On Fri, Jul 16, 2021 at 09:26:24PM +0000, Oliver Upton wrote: > Introduce a KVM selftest to verify that userspace manipulation of the > TSC (via the new vCPU attribute) results in the correct behavior within > the guest. > > Signed-off-by: Oliver Upton <[email protected]> > --- > tools/testing/selftests/kvm/.gitignore | 1 + > tools/testing/selftests/kvm/Makefile | 1 + > .../kvm/system_counter_offset_test.c | 133 ++++++++++++++++++ > 3 files changed, 135 insertions(+) > create mode 100644 tools/testing/selftests/kvm/system_counter_offset_test.c > > diff --git a/tools/testing/selftests/kvm/.gitignore > b/tools/testing/selftests/kvm/.gitignore > index d0877d01e771..2752813d5090 100644 > --- a/tools/testing/selftests/kvm/.gitignore > +++ b/tools/testing/selftests/kvm/.gitignore > @@ -50,3 +50,4 @@ > /set_memory_region_test > /steal_time > /kvm_binary_stats_test > +/system_counter_offset_test > diff --git a/tools/testing/selftests/kvm/Makefile > b/tools/testing/selftests/kvm/Makefile > index f7e24f334c6e..7bf2e5fb1d5a 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -83,6 +83,7 @@ TEST_GEN_PROGS_x86_64 += memslot_perf_test > TEST_GEN_PROGS_x86_64 += set_memory_region_test > TEST_GEN_PROGS_x86_64 += steal_time > TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test > +TEST_GEN_PROGS_x86_64 += system_counter_offset_test > > TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions > TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list > diff --git a/tools/testing/selftests/kvm/system_counter_offset_test.c > b/tools/testing/selftests/kvm/system_counter_offset_test.c > new file mode 100644 > index 000000000000..7e9015770759 > --- /dev/null > +++ b/tools/testing/selftests/kvm/system_counter_offset_test.c > @@ -0,0 +1,133 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2021, Google LLC. > + * > + * Tests for adjusting the system counter from userspace > + */ > +#include <asm/kvm_para.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 > + > +#ifdef __x86_64__ > + > +struct test_case { > + uint64_t tsc_offset; > +}; > + > +static struct test_case test_cases[] = { > + { 0 }, > + { 180 * NSEC_PER_SEC }, > + { -180 * NSEC_PER_SEC }, > +}; > + > +static void check_preconditions(struct kvm_vm *vm) > +{ > + if (!_vcpu_has_device_attr(vm, VCPU_ID, KVM_VCPU_TSC_CTRL, > KVM_VCPU_TSC_OFFSET)) > + return; > + > + print_skip("KVM_VCPU_TSC_OFFSET not supported; skipping test"); > + exit(KSFT_SKIP); > +} > + > +static void setup_system_counter(struct kvm_vm *vm, struct test_case *test) > +{ > + vcpu_access_device_attr(vm, VCPU_ID, KVM_VCPU_TSC_CTRL, > + KVM_VCPU_TSC_OFFSET, &test->tsc_offset, true); > +} > + > +static uint64_t guest_read_system_counter(struct test_case *test) > +{ > + return rdtsc(); > +} > + > +static uint64_t host_read_guest_system_counter(struct test_case *test) > +{ > + return rdtsc() + test->tsc_offset; > +} > + > +#else /* __x86_64__ */ > + > +#error test not implemented for this architecture! > + > +#endif > + > +#define GUEST_SYNC_CLOCK(__stage, __val) \ > + GUEST_SYNC_ARGS(__stage, __val, 0, 0, 0) > + > +static void guest_main(void) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(test_cases); i++) { > + struct test_case *test = &test_cases[i]; > + > + GUEST_SYNC_CLOCK(i, guest_read_system_counter(test)); > + } > + > + GUEST_DONE(); > +} > + > +static void handle_sync(struct ucall *uc, uint64_t start, uint64_t end) > +{ > + uint64_t obs = uc->args[2]; > + > + TEST_ASSERT(start <= obs && obs <= end, > + "unexpected system counter value: %"PRIu64" expected range: > [%"PRIu64", %"PRIu64"]", > + obs, start, end); > + > + pr_info("system counter value: %"PRIu64" expected range [%"PRIu64", > %"PRIu64"]\n", > + obs, start, end); > +} > + > +static void handle_abort(struct ucall *uc) > +{ > + TEST_FAIL("%s at %s:%ld", (const char *)uc->args[0], > + __FILE__, uc->args[1]); > +} > + > +static void enter_guest(struct kvm_vm *vm) > +{ > + uint64_t start, end; > + struct ucall uc; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(test_cases); i++) { > + struct test_case *test = &test_cases[i]; > + > + setup_system_counter(vm, test); > + start = host_read_guest_system_counter(test); > + vcpu_run(vm, VCPU_ID); > + end = host_read_guest_system_counter(test); > + > + 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; > + } > + } > +} > + > +int main(void) > +{ > + struct kvm_vm *vm; > + > + vm = vm_create_default(VCPU_ID, 0, guest_main); > + check_preconditions(vm); > + ucall_init(vm, NULL); > + > + 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 >
Reviewed-by: Andrew Jones <[email protected]> _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
