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 <asm/kvm.h>
14#ifndef __riscv
15#include <asm/kvm_para.h>
16#endif
17
18#include "test_util.h"
19#include "kvm_util.h"
20#include "processor.h"
21
22#define NR_VCPUS 4
23#define ST_GPA_BASE (1 << 30)
24
25static void *st_gva[NR_VCPUS];
26static 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
33static void check_status(struct kvm_steal_time *st)
34{
35 GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
36 GUEST_ASSERT_EQ(READ_ONCE(st->flags), 0);
37 GUEST_ASSERT_EQ(READ_ONCE(st->preempted), 0);
38}
39
40static void guest_code(int cpu)
41{
42 struct kvm_steal_time *st = st_gva[cpu];
43 uint32_t version;
44
45 GUEST_ASSERT_EQ(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
63static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
64{
65 return kvm_cpu_has(X86_FEATURE_KVM_STEAL_TIME);
66}
67
68static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
69{
70 int ret;
71
72 /* ST_GPA_BASE is identity mapped */
73 st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
74 sync_global_to_guest(vcpu->vm, st_gva[i]);
75
76 ret = _vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME,
77 (ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK);
78 TEST_ASSERT(ret == 0, "Bad GPA didn't fail");
79
80 vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
81}
82
83static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
84{
85 struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
86 int i;
87
88 pr_info("VCPU%d:\n", vcpu_idx);
89 pr_info(" steal: %lld\n", st->steal);
90 pr_info(" version: %d\n", st->version);
91 pr_info(" flags: %d\n", st->flags);
92 pr_info(" preempted: %d\n", st->preempted);
93 pr_info(" u8_pad: ");
94 for (i = 0; i < 3; ++i)
95 pr_info("%d", st->u8_pad[i]);
96 pr_info("\n pad: ");
97 for (i = 0; i < 11; ++i)
98 pr_info("%d", st->pad[i]);
99 pr_info("\n");
100}
101
102#elif defined(__aarch64__)
103
104/* PV_TIME_ST must have 64-byte alignment */
105#define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63)
106
107#define SMCCC_ARCH_FEATURES 0x80000001
108#define PV_TIME_FEATURES 0xc5000020
109#define PV_TIME_ST 0xc5000021
110
111struct st_time {
112 uint32_t rev;
113 uint32_t attr;
114 uint64_t st_time;
115};
116
117static int64_t smccc(uint32_t func, uint64_t arg)
118{
119 struct arm_smccc_res res;
120
121 smccc_hvc(func, arg, 0, 0, 0, 0, 0, 0, &res);
122 return res.a0;
123}
124
125static void check_status(struct st_time *st)
126{
127 GUEST_ASSERT_EQ(READ_ONCE(st->rev), 0);
128 GUEST_ASSERT_EQ(READ_ONCE(st->attr), 0);
129}
130
131static void guest_code(int cpu)
132{
133 struct st_time *st;
134 int64_t status;
135
136 status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES);
137 GUEST_ASSERT_EQ(status, 0);
138 status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES);
139 GUEST_ASSERT_EQ(status, 0);
140 status = smccc(PV_TIME_FEATURES, PV_TIME_ST);
141 GUEST_ASSERT_EQ(status, 0);
142
143 status = smccc(PV_TIME_ST, 0);
144 GUEST_ASSERT_NE(status, -1);
145 GUEST_ASSERT_EQ(status, (ulong)st_gva[cpu]);
146
147 st = (struct st_time *)status;
148 GUEST_SYNC(0);
149
150 check_status(st);
151 WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
152 GUEST_SYNC(1);
153
154 check_status(st);
155 WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
156 GUEST_DONE();
157}
158
159static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
160{
161 struct kvm_device_attr dev = {
162 .group = KVM_ARM_VCPU_PVTIME_CTRL,
163 .attr = KVM_ARM_VCPU_PVTIME_IPA,
164 };
165
166 return !__vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
167}
168
169static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
170{
