tools/testing/selftests/kvm/dirty_log_perf_test.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * KVM dirty page logging performance test
  *
  * Based on dirty_log_test.c
  *
  * Copyright (C) 2018, Red Hat, Inc.
  * Copyright (C) 2020, Google, Inc.
  */

 #define _GNU_SOURCE /* for program_invocation_name */

 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <time.h>
 #include <pthread.h>
 #include <linux/bitmap.h>
 #include <linux/bitops.h>

 #include "kvm_util.h"
 #include "perf_test_util.h"
 #include "processor.h"
 #include "test_util.h"

 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
 #define TEST_HOST_LOOP_N		2UL

 /* Host variables */
 static bool host_quit;
 static uint64_t iteration;
 static uint64_t vcpu_last_completed_iteration[MAX_VCPUS];

 static void *vcpu_worker(void *data)
 {
 	int ret;
 	struct kvm_vm *vm = perf_test_args.vm;
 	uint64_t pages_count = 0;
 	struct kvm_run *run;
 	struct timespec start;
 	struct timespec ts_diff;
 	struct timespec total = (struct timespec){0};
 	struct timespec avg;
 	struct vcpu_args *vcpu_args = (struct vcpu_args *)data;
 	int vcpu_id = vcpu_args->vcpu_id;

 	vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
 	run = vcpu_state(vm, vcpu_id);

 	while (!READ_ONCE(host_quit)) {
 		uint64_t current_iteration = READ_ONCE(iteration);

 		clock_gettime(CLOCK_MONOTONIC, &start);
 		ret = _vcpu_run(vm, vcpu_id);
 		ts_diff = timespec_diff_now(start);

 		TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
 		TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
 			    "Invalid guest sync status: exit_reason=%s\n",
 			    exit_reason_str(run->exit_reason));

 		pr_debug("Got sync event from vCPU %d\n", vcpu_id);
 		vcpu_last_completed_iteration[vcpu_id] = current_iteration;
 		pr_debug("vCPU %d updated last completed iteration to %lu\n",
 			 vcpu_id, vcpu_last_completed_iteration[vcpu_id]);

 		if (current_iteration) {
 			pages_count += vcpu_args->pages;
 			total = timespec_add(total, ts_diff);
 			pr_debug("vCPU %d iteration %lu dirty memory time: %ld.%.9lds\n",
 				vcpu_id, current_iteration, ts_diff.tv_sec,
 				ts_diff.tv_nsec);
 		} else {
 			pr_debug("vCPU %d iteration %lu populate memory time: %ld.%.9lds\n",
 				vcpu_id, current_iteration, ts_diff.tv_sec,
 				ts_diff.tv_nsec);
 		}

 		while (current_iteration == READ_ONCE(iteration) &&
 		       !READ_ONCE(host_quit)) {}
 	}

 	avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
 	pr_debug("\nvCPU %d dirtied 0x%lx pages over %lu iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 		vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
 		total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);

 	return NULL;
 }

 #ifdef USE_CLEAR_DIRTY_LOG
 static u64 dirty_log_manual_caps;
 #endif

 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
 		     uint64_t phys_offset, int wr_fract)
 {
 	pthread_t *vcpu_threads;
 	struct kvm_vm *vm;
 	unsigned long *bmap;
 	uint64_t guest_num_pages;
 	uint64_t host_num_pages;
 	int vcpu_id;
 	struct timespec start;
 	struct timespec ts_diff;
 	struct timespec get_dirty_log_total = (struct timespec){0};
 	struct timespec vcpu_dirty_total = (struct timespec){0};
 	struct timespec avg;
 #ifdef USE_CLEAR_DIRTY_LOG
 	struct kvm_enable_cap cap = {};
 	struct timespec clear_dirty_log_total = (struct timespec){0};
 #endif

 	vm = create_vm(mode, nr_vcpus, guest_percpu_mem_size);

 	perf_test_args.wr_fract = wr_fract;

 	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
 	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 	host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 	bmap = bitmap_alloc(host_num_pages);

