1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * steal/stolen time test 4 * 5 * Copyright (C) 2020, Red Hat, Inc. 6 */ 7 #define _GNU_SOURCE 8 #include <stdio.h> 9 #include <time.h> 10 #include <sched.h> 11 #include <pthread.h> 12 #include <linux/kernel.h> 13 #include <sys/syscall.h> 14 #include <asm/kvm.h> 15 #include <asm/kvm_para.h> 16 17 #include "test_util.h" 18 #include "kvm_util.h" 19 #include "processor.h" 20 21 #define NR_VCPUS 4 22 #define ST_GPA_BASE (1 << 30) 23 #define MIN_RUN_DELAY_NS 200000UL 24 25 static void *st_gva[NR_VCPUS]; 26 static uint64_t guest_stolen_time[NR_VCPUS]; 27 28 #if defined(__x86_64__) 29 30 /* steal_time must have 64-byte alignment */ 31 #define STEAL_TIME_SIZE ((sizeof(struct kvm_steal_time) + 63) & ~63) 32 33 static void check_status(struct kvm_steal_time *st) 34 { 35 GUEST_ASSERT(!(READ_ONCE(st->version) & 1)); 36 GUEST_ASSERT(READ_ONCE(st->flags) == 0); 37 GUEST_ASSERT(READ_ONCE(st->preempted) == 0); 38 } 39 40 static void guest_code(int cpu) 41 { 42 struct kvm_steal_time *st = st_gva[cpu]; 43 uint32_t version; 44 45 GUEST_ASSERT(rdmsr(MSR_KVM_STEAL_TIME) == ((uint64_t)st_gva[cpu] | KVM_MSR_ENABLED)); 46 47 memset(st, 0, sizeof(*st)); 48 GUEST_SYNC(0); 49 50 check_status(st); 51 WRITE_ONCE(guest_stolen_time[cpu], st->steal); 52 version = READ_ONCE(st->version); 53 check_status(st); 54 GUEST_SYNC(1); 55 56 check_status(st); 57 GUEST_ASSERT(version < READ_ONCE(st->version)); 58 WRITE_ONCE(guest_stolen_time[cpu], st->steal); 59 check_status(st); 60 GUEST_DONE(); 61 } 62 63 static void steal_time_init(struct kvm_vm *vm) 64 { 65 int i; 66 67 if (!(kvm_get_supported_cpuid_entry(KVM_CPUID_FEATURES)->eax & 68 KVM_FEATURE_STEAL_TIME)) { 69 print_skip("steal-time not supported"); 70 exit(KSFT_SKIP); 71 } 72 73 for (i = 0; i < NR_VCPUS; ++i) { 74 int ret; 75 76 /* ST_GPA_BASE is identity mapped */ 77 st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE); 78 sync_global_to_guest(vm, st_gva[i]); 79 80 ret = _vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK); 81 TEST_ASSERT(ret == 0, "Bad GPA didn't fail"); 82 83 vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED); 84 } 85 } 86 87 static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid) 88 { 89 struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]); 90 int i; 91 92 pr_info("VCPU%d:\n", vcpuid); 93 pr_info(" steal: %lld\n", st->steal); 94 pr_info(" version: %d\n", st->version); 95 pr_info(" flags: %d\n", st->flags); 96 pr_info(" preempted: %d\n", st->preempted); 97 pr_info(" u8_pad: "); 98 for (i = 0; i < 3; ++i) 99 pr_info("%d", st->u8_pad[i]); 100 pr_info("\n pad: "); 101 for (i = 0; i < 11; ++i) 102 pr_info("%d", st->pad[i]); 103 pr_info("\n"); 104 } 105 106 #elif defined(__aarch64__) 107 108 /* PV_TIME_ST must have 64-byte alignment */ 109 #define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63) 110 111 #define SMCCC_ARCH_FEATURES 0x80000001 112 #define PV_TIME_FEATURES 0xc5000020 113 #define PV_TIME_ST 0xc5000021 114 115 struct st_time { 116 uint32_t rev; 117 uint32_t attr; 118 uint64_t st_time; 119 }; 120 121 static int64_t smccc(uint32_t func, uint32_t arg) 122 { 123 unsigned long ret; 124 