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.
  */

 #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"

 #define  DEBUG                 printf

 #define  VCPU_ID                        1
 /* The memory slot index to track dirty pages */
 #define  TEST_MEM_SLOT_INDEX            1
 /*
  * GPA offset of the testing memory slot. Must be bigger than the
  * default vm mem slot, which is DEFAULT_GUEST_PHY_PAGES.
  */
 #define  TEST_MEM_OFFSET                (1ULL << 30) /* 1G */
 /* Size of the testing memory slot */
 #define  TEST_MEM_PAGES                 (1ULL << 18) /* 1G for 4K pages */
 /* 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               32
 /* Interval for each host loop (ms) */
 #define  TEST_HOST_LOOP_INTERVAL        10

 /*
  * Guest variables.  We use these variables to share data between host
  * and guest.  There are two copies of the variables, one in host memory
  * (which is unused) and one in guest memory.  When the host wants to
  * access these variables, it needs to call addr_gva2hva() to access the
  * guest copy.
  */
 uint64_t guest_random_array[TEST_PAGES_PER_LOOP];
 uint64_t guest_iteration;
 uint64_t guest_page_size;

 /*
  * Writes to the first byte of a random page within the testing memory
  * region continuously.
  */
 void guest_code(void)
 {
 	int i = 0;
 	uint64_t volatile *array = guest_random_array;
 	uint64_t volatile *guest_addr;

 	while (true) {
 		for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
 			/*
 			 * Write to the first 8 bytes of a random page
 			 * on the testing memory region.
 			 */
 			guest_addr = (uint64_t *)
 			    (TEST_MEM_OFFSET +
 			     (array[i] % TEST_MEM_PAGES) * guest_page_size);
 			*guest_addr = guest_iteration;
 		}
 		/* Tell the host that we need more random numbers */
 		GUEST_SYNC(1);
 	}
 }

 /*
  * Host variables.  These variables should only be used by the host
  * rather than the guest.
  */
 bool host_quit;

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

 /* For statistics only */
 uint64_t host_dirty_count;
 uint64_t host_clear_count;
 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.
  */
 unsigned long *host_bmap_track;

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

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

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

 	run = vcpu_state(vm, VCPU_ID);

 	/* Retrieve the guest random array pointer and cache it */
 	guest_array = addr_gva2hva(vm, (vm_vaddr_t)guest_random_array);

 	DEBUG("VCPU starts\n");

 	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);

 	while (!READ_ONCE(host_quit)) {
 		/* Let the guest to dirty these random pages */
 		ret = _vcpu_run(vm, VCPU_ID);
 		guest_args_read(vm, VCPU_ID, &args);
 		if (run->exit_reason == KVM_EXIT_IO &&
 		    args.port == GUEST_PORT_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("VCPU exits, dirtied %"PRIu64" pages\n", pages_count);

 	return NULL;
 }

 void vm_dirty_log_verify(unsigned long *bmap, uint64_t iteration)
 {
 	uint64_t page;
 	uint64_t volatile *value_ptr;

 	for (page = 0; page < TEST_MEM_PAGES; page++) {
 		value_ptr = host_test_mem + page * getpagesize();

 		/* 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);
 			}
 		}
 	}
 }

 void help(char *name)
 {
 	puts("");
 	printf("usage: %s [-i iterations] [-I interval] [-h]\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);
 	puts("");
 	exit(0);
 }

 int main(int argc, char *argv[])
 {
 	pthread_t vcpu_thread;
 	struct kvm_vm *vm;
 	uint64_t volatile *psize, *iteration;
 	unsigned long *bmap, iterations = TEST_HOST_LOOP_N,
 	    interval = TEST_HOST_LOOP_INTERVAL;
 	int opt;

 	while ((opt = getopt(argc, argv, "hi:I:")) != -1) {
 		switch (opt) {
 		case 'i':
 			iterations = strtol(optarg, NULL, 10);
 			break;
 		case 'I':
 			interval = strtol(optarg, NULL, 10);
 			break;
 		case 'h':
 		default:
 			help(argv[0]);
 			break;
 		}
 	}

 	TEST_ASSERT(iterations > 2, "Iteration must be bigger than zero\n");
 	TEST_ASSERT(interval > 0, "Interval must be bigger than zero");

