xref: /linux/tools/testing/selftests/vfio/vfio_dma_mapping_test.c (revision 509d3f45847627f4c5cdce004c3ec79262b5239c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <stdio.h>
3 #include <sys/mman.h>
4 #include <unistd.h>
5 
6 #include <uapi/linux/types.h>
7 #include <linux/iommufd.h>
8 #include <linux/limits.h>
9 #include <linux/mman.h>
10 #include <linux/sizes.h>
11 #include <linux/vfio.h>
12 
13 #include <libvfio.h>
14 
15 #include "kselftest_harness.h"
16 
17 static const char *device_bdf;
18 
19 struct iommu_mapping {
20 	u64 pgd;
21 	u64 p4d;
22 	u64 pud;
23 	u64 pmd;
24 	u64 pte;
25 };
26 
parse_next_value(char ** line,u64 * value)27 static void parse_next_value(char **line, u64 *value)
28 {
29 	char *token;
30 
31 	token = strtok_r(*line, " \t|\n", line);
32 	if (!token)
33 		return;
34 
35 	/* Caller verifies `value`. No need to check return value. */
36 	sscanf(token, "0x%lx", value);
37 }
38 
intel_iommu_mapping_get(const char * bdf,u64 iova,struct iommu_mapping * mapping)39 static int intel_iommu_mapping_get(const char *bdf, u64 iova,
40 				   struct iommu_mapping *mapping)
41 {
42 	char iommu_mapping_path[PATH_MAX], line[PATH_MAX];
43 	u64 line_iova = -1;
44 	int ret = -ENOENT;
45 	FILE *file;
46 	char *rest;
47 
48 	snprintf(iommu_mapping_path, sizeof(iommu_mapping_path),
49 		 "/sys/kernel/debug/iommu/intel/%s/domain_translation_struct",
50 		 bdf);
51 
52 	printf("Searching for IOVA 0x%lx in %s\n", iova, iommu_mapping_path);
53 
54 	file = fopen(iommu_mapping_path, "r");
55 	VFIO_ASSERT_NOT_NULL(file, "fopen(%s) failed", iommu_mapping_path);
56 
57 	while (fgets(line, sizeof(line), file)) {
58 		rest = line;
59 
60 		parse_next_value(&rest, &line_iova);
61 		if (line_iova != (iova / getpagesize()))
62 			continue;
63 
64 		/*
65 		 * Ensure each struct field is initialized in case of empty
66 		 * page table values.
67 		 */
68 		memset(mapping, 0, sizeof(*mapping));
69 		parse_next_value(&rest, &mapping->pgd);
70 		parse_next_value(&rest, &mapping->p4d);
71 		parse_next_value(&rest, &mapping->pud);
72 		parse_next_value(&rest, &mapping->pmd);
73 		parse_next_value(&rest, &mapping->pte);
74 
75 		ret = 0;
76 		break;
77 	}
78 
79 	fclose(file);
80 
81 	if (ret)
82 		printf("IOVA not found\n");
83 
84 	return ret;
85 }
86 
iommu_mapping_get(const char * bdf,u64 iova,struct iommu_mapping * mapping)87 static int iommu_mapping_get(const char *bdf, u64 iova,
88 			     struct iommu_mapping *mapping)
89 {
90 	if (!access("/sys/kernel/debug/iommu/intel", F_OK))
91 		return intel_iommu_mapping_get(bdf, iova, mapping);
92 
93 	return -EOPNOTSUPP;
94 }
95 
FIXTURE(vfio_dma_mapping_test)96 FIXTURE(vfio_dma_mapping_test) {
97 	struct iommu *iommu;
98 	struct vfio_pci_device *device;
99 	struct iova_allocator *iova_allocator;
100 };
101 
FIXTURE_VARIANT(vfio_dma_mapping_test)102 FIXTURE_VARIANT(vfio_dma_mapping_test) {
103 	const char *iommu_mode;
104 	u64 size;
105 	int mmap_flags;
106 };
107 
108 #define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode, _name, _size, _mmap_flags) \
109 FIXTURE_VARIANT_ADD(vfio_dma_mapping_test, _iommu_mode ## _ ## _name) {	       \
110 	.iommu_mode = #_iommu_mode,					       \
111 	.size = (_size),						       \
112 	.mmap_flags = MAP_ANONYMOUS | MAP_PRIVATE | (_mmap_flags),	       \
113 }
114 
