// 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 u32 test_get_pcpu(void){	u32 pcpu;	unsigned int nproc_conf;	cpu_set_t online_cpuset; 	nproc_conf = get_nprocs_conf();	kvm_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;	u32 new_pcpu = test_get_pcpu(); 	pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu); 	ret = __pin_task_to_cpu(pt_vcpu_run[vcpu_idx], new_pcpu); 	/* 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; 	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++)		kvm_pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run,				   (void *)(unsigned long)i); 	/* Spawn a thread to control the vCPU migrations */	if (test_args.migration_freq_ms) {		srand(time(NULL)); 		kvm_pthread_create(&pt_vcpu_migration, NULL, test_vcpu_migration, NULL);	} 	for (i = 0; i < test_args.nr_vcpus; i++)		kvm_pthread_join(pt_vcpu_run[i], NULL); 	if (test_args.migration_freq_ms)		kvm_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;}