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|
// SPDX-License-Identifier: GPL-2.0-only
/*
* arch_timer.c - Tests the aarch64 timer IRQ functionality
*
* The test validates both the virtual and physical timer IRQs using
* CVAL and TVAL registers. This consitutes the four stages in the test.
* The guest's main thread configures the timer interrupt for a stage
* 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.
*
* 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), and iterations per stage (-i).
* 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.
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <pthread.h>
#include <linux/kvm.h>
#include <linux/sizes.h>
#include <linux/bitmap.h>
#include <sys/sysinfo.h>
#include "kvm_util.h"
#include "processor.h"
#include "delay.h"
#include "arch_timer.h"
#include "gic.h"
#include "vgic.h"
#define NR_VCPUS_DEF 4
#define NR_TEST_ITERS_DEF 5
#define TIMER_TEST_PERIOD_MS_DEF 10
#define TIMER_TEST_ERR_MARGIN_US 100
#define TIMER_TEST_MIGRATION_FREQ_MS 2
struct test_args {
int nr_vcpus;
int nr_iter;
int timer_period_ms;
int migration_freq_ms;
};
static 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,
};
#define msecs_to_usecs(msec) ((msec) * 1000LL)
#define GICD_BASE_GPA 0x8000000ULL
#define GICR_BASE_GPA 0x80A0000ULL
enum guest_stage {
GUEST_STAGE_VTIMER_CVAL = 1,
GUEST_STAGE_VTIMER_TVAL,
GUEST_STAGE_PTIMER_CVAL,
GUEST_STAGE_PTIMER_TVAL,
GUEST_STAGE_MAX,
};
/* Shared variables between host and guest */
struct test_vcpu_shared_data {
int nr_iter;
enum guest_stage guest_stage;
uint64_t xcnt;
};
static struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];
static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
static int vtimer_irq, ptimer_irq;
static unsigned long *vcpu_done_map;
static pthread_mutex_t vcpu_done_map_lock;
static void
guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
{
switch (shared_data->guest_stage) {
case GUEST_STAGE_VTIMER_CVAL:
timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
shared_data->xcnt = timer_get_cntct(VIRTUAL);
timer_set_ctl(VIRTUAL, CTL_ENABLE);
break;
case GUEST_STAGE_VTIMER_TVAL:
timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
shared_data->xcnt = timer_get_cntct(VIRTUAL);
timer_set_ctl(VIRTUAL, CTL_ENABLE);
break;
case GUEST_STAGE_PTIMER_CVAL:
timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
shared_data->xcnt = timer_get_cntct(PHYSICAL);
timer_set_ctl(PHYSICAL, CTL_ENABLE);
break;
case GUEST_STAGE_PTIMER_TVAL:
timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
shared_data->xcnt = timer_get_cntct(PHYSICAL);
timer_set_ctl(PHYSICAL, CTL_ENABLE);
break;
default:
GUEST_ASSERT(0);
}
}
static void guest_validate_irq(unsigned int intid,
struct test_vcpu_shared_data *shared_data)
{
enum guest_stage stage = shared_data->guest_stage;
uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
unsigned long xctl = 0;
unsigned int timer_irq = 0;
if (stage == GUEST_STAGE_VTIMER_CVAL ||
stage == GUEST_STAGE_VTIMER_TVAL) {
xctl = timer_get_ctl(VIRTUAL);
timer_set_ctl(VIRTUAL, CTL_IMASK);
xcnt = timer_get_cntct(VIRTUAL);
cval = timer_get_cval(VIRTUAL);
timer_irq = vtimer_irq;
} else if (stage == GUEST_STAGE_PTIMER_CVAL ||
stage == GUEST_STAGE_PTIMER_TVAL) {
xctl = timer_get_ctl(PHYSICAL);
timer_set_ctl(PHYSICAL, CTL_IMASK);
xcnt = timer_get_cntct(PHYSICAL);
cval = timer_get_cval(PHYSICAL);
timer_irq = ptimer_irq;
} else {
GUEST_ASSERT(0);
}
xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
/* Make sure we are dealing with the correct timer IRQ */
GUEST_ASSERT_2(intid == timer_irq, intid, timer_irq);
/* Basic 'timer condition met' check */
GUEST_ASSERT_3(xcnt >= cval, xcnt, cval, xcnt_diff_us);
GUEST_ASSERT_1(xctl & CTL_ISTATUS, xctl);
}
static void guest_irq_handler(struct ex_regs *regs)
{
unsigned int intid = gic_get_and_ack_irq();
uint32_t cpu = guest_get_vcpuid();
struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
guest_validate_irq(intid, shared_data);
WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
gic_set_eoi(intid);
}
static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
enum guest_stage stage)
{
uint32_t irq_iter, config_iter;
shared_data->guest_stage = stage;
shared_data->nr_iter = 0;
for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
/* Setup the next interrupt */
guest_configure_timer_action(shared_data);
/* Setup a timeout for the interrupt to arrive */
udelay(msecs_to_usecs(test_args.timer_period_ms) +
TIMER_TEST_ERR_MARGIN_US);
irq_iter = READ_ONCE(shared_data->nr_iter);
GUEST_ASSERT_2(config_iter + 1 == irq_iter,
config_iter + 1, irq_iter);
}
}
static void guest_code(void)
{
uint32_t cpu = guest_get_vcpuid();
struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
local_irq_disable();
gic_init(GIC_V3, test_args.nr_vcpus,
(void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
timer_set_ctl(VIRTUAL, CTL_IMASK);
timer_set_ctl(PHYSICAL, CTL_IMASK);
gic_irq_enable(vtimer_irq);
gic_irq_enable(ptimer_irq);
local_irq_enable();
guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
GUEST_DONE();
}
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);
REPORT_GUEST_ASSERT_N(uc, "values: %lu, %lu; %lu, vcpu %u; stage; %u; iter: %u",
GUEST_ASSERT_ARG(uc, 0),
GUEST_ASSERT_ARG(uc, 1),
GUEST_ASSERT_ARG(uc, 2),
vcpu_idx,
shared_data->guest_stage,
shared_data->nr_iter);
break;
default:
TEST_FAIL("Unexpected guest exit\n");
}
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\n",
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\n");
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\n", 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\n");
}
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_init_timer_irq(struct kvm_vm *vm)
{
/* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
KVM_ARM_VCPU_TIMER_IRQ_PTIMER, &ptimer_irq);
vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
KVM_ARM_VCPU_TIMER_IRQ_VTIMER, &vtimer_irq);
sync_global_to_guest(vm, ptimer_irq);
sync_global_to_guest(vm, vtimer_irq);
pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
}
static int gic_fd;
static struct kvm_vm *test_vm_create(void)
{
struct kvm_vm *vm;
unsigned int i;
int nr_vcpus = test_args.nr_vcpus;
vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
vm_init_descriptor_tables(vm);
vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
for (i = 0; i < nr_vcpus; i++)
vcpu_init_descriptor_tables(vcpus[i]);
test_init_timer_irq(vm);
gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
__TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
/* Make all the test's cmdline args visible to the guest */
sync_global_to_guest(vm, test_args);
return vm;
}
static void test_vm_cleanup(struct kvm_vm *vm)
{
close(gic_fd);
kvm_vm_free(vm);
}
static void test_print_help(char *name)
{
pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\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-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:")) != -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 '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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