115 FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous, 0, 0);
116 FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous_hugetlb_2mb, SZ_2M, MAP_HUGETLB | MAP_HUGE_2MB);
117 FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous_hugetlb_1gb, SZ_1G, MAP_HUGETLB | MAP_HUGE_1GB);
118 
119 #undef FIXTURE_VARIANT_ADD_IOMMU_MODE
120 
FIXTURE_SETUP(vfio_dma_mapping_test)121 FIXTURE_SETUP(vfio_dma_mapping_test)
122 {
123 	self->iommu = iommu_init(variant->iommu_mode);
124 	self->device = vfio_pci_device_init(device_bdf, self->iommu);
125 	self->iova_allocator = iova_allocator_init(self->iommu);
126 }
127 
FIXTURE_TEARDOWN(vfio_dma_mapping_test)128 FIXTURE_TEARDOWN(vfio_dma_mapping_test)
129 {
130 	iova_allocator_cleanup(self->iova_allocator);
131 	vfio_pci_device_cleanup(self->device);
132 	iommu_cleanup(self->iommu);
133 }
134 
TEST_F(vfio_dma_mapping_test,dma_map_unmap)135 TEST_F(vfio_dma_mapping_test, dma_map_unmap)
136 {
137 	const u64 size = variant->size ?: getpagesize();
138 	const int flags = variant->mmap_flags;
139 	struct dma_region region;
140 	struct iommu_mapping mapping;
141 	u64 mapping_size = size;
142 	u64 unmapped;
143 	int rc;
144 
145 	region.vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
146 
147 	/* Skip the test if there aren't enough HugeTLB pages available. */
148 	if (flags & MAP_HUGETLB && region.vaddr == MAP_FAILED)
149 		SKIP(return, "mmap() failed: %s (%d)\n", strerror(errno), errno);
150 	else
151 		ASSERT_NE(region.vaddr, MAP_FAILED);
152 
153 	region.iova = iova_allocator_alloc(self->iova_allocator, size);
154 	region.size = size;
155 
156 	iommu_map(self->iommu, &region);
157 	printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", region.vaddr, size, region.iova);
158 
159 	ASSERT_EQ(region.iova, to_iova(self->device, region.vaddr));
160 
161 	rc = iommu_mapping_get(device_bdf, region.iova, &mapping);
162 	if (rc == -EOPNOTSUPP)
163 		goto unmap;
164 
165 	/*
166 	 * IOMMUFD compatibility-mode does not support huge mappings when
167 	 * using VFIO_TYPE1_IOMMU.
168 	 */
169 	if (!strcmp(variant->iommu_mode, "iommufd_compat_type1"))
170 		mapping_size = SZ_4K;
171 
172 	ASSERT_EQ(0, rc);
173 	printf("Found IOMMU mappings for IOVA 0x%lx:\n", region.iova);
174 	printf("PGD: 0x%016lx\n", mapping.pgd);
175 	printf("P4D: 0x%016lx\n", mapping.p4d);
176 	printf("PUD: 0x%016lx\n", mapping.pud);
177 	printf("PMD: 0x%016lx\n", mapping.pmd);
178 	printf("PTE: 0x%016lx\n", mapping.pte);
179 
180 	switch (mapping_size) {
181 	case SZ_4K:
182 		ASSERT_NE(0, mapping.pte);
183 		break;
184 	case SZ_2M:
185 		ASSERT_EQ(0, mapping.pte);
186 		ASSERT_NE(0, mapping.pmd);
187 		break;
188 	case SZ_1G:
189 		ASSERT_EQ(0, mapping.pte);
190 		ASSERT_EQ(0, mapping.pmd);
191 		ASSERT_NE(0, mapping.pud);
192 		break;
193 	default:
194 		VFIO_FAIL("Unrecognized size: 0x%lx\n", mapping_size);
195 	}
196 
197 unmap:
198 	rc = __iommu_unmap(self->iommu, &region, &unmapped);
199 	ASSERT_EQ(rc, 0);
200 	ASSERT_EQ(unmapped, region.size);
201 	printf("Unmapped IOVA 0x%lx\n", region.iova);
202 	ASSERT_NE(0, __to_iova(self->device, region.vaddr, NULL));
203 	ASSERT_NE(0, iommu_mapping_get(device_bdf, region.iova, &mapping));
204 
205 	ASSERT_TRUE(!munmap(region.vaddr, size));
206 }
207 
FIXTURE(vfio_dma_map_limit_test)208 FIXTURE(vfio_dma_map_limit_test) {
