--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * steal/stolen time test
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <time.h>
+#include <sched.h>
+#include <pthread.h>
+#include <linux/kernel.h>
+#include <sys/syscall.h>
+#include <asm/kvm.h>
+#include <asm/kvm_para.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+#define NR_VCPUS 4
+#define ST_GPA_BASE (1 << 30)
+#define MIN_RUN_DELAY_NS 200000UL
+
+static void *st_gva[NR_VCPUS];
+static uint64_t guest_stolen_time[NR_VCPUS];
+
+#if defined(__x86_64__)
+
+/* steal_time must have 64-byte alignment */
+#define STEAL_TIME_SIZE ((sizeof(struct kvm_steal_time) + 63) & ~63)
+
+static void check_status(struct kvm_steal_time *st)
+{
+ GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
+ GUEST_ASSERT(READ_ONCE(st->flags) == 0);
+ GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
+}
+
+static void guest_code(int cpu)
+{
+ struct kvm_steal_time *st = st_gva[cpu];
+ uint32_t version;
+
+ GUEST_ASSERT(rdmsr(MSR_KVM_STEAL_TIME) == ((uint64_t)st_gva[cpu] | KVM_MSR_ENABLED));
+
+ memset(st, 0, sizeof(*st));
+ GUEST_SYNC(0);
+
+ check_status(st);
+ WRITE_ONCE(guest_stolen_time[cpu], st->steal);
+ version = READ_ONCE(st->version);
+ check_status(st);
+ GUEST_SYNC(1);
+
+ check_status(st);
+ GUEST_ASSERT(version < READ_ONCE(st->version));
+ WRITE_ONCE(guest_stolen_time[cpu], st->steal);
+ check_status(st);
+ GUEST_DONE();
+}
+
+static void steal_time_init(struct kvm_vm *vm)
+{
+ int i;
+
+ if (!(kvm_get_supported_cpuid_entry(KVM_CPUID_FEATURES)->eax &
+ KVM_FEATURE_STEAL_TIME)) {
+ print_skip("steal-time not supported");
+ exit(KSFT_SKIP);
+ }
+
+ for (i = 0; i < NR_VCPUS; ++i) {
+ int ret;
+
+ vcpu_set_cpuid(vm, i, kvm_get_supported_cpuid());
+
+ /* ST_GPA_BASE is identity mapped */
+ st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
+ sync_global_to_guest(vm, st_gva[i]);
+
+ ret = _vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK);
+ TEST_ASSERT(ret == 0, "Bad GPA didn't fail");
+
+ vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
+ }
+}
+
+static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]);
+ int i;
+
+ pr_info("VCPU%d:\n", vcpuid);
+ pr_info(" steal: %lld\n", st->steal);
+ pr_info(" version: %d\n", st->version);
+ pr_info(" flags: %d\n", st->flags);
+ pr_info(" preempted: %d\n", st->preempted);
+ pr_info(" u8_pad: ");
+ for (i = 0; i < 3; ++i)
+ pr_info("%d", st->u8_pad[i]);
+ pr_info("\n pad: ");
+ for (i = 0; i < 11; ++i)
+ pr_info("%d", st->pad[i]);
+ pr_info("\n");
+}
+
+#elif defined(__aarch64__)
+
+/* PV_TIME_ST must have 64-byte alignment */
+#define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63)
+
+#define SMCCC_ARCH_FEATURES 0x80000001
+#define PV_TIME_FEATURES 0xc5000020
+#define PV_TIME_ST 0xc5000021
+
+struct st_time {
+ uint32_t rev;
+ uint32_t attr;
+ uint64_t st_time;
+};
+
+static int64_t smccc(uint32_t func, uint32_t arg)
+{
+ unsigned long ret;
+
+ asm volatile(
+ "mov x0, %1\n"
+ "mov x1, %2\n"
+ "hvc #0\n"
+ "mov %0, x0\n"
+ : "=r" (ret) : "r" (func), "r" (arg) :
+ "x0", "x1", "x2", "x3");
+
+ return ret;
+}
+
+static void check_status(struct st_time *st)
+{
+ GUEST_ASSERT(READ_ONCE(st->rev) == 0);
+ GUEST_ASSERT(READ_ONCE(st->attr) == 0);
+}
+
+static void guest_code(int cpu)
+{
+ struct st_time *st;
+ int64_t status;
+
+ status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES);
+ GUEST_ASSERT(status == 0);
+ status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES);
+ GUEST_ASSERT(status == 0);
+ status = smccc(PV_TIME_FEATURES, PV_TIME_ST);
+ GUEST_ASSERT(status == 0);
+
+ status = smccc(PV_TIME_ST, 0);
+ GUEST_ASSERT(status != -1);
+ GUEST_ASSERT(status == (ulong)st_gva[cpu]);
+
+ st = (struct st_time *)status;
+ GUEST_SYNC(0);
+
+ check_status(st);
+ WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
+ GUEST_SYNC(1);
+
+ check_status(st);
+ WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
+ GUEST_DONE();
+}
+
+static void steal_time_init(struct kvm_vm *vm)
+{
+ struct kvm_device_attr dev = {
+ .group = KVM_ARM_VCPU_PVTIME_CTRL,
+ .attr = KVM_ARM_VCPU_PVTIME_IPA,
+ };
+ int i, ret;
+
+ ret = _vcpu_ioctl(vm, 0, KVM_HAS_DEVICE_ATTR, &dev);
+ if (ret != 0 && errno == ENXIO) {
+ print_skip("steal-time not supported");
+ exit(KSFT_SKIP);
+ }
+
+ for (i = 0; i < NR_VCPUS; ++i) {
+ uint64_t st_ipa;
+
+ vcpu_ioctl(vm, i, KVM_HAS_DEVICE_ATTR, &dev);
