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.
  */

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

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

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

 static int nr_vcpus = 1;
 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;

 /* Host variables */
 static u64 dirty_log_manual_caps;
 static bool host_quit;
 static int iteration;
 static int vcpu_last_completed_iteration[KVM_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 perf_test_vcpu_args *vcpu_args = (struct perf_test_vcpu_args *)data;
 	int vcpu_id = vcpu_args->vcpu_id;

 	run = vcpu_state(vm, vcpu_id);

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

 		clock_gettime(CLOCK_MONOTONIC, &start);
 		ret = _vcpu_run(vm, vcpu_id);
 		ts_diff = timespec_elapsed(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 %d\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 %d dirty memory time: %ld.%.9lds\n",
 				vcpu_id, current_iteration, ts_diff.tv_sec,
 				ts_diff.tv_nsec);
 		} else {
 			pr_debug("vCPU %d iteration %d 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 %d 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;
 }

 struct test_params {
 	unsigned long iterations;
 	uint64_t phys_offset;
 	int wr_fract;
 	bool partition_vcpu_memory_access;
 	enum vm_mem_backing_src_type backing_src;
 	int slots;
 };

 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
 {
 	int i;

 	for (i = 0; i < slots; i++) {
 		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 		int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;

 		vm_mem_region_set_flags(vm, slot, flags);
 	}
 }

 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
 {
 	toggle_dirty_logging(vm, slots, true);
 }

 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
 {
 	toggle_dirty_logging(vm, slots, false);
 }

 static void get_dirty_log(struct kvm_vm *vm, int slots, unsigned long *bitmap,
 			  uint64_t nr_pages)
 {
 	uint64_t slot_pages = nr_pages / slots;
 	int i;

 	for (i = 0; i < slots; i++) {
 		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 		unsigned long *slot_bitmap = bitmap + i * slot_pages;

 		kvm_vm_get_dirty_log(vm, slot, slot_bitmap);
 	}
 }

 static void clear_dirty_log(struct kvm_vm *vm, int slots, unsigned long *bitmap,
 			    uint64_t nr_pages)
 {
 	uint64_t slot_pages = nr_pages / slots;
 	int i;

 	for (i = 0; i < slots; i++) {
 		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 		unsigned long *slot_bitmap = bitmap + i * slot_pages;

 		kvm_vm_clear_dirty_log(vm, slot, slot_bitmap, 0, slot_pages);
 	}
 }

 static void run_test(enum vm_guest_mode mode, void *arg)
 {
 	struct test_params *p = arg;
 	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;
 	struct kvm_enable_cap cap = {};
 	struct timespec clear_dirty_log_total = (struct timespec){0};

 	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 				 p->slots, p->backing_src);

 	perf_test_args.wr_fract = p->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_zalloc(host_num_pages);

 	if (dirty_log_manual_caps) {
 		cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 		cap.args[0] = dirty_log_manual_caps;
 		vm_enable_cap(vm, &cap);
 	}

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

 	perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
 			      p->partition_vcpu_memory_access);

 	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++) {
 		vcpu_last_completed_iteration[vcpu_id] = -1;

 		pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 			       &perf_test_args.vcpu_args[vcpu_id]);
 	}

 	/* Allow the vCPUs to populate memory */
 	pr_debug("Starting iteration %d - Populating\n", iteration);
 	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 		while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
 		       iteration)
 			;
 	}

 	ts_diff = timespec_elapsed(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);
 	enable_dirty_logging(vm, p->slots);
 	ts_diff = timespec_elapsed(start);
 	pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);

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

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

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

 		clock_gettime(CLOCK_MONOTONIC, &start);
 		get_dirty_log(vm, p->slots, bmap, host_num_pages);
 		ts_diff = timespec_elapsed(start);
 		get_dirty_log_total = timespec_add(get_dirty_log_total,
 						   ts_diff);
 		pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
 			iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

 		if (dirty_log_manual_caps) {
 			clock_gettime(CLOCK_MONOTONIC, &start);
 			clear_dirty_log(vm, p->slots, bmap, host_num_pages);
 			ts_diff = timespec_elapsed(start);
 			clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 							     ts_diff);
 			pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
 				iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 		}
 	}

 	/* Disable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	disable_dirty_logging(vm, p->slots);
 	ts_diff = timespec_elapsed(start);
 	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);

 	/* 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);

