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

 // SPDX-License-Identifier: GPL-2.0
 /*
  * KVM dirty page logging test
  *
  * Copyright (C) 2018, Red Hat, 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 "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"

 #define DEBUG printf

 #define VCPU_ID				1

 /* The memory slot index to track dirty pages */
 #define TEST_MEM_SLOT_INDEX		1

 /* Default guest test memory offset, 1G */
 #define DEFAULT_GUEST_TEST_MEM		0x40000000

 /* How many pages to dirty for each guest loop */
 #define TEST_PAGES_PER_LOOP		1024

 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
 #define TEST_HOST_LOOP_N		32UL

 /* Interval for each host loop (ms) */
 #define TEST_HOST_LOOP_INTERVAL		10UL

 /*
  * Guest/Host shared variables. Ensure addr_gva2hva() and/or
  * sync_global_to/from_guest() are used when accessing from
  * the host. READ/WRITE_ONCE() should also be used with anything
  * that may change.
  */
 static uint64_t host_page_size;
 static uint64_t guest_page_size;
 static uint64_t guest_num_pages;
 static uint64_t random_array[TEST_PAGES_PER_LOOP];
 static uint64_t iteration;

 /*
  * Guest physical memory offset of the testing memory slot.
  * This will be set to the topmost valid physical address minus
  * the test memory size.
  */
 static uint64_t guest_test_phys_mem;

 /*
  * Guest virtual memory offset of the testing memory slot.
  * Must not conflict with identity mapped test code.
  */
 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;

 /*
  * Continuously write to the first 8 bytes of a random pages within
  * the testing memory region.
  */
 static void guest_code(void)
 {
 	int i;

 	while (true) {
 		for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
 			uint64_t addr = guest_test_virt_mem;
 			addr += (READ_ONCE(random_array[i]) % guest_num_pages)
 				* guest_page_size;
 			addr &= ~(host_page_size - 1);
 			*(uint64_t *)addr = READ_ONCE(iteration);
 		}

 		/* Tell the host that we need more random numbers */
 		GUEST_SYNC(1);
 	}
 }

 /* Host variables */
 static bool host_quit;

 /* Points to the test VM memory region on which we track dirty logs */
 static void *host_test_mem;
 static uint64_t host_num_pages;

 /* For statistics only */
 static uint64_t host_dirty_count;
 static uint64_t host_clear_count;
 static uint64_t host_track_next_count;

 /*
  * We use this bitmap to track some pages that should have its dirty
  * bit set in the _next_ iteration.  For example, if we detected the
  * page value changed to current iteration but at the same time the
  * page bit is cleared in the latest bitmap, then the system must
  * report that write in the next get dirty log call.
  */
 static unsigned long *host_bmap_track;

 static void generate_random_array(uint64_t *guest_array, uint64_t size)
 {
 	uint64_t i;

 	for (i = 0; i < size; i++)
 		guest_array[i] = random();
 }

 static void *vcpu_worker(void *data)
 {
 	int ret;
 	struct kvm_vm *vm = data;
 	uint64_t *guest_array;
 	uint64_t pages_count = 0;
 	struct kvm_run *run;

 	run = vcpu_state(vm, VCPU_ID);

 	guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
 	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);

 	while (!READ_ONCE(host_quit)) {
 		/* Let the guest dirty the random pages */
 		ret = _vcpu_run(vm, VCPU_ID);
 		TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
 		if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
 			pages_count += TEST_PAGES_PER_LOOP;
 			generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
 		} else {
 			TEST_ASSERT(false,
 				    "Invalid guest sync status: "
 				    "exit_reason=%s\n",
 				    exit_reason_str(run->exit_reason));
 		}
 	}

 	DEBUG("Dirtied %"PRIu64" pages\n", pages_count);

 	return NULL;
 }

 static void vm_dirty_log_verify(unsigned long *bmap)
 {
 	uint64_t page;
 	uint64_t *value_ptr;
 	uint64_t step = host_page_size >= guest_page_size ? 1 :
 				guest_page_size / host_page_size;

 	for (page = 0; page < host_num_pages; page += step) {
 		value_ptr = host_test_mem + page * host_page_size;

