On Fri, Jul 16, 2021 at 09:26:22PM +0000, Oliver Upton wrote: > Add a selftest for the new KVM clock UAPI that was introduced. Ensure > that the KVM clock is consistent between userspace and the guest, and > that the difference in realtime will only ever cause the KVM clock to > advance forward. > > Signed-off-by: Oliver Upton <[email protected]> > --- > tools/testing/selftests/kvm/.gitignore | 1 + > tools/testing/selftests/kvm/Makefile | 1 + > .../testing/selftests/kvm/include/kvm_util.h | 2 + > .../selftests/kvm/x86_64/kvm_clock_test.c | 210 ++++++++++++++++++ > 4 files changed, 214 insertions(+) > create mode 100644 tools/testing/selftests/kvm/x86_64/kvm_clock_test.c > > diff --git a/tools/testing/selftests/kvm/.gitignore > b/tools/testing/selftests/kvm/.gitignore > index 06a351b4f93b..d0877d01e771 100644 > --- a/tools/testing/selftests/kvm/.gitignore > +++ b/tools/testing/selftests/kvm/.gitignore > @@ -11,6 +11,7 @@ > /x86_64/emulator_error_test > /x86_64/get_cpuid_test > /x86_64/get_msr_index_features > +/x86_64/kvm_clock_test > /x86_64/kvm_pv_test > /x86_64/hyperv_clock > /x86_64/hyperv_cpuid > diff --git a/tools/testing/selftests/kvm/Makefile > b/tools/testing/selftests/kvm/Makefile > index b853be2ae3c6..f7e24f334c6e 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -46,6 +46,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/get_cpuid_test > TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock > TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid > TEST_GEN_PROGS_x86_64 += x86_64/hyperv_features > +TEST_GEN_PROGS_x86_64 += x86_64/kvm_clock_test > TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_test > TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test > TEST_GEN_PROGS_x86_64 += x86_64/mmu_role_test > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h > b/tools/testing/selftests/kvm/include/kvm_util.h > index 010b59b13917..a8ac5d52e17b 100644 > --- a/tools/testing/selftests/kvm/include/kvm_util.h > +++ b/tools/testing/selftests/kvm/include/kvm_util.h > @@ -19,6 +19,8 @@ > #define KVM_DEV_PATH "/dev/kvm" > #define KVM_MAX_VCPUS 512 > > +#define NSEC_PER_SEC 1000000000L > + > /* > * Callers of kvm_util only have an incomplete/opaque description of the > * structure kvm_util is using to maintain the state of a VM. > diff --git a/tools/testing/selftests/kvm/x86_64/kvm_clock_test.c > b/tools/testing/selftests/kvm/x86_64/kvm_clock_test.c > new file mode 100644 > index 000000000000..34c48f2dde54 > --- /dev/null > +++ b/tools/testing/selftests/kvm/x86_64/kvm_clock_test.c > @@ -0,0 +1,210 @@ > +// 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())); > + } > + > + GUEST_DONE(); > +} > + > +#define EXPECTED_FLAGS (KVM_CLOCK_REAL_TIME | 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_REAL_TIME; > + 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; > + case UCALL_DONE: > + return; > + } > + } > +} > + > +#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) > +{ > + struct kvm_cpuid2 *best; > + 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_REAL_TIME)) { > + print_skip("KVM_CLOCK_REAL_TIME not supported; flags: %x", > + flags); > + exit(KSFT_SKIP); > + } > + > + check_clocksource(); > + > + vm = vm_create_default(VCPU_ID, 0, guest_main); > + > + best = kvm_get_supported_cpuid(); > + vcpu_set_cpuid(vm, VCPU_ID, best);
Default vm types (which use default vcpu types) will already set cpuids like this for x86. See the bottom of lib/x86_64/processor.c:vm_vcpu_add_default Thanks, drew > + > + 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); > +} > -- > 2.32.0.402.g57bb445576-goog > > _______________________________________________ > kvmarm mailing list > [email protected] > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm > _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