125 asm volatile( 126 "mov x0, %1\n" 127 "mov x1, %2\n" 128 "hvc #0\n" 129 "mov %0, x0\n" 130 : "=r" (ret) : "r" (func), "r" (arg) : 131 "x0", "x1", "x2", "x3"); 132 133 return ret; 134 } 135 136 static void check_status(struct st_time *st) 137 { 138 GUEST_ASSERT(READ_ONCE(st->rev) == 0); 139 GUEST_ASSERT(READ_ONCE(st->attr) == 0); 140 } 141 142 static void guest_code(int cpu) 143 { 144 struct st_time *st; 145 int64_t status; 146 147 status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES); 148 GUEST_ASSERT(status == 0); 149 status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES); 150 GUEST_ASSERT(status == 0); 151 status = smccc(PV_TIME_FEATURES, PV_TIME_ST); 152 GUEST_ASSERT(status == 0); 153 154 status = smccc(PV_TIME_ST, 0); 155 GUEST_ASSERT(status != -1); 156 GUEST_ASSERT(status == (ulong)st_gva[cpu]); 157 158 st = (struct st_time *)status; 159 GUEST_SYNC(0); 160 161 check_status(st); 162 WRITE_ONCE(guest_stolen_time[cpu], st->st_time); 163 GUEST_SYNC(1); 164 165 check_status(st); 166 WRITE_ONCE(guest_stolen_time[cpu], st->st_time); 167 GUEST_DONE(); 168 } 169 170 static void steal_time_init(struct kvm_vm *vm) 171 { 172 struct kvm_device_attr dev = { 173 .group = KVM_ARM_VCPU_PVTIME_CTRL, 174 .attr = KVM_ARM_VCPU_PVTIME_IPA, 175 }; 176 int i, ret; 177 178 ret = _vcpu_ioctl(vm, 0, KVM_HAS_DEVICE_ATTR, &dev); 179 if (ret != 0 && errno == ENXIO) { 180 print_skip("steal-time not supported"); 181 exit(KSFT_SKIP); 182 } 183 184 for (i = 0; i < NR_VCPUS; ++i) { 185 uint64_t st_ipa; 186 187 vcpu_ioctl(vm, i, KVM_HAS_DEVICE_ATTR, &dev); 188 189 dev.addr = (uint64_t)&st_ipa; 190 191 /* ST_GPA_BASE is identity mapped */ 192 st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE); 193 sync_global_to_guest(vm, st_gva[i]); 194 195 st_ipa = (ulong)st_gva[i] | 1; 196 ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev); 197 TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL"); 198 199 st_ipa = (ulong)st_gva[i]; 200 vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev); 201 202 ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev); 203 TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST"); 204 205 } 206 } 207 208 static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid) 209 { 210 struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]); 211 212 pr_info("VCPU%d:\n", vcpuid); 213 pr_info(" rev: %d\n", st->rev); 214 pr_info(" attr: %d\n", st->attr); 215 pr_info(" st_time: %ld\n", st->st_time); 216 } 217 218 #endif 219 220 static long get_run_delay(void) 221 { 222 char path[64]; 223 long val[2]; 224 FILE *fp; 225 226 sprintf(path, "/proc/%ld/schedstat", syscall(SYS_gettid)); 227 fp = fopen(path, "r"); 228 fscanf(fp, "%ld %ld ", &val[0], &val[1]); 229 fclose(fp); 230 231 return val[1]; 232 } 233 234 static void *do_steal_time(void *arg) 235 { 236 struct timespec ts, stop; 237 238 clock_gettime(CLOCK_MONOTONIC, &ts); 239 stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS); 240 241 while (1) { 242 clock_gettime(CLOCK_MONOTONIC, &ts); 243 if (timespec_to_ns(timespec_sub(ts, stop)) >= 0) 244 break; 245 } 246 247 return NULL; 248 } 249 250 static void run_vcpu(struct kvm_vm *vm, uint32_t