 		/* If this is a special page that we were tracking... */
 		if (test_and_clear_bit(page, host_bmap_track)) {
 			host_track_next_count++;
 			TEST_ASSERT(test_bit(page, bmap),
 				    "Page %"PRIu64" should have its dirty bit "
 				    "set in this iteration but it is missing",
 				    page);
 		}

 		if (test_bit(page, bmap)) {
 			host_dirty_count++;
 			/*
 			 * If the bit is set, the value written onto
 			 * the corresponding page should be either the
 			 * previous iteration number or the current one.
 			 */
 			TEST_ASSERT(*value_ptr == iteration ||
 				    *value_ptr == iteration - 1,
 				    "Set page %"PRIu64" value %"PRIu64
 				    " incorrect (iteration=%"PRIu64")",
 				    page, *value_ptr, iteration);
 		} else {
 			host_clear_count++;
 			/*
 			 * If cleared, the value written can be any
 			 * value smaller or equals to the iteration
 			 * number.  Note that the value can be exactly
 			 * (iteration-1) if that write can happen
 			 * like this:
 			 *
 			 * (1) increase loop count to "iteration-1"
 			 * (2) write to page P happens (with value
 			 *     "iteration-1")
 			 * (3) get dirty log for "iteration-1"; we'll
 			 *     see that page P bit is set (dirtied),
 			 *     and not set the bit in host_bmap_track
 			 * (4) increase loop count to "iteration"
 			 *     (which is current iteration)
 			 * (5) get dirty log for current iteration,
 			 *     we'll see that page P is cleared, with
 			 *     value "iteration-1".
 			 */
 			TEST_ASSERT(*value_ptr <= iteration,
 				    "Clear page %"PRIu64" value %"PRIu64
 				    " incorrect (iteration=%"PRIu64")",
 				    page, *value_ptr, iteration);
 			if (*value_ptr == iteration) {
 				/*
 				 * This page is _just_ modified; it
 				 * should report its dirtyness in the
 				 * next run
 				 */
 				set_bit(page, host_bmap_track);
 			}
 		}
 	}
 }

 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
 				uint64_t extra_mem_pages, void *guest_code,
 				unsigned long type)
 {
 	struct kvm_vm *vm;
 	uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;

 	vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages,
 			O_RDWR, type);
 	kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
 #ifdef __x86_64__
 	vm_create_irqchip(vm);
 #endif
 	vm_vcpu_add_default(vm, vcpuid, guest_code);
 	return vm;
 }

 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
 		     unsigned long interval, uint64_t phys_offset)
 {
 	unsigned int guest_pa_bits, guest_page_shift;
 	pthread_t vcpu_thread;
 	struct kvm_vm *vm;
 	uint64_t max_gfn;
 	unsigned long *bmap;
 	unsigned long type = 0;

 	switch (mode) {
 	case VM_MODE_P52V48_4K:
 		guest_pa_bits = 52;
 		guest_page_shift = 12;
 		break;
 	case VM_MODE_P52V48_64K:
 		guest_pa_bits = 52;
 		guest_page_shift = 16;
 		break;
 	case VM_MODE_P48V48_4K:
 		guest_pa_bits = 48;
 		guest_page_shift = 12;
 		break;
 	case VM_MODE_P48V48_64K:
 		guest_pa_bits = 48;
 		guest_page_shift = 16;
 		break;
 	case VM_MODE_P40V48_4K:
 		guest_pa_bits = 40;
 		guest_page_shift = 12;
 		break;
 	case VM_MODE_P40V48_64K:
 		guest_pa_bits = 40;
 		guest_page_shift = 16;
 		break;
 	default:
 		TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode);
 	}

 	DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode));

 #ifdef __x86_64__
 	/*
 	 * FIXME
 	 * The x86_64 kvm selftests framework currently only supports a
 	 * single PML4 which restricts the number of physical address
 	 * bits we can change to 39.
 	 */
 	guest_pa_bits = 39;
 #endif
 #ifdef __aarch64__
 	if (guest_pa_bits != 40)
 		type = KVM_VM_TYPE_ARM_IPA_SIZE(guest_pa_bits);
 #endif
 	max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1;
 	guest_page_size = (1ul << guest_page_shift);
 	/*
 	 * A little more than 1G of guest page sized pages.  Cover the
 	 * case where the size is not aligned to 64 pages.
 	 */
 	guest_num_pages = (1ul << (30 - guest_page_shift)) + 16;
 	host_page_size = getpagesize();
 	host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
 			 !!((guest_num_pages * guest_page_size) % host_page_size);

 	if (!phys_offset) {
 		guest_test_phys_mem = (max_gfn - guest_num_pages) * guest_page_size;
 		guest_test_phys_mem &= ~(host_page_size - 1);
 	} else {
 		guest_test_phys_mem = phys_offset;
 	}

