1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * kvm_binary_stats_test
4 *
5 * Copyright (C) 2021, Google LLC.
6 *
7 * Test the fd-based interface for KVM statistics.
8 */
9 #include <fcntl.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <errno.h>
14
15 #include "test_util.h"
16
17 #include "kvm_util.h"
18 #include "asm/kvm.h"
19 #include "linux/kvm.h"
20 #include "kselftest.h"
21
stats_test(int stats_fd)22 static void stats_test(int stats_fd)
23 {
24 ssize_t ret;
25 int i;
26 size_t size_desc;
27 size_t size_data = 0;
28 struct kvm_stats_header header;
29 char *id;
30 struct kvm_stats_desc *stats_desc;
31 u64 *stats_data;
32 struct kvm_stats_desc *pdesc;
33 u32 type, unit, base;
34
35 /* Read kvm stats header */
36 read_stats_header(stats_fd, &header);
37
38 size_desc = get_stats_descriptor_size(&header);
39
40 /* Read kvm stats id string */
41 id = malloc(header.name_size);
42 TEST_ASSERT(id, "Allocate memory for id string");
43
44 ret = pread(stats_fd, id, header.name_size, sizeof(header));
45 TEST_ASSERT(ret == header.name_size,
46 "Expected header size '%u', read '%lu' bytes",
47 header.name_size, ret);
48
49 /* Check id string, that should start with "kvm" */
50 TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header.name_size,
51 "Invalid KVM stats type, id: %s", id);
52
53 /* Sanity check for other fields in header */
54 if (header.num_desc == 0) {
55 ksft_print_msg("No KVM stats defined!\n");
56 return;
57 }
58 /*
59 * The descriptor and data offsets must be valid, they must not overlap
60 * the header, and the descriptor and data blocks must not overlap each
61 * other. Note, the data block is rechecked after its size is known.
62 */
63 TEST_ASSERT(header.desc_offset && header.desc_offset >= sizeof(header) &&
64 header.data_offset && header.data_offset >= sizeof(header),
65 "Invalid offset fields in header");
66
67 TEST_ASSERT(header.desc_offset > header.data_offset ||
68 (header.desc_offset + size_desc * header.num_desc <= header.data_offset),
69 "Descriptor block is overlapped with data block");
70
71 /* Read kvm stats descriptors */
72 stats_desc = read_stats_descriptors(stats_fd, &header);
73
74 /* Sanity check for fields in descriptors */
75 for (i = 0; i < header.num_desc; ++i) {
76 pdesc = get_stats_descriptor(stats_desc, i, &header);
77 type = pdesc->flags & KVM_STATS_TYPE_MASK;
78 unit = pdesc->flags & KVM_STATS_UNIT_MASK;
79 base = pdesc->flags & KVM_STATS_BASE_MASK;
80
81 /* Check name string */
82 TEST_ASSERT(strlen(pdesc->name) < header.name_size,
83 "KVM stats name (index: %d) too long", i);
84
85 /* Check type,unit,base boundaries */
86 TEST_ASSERT(type <= KVM_STATS_TYPE_MAX,
87 "Unknown KVM stats (%s) type: %u", pdesc->name, type);
88 TEST_ASSERT(unit <= KVM_STATS_UNIT_MAX,
89 "Unknown KVM stats (%s) unit: %u", pdesc->name, unit);
90 TEST_ASSERT(base <= KVM_STATS_BASE_MAX,
91 "Unknown KVM stats (%s) base: %u", pdesc->name, base);
92
93 /*
94 * Check exponent for stats unit
95 * Exponent for counter should be greater than or equal to 0
96 * Exponent for unit bytes should be greater than or equal to 0
97 * Exponent for unit seconds should be less than or equal to 0
98 * Exponent for unit clock cycles should be greater than or
99 * equal to 0
100 * Exponent for unit boolean should be 0
101 */
102 switch (pdesc->flags & KVM_STATS_UNIT_MASK) {
103 case KVM_STATS_UNIT_NONE:
104 case KVM_STATS_UNIT_BYTES:
105 case KVM_STATS_UNIT_CYCLES:
106 TEST_ASSERT(pdesc->exponent >= 0,
107 "Unsupported KVM stats (%s) exponent: %i",
108 pdesc->name, pdesc->exponent);
109 break;
110 case KVM_STATS_UNIT_SECONDS:
111 TEST_ASSERT(pdesc->exponent <= 0,
112 "Unsupported KVM stats (%s) exponent: %i",
113 pdesc->name, pdesc->exponent);
114 break;
115 case KVM_STATS_UNIT_BOOLEAN:
116 TEST_ASSERT(pdesc->exponent == 0,
117 "Unsupported KVM stats (%s) exponent: %d",
118 pdesc->name, pdesc->exponent);
119 break;
120 }
121
122 /* Check size field, which should not be zero */
123 TEST_ASSERT(pdesc->size,
124 "KVM descriptor(%s) with size of 0", pdesc->name);
125 /* Check bucket_size field */
126 switch (pdesc->flags & KVM_STATS_TYPE_MASK) {
127 case KVM_STATS_TYPE_LINEAR_HIST:
128 TEST_ASSERT(pdesc->bucket_size,
129 "Bucket size of Linear Histogram stats (%s) is zero",
130 pdesc->name);
131 break;
132 default:
133 TEST_ASSERT(!pdesc->bucket_size,
134 "Bucket size of stats (%s) is not zero",
135 pdesc->name);
136 }
137 size_data = max(size_data, pdesc->offset + pdesc->size * sizeof(*stats_data));
138 }
139
140 /*
141 * Now that the size of the data block is known, verify the data block
142 * doesn't overlap the descriptor block.
