);

 	query.allowed_iovas = (uintptr_t)ranges;

 	ioctl_assert(iommu->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);
 	*nranges = query.num_iovas;

 	return ranges;
 }

 static int iova_range_comp(const void *a, const void *b)
 {
 	const struct iommu_iova_range *ra = a, *rb = b;

 	if (ra->start < rb->start)
 		return -1;

 	if (ra->start > rb->start)
 		return 1;

 	return 0;
 }

 /* Return sorted IOVA ranges of the device. Free with free(). */
 struct iommu_iova_range *iommu_iova_ranges(struct iommu *iommu, u32 *nranges)
 {
 	struct iommu_iova_range *ranges;

 	if (iommu->iommufd)
 		ranges = iommufd_iova_ranges(iommu, nranges);
 	else
 		ranges = vfio_iommu_iova_ranges(iommu, nranges);

 	if (!ranges)
 		return NULL;

 	VFIO_ASSERT_GT(*nranges, 0);

 	/* Sort and check that ranges are sane and non-overlapping */
 	qsort(ranges, *nranges, sizeof(*ranges), iova_range_comp);
 	VFIO_ASSERT_LT(ranges[0].start, ranges[0].last);

 	for (u32 i = 1; i < *nranges; i++) {
 		VFIO_ASSERT_LT(ranges[i].start, ranges[i].last);
 		VFIO_ASSERT_LT(ranges[i - 1].last, ranges[i].start);
 	}

 	return ranges;
 }

 static u32 iommufd_ioas_alloc(int iommufd)
 {
 	struct iommu_ioas_alloc args = {
 		.size = sizeof(args),
 	};

 	ioctl_assert(iommufd, IOMMU_IOAS_ALLOC, &args);
 	return args.out_ioas_id;
 }

 struct iommu *iommu_init(const char *iommu_mode)
 {
 	const char *container_path;
 	struct iommu *iommu;
 	int version;

 	iommu = calloc(1, sizeof(*iommu));
 	VFIO_ASSERT_NOT_NULL(iommu);

 	INIT_LIST_HEAD(&iommu->dma_regions);

 	iommu->mode = lookup_iommu_mode(iommu_mode);

 	container_path = iommu->mode->container_path;
 	if (container_path) {
 		iommu->container_fd = open(container_path, O_RDWR);
 		VFIO_ASSERT_GE(iommu->container_fd, 0, "open(%s) failed\n", container_path);

 		version = ioctl(iommu->container_fd, VFIO_GET_API_VERSION);
 		VFIO_ASSERT_EQ(version, VFIO_API_VERSION, "Unsupported version: %d\n", version);
 	} else {
 		/*
 		 * Require device->iommufd to be >0 so that a simple non-0 check can be
 		 * used to check if iommufd is enabled. In practice open() will never
 		 * return 0 unless stdin is closed.
 		 */
 		iommu->iommufd = open("/dev/iommu", O_RDWR);
 		VFIO_ASSERT_GT(iommu->iommufd, 0);

 		iommu->ioas_id = iommufd_ioas_alloc(iommu->iommufd);
 	}

 	return iommu;
 }

 void iommu_cleanup(struct iommu *iommu)
 {
 	if (iommu->iommufd)
 		VFIO_ASSERT_EQ(close(iommu->iommufd), 0);
 	else
 		VFIO_ASSERT_EQ(close(iommu->container_fd), 0);

 	free(iommu);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	#include <dirent.h>
	#include <fcntl.h>
	#include <libgen.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include <sys/eventfd.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>

	#include <linux/limits.h>
	#include <linux/mman.h>
	#include <linux/types.h>
	#include <linux/vfio.h>
	#include <linux/iommufd.h>

	#include "../../../kselftest.h"
	#include <libvfio.h>

	const char *default_iommu_mode = "iommufd";