209 	struct iommu *iommu;
210 	struct vfio_pci_device *device;
211 	struct dma_region region;
212 	size_t mmap_size;
213 };
214 
FIXTURE_VARIANT(vfio_dma_map_limit_test)215 FIXTURE_VARIANT(vfio_dma_map_limit_test) {
216 	const char *iommu_mode;
217 };
218 
219 #define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode)			       \
220 FIXTURE_VARIANT_ADD(vfio_dma_map_limit_test, _iommu_mode) {		       \
221 	.iommu_mode = #_iommu_mode,					       \
222 }
223 
224 FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES();
225 
226 #undef FIXTURE_VARIANT_ADD_IOMMU_MODE
227 
FIXTURE_SETUP(vfio_dma_map_limit_test)228 FIXTURE_SETUP(vfio_dma_map_limit_test)
229 {
230 	struct dma_region *region = &self->region;
231 	struct iommu_iova_range *ranges;
232 	u64 region_size = getpagesize();
233 	iova_t last_iova;
234 	u32 nranges;
235 
236 	/*
237 	 * Over-allocate mmap by double the size to provide enough backing vaddr
238 	 * for overflow tests
239 	 */
240 	self->mmap_size = 2 * region_size;
241 
242 	self->iommu = iommu_init(variant->iommu_mode);
243 	self->device = vfio_pci_device_init(device_bdf, self->iommu);
244 	region->vaddr = mmap(NULL, self->mmap_size, PROT_READ | PROT_WRITE,
245 			     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
246 	ASSERT_NE(region->vaddr, MAP_FAILED);
247 
248 	ranges = iommu_iova_ranges(self->iommu, &nranges);
249 	VFIO_ASSERT_NOT_NULL(ranges);
250 	last_iova = ranges[nranges - 1].last;
251 	free(ranges);
252 
253 	/* One page prior to the last iova */
254 	region->iova = last_iova & ~(region_size - 1);
255 	region->size = region_size;
256 }
257 
FIXTURE_TEARDOWN(vfio_dma_map_limit_test)258 FIXTURE_TEARDOWN(vfio_dma_map_limit_test)
259 {
260 	vfio_pci_device_cleanup(self->device);
261 	iommu_cleanup(self->iommu);
262 	ASSERT_EQ(munmap(self->region.vaddr, self->mmap_size), 0);
263 }
264 
TEST_F(vfio_dma_map_limit_test,unmap_range)265 TEST_F(vfio_dma_map_limit_test, unmap_range)
266 {
267 	struct dma_region *region = &self->region;
268 	u64 unmapped;
269 	int rc;
270 
271 	iommu_map(self->iommu, region);
272 	ASSERT_EQ(region->iova, to_iova(self->device, region->vaddr));
273 
274 	rc = __iommu_unmap(self->iommu, region, &unmapped);
275 	ASSERT_EQ(rc, 0);
276 	ASSERT_EQ(unmapped, region->size);
277 }
278 
TEST_F(vfio_dma_map_limit_test,unmap_all)279 TEST_F(vfio_dma_map_limit_test, unmap_all)
280 {
281 	struct dma_region *region = &self->region;
282 	u64 unmapped;
283 	int rc;
284 
285 	iommu_map(self->iommu, region);
286 	ASSERT_EQ(region->iova, to_iova(self->device, region->vaddr));
287 
288 	rc = __iommu_unmap_all(self->iommu, &unmapped);
289 	ASSERT_EQ(rc, 0);
290 	ASSERT_EQ(unmapped, region->size);
291 }
292 
TEST_F(vfio_dma_map_limit_test,overflow)293 TEST_F(vfio_dma_map_limit_test, overflow)
294 {
295 	struct dma_region *region = &self->region;
296 	int rc;
297 
298 	region->iova = ~(iova_t)0 & ~(region->size - 1);
299 	region->size = self->mmap_size;
300 
301 	rc = __iommu_map(self->iommu, region);
302 	ASSERT_EQ(rc, -EOVERFLOW);
303 
304 	rc = __iommu_unmap(self->iommu, region, NULL);
305 	ASSERT_EQ(rc, -EOVERFLOW);
306 }
307 
main(int argc,char * argv[])308 int main(int argc, char *argv[])
309 {
310 	device_bdf = vfio_selftests_get_bdf(&argc, argv);
311 	return test_harness_run(argc, argv);
312 }
313