 #ifdef USE_CLEAR_DIRTY_LOG
 	cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 	cap.args[0] = dirty_log_manual_caps;
 	vm_enable_cap(vm, &cap);
 #endif

 	vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
 	TEST_ASSERT(vcpu_threads, "Memory allocation failed");

 	add_vcpus(vm, nr_vcpus, guest_percpu_mem_size);

 	sync_global_to_guest(vm, perf_test_args);

 	/* Start the iterations */
 	iteration = 0;
 	host_quit = false;

 	clock_gettime(CLOCK_MONOTONIC, &start);
 	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 		pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 			       &perf_test_args.vcpu_args[vcpu_id]);
 	}

 	/* Allow the vCPU to populate memory */
 	pr_debug("Starting iteration %lu - Populating\n", iteration);
 	while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
 		pr_debug("Waiting for vcpu_last_completed_iteration == %lu\n",
 			iteration);

 	ts_diff = timespec_diff_now(start);
 	pr_info("Populate memory time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);

 	/* Enable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX,
 				KVM_MEM_LOG_DIRTY_PAGES);
 	ts_diff = timespec_diff_now(start);
 	pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);

 	while (iteration < iterations) {
 		/*
 		 * Incrementing the iteration number will start the vCPUs
 		 * dirtying memory again.
 		 */
 		clock_gettime(CLOCK_MONOTONIC, &start);
 		iteration++;

 		pr_debug("Starting iteration %lu\n", iteration);
 		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 			while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
 				pr_debug("Waiting for vCPU %d vcpu_last_completed_iteration == %lu\n",
 					 vcpu_id, iteration);
 		}

 		ts_diff = timespec_diff_now(start);
 		vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
 		pr_info("Iteration %lu dirty memory time: %ld.%.9lds\n",
 			iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

 		clock_gettime(CLOCK_MONOTONIC, &start);
 		kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);

 		ts_diff = timespec_diff_now(start);
 		get_dirty_log_total = timespec_add(get_dirty_log_total,
 						   ts_diff);
 		pr_info("Iteration %lu get dirty log time: %ld.%.9lds\n",
 			iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

 #ifdef USE_CLEAR_DIRTY_LOG
 		clock_gettime(CLOCK_MONOTONIC, &start);
 		kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
 				       host_num_pages);

 		ts_diff = timespec_diff_now(start);
 		clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 						     ts_diff);
 		pr_info("Iteration %lu clear dirty log time: %ld.%.9lds\n",
 			iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 #endif
 	}

 	/* Tell the vcpu thread to quit */
 	host_quit = true;
 	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 		pthread_join(vcpu_threads[vcpu_id], NULL);

 	/* Disable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0);
 	ts_diff = timespec_diff_now(start);
 	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);

 	avg = timespec_div(get_dirty_log_total, iterations);
 	pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 		iterations, get_dirty_log_total.tv_sec,
 		get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);

 #ifdef USE_CLEAR_DIRTY_LOG
 	avg = timespec_div(clear_dirty_log_total, iterations);
 	pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 		iterations, clear_dirty_log_total.tv_sec,
 		clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 #endif

 	free(bmap);
 	free(vcpu_threads);
 	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }

 struct guest_mode {
 	bool supported;
 	bool enabled;
 };
 static struct guest_mode guest_modes[NUM_VM_MODES];

 #define guest_mode_init(mode, supported, enabled) ({ \
 	guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
 })

 static void help(char *name)
 {
 	int i;

