Commit 94c4b76b authored by Andrew Jones's avatar Andrew Jones Committed by Paolo Bonzini

KVM: selftests: Introduce steal-time test

The steal-time test confirms what is reported to the guest as stolen
time is consistent with the run_delay reported for the VCPU thread
on the host. Both x86_64 and AArch64 have the concept of steal/stolen
time so this test is introduced for both architectures.

While adding the test we ensure .gitignore has all tests listed
(it was missing s390x/resets) and that the Makefile has all tests
listed in alphabetical order (not really necessary, but it almost
was already...). We also extend the common API with a new num-guest-
pages call and a new timespec call.
Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent beca5470
/s390x/memop
/s390x/resets
/s390x/sync_regs_test
/x86_64/cr4_cpuid_sync_test
/x86_64/evmcs_test
......@@ -20,3 +21,4 @@
/demand_paging_test
/dirty_log_test
/kvm_create_max_vcpus
/steal_time
......@@ -21,28 +21,30 @@ TEST_GEN_PROGS_x86_64 += x86_64/set_memory_region_test
TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
TEST_GEN_PROGS_x86_64 += x86_64/smm_test
TEST_GEN_PROGS_x86_64 += x86_64/state_test
TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
TEST_GEN_PROGS_x86_64 += x86_64/sync_regs_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += demand_paging_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
TEST_GEN_PROGS_x86_64 += steal_time
TEST_GEN_PROGS_aarch64 += clear_dirty_log_test
TEST_GEN_PROGS_aarch64 += dirty_log_test
TEST_GEN_PROGS_aarch64 += demand_paging_test
TEST_GEN_PROGS_aarch64 += dirty_log_test
TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
TEST_GEN_PROGS_aarch64 += steal_time
TEST_GEN_PROGS_s390x = s390x/memop
TEST_GEN_PROGS_s390x += s390x/sync_regs_test
TEST_GEN_PROGS_s390x += s390x/resets
TEST_GEN_PROGS_s390x += dirty_log_test
TEST_GEN_PROGS_s390x += s390x/sync_regs_test
TEST_GEN_PROGS_s390x += demand_paging_test
TEST_GEN_PROGS_s390x += dirty_log_test
TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
......
......@@ -255,6 +255,7 @@ unsigned int vm_get_page_size(struct kvm_vm *vm);
unsigned int vm_get_page_shift(struct kvm_vm *vm);
unsigned int vm_get_max_gfn(struct kvm_vm *vm);
unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
unsigned int vm_num_host_pages(enum vm_guest_mode mode, unsigned int num_guest_pages);
unsigned int vm_num_guest_pages(enum vm_guest_mode mode, unsigned int num_host_pages);
static inline unsigned int
......
......@@ -59,5 +59,6 @@ size_t parse_size(const char *size);
int64_t timespec_to_ns(struct timespec ts);
struct timespec timespec_diff(struct timespec start, struct timespec end);
struct timespec timespec_add_ns(struct timespec ts, int64_t ns);
#endif /* SELFTEST_KVM_TEST_UTIL_H */
......@@ -1769,3 +1769,10 @@ vm_num_guest_pages(enum vm_guest_mode mode, unsigned int num_host_pages)
return vm_calc_num_pages(num_host_pages, getpageshift(),
vm_guest_mode_params[mode].page_shift, false);
}
unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size)
{
unsigned int n;
n = DIV_ROUND_UP(size, vm_guest_mode_params[mode].page_size);
return vm_adjust_num_guest_pages(mode, n);
}
......@@ -71,6 +71,21 @@ struct timespec timespec_diff(struct timespec start, struct timespec end)
return temp;
}
struct timespec timespec_add_ns(struct timespec ts, int64_t ns)
{
struct timespec res;
res.tv_sec = ts.tv_sec;
res.tv_nsec = ts.tv_nsec + ns;
if (res.tv_nsec > 1000000000UL) {
res.tv_sec += 1;
res.tv_nsec -= 1000000000UL;
}
return res;
}
void print_skip(const char *fmt, ...)
{
va_list ap;
......
// 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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