 	DEBUG("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);

 	bmap = bitmap_alloc(host_num_pages);
 	host_bmap_track = bitmap_alloc(host_num_pages);

 	vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code, type);

 #ifdef USE_CLEAR_DIRTY_LOG
 	struct kvm_enable_cap cap = {};

 	cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 	cap.args[0] = 1;
 	vm_enable_cap(vm, &cap);
 #endif

 	/* Add an extra memory slot for testing dirty logging */
 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
 				    guest_test_phys_mem,
 				    TEST_MEM_SLOT_INDEX,
 				    guest_num_pages,
 				    KVM_MEM_LOG_DIRTY_PAGES);

 	/* Do mapping for the dirty track memory slot */
 	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
 		 guest_num_pages * guest_page_size, 0);

 	/* Cache the HVA pointer of the region */
 	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);

 #ifdef __x86_64__
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 #endif
 #ifdef __aarch64__
 	ucall_init(vm, UCALL_MMIO, NULL);
 #endif

 	/* Export the shared variables to the guest */
 	sync_global_to_guest(vm, host_page_size);
 	sync_global_to_guest(vm, guest_page_size);
 	sync_global_to_guest(vm, guest_test_virt_mem);
 	sync_global_to_guest(vm, guest_num_pages);

 	/* Start the iterations */
 	iteration = 1;
 	sync_global_to_guest(vm, iteration);
 	host_quit = false;
 	host_dirty_count = 0;
 	host_clear_count = 0;
 	host_track_next_count = 0;

 	pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);

 	while (iteration < iterations) {
 		/* Give the vcpu thread some time to dirty some pages */
 		usleep(interval * 1000);
 		kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
 #ifdef USE_CLEAR_DIRTY_LOG
 		kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
 				       host_num_pages);
 #endif
 		vm_dirty_log_verify(bmap);
 		iteration++;
 		sync_global_to_guest(vm, iteration);
 	}

 	/* Tell the vcpu thread to quit */
 	host_quit = true;
 	pthread_join(vcpu_thread, NULL);

 	DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
 	      "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
 	      host_track_next_count);

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

 struct vm_guest_mode_params {
 	bool supported;
 	bool enabled;
 };
 struct vm_guest_mode_params vm_guest_mode_params[NUM_VM_MODES];

 #define vm_guest_mode_params_init(mode, supported, enabled)					\
 ({												\
 	vm_guest_mode_params[mode] = (struct vm_guest_mode_params){ supported, enabled };	\
 })

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

 	puts("");
 	printf("usage: %s [-h] [-i iterations] [-I interval] "
 	       "[-p offset] [-m mode]\n", name);
 	puts("");
 	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 	       TEST_HOST_LOOP_N);
 	printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
 	       TEST_HOST_LOOP_INTERVAL);
 	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),
 		       vm_guest_mode_params[i].supported ? " (supported)" : "");
 	}
 	puts("");
 	exit(0);
 }

 int main(int argc, char *argv[])
 {
 	unsigned long iterations = TEST_HOST_LOOP_N;
 	unsigned long interval = TEST_HOST_LOOP_INTERVAL;
 	bool mode_selected = false;
 	uint64_t phys_offset = 0;
 	unsigned int mode;
 	int opt, i;
 #ifdef __aarch64__
 	unsigned int host_ipa_limit;
 #endif

 #ifdef USE_CLEAR_DIRTY_LOG
 	if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) {
 		fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n");
 		exit(KSFT_SKIP);
 	}
 #endif

 #ifdef __x86_64__
 	vm_guest_mode_params_init(VM_MODE_P52V48_4K, true, true);
 #endif
 #ifdef __aarch64__
 	vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true);
 	vm_guest_mode_params_init(VM_MODE_P40V48_64K, true, true);

 	host_ipa_limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
 	if (host_ipa_limit >= 52)
 		vm_guest_mode_params_init(VM_MODE_P52V48_64K, true, true);
 	if (host_ipa_limit >= 48) {
 		vm_guest_mode_params_init(VM_MODE_P48V48_4K, true, true);
 		vm_guest_mode_params_init(VM_MODE_P48V48_64K, true, true);
 	}
 #endif

 	while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
 		switch (opt) {
 		case 'i':
 			iterations = strtol(optarg, NULL, 10);
 			break;
 		case 'I':
 			interval = 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)
 					vm_guest_mode_params[i].enabled = false;
 				mode_selected = true;
 			}
 			mode = strtoul(optarg, NULL, 10);
 			TEST_ASSERT(mode < NUM_VM_MODES,
 				    "Guest mode ID %d too big", mode);
 			vm_guest_mode_params[mode].enabled = true;
 			break;
 		case 'h':
 		default:
 			help(argv[0]);
 			break;
 		}
 	}