 	puts("");
 	printf("usage: %s [-h] [-i iterations] [-p offset] "
 	       "[-m mode] [-b vcpu bytes] [-v vcpus]\n", name);
 	puts("");
 	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 	       TEST_HOST_LOOP_N);
 	printf(" -p: specify guest physical test memory offset\n"
 	       "     Warning: a low offset can conflict with the loaded test code.\n");
 	printf(" -m: specify the guest mode ID to test "
 	       "(default: test all supported modes)\n"
 	       "     This option may be used multiple times.\n"
 	       "     Guest mode IDs:\n");
 	for (i = 0; i < NUM_VM_MODES; ++i) {
 		printf("         %d:    %s%s\n", i, vm_guest_mode_string(i),
 		       guest_modes[i].supported ? " (supported)" : "");
 	}
 	printf(" -b: specify the size of the memory region which should be\n"
 	       "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 	       "     (default: 1G)\n");
 	printf(" -f: specify the fraction of pages which should be written to\n"
 	       "     as opposed to simply read, in the form\n"
 	       "     1/<fraction of pages to write>.\n"
 	       "     (default: 1 i.e. all pages are written to.)\n");
 	printf(" -v: specify the number of vCPUs to run.\n");
 	puts("");
 	exit(0);
 }

 int main(int argc, char *argv[])
 {
 	unsigned long iterations = TEST_HOST_LOOP_N;
 	bool mode_selected = false;
 	uint64_t phys_offset = 0;
 	unsigned int mode;
 	int opt, i;
 	int wr_fract = 1;

 #ifdef USE_CLEAR_DIRTY_LOG
 	dirty_log_manual_caps =
 		kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 	if (!dirty_log_manual_caps) {
 		print_skip("KVM_CLEAR_DIRTY_LOG not available");
 		exit(KSFT_SKIP);
 	}
 	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 				  KVM_DIRTY_LOG_INITIALLY_SET);
 #endif

 #ifdef __x86_64__
 	guest_mode_init(VM_MODE_PXXV48_4K, true, true);
 #endif
 #ifdef __aarch64__
 	guest_mode_init(VM_MODE_P40V48_4K, true, true);
 	guest_mode_init(VM_MODE_P40V48_64K, true, true);

 	{
 		unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);

 		if (limit >= 52)
 			guest_mode_init(VM_MODE_P52V48_64K, true, true);
 		if (limit >= 48) {
 			guest_mode_init(VM_MODE_P48V48_4K, true, true);
 			guest_mode_init(VM_MODE_P48V48_64K, true, true);
 		}
 	}
 #endif
 #ifdef __s390x__
 	guest_mode_init(VM_MODE_P40V48_4K, true, true);
 #endif

 	while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:")) != -1) {
 		switch (opt) {
 		case 'i':
 			iterations = strtol(optarg, NULL, 10);
 			break;
 		case 'p':
 			phys_offset = strtoull(optarg, NULL, 0);
 			break;
 		case 'm':
 			if (!mode_selected) {
 				for (i = 0; i < NUM_VM_MODES; ++i)
 					guest_modes[i].enabled = false;
 				mode_selected = true;
 			}
 			mode = strtoul(optarg, NULL, 10);
 			TEST_ASSERT(mode < NUM_VM_MODES,
 				    "Guest mode ID %d too big", mode);
 			guest_modes[mode].enabled = true;
 			break;
 		case 'b':
 			guest_percpu_mem_size = parse_size(optarg);
 			break;
 		case 'f':
 			wr_fract = atoi(optarg);
 			TEST_ASSERT(wr_fract >= 1,
 				    "Write fraction cannot be less than one");
 			break;
 		case 'v':
 			nr_vcpus = atoi(optarg);
 			TEST_ASSERT(nr_vcpus > 0,
 				    "Must have a positive number of vCPUs");
 			TEST_ASSERT(nr_vcpus <= MAX_VCPUS,
 				    "This test does not currently support\n"
 				    "more than %d vCPUs.", MAX_VCPUS);
 			break;
 		case 'h':
 		default:
 			help(argv[0]);
 			break;
 		}
 	}

 	TEST_ASSERT(iterations >= 2, "The test should have at least two iterations");

 	pr_info("Test iterations: %"PRIu64"\n",	iterations);

 	for (i = 0; i < NUM_VM_MODES; ++i) {
 		if (!guest_modes[i].enabled)
 			continue;
 		TEST_ASSERT(guest_modes[i].supported,
 			    "Guest mode ID %d (%s) not supported.",
 			    i, vm_guest_mode_string(i));
 		run_test(i, iterations, phys_offset, wr_fract);
 	}

