// SPDX-License-Identifier: GPL-2.0-only
/*
* arch_timer.c - Tests the arch timer IRQ functionality
*
* The guest's main thread configures the timer interrupt and waits
* for it to fire, with a timeout equal to the timer period.
* It asserts that the timeout doesn't exceed the timer period plus
* a user configurable error margin(default to 100us)
*
* On the other hand, upon receipt of an interrupt, the guest's interrupt
* handler validates the interrupt by checking if the architectural state
* is in compliance with the specifications.
*
* The test provides command-line options to configure the timer's
* period (-p), number of vCPUs (-n), iterations per stage (-i) and timer
* interrupt arrival error margin (-e). To stress-test the timer stack
* even more, an option to migrate the vCPUs across pCPUs (-m), at a
* particular rate, is also provided.
*
* Copyright (c) 2021, Google LLC.
*/
#include <stdlib.h>
#include <pthread.h>
#include <linux/sizes.h>
#include <linux/bitmap.h>
#include <sys/sysinfo.h>
#include "timer_test.h"
#include "ucall_common.h"
struct test_args test_args = {
.nr_vcpus = NR_VCPUS_DEF,
.nr_iter = NR_TEST_ITERS_DEF,
.timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
.migration_freq_ms = TIMER_TEST_MIGRATION_FREQ_MS,
.timer_err_margin_us = TIMER_TEST_ERR_MARGIN_US,
.reserved = 1,
};
struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];
static unsigned long *vcpu_done_map;
static pthread_mutex_t vcpu_done_map_lock;
static void *test_vcpu_run(void *arg)
{
unsigned int vcpu_idx = (unsigned long)arg;
struct ucall uc;
struct kvm_vcpu *vcpu = vcpus[vcpu_idx];
struct kvm_vm *vm = vcpu->vm;
struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpu_idx];
vcpu_run(vcpu);
/* Currently, any exit from guest is an indication of completion */
pthread_mutex_lock(&vcpu_done_map_lock);
__set_bit(vcpu_idx, vcpu_done_map);
pthread_mutex_unlock(&vcpu_done_map_lock);
switch (get_ucall(vcpu, &uc)) {
case UCALL_SYNC:
case UCALL_DONE:
break;
case UCALL_ABORT:
sync_global_from_guest(vm, *shared_data);
fprintf(stderr, "Guest assert failed, vcpu %u; stage; %u; iter: %u\n",
vcpu_idx, shared_data->guest_stage, shared_data->nr_iter);
REPORT_GUEST_ASSERT(uc);
break;
default:
TEST_FAIL("Unexpected guest exit");
}
pr_info("PASS(vCPU-%d).\n", vcpu_idx);
return NULL;
}
static uint32_t test_get_pcpu(void)
{
uint32_t pcpu;
unsigned int nproc_conf;
cpu_set_t online_cpuset;
nproc_conf = get_nprocs_conf();
sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset);
/* Randomly find an available pCPU to place a vCPU on */
do {
pcpu = rand() % nproc_conf;
} while (!CPU_ISSET(pcpu, &online_cpuset));
return pcpu;
}
static int test_migrate_vcpu(unsigned int vcpu_idx)
{
int ret;
cpu_set_t cpuset;
uint32_t new_pcpu = test_get_pcpu();
CPU_ZERO(&cpuset);
CPU_SET(new_pcpu, &cpuset);
pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu);
ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx],
sizeof(cpuset), &cpuset);
/* Allow the error where the vCPU thread is already finished */
TEST_ASSERT(ret == 0 || ret == ESRCH,
"Failed to migrate the vCPU:%u to pCPU: %u; ret: %d",
vcpu_idx, new_pcpu, ret);
return ret;
}
static void *test_vcpu_migration(void *arg)
{
unsigned int i, n_done;
bool vcpu_done;
do {
usleep(msecs_to_usecs(test_args.migration_freq_ms));
for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) {
pthread_mutex_lock(&vcpu_done_map_lock);
vcpu_done = test_bit(i, vcpu_done_map);
pthread_mutex_unlock(&vcpu_done_map_lock);
if (vcpu_done) {
n_done++;
continue;
}
test_migrate_vcpu(i);
}
} while (test_args.nr_vcpus != n_done);
return NULL;
}
static void test_run(struct kvm_vm *vm)
{
pthread_t pt_vcpu_migration;
unsigned int i;
int ret;
pthread_mutex_init(&vcpu_done_map_lock, NULL);
vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus);
TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap");
for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++) {
ret = pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run,
(void *)(unsigned long)i);
TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread", i);
}
/* Spawn a thread to control the vCPU migrations */
if (test_args.migration_freq_ms) {
srand(time(NULL));
ret = pthread_create(&pt_vcpu_migration, NULL,
test_vcpu_migration, NULL);
TEST_ASSERT(!ret, "Failed to create the migration pthread");
}
for (i = 0; i < test_args.nr_vcpus; i++)
pthread_join(pt_vcpu_run[i], NULL);
if (test_args.migration_freq_ms)
pthread_join(pt_vcpu_migration, NULL);
bitmap_free(vcpu_done_map);
}
static void test_print_help(char *name)
{
pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n"
"\t\t [-m migration_freq_ms] [-o counter_offset]\n"
"\t\t [-e timer_err_margin_us]\n", name);
pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
NR_VCPUS_DEF, KVM_MAX_VCPUS);
pr_info("\t-i: Number of iterations per stage (default: %u)\n",
NR_TEST_ITERS_DEF);
pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
TIMER_TEST_PERIOD_MS_DEF);
pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
TIMER_TEST_MIGRATION_FREQ_MS);
pr_info("\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n");
pr_info("\t-e: Interrupt arrival error margin (in us) of the guest timer (default: %u)\n",
TIMER_TEST_ERR_MARGIN_US);
pr_info("\t-h: print this help screen\n");
}
static bool parse_args(int argc, char *argv[])
{
int opt;
while ((opt = getopt(argc, argv, "hn:i:p:m:o:e:")) != -1) {
switch (opt) {
case 'n':
test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg);
if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
pr_info("Max allowed vCPUs: %u\n",
KVM_MAX_VCPUS);
goto err;
}
break;
case 'i':
test_args.nr_iter = atoi_positive("Number of iterations", optarg);
break;
case 'p':
test_args.timer_period_ms = atoi_positive("Periodicity", optarg);
break;
case 'm':
test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
break;
case 'e':
test_args.timer_err_margin_us = atoi_non_negative("Error Margin", optarg);
break;
case 'o':
test_args.counter_offset = strtol(optarg, NULL, 0);
test_args.reserved = 0;
break;
case 'h':
default:
goto err;
}
}
return true;
err:
test_print_help(argv[0]);
return false;
}
int main(int argc, char *argv[])
{
struct kvm_vm *vm;
if (!parse_args(argc, argv))
exit(KSFT_SKIP);
__TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2,
"At least two physical CPUs needed for vCPU migration");
vm = test_vm_create();
test_run(vm);
test_vm_cleanup(vm);
return 0;
}
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