 	TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
 	TEST_ASSERT(interval > 0, "Interval must be greater than zero");

 	DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
 	      iterations, interval);

 	srandom(time(0));

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

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* KVM dirty page logging test
	*
	* Copyright (C) 2018, Red Hat, 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 "test_util.h"
	#include "kvm_util.h"
	#include "processor.h"

	#define DEBUG printf

	#define VCPU_ID 1

	/* The memory slot index to track dirty pages */
	#define TEST_MEM_SLOT_INDEX 1

	/* Default guest test memory offset, 1G */
	#define DEFAULT_GUEST_TEST_MEM 0x40000000

	/* How many pages to dirty for each guest loop */
	#define TEST_PAGES_PER_LOOP 1024

	/* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
	#define TEST_HOST_LOOP_N 32UL

	/* Interval for each host loop (ms) */
	#define TEST_HOST_LOOP_INTERVAL 10UL

	/*
	* Guest/Host shared variables. Ensure addr_gva2hva() and/or
	* sync_global_to/from_guest() are used when accessing from
	* the host. READ/WRITE_ONCE() should also be used with anything
	* that may change.
	*/
	static uint64_t host_page_size;
	static uint64_t guest_page_size;
	static uint64_t guest_num_pages;
	static uint64_t random_array[TEST_PAGES_PER_LOOP];
	static uint64_t iteration;

	/*
	* Guest physical memory offset of the testing memory slot.
	* This will be set to the topmost valid physical address minus
	* the test memory size.
	*/
	static uint64_t guest_test_phys_mem;

	/*
	* Guest virtual memory offset of the testing memory slot.
	* Must not conflict with identity mapped test code.
	*/
	static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;

	/*
	* Continuously write to the first 8 bytes of a random pages within
	* the testing memory region.
	*/
	static void guest_code(void)
	{
	int i;

	while (true) {
	for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
	uint64_t addr = guest_test_virt_mem;
	addr += (READ_ONCE(random_array[i]) % guest_num_pages)
	* guest_page_size;
	addr &= ~(host_page_size - 1);
	(uint64_t )addr = READ_ONCE(iteration);
	}

	/* Tell the host that we need more random numbers */
	GUEST_SYNC(1);
	}
	}

	/* Host variables */
	static bool host_quit;

	/* Points to the test VM memory region on which we track dirty logs */
	static void *host_test_mem;
	static uint64_t host_num_pages;

	/* For statistics only */
	static uint64_t host_dirty_count;
	static uint64_t host_clear_count;
	static uint64_t host_track_next_count;

	/*
	* We use this bitmap to track some pages that should have its dirty
	* bit set in the _next_ iteration. For example, if we detected the
	* page value changed to current iteration but at the same time the
	* page bit is cleared in the latest bitmap, then the system must
	* report that write in the next get dirty log call.
	*/
	static unsigned long *host_bmap_track;

	static void generate_random_array(uint64_t *guest_array, uint64_t size)
	{
	uint64_t i;

	for (i = 0; i < size; i++)
	guest_array[i] = random();
	}

	static void vcpu_worker(void data)
	{
	int ret;
	struct kvm_vm *vm = data;
	uint64_t *guest_array;
	uint64_t pages_count = 0;
	struct kvm_run *run;

	run = vcpu_state(vm, VCPU_ID);

	guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);

	while (!READ_ONCE(host_quit)) {
	/* Let the guest dirty the random pages */
	ret = _vcpu_run(vm, VCPU_ID);
	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
	if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
	pages_count += TEST_PAGES_PER_LOOP;
	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
	} else {
	TEST_ASSERT(false,
	"Invalid guest sync status: "
	"exit_reason=%s\n",
	exit_reason_str(run->exit_reason));
	}
	}

	DEBUG("Dirtied %"PRIu64" pages\n", pages_count);

	return NULL;
	}

	static void vm_dirty_log_verify(unsigned long *bmap)
	{
	uint64_t page;
	uint64_t *value_ptr;
	uint64_t step = host_page_size >= guest_page_size ? 1 :
	guest_page_size / host_page_size;

	for (page = 0; page < host_num_pages; page += step) {
	value_ptr = host_test_mem + page * host_page_size;