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* KVM dirty page logging performance test
	*
	* Based on dirty_log_test.c
	*
	* Copyright (C) 2018, Red Hat, Inc.
	* Copyright (C) 2020, Google, Inc.
	*/

	#define _GNU_SOURCE /* for program_invocation_name */

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <time.h>
	#include <pthread.h>
	#include <linux/bitmap.h>
	#include <linux/bitops.h>

	#include "kvm_util.h"
	#include "perf_test_util.h"
	#include "processor.h"
	#include "test_util.h"

	/* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
	#define TEST_HOST_LOOP_N 2UL

	/* Host variables */
	static bool host_quit;
	static uint64_t iteration;
	static uint64_t vcpu_last_completed_iteration[MAX_VCPUS];

	static void vcpu_worker(void data)
	{
	int ret;
	struct kvm_vm *vm = perf_test_args.vm;
	uint64_t pages_count = 0;
	struct kvm_run *run;
	struct timespec start;
	struct timespec ts_diff;
	struct timespec total = (struct timespec){0};
	struct timespec avg;
	struct vcpu_args vcpu_args = (struct vcpu_args )data;
	int vcpu_id = vcpu_args->vcpu_id;

	vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
	run = vcpu_state(vm, vcpu_id);

	while (!READ_ONCE(host_quit)) {
	uint64_t current_iteration = READ_ONCE(iteration);

	clock_gettime(CLOCK_MONOTONIC, &start);
	ret = _vcpu_run(vm, vcpu_id);
	ts_diff = timespec_diff_now(start);

	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
	TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
	"Invalid guest sync status: exit_reason=%s\n",
	exit_reason_str(run->exit_reason));

	pr_debug("Got sync event from vCPU %d\n", vcpu_id);
	vcpu_last_completed_iteration[vcpu_id] = current_iteration;
	pr_debug("vCPU %d updated last completed iteration to %lu\n",
	vcpu_id, vcpu_last_completed_iteration[vcpu_id]);

	if (current_iteration) {
	pages_count += vcpu_args->pages;
	total = timespec_add(total, ts_diff);
	pr_debug("vCPU %d iteration %lu dirty memory time: %ld.%.9lds\n",
	vcpu_id, current_iteration, ts_diff.tv_sec,
	ts_diff.tv_nsec);
	} else {
	pr_debug("vCPU %d iteration %lu populate memory time: %ld.%.9lds\n",
	vcpu_id, current_iteration, ts_diff.tv_sec,
	ts_diff.tv_nsec);
	}

	while (current_iteration == READ_ONCE(iteration) &&
	!READ_ONCE(host_quit)) {}
	}

	avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
	pr_debug("\nvCPU %d dirtied 0x%lx pages over %lu iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
	vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
	total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);

	return NULL;
	}

	#ifdef USE_CLEAR_DIRTY_LOG
	static u64 dirty_log_manual_caps;
	#endif

	static void run_test(enum vm_guest_mode mode, unsigned long iterations,
	uint64_t phys_offset, int wr_fract)
	{
	pthread_t *vcpu_threads;
	struct kvm_vm *vm;
	unsigned long *bmap;
	uint64_t guest_num_pages;
	uint64_t host_num_pages;
	int vcpu_id;
	struct timespec start;
	struct timespec ts_diff;
	struct timespec get_dirty_log_total = (struct timespec){0};
	struct timespec vcpu_dirty_total = (struct timespec){0};
	struct timespec avg;
	#ifdef USE_CLEAR_DIRTY_LOG
	struct kvm_enable_cap cap = {};
	struct timespec clear_dirty_log_total = (struct timespec){0};
	#endif

	vm = create_vm(mode, nr_vcpus, guest_percpu_mem_size);

	perf_test_args.wr_fract = wr_fract;

	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
	host_num_pages = vm_num_host_pages(mode, guest_num_pages);
	bmap = bitmap_alloc(host_num_pages);

