1 files changed, 465 insertions, 0 deletions
diff --git a/tools/testing/selftests/vfio/lib/iommu.c b/tools/testing/selftests/vfio/lib/iommu.c
new file mode 100644
index 000000000000..8079d43523f3
--- /dev/null
+++ b/tools/testing/selftests/vfio/lib/iommu.c
@@ -0,0 +1,465 @@
+// 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 <uapi/linux/types.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);
+}