	/* Reminder: Keep in sync with FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(). */
	static const struct iommu_mode iommu_modes[] = {
	{
	.name = "vfio_type1_iommu",
	.container_path = "/dev/vfio/vfio",
	.iommu_type = VFIO_TYPE1_IOMMU,
	},
	{
	.name = "vfio_type1v2_iommu",
	.container_path = "/dev/vfio/vfio",
	.iommu_type = VFIO_TYPE1v2_IOMMU,
	},
	{
	.name = "iommufd_compat_type1",
	.container_path = "/dev/iommu",
	.iommu_type = VFIO_TYPE1_IOMMU,
	},
	{
	.name = "iommufd_compat_type1v2",
	.container_path = "/dev/iommu",
	.iommu_type = VFIO_TYPE1v2_IOMMU,
	},
	{
	.name = "iommufd",
	},
	};

	static const struct iommu_mode lookup_iommu_mode(const char iommu_mode)
	{
	int i;

	if (!iommu_mode)
	iommu_mode = default_iommu_mode;

	for (i = 0; i < ARRAY_SIZE(iommu_modes); i++) {
	if (strcmp(iommu_mode, iommu_modes[i].name))
	continue;

	return &iommu_modes[i];
	}

	VFIO_FAIL("Unrecognized IOMMU mode: %s\n", iommu_mode);
	}

	int __iommu_hva2iova(struct iommu iommu, void vaddr, iova_t *iova)
	{
	struct dma_region *region;

	list_for_each_entry(region, &iommu->dma_regions, link) {
	if (vaddr < region->vaddr)
	continue;

	if (vaddr >= region->vaddr + region->size)
	continue;

	if (iova)
	*iova = region->iova + (vaddr - region->vaddr);

	return 0;
	}

	return -ENOENT;
	}

	iova_t iommu_hva2iova(struct iommu iommu, void vaddr)
	{
	iova_t iova;
	int ret;

	ret = __iommu_hva2iova(iommu, vaddr, &iova);
	VFIO_ASSERT_EQ(ret, 0, "%p is not mapped into the iommu\n", vaddr);

	return iova;
	}

	static int vfio_iommu_map(struct iommu iommu, struct dma_region region)
	{
	struct vfio_iommu_type1_dma_map args = {
	.argsz = sizeof(args),
	.flags = VFIO_DMA_MAP_FLAG_READ \| VFIO_DMA_MAP_FLAG_WRITE,
	.vaddr = (u64)region->vaddr,
	.iova = region->iova,
	.size = region->size,
	};

	if (ioctl(iommu->container_fd, VFIO_IOMMU_MAP_DMA, &args))
	return -errno;

	return 0;
	}

	static int iommufd_map(struct iommu iommu, struct dma_region region)
	{
	struct iommu_ioas_map args = {
	.size = sizeof(args),
	.flags = IOMMU_IOAS_MAP_READABLE \|
	IOMMU_IOAS_MAP_WRITEABLE \|
	IOMMU_IOAS_MAP_FIXED_IOVA,
	.user_va = (u64)region->vaddr,
	.iova = region->iova,
	.length = region->size,
	.ioas_id = iommu->ioas_id,
	};

	if (ioctl(iommu->iommufd, IOMMU_IOAS_MAP, &args))
	return -errno;

	return 0;
	}

	int __iommu_map(struct iommu iommu, struct dma_region region)
	{
	int ret;

	if (iommu->iommufd)
	ret = iommufd_map(iommu, region);
	else
	ret = vfio_iommu_map(iommu, region);

	if (ret)
	return ret;

	list_add(&region->link, &iommu->dma_regions);

	return 0;
	}

	static int __vfio_iommu_unmap(int fd, u64 iova, u64 size, u32 flags, u64 *unmapped)
	{
	struct vfio_iommu_type1_dma_unmap args = {
	.argsz = sizeof(args),
	.iova = iova,
	.size = size,
	.flags = flags,
	};

	if (ioctl(fd, VFIO_IOMMU_UNMAP_DMA, &args))
	return -errno;

	if (unmapped)
	*unmapped = args.size;

	return 0;
	}

	static int vfio_iommu_unmap(struct iommu iommu, struct dma_region region,
	u64 *unmapped)
	{
	return __vfio_iommu_unmap(iommu->container_fd, region->iova,
	region->size, 0, unmapped);
	}

	static int __iommufd_unmap(int fd, u64 iova, u64 length, u32 ioas_id, u64 *unmapped)
	{
	struct iommu_ioas_unmap args = {
	.size = sizeof(args),
	.iova = iova,
	.length = length,
	.ioas_id = ioas_id,
	};

	if (ioctl(fd, IOMMU_IOAS_UNMAP, &args))
	return -errno;

	if (unmapped)
	*unmapped = args.length;

	return 0;
	}

	static int iommufd_unmap(struct iommu iommu, struct dma_region region,
	u64 *unmapped)
	{
	return __iommufd_unmap(iommu->iommufd, region->iova, region->size,
	iommu->ioas_id, unmapped);
	}