	#ifdef USE_CLEAR_DIRTY_LOG
	cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
	cap.args[0] = dirty_log_manual_caps;
	vm_enable_cap(vm, &cap);
	#endif

	vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
	TEST_ASSERT(vcpu_threads, "Memory allocation failed");

	add_vcpus(vm, nr_vcpus, guest_percpu_mem_size);

	sync_global_to_guest(vm, perf_test_args);

	/* Start the iterations */
	iteration = 0;
	host_quit = false;

	clock_gettime(CLOCK_MONOTONIC, &start);
	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
	pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
	&perf_test_args.vcpu_args[vcpu_id]);
	}

	/* Allow the vCPU to populate memory */
	pr_debug("Starting iteration %lu - Populating\n", iteration);
	while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
	pr_debug("Waiting for vcpu_last_completed_iteration == %lu\n",
	iteration);

	ts_diff = timespec_diff_now(start);
	pr_info("Populate memory time: %ld.%.9lds\n",
	ts_diff.tv_sec, ts_diff.tv_nsec);

	/* Enable dirty logging */
	clock_gettime(CLOCK_MONOTONIC, &start);
	vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX,
	KVM_MEM_LOG_DIRTY_PAGES);
	ts_diff = timespec_diff_now(start);
	pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
	ts_diff.tv_sec, ts_diff.tv_nsec);

	while (iteration < iterations) {
	/*
	* Incrementing the iteration number will start the vCPUs
	* dirtying memory again.
	*/
	clock_gettime(CLOCK_MONOTONIC, &start);
	iteration++;

	pr_debug("Starting iteration %lu\n", iteration);
	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
	while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
	pr_debug("Waiting for vCPU %d vcpu_last_completed_iteration == %lu\n",
	vcpu_id, iteration);
	}

	ts_diff = timespec_diff_now(start);
	vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
	pr_info("Iteration %lu dirty memory time: %ld.%.9lds\n",
	iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

	clock_gettime(CLOCK_MONOTONIC, &start);
	kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);

	ts_diff = timespec_diff_now(start);
	get_dirty_log_total = timespec_add(get_dirty_log_total,
	ts_diff);
	pr_info("Iteration %lu get dirty log time: %ld.%.9lds\n",
	iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

	#ifdef USE_CLEAR_DIRTY_LOG
	clock_gettime(CLOCK_MONOTONIC, &start);
	kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
	host_num_pages);

	ts_diff = timespec_diff_now(start);
	clear_dirty_log_total = timespec_add(clear_dirty_log_total,
	ts_diff);
	pr_info("Iteration %lu clear dirty log time: %ld.%.9lds\n",
	iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
	#endif
	}

	/* Tell the vcpu thread to quit */
	host_quit = true;
	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
	pthread_join(vcpu_threads[vcpu_id], NULL);

	/* Disable dirty logging */
	clock_gettime(CLOCK_MONOTONIC, &start);
	vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0);
	ts_diff = timespec_diff_now(start);
	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
	ts_diff.tv_sec, ts_diff.tv_nsec);

	avg = timespec_div(get_dirty_log_total, iterations);
	pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
	iterations, get_dirty_log_total.tv_sec,
	get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);

	#ifdef USE_CLEAR_DIRTY_LOG
	avg = timespec_div(clear_dirty_log_total, iterations);
	pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
	iterations, clear_dirty_log_total.tv_sec,
	clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
	#endif

	free(bmap);
	free(vcpu_threads);
	ucall_uninit(vm);
	kvm_vm_free(vm);
	}

	struct guest_mode {
	bool supported;
	bool enabled;
	};
	static struct guest_mode guest_modes[NUM_VM_MODES];