171 struct kvm_vm *vm = vcpu->vm;
172 uint64_t st_ipa;
173 int ret;
174
175 struct kvm_device_attr dev = {
176 .group = KVM_ARM_VCPU_PVTIME_CTRL,
177 .attr = KVM_ARM_VCPU_PVTIME_IPA,
178 .addr = (uint64_t)&st_ipa,
179 };
180
181 vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
182
183 /* ST_GPA_BASE is identity mapped */
184 st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
185 sync_global_to_guest(vm, st_gva[i]);
186
187 st_ipa = (ulong)st_gva[i] | 1;
188 ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
189 TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL");
190
191 st_ipa = (ulong)st_gva[i];
192 vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
193
194 ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
195 TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST");
196}
197
198static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
199{
200 struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
201
202 pr_info("VCPU%d:\n", vcpu_idx);
203 pr_info(" rev: %d\n", st->rev);
204 pr_info(" attr: %d\n", st->attr);
205 pr_info(" st_time: %ld\n", st->st_time);
206}
207
208#elif defined(__riscv)
209
210/* SBI STA shmem must have 64-byte alignment */
211#define STEAL_TIME_SIZE ((sizeof(struct sta_struct) + 63) & ~63)
212
213static vm_paddr_t st_gpa[NR_VCPUS];
214
215struct sta_struct {
216 uint32_t sequence;
217 uint32_t flags;
218 uint64_t steal;
219 uint8_t preempted;
220 uint8_t pad[47];
221} __packed;
222
223static void sta_set_shmem(vm_paddr_t gpa, unsigned long flags)
224{
225 unsigned long lo = (unsigned long)gpa;
226#if __riscv_xlen == 32
227 unsigned long hi = (unsigned long)(gpa >> 32);
228#else
229 unsigned long hi = gpa == -1 ? -1 : 0;
230#endif
231 struct sbiret ret = sbi_ecall(SBI_EXT_STA, 0, lo, hi, flags, 0, 0, 0);
232
233 GUEST_ASSERT(ret.value == 0 && ret.error == 0);
234}
235
236static void check_status(struct sta_struct *st)
237{
238 GUEST_ASSERT(!(READ_ONCE(st->sequence) & 1));
239 GUEST_ASSERT(READ_ONCE(st->flags) == 0);
240 GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
241}
242
243static void guest_code(int cpu)
244{
245 struct sta_struct *st = st_gva[cpu];
246 uint32_t sequence;
247 long out_val = 0;
248 bool probe;
249
250 probe = guest_sbi_probe_extension(SBI_EXT_STA, &out_val);
251 GUEST_ASSERT(probe && out_val == 1);
252
253 sta_set_shmem(st_gpa[cpu], 0);
254 GUEST_SYNC(0);
255
256 check_status(st);
257 WRITE_ONCE(guest_stolen_time[cpu], st->steal);
258 sequence = READ_ONCE(st->sequence);
259 check_status(st);
260 GUEST_SYNC(1);
261
262 check_status(st);
263 GUEST_ASSERT(sequence < READ_ONCE(st->sequence));
264 WRITE_ONCE(guest_stolen_time[cpu], st->steal);
265 check_status(st);
266 GUEST_DONE();
267}
268
269static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
270{
271 uint64_t id = RISCV_SBI_EXT_REG(KVM_RISCV_SBI_EXT_STA);
272 unsigned long enabled;
273
274 vcpu_get_reg(vcpu, id, &enabled);
275 TEST_ASSERT(enabled == 0 || enabled == 1, "Expected boolean result");
276
277 return enabled;
278}
279
280static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
281{
282 /* ST_GPA_BASE is identity mapped */
283 st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
284 st_gpa[i] = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)st_gva[i]);
285 sync_global_to_guest(vcpu->vm, st_gva[i]);
286 sync_global_to_guest(vcpu->vm, st_gpa[i]);
287}
288
289static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
290{
291 struct sta_struct *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
292 int i;
293
294 pr_info("VCPU%d:\n", vcpu_idx);
295 pr_info(" sequence: %d\n", st->sequence);
296 pr_info(" flags: %d\n", st->flags);
297 pr_info(" steal: %"PRIu64"\n", st->steal);