143 */
144 TEST_ASSERT(header.data_offset >= header.desc_offset ||
145 header.data_offset + size_data <= header.desc_offset,
146 "Data block is overlapped with Descriptor block");
147
148 /* Check validity of all stats data size */
149 TEST_ASSERT(size_data >= header.num_desc * sizeof(*stats_data),
150 "Data size is not correct");
151
152 /* Allocate memory for stats data */
153 stats_data = malloc(size_data);
154 TEST_ASSERT(stats_data, "Allocate memory for stats data");
155 /* Read kvm stats data as a bulk */
156 ret = pread(stats_fd, stats_data, size_data, header.data_offset);
157 TEST_ASSERT(ret == size_data, "Read KVM stats data");
158 /* Read kvm stats data one by one */
159 for (i = 0; i < header.num_desc; ++i) {
160 pdesc = get_stats_descriptor(stats_desc, i, &header);
161 read_stat_data(stats_fd, &header, pdesc, stats_data,
162 pdesc->size);
163 }
164
165 free(stats_data);
166 free(stats_desc);
167 free(id);
168
169 close(stats_fd);
170 TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed");
171 }
172
173 #define DEFAULT_NUM_VM 4
174 #define DEFAULT_NUM_VCPU 4
175
176 /*
177 * Usage: kvm_bin_form_stats [#vm] [#vcpu]
178 * The first parameter #vm set the number of VMs being created.
179 * The second parameter #vcpu set the number of VCPUs being created.
180 * By default, DEFAULT_NUM_VM VM and DEFAULT_NUM_VCPU VCPU for the VM would be
181 * created for testing.
182 */
183
main(int argc,char * argv[])184 int main(int argc, char *argv[])
185 {
186 int vm_stats_fds, *vcpu_stats_fds;
187 int i, j;
188 struct kvm_vcpu **vcpus;
189 struct kvm_vm **vms;
190 int max_vm = DEFAULT_NUM_VM;
191 int max_vcpu = DEFAULT_NUM_VCPU;
192
193 /* Get the number of VMs and VCPUs that would be created for testing. */
194 if (argc > 1) {
195 max_vm = strtol(argv[1], NULL, 0);
196 if (max_vm <= 0)
197 max_vm = DEFAULT_NUM_VM;
198 }
199 if (argc > 2) {
200 max_vcpu = strtol(argv[2], NULL, 0);
201 if (max_vcpu <= 0)
202 max_vcpu = DEFAULT_NUM_VCPU;
203 }
204
205 ksft_print_header();
206
207 /* Check the extension for binary stats */
208 TEST_REQUIRE(kvm_has_cap(KVM_CAP_BINARY_STATS_FD));
209
210 ksft_set_plan(max_vm);
211
212 /* Create VMs and VCPUs */
213 vms = malloc(sizeof(vms[0]) * max_vm);
214 TEST_ASSERT(vms, "Allocate memory for storing VM pointers");
215
216 vcpus = malloc(sizeof(struct kvm_vcpu *) * max_vm * max_vcpu);
217 TEST_ASSERT(vcpus, "Allocate memory for storing vCPU pointers");
218
219 /*
220 * Not per-VM as the array is populated, used, and invalidated within a
221 * single for-loop iteration.
222 */
223 vcpu_stats_fds = calloc(max_vm, sizeof(*vcpu_stats_fds));
224 TEST_ASSERT(vcpu_stats_fds, "Allocate memory for VM stats fds");
225
226 for (i = 0; i < max_vm; ++i) {
227 vms[i] = vm_create_barebones();
228 for (j = 0; j < max_vcpu; ++j)
229 vcpus[i * max_vcpu + j] = __vm_vcpu_add(vms[i], j);
230 }
231
232 /*
233 * Check stats read for every VM and vCPU, with a variety of flavors.
234 * Note, stats_test() closes the passed in stats fd.
235 */
236 for (i = 0; i < max_vm; ++i) {
237 /*
238 * Verify that creating multiple userspace references to a
239 * single stats file works and doesn't cause explosions.
240 */
241 vm_stats_fds = vm_get_stats_fd(vms[i]);
242 stats_test(dup(vm_stats_fds));
243
244 /* Verify userspace can instantiate multiple stats files. */
245 stats_test(vm_get_stats_fd(vms[i]));
246
247 for (j = 0; j < max_vcpu; ++j) {
248 vcpu_stats_fds[j] = vcpu_get_stats_fd(vcpus[i * max_vcpu + j]);
249 stats_test(dup(vcpu_stats_fds[j]));
250 stats_test(vcpu_get_stats_fd(vcpus[i * max_vcpu + j]));
251 }
252
253 /*
254 * Close the VM fd and redo the stats tests. KVM should gift a
255 * reference (to the VM) to each stats fd, i.e. stats should
256 * still be accessible even after userspace has put its last
257 * _direct_ reference to the VM.
258 */
259 kvm_vm_free(vms[i]);
260
261 stats_test(vm_stats_fds);
262 for (j = 0; j < max_vcpu; ++j)
263 stats_test(vcpu_stats_fds[j]);
264
265 ksft_test_result_pass("vm%i\n", i);
266 }
267
268 free(vms);
269 free(vcpus);
270 free(vcpu_stats_fds);
271
272 ksft_finished(); /* Print results and exit() accordingly */
273 }
274