vcpuid) 251 { 252 struct ucall uc; 253 254 vcpu_args_set(vm, vcpuid, 1, vcpuid); 255 256 vcpu_ioctl(vm, vcpuid, KVM_RUN, NULL); 257 258 switch (get_ucall(vm, vcpuid, &uc)) { 259 case UCALL_SYNC: 260 case UCALL_DONE: 261 break; 262 case UCALL_ABORT: 263 TEST_ASSERT(false, "%s at %s:%ld", (const char *)uc.args[0], 264 __FILE__, uc.args[1]); 265 default: 266 TEST_ASSERT(false, "Unexpected exit: %s", 267 exit_reason_str(vcpu_state(vm, vcpuid)->exit_reason)); 268 } 269 } 270 271 int main(int ac, char **av) 272 { 273 struct kvm_vm *vm; 274 pthread_attr_t attr; 275 pthread_t thread; 276 cpu_set_t cpuset; 277 unsigned int gpages; 278 long stolen_time; 279 long run_delay; 280 bool verbose; 281 int i; 282 283 verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10)); 284 285 /* Set CPU affinity so we can force preemption of the VCPU */ 286 CPU_ZERO(&cpuset); 287 CPU_SET(0, &cpuset); 288 pthread_attr_init(&attr); 289 pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset); 290 pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset); 291 292 /* Create a one VCPU guest and an identity mapped memslot for the steal time structure */ 293 vm = vm_create_default(0, 0, guest_code); 294 gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS); 295 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0); 296 virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages); 297 ucall_init(vm, NULL); 298 299 /* Add the rest of the VCPUs */ 300 for (i = 1; i < NR_VCPUS; ++i) 301 vm_vcpu_add_default(vm, i, guest_code); 302 303 steal_time_init(vm); 304 305 /* Run test on each VCPU */ 306 for (i = 0; i < NR_VCPUS; ++i) { 307 /* First VCPU run initializes steal-time */ 308 run_vcpu(vm, i); 309 310 /* Second VCPU run, expect guest stolen time to be <= run_delay */ 311 run_vcpu(vm, i); 312 sync_global_from_guest(vm, guest_stolen_time[i]); 313 stolen_time = guest_stolen_time[i]; 314 run_delay = get_run_delay(); 315 TEST_ASSERT(stolen_time <= run_delay, 316 "Expected stolen time <= %ld, got %ld", 317 run_delay, stolen_time); 318 319 /* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */ 320 run_delay = get_run_delay(); 321 pthread_create(&thread, &attr, do_steal_time, NULL); 322 do 323 sched_yield(); 324 while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS); 325 pthread_join(thread, NULL); 326 run_delay = get_run_delay() - run_delay; 327 TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS, 328 "Expected run_delay >= %ld, got %ld", 329 MIN_RUN_DELAY_NS, run_delay); 330 331 /* Run VCPU again to confirm stolen time is consistent with run_delay */ 332 run_vcpu(vm, i); 333 sync_global_from_guest(vm, guest_stolen_time[i]); 334 stolen_time = guest_stolen_time[i] - stolen_time; 335 TEST_ASSERT(stolen_time >= run_delay, 336 "Expected stolen time >= %ld, got %ld", 337 run_delay, stolen_time); 338 339 if (verbose) { 340 pr_info("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld", i, 341 guest_stolen_time[i], stolen_time); 342 if (stolen_time == run_delay) 343 pr_info(" (BONUS: guest test-stolen-time even exactly matches test-run_delay)"); 344 pr_info("\n"); 345 steal_time_dump(vm, i); 346 } 347 } 348 349 return 0; 350 } 351