+
+ dev.addr = (uint64_t)&st_ipa;
+
+ /* ST_GPA_BASE is identity mapped */
+ st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
+ sync_global_to_guest(vm, st_gva[i]);
+
+ st_ipa = (ulong)st_gva[i] | 1;
+ ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+ TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL");
+
+ st_ipa = (ulong)st_gva[i];
+ vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+
+ ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+ TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST");
+
+ }
+}
+
+static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]);
+
+ pr_info("VCPU%d:\n", vcpuid);
+ pr_info(" rev: %d\n", st->rev);
+ pr_info(" attr: %d\n", st->attr);
+ pr_info(" st_time: %ld\n", st->st_time);
+}
+
+#endif
+
+static long get_run_delay(void)
+{
+ char path[64];
+ long val[2];
+ FILE *fp;
+
+ sprintf(path, "/proc/%ld/schedstat", syscall(SYS_gettid));
+ fp = fopen(path, "r");
+ fscanf(fp, "%ld %ld ", &val[0], &val[1]);
+ fclose(fp);
+
+ return val[1];
+}
+
+static void *do_steal_time(void *arg)
+{
+ struct timespec ts, stop;
+
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS);
+
+ while (1) {
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ if (ts.tv_sec > stop.tv_sec || ts.tv_nsec >= stop.tv_nsec)
+ break;
+ }
+
+ return NULL;
+}
+
+static void run_vcpu(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct ucall uc;
+
+ vcpu_args_set(vm, vcpuid, 1, vcpuid);
+
+ vcpu_ioctl(vm, vcpuid, KVM_RUN, NULL);
+
+ switch (get_ucall(vm, vcpuid, &uc)) {
+ case UCALL_SYNC:
+ case UCALL_DONE:
+ break;
+ case UCALL_ABORT:
+ TEST_ASSERT(false, "%s at %s:%ld", (const char *)uc.args[0],
+ __FILE__, uc.args[1]);
+ default:
+ TEST_ASSERT(false, "Unexpected exit: %s",
+ exit_reason_str(vcpu_state(vm, vcpuid)->exit_reason));
+ }
+}
+
+int main(int ac, char **av)
+{
+ struct kvm_vm *vm;
+ pthread_attr_t attr;
+ pthread_t thread;
+ cpu_set_t cpuset;
+ unsigned int gpages;
+ long stolen_time;
+ long run_delay;
+ bool verbose;
+ int i;
+
+ verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));
+
+ /* Set CPU affinity so we can force preemption of the VCPU */
+ CPU_ZERO(&cpuset);
+ CPU_SET(0, &cpuset);
+ pthread_attr_init(&attr);
+ pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
+ pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
+
+ /* Create a one VCPU guest and an identity mapped memslot for the steal time structure */
+ vm = vm_create_default(0, 0, guest_code);
+ gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS);
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);
+ virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages, 0);
+ ucall_init(vm, NULL);
+
+ /* Add the rest of the VCPUs */
+ for (i = 1; i < NR_VCPUS; ++i)
+ vm_vcpu_add_default(vm, i, guest_code);
+
+ steal_time_init(vm);
+
+ /* Run test on each VCPU */
+ for (i = 0; i < NR_VCPUS; ++i) {
+ /* First VCPU run initializes steal-time */
+ run_vcpu(vm, i);
+
+ /* Second VCPU run, expect guest stolen time to be <= run_delay */
+ run_vcpu(vm, i);
+ sync_global_from_guest(vm, guest_stolen_time[i]);
+ stolen_time = guest_stolen_time[i];
+ run_delay = get_run_delay();
+ TEST_ASSERT(stolen_time <= run_delay,
+ "Expected stolen time <= %ld, got %ld",
+ run_delay, stolen_time);
+
+ /* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */
+ run_delay = get_run_delay();
+ pthread_create(&thread, &attr, do_steal_time, NULL);
+ do
+ pthread_yield();
+ while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
+ pthread_join(thread, NULL);
+ run_delay = get_run_delay() - run_delay;
+ TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
+ "Expected run_delay >= %ld, got %ld",
+ MIN_RUN_DELAY_NS, run_delay);
+
+ /* Run VCPU again to confirm stolen time is consistent with run_delay */
+ run_vcpu(vm, i);
+ sync_global_from_guest(vm, guest_stolen_time[i]);
+ stolen_time = guest_stolen_time[i] - stolen_time;
+ TEST_ASSERT(stolen_time >= run_delay,
+ "Expected stolen time >= %ld, got %ld",
+ run_delay, stolen_time);
+
+ if (verbose) {
+ pr_info("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld", i,
+ guest_stolen_time[i], stolen_time);
+ if (stolen_time == run_delay)
+ pr_info(" (BONUS: guest test-stolen-time even exactly matches test-run_delay)");
+ pr_info("\n");
+ steal_time_dump(vm, i);
+ }
+ }
+
+ return 0;
+}
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