xref: /linux/tools/testing/selftests/vfio/vfio_dma_mapping_test.c (revision 1f9c8edd6a7e9b0fd914cfeef8ce075307e8e702)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <stdio.h>
3 #include <sys/mman.h>
4 #include <unistd.h>
5 
6 #include <linux/limits.h>
7 #include <linux/mman.h>
8 #include <linux/sizes.h>
9 #include <linux/vfio.h>
10 
11 #include <vfio_util.h>
12 
13 #include "../kselftest_harness.h"
14 
15 static const char *device_bdf;
16 
17 struct iommu_mapping {
18 	u64 pgd;
19 	u64 p4d;
20 	u64 pud;
21 	u64 pmd;
22 	u64 pte;
23 };
24 
25 static void parse_next_value(char **line, u64 *value)
26 {
27 	char *token;
28 
29 	token = strtok_r(*line, " \t|\n", line);
30 	if (!token)
31 		return;
32 
33 	/* Caller verifies `value`. No need to check return value. */
34 	sscanf(token, "0x%lx", value);
35 }
36 
37 static int intel_iommu_mapping_get(const char *bdf, u64 iova,
38 				   struct iommu_mapping *mapping)
39 {
40 	char iommu_mapping_path[PATH_MAX], line[PATH_MAX];
41 	u64 line_iova = -1;
42 	int ret = -ENOENT;
43 	FILE *file;
44 	char *rest;
45 
46 	snprintf(iommu_mapping_path, sizeof(iommu_mapping_path),
47 		 "/sys/kernel/debug/iommu/intel/%s/domain_translation_struct",
48 		 bdf);
49 
50 	printf("Searching for IOVA 0x%lx in %s\n", iova, iommu_mapping_path);
51 
52 	file = fopen(iommu_mapping_path, "r");
53 	VFIO_ASSERT_NOT_NULL(file, "fopen(%s) failed", iommu_mapping_path);
54 
55 	while (fgets(line, sizeof(line), file)) {
56 		rest = line;
57 
58 		parse_next_value(&rest, &line_iova);
59 		if (line_iova != (iova / getpagesize()))
60 			continue;
61 
62 		/*
63 		 * Ensure each struct field is initialized in case of empty
64 		 * page table values.
65 		 */
66 		memset(mapping, 0, sizeof(*mapping));
67 		parse_next_value(&rest, &mapping->pgd);
68 		parse_next_value(&rest, &mapping->p4d);
69 		parse_next_value(&rest, &mapping->pud);
70 		parse_next_value(&rest, &mapping->pmd);
71 		parse_next_value(&rest, &mapping->pte);
72 
73 		ret = 0;
74 		break;
75 	}
76 
77 	fclose(file);
78 
79 	if (ret)
80 		printf("IOVA not found\n");
81 
82 	return ret;
83 }
84 
85 static int iommu_mapping_get(const char *bdf, u64 iova,
86 			     struct iommu_mapping *mapping)
87 {
88 	if (!access("/sys/kernel/debug/iommu/intel", F_OK))
89 		return intel_iommu_mapping_get(bdf, iova, mapping);
90 
91 	return -EOPNOTSUPP;
92 }
93 
94 FIXTURE(vfio_dma_mapping_test) {
95 	struct vfio_pci_device *device;
96 };
97 
98 FIXTURE_VARIANT(vfio_dma_mapping_test) {
99 	u64 size;
100 	int mmap_flags;
101 };
102 
103 FIXTURE_VARIANT_ADD(vfio_dma_mapping_test, anonymous) {
104 	.mmap_flags = MAP_ANONYMOUS | MAP_PRIVATE,
105 };
106 
107 FIXTURE_VARIANT_ADD(vfio_dma_mapping_test, anonymous_hugetlb_2mb) {
108 	.size = SZ_2M,
109 	.mmap_flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_HUGETLB | MAP_HUGE_2MB,
110 };
111 
112 FIXTURE_VARIANT_ADD(vfio_dma_mapping_test, anonymous_hugetlb_1gb) {
113 	.size = SZ_1G,
114 	.mmap_flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_HUGETLB | MAP_HUGE_1GB,
115 };
116 
117 FIXTURE_SETUP(vfio_dma_mapping_test)
118 {
119 	self->device = vfio_pci_device_init(device_bdf, VFIO_TYPE1_IOMMU);
120 }
121 
122 FIXTURE_TEARDOWN(vfio_dma_mapping_test)
123 {
124 	vfio_pci_device_cleanup(self->device);
125 }
126 
127 TEST_F(vfio_dma_mapping_test, dma_map_unmap)
128 {
129 	const u64 size = variant->size ?: getpagesize();
130 	const int flags = variant->mmap_flags;
131 	struct vfio_dma_region region;
132 	struct iommu_mapping mapping;
133 	int rc;
134 
135 	region.vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
136 
137 	/* Skip the test if there aren't enough HugeTLB pages available. */
138 	if (flags & MAP_HUGETLB && region.vaddr == MAP_FAILED)
139 		SKIP(return, "mmap() failed: %s (%d)\n", strerror(errno), errno);
140 	else
141 		ASSERT_NE(region.vaddr, MAP_FAILED);
142 
143 	region.iova = (u64)region.vaddr;
144 	region.size = size;
145 
146 	vfio_pci_dma_map(self->device, &region);
147 	printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", region.vaddr, size, region.iova);
148 
149 	ASSERT_EQ(region.iova, to_iova(self->device, region.vaddr));
150 
151 	rc = iommu_mapping_get(device_bdf, region.iova, &mapping);
152 	if (rc == -EOPNOTSUPP)
153 		goto unmap;
154 
155 	ASSERT_EQ(0, rc);
156 	printf("Found IOMMU mappings for IOVA 0x%lx:\n", region.iova);
157 	printf("PGD: 0x%016lx\n", mapping.pgd);
158 	printf("P4D: 0x%016lx\n", mapping.p4d);
159 	printf("PUD: 0x%016lx\n", mapping.pud);
160 	printf("PMD: 0x%016lx\n", mapping.pmd);
161 	printf("PTE: 0x%016lx\n", mapping.pte);
162 
163 	switch (size) {
164 	case SZ_4K:
165 		ASSERT_NE(0, mapping.pte);
166 		break;
167 	case SZ_2M:
168 		ASSERT_EQ(0, mapping.pte);
169 		ASSERT_NE(0, mapping.pmd);
170 		break;
171 	case SZ_1G:
172 		ASSERT_EQ(0, mapping.pte);
173 		ASSERT_EQ(0, mapping.pmd);
174 		ASSERT_NE(0, mapping.pud);
175 		break;
176 	default:
177 		VFIO_FAIL("Unrecognized size: 0x%lx\n", size);
178 	}
179 
180 unmap:
181 	vfio_pci_dma_unmap(self->device, &region);
182 	printf("Unmapped IOVA 0x%lx\n", region.iova);
183 	ASSERT_EQ(INVALID_IOVA, __to_iova(self->device, region.vaddr));
184 	ASSERT_NE(0, iommu_mapping_get(device_bdf, region.iova, &mapping));
185 
186 	ASSERT_TRUE(!munmap(region.vaddr, size));
187 }
188 
189 int main(int argc, char *argv[])
190 {
191 	device_bdf = vfio_selftests_get_bdf(&argc, argv);
192 	return test_harness_run(argc, argv);
193 }
194