298 pr_info(" preempted: %d\n", st->preempted);
299 pr_info(" pad: ");
300 for (i = 0; i < 47; ++i)
301 pr_info("%d", st->pad[i]);
302 pr_info("\n");
303}
304
305#endif
306
307static void *do_steal_time(void *arg)
308{
309 struct timespec ts, stop;
310
311 clock_gettime(CLOCK_MONOTONIC, &ts);
312 stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS);
313
314 while (1) {
315 clock_gettime(CLOCK_MONOTONIC, &ts);
316 if (timespec_to_ns(timespec_sub(ts, stop)) >= 0)
317 break;
318 }
319
320 return NULL;
321}
322
323static void run_vcpu(struct kvm_vcpu *vcpu)
324{
325 struct ucall uc;
326
327 vcpu_run(vcpu);
328
329 switch (get_ucall(vcpu, &uc)) {
330 case UCALL_SYNC:
331 case UCALL_DONE:
332 break;
333 case UCALL_ABORT:
334 REPORT_GUEST_ASSERT(uc);
335 default:
336 TEST_ASSERT(false, "Unexpected exit: %s",
337 exit_reason_str(vcpu->run->exit_reason));
338 }
339}
340
341int main(int ac, char **av)
342{
343 struct kvm_vcpu *vcpus[NR_VCPUS];
344 struct kvm_vm *vm;
345 pthread_attr_t attr;
346 pthread_t thread;
347 cpu_set_t cpuset;
348 unsigned int gpages;
349 long stolen_time;
350 long run_delay;
351 bool verbose;
352 int i;
353
354 verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));
355
356 /* Set CPU affinity so we can force preemption of the VCPU */
357 CPU_ZERO(&cpuset);
358 CPU_SET(0, &cpuset);
359 pthread_attr_init(&attr);
360 pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
361 pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
362
363 /* Create a VM and an identity mapped memslot for the steal time structure */
364 vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus);
365 gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS);
366 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);
367 virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages);
368
369 TEST_REQUIRE(is_steal_time_supported(vcpu: vcpus[0]));
370
371 /* Run test on each VCPU */
372 for (i = 0; i < NR_VCPUS; ++i) {
373 steal_time_init(vcpu: vcpus[i], i);
374
375 vcpu_args_set(vcpus[i], 1, i);
376
377 /* First VCPU run initializes steal-time */
378 run_vcpu(vcpu: vcpus[i]);
379
380 /* Second VCPU run, expect guest stolen time to be <= run_delay */
381 run_vcpu(vcpu: vcpus[i]);
382 sync_global_from_guest(vm, guest_stolen_time[i]);
383 stolen_time = guest_stolen_time[i];
384 run_delay = get_run_delay();
385 TEST_ASSERT(stolen_time <= run_delay,
386 "Expected stolen time <= %ld, got %ld",
387 run_delay, stolen_time);
388
389 /* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */
390 run_delay = get_run_delay();
391 pthread_create(&thread, &attr, do_steal_time, NULL);
392 do
393 sched_yield();
394 while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
395 pthread_join(thread, NULL);
396 run_delay = get_run_delay() - run_delay;
397 TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
398 "Expected run_delay >= %ld, got %ld",
399 MIN_RUN_DELAY_NS, run_delay);
400
401 /* Run VCPU again to confirm stolen time is consistent with run_delay */
402 run_vcpu(vcpu: vcpus[i]);
403 sync_global_from_guest(vm, guest_stolen_time[i]);
404 stolen_time = guest_stolen_time[i] - stolen_time;
405 TEST_ASSERT(stolen_time >= run_delay,
406 "Expected stolen time >= %ld, got %ld",
407 run_delay, stolen_time);
408
409 if (verbose) {
410 pr_info("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld", i,
411 guest_stolen_time[i], stolen_time);
412 if (stolen_time == run_delay)
413 pr_info(" (BONUS: guest test-stolen-time even exactly matches test-run_delay)");
414 pr_info("\n");
415 steal_time_dump(vm, vcpu_idx: i);
416 }
417 }
418
419 return 0;
420}
421

source code of linux/tools/testing/selftests/kvm/steal_time.c