	int __iommu_unmap(struct iommu iommu, struct dma_region region, u64 *unmapped)
	{
	int ret;

	if (iommu->iommufd)
	ret = iommufd_unmap(iommu, region, unmapped);
	else
	ret = vfio_iommu_unmap(iommu, region, unmapped);

	if (ret)
	return ret;

	list_del_init(&region->link);

	return 0;
	}

	int __iommu_unmap_all(struct iommu iommu, u64 unmapped)
	{
	int ret;
	struct dma_region curr, next;

	if (iommu->iommufd)
	ret = __iommufd_unmap(iommu->iommufd, 0, UINT64_MAX,
	iommu->ioas_id, unmapped);
	else
	ret = __vfio_iommu_unmap(iommu->container_fd, 0, 0,
	VFIO_DMA_UNMAP_FLAG_ALL, unmapped);

	if (ret)
	return ret;

	list_for_each_entry_safe(curr, next, &iommu->dma_regions, link)
	list_del_init(&curr->link);

	return 0;
	}

	static struct vfio_info_cap_header next_cap_hdr(void buf, u32 bufsz,
	u32 *cap_offset)
	{
	struct vfio_info_cap_header *hdr;

	if (!*cap_offset)
	return NULL;

	VFIO_ASSERT_LT(*cap_offset, bufsz);
	VFIO_ASSERT_GE(bufsz - cap_offset, sizeof(hdr));

	hdr = (struct vfio_info_cap_header )((u8 )buf + *cap_offset);
	*cap_offset = hdr->next;

	return hdr;
	}

	static struct vfio_info_cap_header vfio_iommu_info_cap_hdr(struct vfio_iommu_type1_info info,
	u16 cap_id)
	{
	struct vfio_info_cap_header *hdr;
	u32 cap_offset = info->cap_offset;
	u32 max_depth;
	u32 depth = 0;

	if (!(info->flags & VFIO_IOMMU_INFO_CAPS))
	return NULL;

	if (cap_offset)
	VFIO_ASSERT_GE(cap_offset, sizeof(*info));

	max_depth = (info->argsz - sizeof(info)) / sizeof(hdr);

	while ((hdr = next_cap_hdr(info, info->argsz, &cap_offset))) {
	depth++;
	VFIO_ASSERT_LE(depth, max_depth, "Capability chain contains a cycle\n");

	if (hdr->id == cap_id)
	return hdr;
	}

	return NULL;
	}

	/* Return buffer including capability chain, if present. Free with free() */
	static struct vfio_iommu_type1_info *vfio_iommu_get_info(int container_fd)
	{
	struct vfio_iommu_type1_info *info;

	info = malloc(sizeof(*info));
	VFIO_ASSERT_NOT_NULL(info);

	*info = (struct vfio_iommu_type1_info) {
	.argsz = sizeof(*info),
	};

	ioctl_assert(container_fd, VFIO_IOMMU_GET_INFO, info);
	VFIO_ASSERT_GE(info->argsz, sizeof(*info));

	info = realloc(info, info->argsz);
	VFIO_ASSERT_NOT_NULL(info);

	ioctl_assert(container_fd, VFIO_IOMMU_GET_INFO, info);
	VFIO_ASSERT_GE(info->argsz, sizeof(*info));

	return info;
	}

	/*
	* Return iova ranges for the device's container. Normalize vfio_iommu_type1 to
	* report iommufd's iommu_iova_range. Free with free().
	*/
	static struct iommu_iova_range vfio_iommu_iova_ranges(struct iommu iommu,
	u32 *nranges)
	{
	struct vfio_iommu_type1_info_cap_iova_range *cap_range;
	struct vfio_iommu_type1_info *info;
	struct vfio_info_cap_header *hdr;
	struct iommu_iova_range *ranges = NULL;

	info = vfio_iommu_get_info(iommu->container_fd);
	hdr = vfio_iommu_info_cap_hdr(info, VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);
	VFIO_ASSERT_NOT_NULL(hdr);

	cap_range = container_of(hdr, struct vfio_iommu_type1_info_cap_iova_range, header);
	VFIO_ASSERT_GT(cap_range->nr_iovas, 0);

	ranges = calloc(cap_range->nr_iovas, sizeof(*ranges));
	VFIO_ASSERT_NOT_NULL(ranges);

	for (u32 i = 0; i < cap_range->nr_iovas; i++) {
	ranges[i] = (struct iommu_iova_range){
	.start = cap_range->iova_ranges[i].start,
	.last = cap_range->iova_ranges[i].end,
	};
	}