	/* If this is a special page that we were tracking... */
	if (test_and_clear_bit(page, host_bmap_track)) {
	host_track_next_count++;
	TEST_ASSERT(test_bit(page, bmap),
	"Page %"PRIu64" should have its dirty bit "
	"set in this iteration but it is missing",
	page);
	}

	if (test_bit(page, bmap)) {
	host_dirty_count++;
	/*
	* If the bit is set, the value written onto
	* the corresponding page should be either the
	* previous iteration number or the current one.
	*/
	TEST_ASSERT(*value_ptr == iteration \|\|
	*value_ptr == iteration - 1,
	"Set page %"PRIu64" value %"PRIu64
	" incorrect (iteration=%"PRIu64")",
	page, *value_ptr, iteration);
	} else {
	host_clear_count++;
	/*
	* If cleared, the value written can be any
	* value smaller or equals to the iteration
	* number. Note that the value can be exactly
	* (iteration-1) if that write can happen
	* like this:
	*
	* (1) increase loop count to "iteration-1"
	* (2) write to page P happens (with value
	* "iteration-1")
	* (3) get dirty log for "iteration-1"; we'll
	* see that page P bit is set (dirtied),
	* and not set the bit in host_bmap_track
	* (4) increase loop count to "iteration"
	* (which is current iteration)
	* (5) get dirty log for current iteration,
	* we'll see that page P is cleared, with
	* value "iteration-1".
	*/
	TEST_ASSERT(*value_ptr <= iteration,
	"Clear page %"PRIu64" value %"PRIu64
	" incorrect (iteration=%"PRIu64")",
	page, *value_ptr, iteration);
	if (*value_ptr == iteration) {
	/*
	* This page is _just_ modified; it
	* should report its dirtyness in the
	* next run
	*/
	set_bit(page, host_bmap_track);
	}
	}
	}
	}

	static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
	uint64_t extra_mem_pages, void *guest_code,
	unsigned long type)
	{
	struct kvm_vm *vm;
	uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;

	vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages,
	O_RDWR, type);
	kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
	#ifdef __x86_64__
	vm_create_irqchip(vm);
	#endif
	vm_vcpu_add_default(vm, vcpuid, guest_code);
	return vm;
	}

	static void run_test(enum vm_guest_mode mode, unsigned long iterations,
	unsigned long interval, uint64_t phys_offset)
	{
	unsigned int guest_pa_bits, guest_page_shift;
	pthread_t vcpu_thread;
	struct kvm_vm *vm;
	uint64_t max_gfn;
	unsigned long *bmap;
	unsigned long type = 0;

	switch (mode) {
	case VM_MODE_P52V48_4K:
	guest_pa_bits = 52;
	guest_page_shift = 12;
	break;
	case VM_MODE_P52V48_64K:
	guest_pa_bits = 52;
	guest_page_shift = 16;
	break;
	case VM_MODE_P48V48_4K:
	guest_pa_bits = 48;
	guest_page_shift = 12;
	break;
	case VM_MODE_P48V48_64K:
	guest_pa_bits = 48;
	guest_page_shift = 16;
	break;
	case VM_MODE_P40V48_4K:
	guest_pa_bits = 40;
	guest_page_shift = 12;
	break;
	case VM_MODE_P40V48_64K:
	guest_pa_bits = 40;
	guest_page_shift = 16;
	break;
	default:
	TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode);
	}

	DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode));

	#ifdef __x86_64__
	/*
	* FIXME
	* The x86_64 kvm selftests framework currently only supports a
	* single PML4 which restricts the number of physical address
	* bits we can change to 39.
	*/
	guest_pa_bits = 39;
	#endif
	#ifdef __aarch64__
	if (guest_pa_bits != 40)
	type = KVM_VM_TYPE_ARM_IPA_SIZE(guest_pa_bits);
	#endif
	max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1;
	guest_page_size = (1ul << guest_page_shift);
	/*
	* A little more than 1G of guest page sized pages. Cover the
	* case where the size is not aligned to 64 pages.
	*/
	guest_num_pages = (1ul << (30 - guest_page_shift)) + 16;
	host_page_size = getpagesize();
	host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
	!!((guest_num_pages * guest_page_size) % host_page_size);

	if (!phys_offset) {
	guest_test_phys_mem = (max_gfn - guest_num_pages) * guest_page_size;
	guest_test_phys_mem &= ~(host_page_size - 1);
	} else {
	guest_test_phys_mem = phys_offset;
	}

	DEBUG("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);

	bmap = bitmap_alloc(host_num_pages);
	host_bmap_track = bitmap_alloc(host_num_pages);

	vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code, type);