	#define guest_mode_init(mode, supported, enabled) ({ \
	guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
	})

	static void help(char *name)
	{
	int i;

	puts("");
	printf("usage: %s [-h] [-i iterations] [-p offset] "
	"[-m mode] [-b vcpu bytes] [-v vcpus]\n", name);
	puts("");
	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
	TEST_HOST_LOOP_N);
	printf(" -p: specify guest physical test memory offset\n"
	" Warning: a low offset can conflict with the loaded test code.\n");
	printf(" -m: specify the guest mode ID to test "
	"(default: test all supported modes)\n"
	" This option may be used multiple times.\n"
	" Guest mode IDs:\n");
	for (i = 0; i < NUM_VM_MODES; ++i) {
	printf(" %d: %s%s\n", i, vm_guest_mode_string(i),
	guest_modes[i].supported ? " (supported)" : "");
	}
	printf(" -b: specify the size of the memory region which should be\n"
	" dirtied by each vCPU. e.g. 10M or 3G.\n"
	" (default: 1G)\n");
	printf(" -f: specify the fraction of pages which should be written to\n"
	" as opposed to simply read, in the form\n"
	" 1/<fraction of pages to write>.\n"
	" (default: 1 i.e. all pages are written to.)\n");
	printf(" -v: specify the number of vCPUs to run.\n");
	puts("");
	exit(0);
	}

	int main(int argc, char *argv[])
	{
	unsigned long iterations = TEST_HOST_LOOP_N;
	bool mode_selected = false;
	uint64_t phys_offset = 0;
	unsigned int mode;
	int opt, i;
	int wr_fract = 1;

	#ifdef USE_CLEAR_DIRTY_LOG
	dirty_log_manual_caps =
	kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
	if (!dirty_log_manual_caps) {
	print_skip("KVM_CLEAR_DIRTY_LOG not available");
	exit(KSFT_SKIP);
	}
	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE \|
	KVM_DIRTY_LOG_INITIALLY_SET);
	#endif

	#ifdef __x86_64__
	guest_mode_init(VM_MODE_PXXV48_4K, true, true);
	#endif
	#ifdef __aarch64__
	guest_mode_init(VM_MODE_P40V48_4K, true, true);
	guest_mode_init(VM_MODE_P40V48_64K, true, true);

	{
	unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);

	if (limit >= 52)
	guest_mode_init(VM_MODE_P52V48_64K, true, true);
	if (limit >= 48) {
	guest_mode_init(VM_MODE_P48V48_4K, true, true);
	guest_mode_init(VM_MODE_P48V48_64K, true, true);
	}
	}
	#endif
	#ifdef __s390x__
	guest_mode_init(VM_MODE_P40V48_4K, true, true);
	#endif

	while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:")) != -1) {
	switch (opt) {
	case 'i':
	iterations = strtol(optarg, NULL, 10);
	break;
	case 'p':
	phys_offset = strtoull(optarg, NULL, 0);
	break;
	case 'm':
	if (!mode_selected) {
	for (i = 0; i < NUM_VM_MODES; ++i)
	guest_modes[i].enabled = false;
	mode_selected = true;
	}
	mode = strtoul(optarg, NULL, 10);
	TEST_ASSERT(mode < NUM_VM_MODES,
	"Guest mode ID %d too big", mode);
	guest_modes[mode].enabled = true;
	break;
	case 'b':
	guest_percpu_mem_size = parse_size(optarg);
	break;
	case 'f':
	wr_fract = atoi(optarg);
	TEST_ASSERT(wr_fract >= 1,
	"Write fraction cannot be less than one");
	break;
	case 'v':
	nr_vcpus = atoi(optarg);
	TEST_ASSERT(nr_vcpus > 0,
	"Must have a positive number of vCPUs");
	TEST_ASSERT(nr_vcpus <= MAX_VCPUS,
	"This test does not currently support\n"
	"more than %d vCPUs.", MAX_VCPUS);
	break;
	case 'h':
	default:
	help(argv[0]);
	break;
	}
	}

	TEST_ASSERT(iterations >= 2, "The test should have at least two iterations");

	pr_info("Test iterations: %"PRIu64"\n", iterations);

	for (i = 0; i < NUM_VM_MODES; ++i) {
	if (!guest_modes[i].enabled)
	continue;
	TEST_ASSERT(guest_modes[i].supported,
	"Guest mode ID %d (%s) not supported.",
	i, vm_guest_mode_string(i));
	run_test(i, iterations, phys_offset, wr_fract);
	}

	return 0;
	}