From 1838b06bf01ac2b1b9ea808aa5962d5324b4da8f Mon Sep 17 00:00:00 2001 From: Ignacio Alvarado Date: Sat, 13 Feb 2021 00:14:52 +0000 Subject: selftests: kvm: add hardware_disable test This test launches 512 VMs in serial and kills them after a random amount of time. The test was original written to exercise KVM user notifiers in the context of1650b4ebc99d: - KVM: Disable irq while unregistering user notifier - https://lore.kernel.org/kvm/CACXrx53vkO=HKfwWwk+fVpvxcNjPrYmtDZ10qWxFvVX_PTGp3g@mail.gmail.com/ Recently, this test piqued my interest because it proved useful to for AMD SNP in exercising the "in-use" pages, described in APM section 15.36.12, "Running SNP-Active Virtual Machines". Signed-off-by: Ignacio Alvarado Signed-off-by: Marc Orr Message-Id: <20210213001452.1719001-1-marcorr@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../testing/selftests/kvm/hardware_disable_test.c | 165 +++++++++++++++++++++ 3 files changed, 167 insertions(+) create mode 100644 tools/testing/selftests/kvm/hardware_disable_test.c (limited to 'tools') diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 3a84394829ea..32b87cc77c8e 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -33,6 +33,7 @@ /demand_paging_test /dirty_log_test /dirty_log_perf_test +/hardware_disable_test /kvm_create_max_vcpus /memslot_modification_stress_test /set_memory_region_test diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 8c8eda429576..a6d61f451f88 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -67,6 +67,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/xen_vmcall_test TEST_GEN_PROGS_x86_64 += demand_paging_test TEST_GEN_PROGS_x86_64 += dirty_log_test TEST_GEN_PROGS_x86_64 += dirty_log_perf_test +TEST_GEN_PROGS_x86_64 += hardware_disable_test TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus TEST_GEN_PROGS_x86_64 += memslot_modification_stress_test TEST_GEN_PROGS_x86_64 += set_memory_region_test diff --git a/tools/testing/selftests/kvm/hardware_disable_test.c b/tools/testing/selftests/kvm/hardware_disable_test.c new file mode 100644 index 000000000000..2f2eeb8a1d86 --- /dev/null +++ b/tools/testing/selftests/kvm/hardware_disable_test.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This test is intended to reproduce a crash that happens when + * kvm_arch_hardware_disable is called and it attempts to unregister the user + * return notifiers. + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "kvm_util.h" + +#define VCPU_NUM 4 +#define SLEEPING_THREAD_NUM (1 << 4) +#define FORK_NUM (1ULL << 9) +#define DELAY_US_MAX 2000 +#define GUEST_CODE_PIO_PORT 4 + +sem_t *sem; + +/* Arguments for the pthreads */ +struct payload { + struct kvm_vm *vm; + uint32_t index; +}; + +static void guest_code(void) +{ + for (;;) + ; /* Some busy work */ + printf("Should not be reached.\n"); +} + +static void *run_vcpu(void *arg) +{ + struct payload *payload = (struct payload *)arg; + struct kvm_run *state = vcpu_state(payload->vm, payload->index); + + vcpu_run(payload->vm, payload->index); + + TEST_ASSERT(false, "%s: exited with reason %d: %s\n", + __func__, state->exit_reason, + exit_reason_str(state->exit_reason)); + pthread_exit(NULL); +} + +static void *sleeping_thread(void *arg) +{ + int fd; + + while (true) { + fd = open("/dev/null", O_RDWR); + close(fd); + } + TEST_ASSERT(false, "%s: exited\n", __func__); + pthread_exit(NULL); +} + +static inline void check_create_thread(pthread_t *thread, pthread_attr_t *attr, + void *(*f)(void *), void *arg) +{ + int r; + + r = pthread_create(thread, attr, f, arg); + TEST_ASSERT(r == 0, "%s: failed to create thread", __func__); +} + +static inline void check_set_affinity(pthread_t thread, cpu_set_t *cpu_set) +{ + int r; + + r = pthread_setaffinity_np(thread, sizeof(cpu_set_t), cpu_set); + TEST_ASSERT(r == 0, "%s: failed set affinity", __func__); +} + +static inline void check_join(pthread_t thread, void **retval) +{ + int r; + + r = pthread_join(thread, retval); + TEST_ASSERT(r == 0, "%s: failed to join thread", __func__); +} + +static void run_test(uint32_t run) +{ + struct kvm_vm *vm; + cpu_set_t cpu_set; + pthread_t threads[VCPU_NUM]; + pthread_t throw_away; + struct payload payloads[VCPU_NUM]; + void *b; + uint32_t i, j; + + CPU_ZERO(&cpu_set); + for (i = 0; i < VCPU_NUM; i++) + CPU_SET(i, &cpu_set); + + vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR); + kvm_vm_elf_load(vm, program_invocation_name, 0, 0); + vm_create_irqchip(vm); + + fprintf(stderr, "%s: [%d] start vcpus\n", __func__, run); + for (i = 0; i < VCPU_NUM; ++i) { + vm_vcpu_add_default(vm, i, guest_code); + payloads[i].vm = vm; + payloads[i].index = i; + + check_create_thread(&threads[i], NULL, run_vcpu, + (void *)&payloads[i]); + check_set_affinity(threads[i], &cpu_set); + + for (j = 0; j < SLEEPING_THREAD_NUM; ++j) { + check_create_thread(&throw_away, NULL, sleeping_thread, + (void *)NULL); + check_set_affinity(throw_away, &cpu_set); + } + } + fprintf(stderr, "%s: [%d] all threads launched\n", __func__, run); + sem_post(sem); + for (i = 0; i < VCPU_NUM; ++i) + check_join(threads[i], &b); + /* Should not be reached */ + TEST_ASSERT(false, "%s: [%d] child escaped the ninja\n", __func__, run); +} + +int main(int argc, char **argv) +{ + uint32_t i; + int s, r; + pid_t pid; + + sem = sem_open("vm_sem", O_CREAT | O_EXCL, 0644, 0); + sem_unlink("vm_sem"); + + for (i = 0; i < FORK_NUM; ++i) { + pid = fork(); + TEST_ASSERT(pid >= 0, "%s: unable to fork", __func__); + if (pid == 0) + run_test(i); /* This function always exits */ + + fprintf(stderr, "%s: [%d] waiting semaphore\n", __func__, i); + sem_wait(sem); + r = (rand() % DELAY_US_MAX) + 1; + fprintf(stderr, "%s: [%d] waiting %dus\n", __func__, i, r); + usleep(r); + r = waitpid(pid, &s, WNOHANG); + TEST_ASSERT(r != pid, + "%s: [%d] child exited unexpectedly status: [%d]", + __func__, i, s); + fprintf(stderr, "%s: [%d] killing child\n", __func__, i); + kill(pid, SIGKILL); + } + + sem_destroy(sem); + exit(0); +} -- cgit v1.2.3 From bcd22e145b9a65dd603c7b3d8079e948922787e4 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 15 Feb 2021 11:42:01 -0500 Subject: selftests: kvm: avoid uninitialized variable warning The variable in practice will never be uninitialized, because the loop will always go through at least one iteration. In case it would not, make vcpu_get_cpuid report an assertion failure. Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index de0c76177d02..a8906e60a108 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -720,7 +720,8 @@ struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vm *vm, uint32_t vcpuid) { struct vcpu *vcpu = vcpu_find(vm, vcpuid); struct kvm_cpuid2 *cpuid; - int rc, max_ent; + int max_ent; + int rc = -1; TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid); -- cgit v1.2.3