	#ifdef USE_CLEAR_DIRTY_LOG
	struct kvm_enable_cap cap = {};

	cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
	cap.args[0] = 1;
	vm_enable_cap(vm, &cap);
	#endif

	/* Add an extra memory slot for testing dirty logging */
	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
	guest_test_phys_mem,
	TEST_MEM_SLOT_INDEX,
	guest_num_pages,
	KVM_MEM_LOG_DIRTY_PAGES);

	/* Do mapping for the dirty track memory slot */
	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
	guest_num_pages * guest_page_size, 0);

	/* Cache the HVA pointer of the region */
	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);

	#ifdef __x86_64__
	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
	#endif
	#ifdef __aarch64__
	ucall_init(vm, UCALL_MMIO, NULL);
	#endif

	/* Export the shared variables to the guest */
	sync_global_to_guest(vm, host_page_size);
	sync_global_to_guest(vm, guest_page_size);
	sync_global_to_guest(vm, guest_test_virt_mem);
	sync_global_to_guest(vm, guest_num_pages);

	/* Start the iterations */
	iteration = 1;
	sync_global_to_guest(vm, iteration);
	host_quit = false;
	host_dirty_count = 0;
	host_clear_count = 0;
	host_track_next_count = 0;

	pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);

	while (iteration < iterations) {
	/* Give the vcpu thread some time to dirty some pages */
	usleep(interval * 1000);
	kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
	#ifdef USE_CLEAR_DIRTY_LOG
	kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
	host_num_pages);
	#endif
	vm_dirty_log_verify(bmap);
	iteration++;
	sync_global_to_guest(vm, iteration);
	}

	/* Tell the vcpu thread to quit */
	host_quit = true;
	pthread_join(vcpu_thread, NULL);

	DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
	"track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
	host_track_next_count);

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

	struct vm_guest_mode_params {
	bool supported;
	bool enabled;
	};
	struct vm_guest_mode_params vm_guest_mode_params[NUM_VM_MODES];

	#define vm_guest_mode_params_init(mode, supported, enabled) \
	({ \
	vm_guest_mode_params[mode] = (struct vm_guest_mode_params){ supported, enabled }; \
	})

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

	puts("");
	printf("usage: %s [-h] [-i iterations] [-I interval] "
	"[-p offset] [-m mode]\n", name);
	puts("");
	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
	TEST_HOST_LOOP_N);
	printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
	TEST_HOST_LOOP_INTERVAL);
	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),
	vm_guest_mode_params[i].supported ? " (supported)" : "");
	}
	puts("");
	exit(0);
	}

	int main(int argc, char *argv[])
	{
	unsigned long iterations = TEST_HOST_LOOP_N;
	unsigned long interval = TEST_HOST_LOOP_INTERVAL;
	bool mode_selected = false;
	uint64_t phys_offset = 0;
	unsigned int mode;
	int opt, i;
	#ifdef __aarch64__
	unsigned int host_ipa_limit;
	#endif

	#ifdef USE_CLEAR_DIRTY_LOG
	if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) {
	fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n");
	exit(KSFT_SKIP);
	}
	#endif

	#ifdef __x86_64__
	vm_guest_mode_params_init(VM_MODE_P52V48_4K, true, true);
	#endif
	#ifdef __aarch64__
	vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true);
	vm_guest_mode_params_init(VM_MODE_P40V48_64K, true, true);

	host_ipa_limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
	if (host_ipa_limit >= 52)
	vm_guest_mode_params_init(VM_MODE_P52V48_64K, true, true);
	if (host_ipa_limit >= 48) {
	vm_guest_mode_params_init(VM_MODE_P48V48_4K, true, true);
	vm_guest_mode_params_init(VM_MODE_P48V48_64K, true, true);
	}
	#endif

	while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
	switch (opt) {
	case 'i':
	iterations = strtol(optarg, NULL, 10);
	break;
	case 'I':
	interval = 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)
	vm_guest_mode_params[i].enabled = false;
	mode_selected = true;
	}
	mode = strtoul(optarg, NULL, 10);
	TEST_ASSERT(mode < NUM_VM_MODES,
	"Guest mode ID %d too big", mode);
	vm_guest_mode_params[mode].enabled = true;
	break;
	case 'h':
	default:
	help(argv[0]);
	break;
	}
	}

	TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
	TEST_ASSERT(interval > 0, "Interval must be greater than zero");

	DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
	iterations, interval);

	srandom(time(0));

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

	return 0;
	}