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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2021, Google LLC.
*
* Tests for adjusting the KVM clock from userspace
*/
#include <asm/kvm_para.h>
#include <asm/pvclock.h>
#include <asm/pvclock-abi.h>
#include <stdint.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
#define VCPU_ID 0
struct test_case {
uint64_t kvmclock_base;
int64_t realtime_offset;
};
static struct test_case test_cases[] = {
{ .kvmclock_base = 0 },
{ .kvmclock_base = 180 * NSEC_PER_SEC },
{ .kvmclock_base = 0, .realtime_offset = -180 * NSEC_PER_SEC },
{ .kvmclock_base = 0, .realtime_offset = 180 * NSEC_PER_SEC },
};
#define GUEST_SYNC_CLOCK(__stage, __val) \
GUEST_SYNC_ARGS(__stage, __val, 0, 0, 0)
static void guest_main(vm_paddr_t pvti_pa, struct pvclock_vcpu_time_info *pvti)
{
int i;
wrmsr(MSR_KVM_SYSTEM_TIME_NEW, pvti_pa | KVM_MSR_ENABLED);
for (i = 0; i < ARRAY_SIZE(test_cases); i++)
GUEST_SYNC_CLOCK(i, __pvclock_read_cycles(pvti, rdtsc()));
}
#define EXPECTED_FLAGS (KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC)
static inline void assert_flags(struct kvm_clock_data *data)
{
TEST_ASSERT((data->flags & EXPECTED_FLAGS) == EXPECTED_FLAGS,
"unexpected clock data flags: %x (want set: %x)",
data->flags, EXPECTED_FLAGS);
}
static void handle_sync(struct ucall *uc, struct kvm_clock_data *start,
struct kvm_clock_data *end)
{
uint64_t obs, exp_lo, exp_hi;
obs = uc->args[2];
exp_lo = start->clock;
exp_hi = end->clock;
assert_flags(start);
assert_flags(end);
TEST_ASSERT(exp_lo <= obs && obs <= exp_hi,
"unexpected kvm-clock value: %"PRIu64" expected range: [%"PRIu64", %"PRIu64"]",
obs, exp_lo, exp_hi);
pr_info("kvm-clock value: %"PRIu64" expected range [%"PRIu64", %"PRIu64"]\n",
obs, exp_lo, exp_hi);
}
static void handle_abort(struct ucall *uc)
{
TEST_FAIL("%s at %s:%ld", (const char *)uc->args[0],
__FILE__, uc->args[1]);
}
static void setup_clock(struct kvm_vm *vm, struct test_case *test_case)
{
struct kvm_clock_data data;
memset(&data, 0, sizeof(data));
data.clock = test_case->kvmclock_base;
if (test_case->realtime_offset) {
struct timespec ts;
int r;
data.flags |= KVM_CLOCK_REALTIME;
do {
r = clock_gettime(CLOCK_REALTIME, &ts);
if (!r)
break;
} while (errno == EINTR);
TEST_ASSERT(!r, "clock_gettime() failed: %d\n", r);
data.realtime = ts.tv_sec * NSEC_PER_SEC;
data.realtime += ts.tv_nsec;
data.realtime += test_case->realtime_offset;
}
vm_ioctl(vm, KVM_SET_CLOCK, &data);
}
static void enter_guest(struct kvm_vm *vm)
{
struct kvm_clock_data start, end;
struct kvm_run *run;
struct ucall uc;
int i, r;
run = vcpu_state(vm, VCPU_ID);
for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
setup_clock(vm, &test_cases[i]);
vm_ioctl(vm, KVM_GET_CLOCK, &start);
r = _vcpu_run(vm, VCPU_ID);
vm_ioctl(vm, KVM_GET_CLOCK, &end);
TEST_ASSERT(!r, "vcpu_run failed: %d\n", r);
TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
"unexpected exit reason: %u (%s)",
run->exit_reason, exit_reason_str(run->exit_reason));
switch (get_ucall(vm, VCPU_ID, &uc)) {
case UCALL_SYNC:
handle_sync(&uc, &start, &end);
break;
case UCALL_ABORT:
handle_abort(&uc);
return;
default:
TEST_ASSERT(0, "unhandled ucall: %ld\n", uc.cmd);
}
}
}
#define CLOCKSOURCE_PATH "/sys/devices/system/clocksource/clocksource0/current_clocksource"
static void check_clocksource(void)
{
char *clk_name;
struct stat st;
FILE *fp;
fp = fopen(CLOCKSOURCE_PATH, "r");
if (!fp) {
pr_info("failed to open clocksource file: %d; assuming TSC.\n",
errno);
return;
}
if (fstat(fileno(fp), &st)) {
pr_info("failed to stat clocksource file: %d; assuming TSC.\n",
errno);
goto out;
}
clk_name = malloc(st.st_size);
TEST_ASSERT(clk_name, "failed to allocate buffer to read file\n");
if (!fgets(clk_name, st.st_size, fp)) {
pr_info("failed to read clocksource file: %d; assuming TSC.\n",
ferror(fp));
goto out;
}
TEST_ASSERT(!strncmp(clk_name, "tsc\n", st.st_size),
"clocksource not supported: %s", clk_name);
out:
fclose(fp);
}
int main(void)
{
vm_vaddr_t pvti_gva;
vm_paddr_t pvti_gpa;
struct kvm_vm *vm;
int flags;
flags = kvm_check_cap(KVM_CAP_ADJUST_CLOCK);
if (!(flags & KVM_CLOCK_REALTIME)) {
print_skip("KVM_CLOCK_REALTIME not supported; flags: %x",
flags);
exit(KSFT_SKIP);
}
check_clocksource();
vm = vm_create_default(VCPU_ID, 0, guest_main);
pvti_gva = vm_vaddr_alloc(vm, getpagesize(), 0x10000);
pvti_gpa = addr_gva2gpa(vm, pvti_gva);
vcpu_args_set(vm, VCPU_ID, 2, pvti_gpa, pvti_gva);
enter_guest(vm);
kvm_vm_free(vm);
}
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