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

 	if (dirty_log_manual_caps) {
 		avg = timespec_div(clear_dirty_log_total, p->iterations);
 		pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 			p->iterations, clear_dirty_log_total.tv_sec,
 			clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 	}

 	free(bmap);
 	free(vcpu_threads);
 	perf_test_destroy_vm(vm);
 }

 static void help(char *name)
 {
 	puts("");
 	printf("usage: %s [-h] [-i iterations] [-p offset] "
 	       "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
 	       "[-x memslots]\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");
 	guest_modes_help();
 	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");
 	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 	       "     them into a separate region of memory for each vCPU.\n");
 	printf(" -s: specify the type of memory that should be used to\n"
 	       "     back the guest data region.\n\n");
 	printf(" -x: Split the memory region into this number of memslots.\n"
 	       "     (default: 1)");
 	backing_src_help();
 	puts("");
 	exit(0);
 }

 int main(int argc, char *argv[])
 {
 	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 	struct test_params p = {
 		.iterations = TEST_HOST_LOOP_N,
 		.wr_fract = 1,
 		.partition_vcpu_memory_access = true,
 		.backing_src = VM_MEM_SRC_ANONYMOUS,
 		.slots = 1,
 	};
 	int opt;

 	dirty_log_manual_caps =
 		kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 				  KVM_DIRTY_LOG_INITIALLY_SET);

 	guest_modes_append_default();

 	while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:x:")) != -1) {
 		switch (opt) {
 		case 'i':
 			p.iterations = atoi(optarg);
 			break;
 		case 'p':
 			p.phys_offset = strtoull(optarg, NULL, 0);
 			break;
 		case 'm':
 			guest_modes_cmdline(optarg);
 			break;
 		case 'b':
 			guest_percpu_mem_size = parse_size(optarg);
 			break;
 		case 'f':
 			p.wr_fract = atoi(optarg);
 			TEST_ASSERT(p.wr_fract >= 1,
 				    "Write fraction cannot be less than one");
 			break;
 		case 'v':
 			nr_vcpus = atoi(optarg);
 			TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 				    "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 			break;
 		case 'o':
 			p.partition_vcpu_memory_access = false;
 			break;
 		case 's':
 			p.backing_src = parse_backing_src_type(optarg);
 			break;
 		case 'x':
 			p.slots = atoi(optarg);
 			break;
 		case 'h':
 		default:
 			help(argv[0]);
 			break;
 		}
 	}

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

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

 	for_each_guest_mode(run_test, &p);

 	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.
	*/

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

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

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

	static int nr_vcpus = 1;
	static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;

	/* Host variables */
	static u64 dirty_log_manual_caps;
	static bool host_quit;
	static int iteration;
	static int vcpu_last_completed_iteration[KVM_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 perf_test_vcpu_args vcpu_args = (struct perf_test_vcpu_args )data;
	int vcpu_id = vcpu_args->vcpu_id;

	run = vcpu_state(vm, vcpu_id);

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

	clock_gettime(CLOCK_MONOTONIC, &start);
	ret = _vcpu_run(vm, vcpu_id);
	ts_diff = timespec_elapsed(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 %d\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 %d dirty memory time: %ld.%.9lds\n",
	vcpu_id, current_iteration, ts_diff.tv_sec,
	ts_diff.tv_nsec);
	} else {
	pr_debug("vCPU %d iteration %d 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 %d 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;
	}

	struct test_params {
	unsigned long iterations;
	uint64_t phys_offset;
	int wr_fract;
	bool partition_vcpu_memory_access;
	enum vm_mem_backing_src_type backing_src;
	int slots;
	};

	static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
	{
	int i;

	for (i = 0; i < slots; i++) {
	int slot = PERF_TEST_MEM_SLOT_INDEX + i;
	int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;

	vm_mem_region_set_flags(vm, slot, flags);
	}
	}

	static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
	{
	toggle_dirty_logging(vm, slots, true);
	}

	static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
	{
	toggle_dirty_logging(vm, slots, false);
	}

	static void get_dirty_log(struct kvm_vm vm, int slots, unsigned long bitmap,
	uint64_t nr_pages)
	{
	uint64_t slot_pages = nr_pages / slots;
	int i;

	for (i = 0; i < slots; i++) {
	int slot = PERF_TEST_MEM_SLOT_INDEX + i;
	unsigned long slot_bitmap = bitmap + i slot_pages;

	kvm_vm_get_dirty_log(vm, slot, slot_bitmap);
	}
	}

	static void clear_dirty_log(struct kvm_vm vm, int slots, unsigned long bitmap,
	uint64_t nr_pages)
	{
	uint64_t slot_pages = nr_pages / slots;
	int i;

	for (i = 0; i < slots; i++) {
	int slot = PERF_TEST_MEM_SLOT_INDEX + i;
	unsigned long slot_bitmap = bitmap + i slot_pages;

	kvm_vm_clear_dirty_log(vm, slot, slot_bitmap, 0, slot_pages);
	}
	}

	static void run_test(enum vm_guest_mode mode, void *arg)
	{
	struct test_params *p = arg;
	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;
	struct kvm_enable_cap cap = {};
	struct timespec clear_dirty_log_total = (struct timespec){0};

