--- /dev/null
+// 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);
+}
projects / linux.git / commitdiff