	*nranges = cap_range->nr_iovas;

	free(info);
	return ranges;
	}

	/* Return iova ranges of the device's IOAS. Free with free() */
	static struct iommu_iova_range iommufd_iova_ranges(struct iommu iommu,
	u32 *nranges)
	{
	struct iommu_iova_range *ranges;
	int ret;

	struct iommu_ioas_iova_ranges query = {
	.size = sizeof(query),
	.ioas_id = iommu->ioas_id,
	};

	ret = ioctl(iommu->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);
	VFIO_ASSERT_EQ(ret, -1);
	VFIO_ASSERT_EQ(errno, EMSGSIZE);
	VFIO_ASSERT_GT(query.num_iovas, 0);

	ranges = calloc(query.num_iovas, sizeof(*ranges));
	VFIO_ASSERT_NOT_NULL(ranges);

	query.allowed_iovas = (uintptr_t)ranges;

	ioctl_assert(iommu->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);
	*nranges = query.num_iovas;

	return ranges;
	}

	static int iova_range_comp(const void a, const void b)
	{
	const struct iommu_iova_range ra = a, rb = b;

	if (ra->start < rb->start)
	return -1;

	if (ra->start > rb->start)
	return 1;

	return 0;
	}

	/* Return sorted IOVA ranges of the device. Free with free(). */
	struct iommu_iova_range iommu_iova_ranges(struct iommu iommu, u32 *nranges)
	{
	struct iommu_iova_range *ranges;

	if (iommu->iommufd)
	ranges = iommufd_iova_ranges(iommu, nranges);
	else
	ranges = vfio_iommu_iova_ranges(iommu, nranges);

	if (!ranges)
	return NULL;

	VFIO_ASSERT_GT(*nranges, 0);

	/* Sort and check that ranges are sane and non-overlapping */
	qsort(ranges, nranges, sizeof(ranges), iova_range_comp);
	VFIO_ASSERT_LT(ranges[0].start, ranges[0].last);

	for (u32 i = 1; i < *nranges; i++) {
	VFIO_ASSERT_LT(ranges[i].start, ranges[i].last);
	VFIO_ASSERT_LT(ranges[i - 1].last, ranges[i].start);
	}

	return ranges;
	}

	static u32 iommufd_ioas_alloc(int iommufd)
	{
	struct iommu_ioas_alloc args = {
	.size = sizeof(args),
	};

	ioctl_assert(iommufd, IOMMU_IOAS_ALLOC, &args);
	return args.out_ioas_id;
	}

	struct iommu iommu_init(const char iommu_mode)
	{
	const char *container_path;
	struct iommu *iommu;
	int version;

	iommu = calloc(1, sizeof(*iommu));
	VFIO_ASSERT_NOT_NULL(iommu);

	INIT_LIST_HEAD(&iommu->dma_regions);

	iommu->mode = lookup_iommu_mode(iommu_mode);

	container_path = iommu->mode->container_path;
	if (container_path) {
	iommu->container_fd = open(container_path, O_RDWR);
	VFIO_ASSERT_GE(iommu->container_fd, 0, "open(%s) failed\n", container_path);

	version = ioctl(iommu->container_fd, VFIO_GET_API_VERSION);
	VFIO_ASSERT_EQ(version, VFIO_API_VERSION, "Unsupported version: %d\n", version);
	} else {
	/*
	* Require device->iommufd to be >0 so that a simple non-0 check can be
	* used to check if iommufd is enabled. In practice open() will never
	* return 0 unless stdin is closed.
	*/
	iommu->iommufd = open("/dev/iommu", O_RDWR);
	VFIO_ASSERT_GT(iommu->iommufd, 0);

	iommu->ioas_id = iommufd_ioas_alloc(iommu->iommufd);
	}

	return iommu;
	}

	void iommu_cleanup(struct iommu *iommu)
	{
	if (iommu->iommufd)
	VFIO_ASSERT_EQ(close(iommu->iommufd), 0);
	else
	VFIO_ASSERT_EQ(close(iommu->container_fd), 0);

	free(iommu);
	}