	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
	p->slots, p->backing_src);

	perf_test_args.wr_fract = p->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_zalloc(host_num_pages);

	if (dirty_log_manual_caps) {
	cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
	cap.args[0] = dirty_log_manual_caps;
	vm_enable_cap(vm, &cap);
	}

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

	perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
	p->partition_vcpu_memory_access);

	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++) {
	vcpu_last_completed_iteration[vcpu_id] = -1;

	pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
	&perf_test_args.vcpu_args[vcpu_id]);
	}

	/* Allow the vCPUs to populate memory */
	pr_debug("Starting iteration %d - Populating\n", iteration);
	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
	while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
	iteration)
	;
	}

	ts_diff = timespec_elapsed(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);
	enable_dirty_logging(vm, p->slots);
	ts_diff = timespec_elapsed(start);
	pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
	ts_diff.tv_sec, ts_diff.tv_nsec);

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

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

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

	clock_gettime(CLOCK_MONOTONIC, &start);
	get_dirty_log(vm, p->slots, bmap, host_num_pages);
	ts_diff = timespec_elapsed(start);
	get_dirty_log_total = timespec_add(get_dirty_log_total,
	ts_diff);
	pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
	iteration, ts_diff.tv_sec, ts_diff.tv_nsec);

	if (dirty_log_manual_caps) {
	clock_gettime(CLOCK_MONOTONIC, &start);
	clear_dirty_log(vm, p->slots, bmap, host_num_pages);
	ts_diff = timespec_elapsed(start);
	clear_dirty_log_total = timespec_add(clear_dirty_log_total,
	ts_diff);
	pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
	iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
	}
	}

	/* Disable dirty logging */
	clock_gettime(CLOCK_MONOTONIC, &start);
	disable_dirty_logging(vm, p->slots);
	ts_diff = timespec_elapsed(start);
	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
	ts_diff.tv_sec, ts_diff.tv_nsec);

	/* 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);

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

	if (dirty_log_manual_caps) {
	avg = timespec_div(clear_dirty_log_total, p->iterations);
	pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
	p->iterations, clear_dirty_log_total.tv_sec,
	clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
	}

	free(bmap);
	free(vcpu_threads);
	perf_test_destroy_vm(vm);
	}

	static void help(char *name)
	{
	puts("");
	printf("usage: %s [-h] [-i iterations] [-p offset] "
	"[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
	"[-x memslots]\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");
	guest_modes_help();
	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");
	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
	" them into a separate region of memory for each vCPU.\n");
	printf(" -s: specify the type of memory that should be used to\n"
	" back the guest data region.\n\n");
	printf(" -x: Split the memory region into this number of memslots.\n"
	" (default: 1)");
	backing_src_help();
	puts("");
	exit(0);
	}

	int main(int argc, char *argv[])
	{
	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
	struct test_params p = {
	.iterations = TEST_HOST_LOOP_N,
	.wr_fract = 1,
	.partition_vcpu_memory_access = true,
	.backing_src = VM_MEM_SRC_ANONYMOUS,
	.slots = 1,
	};
	int opt;

	dirty_log_manual_caps =
	kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
	dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE \|
	KVM_DIRTY_LOG_INITIALLY_SET);

	guest_modes_append_default();

	while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:x:")) != -1) {
	switch (opt) {
	case 'i':
	p.iterations = atoi(optarg);
	break;
	case 'p':
	p.phys_offset = strtoull(optarg, NULL, 0);
	break;
	case 'm':
	guest_modes_cmdline(optarg);
	break;
	case 'b':
	guest_percpu_mem_size = parse_size(optarg);
	break;
	case 'f':
	p.wr_fract = atoi(optarg);
	TEST_ASSERT(p.wr_fract >= 1,
	"Write fraction cannot be less than one");
	break;
	case 'v':
	nr_vcpus = atoi(optarg);
	TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
	"Invalid number of vcpus, must be between 1 and %d", max_vcpus);
	break;
	case 'o':
	p.partition_vcpu_memory_access = false;
	break;
	case 's':
	p.backing_src = parse_backing_src_type(optarg);
	break;
	case 'x':
	p.slots = atoi(optarg);
	break;
	case 'h':
	default:
	help(argv[0]);
	break;
	}
	}

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

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

	for_each_guest_mode(run_test, &p);

	return 0;
	}