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

 	srandom(time(0));

 	bmap = bitmap_alloc(TEST_MEM_PAGES);
 	host_bmap_track = bitmap_alloc(TEST_MEM_PAGES);

 	vm = vm_create_default(VCPU_ID, TEST_MEM_PAGES, guest_code);

 	/* Add an extra memory slot for testing dirty logging */
 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
 				    TEST_MEM_OFFSET,
 				    TEST_MEM_SLOT_INDEX,
 				    TEST_MEM_PAGES,
 				    KVM_MEM_LOG_DIRTY_PAGES);
 	/* Cache the HVA pointer of the region */
 	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)TEST_MEM_OFFSET);

 	/* Do 1:1 mapping for the dirty track memory slot */
 	virt_map(vm, TEST_MEM_OFFSET, TEST_MEM_OFFSET,
 		 TEST_MEM_PAGES * getpagesize(), 0);

 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());

 	/* Tell the guest about the page size on the system */
 	psize = addr_gva2hva(vm, (vm_vaddr_t)&guest_page_size);
 	*psize = getpagesize();

 	/* Start the iterations */
 	iteration = addr_gva2hva(vm, (vm_vaddr_t)&guest_iteration);
 	*iteration = 1;

 	/* Start dirtying pages */
 	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);
 		vm_dirty_log_verify(bmap, *iteration);
 		(*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);
 	kvm_vm_free(vm);

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

	#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"

	#define DEBUG printf

	#define VCPU_ID 1
	/* The memory slot index to track dirty pages */
	#define TEST_MEM_SLOT_INDEX 1
	/*
	* GPA offset of the testing memory slot. Must be bigger than the
	* default vm mem slot, which is DEFAULT_GUEST_PHY_PAGES.
	*/
	#define TEST_MEM_OFFSET (1ULL << 30) /* 1G */
	/* Size of the testing memory slot */
	#define TEST_MEM_PAGES (1ULL << 18) /* 1G for 4K pages */
	/* 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 32
	/* Interval for each host loop (ms) */
	#define TEST_HOST_LOOP_INTERVAL 10

	/*
	* Guest variables. We use these variables to share data between host
	* and guest. There are two copies of the variables, one in host memory
	* (which is unused) and one in guest memory. When the host wants to
	* access these variables, it needs to call addr_gva2hva() to access the
	* guest copy.
	*/
	uint64_t guest_random_array[TEST_PAGES_PER_LOOP];
	uint64_t guest_iteration;
	uint64_t guest_page_size;

	/*
	* Writes to the first byte of a random page within the testing memory
	* region continuously.
	*/
	void guest_code(void)
	{
	int i = 0;
	uint64_t volatile *array = guest_random_array;
	uint64_t volatile *guest_addr;

	while (true) {
	for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
	/*
	* Write to the first 8 bytes of a random page
	* on the testing memory region.
	*/
	guest_addr = (uint64_t *)
	(TEST_MEM_OFFSET +
	(array[i] % TEST_MEM_PAGES) * guest_page_size);
	*guest_addr = guest_iteration;
	}
	/* Tell the host that we need more random numbers */
	GUEST_SYNC(1);
	}
	}

	/*
	* Host variables. These variables should only be used by the host
	* rather than the guest.
	*/
	bool host_quit;

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

	/* For statistics only */
	uint64_t host_dirty_count;
	uint64_t host_clear_count;
	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.
	*/
	unsigned long *host_bmap_track;

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

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

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

	run = vcpu_state(vm, VCPU_ID);

	/* Retrieve the guest random array pointer and cache it */
	guest_array = addr_gva2hva(vm, (vm_vaddr_t)guest_random_array);

	DEBUG("VCPU starts\n");

	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);

	while (!READ_ONCE(host_quit)) {
	/* Let the guest to dirty these random pages */
	ret = _vcpu_run(vm, VCPU_ID);
	guest_args_read(vm, VCPU_ID, &args);
	if (run->exit_reason == KVM_EXIT_IO &&
	args.port == GUEST_PORT_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("VCPU exits, dirtied %"PRIu64" pages\n", pages_count);

	return NULL;
	}

	void vm_dirty_log_verify(unsigned long *bmap, uint64_t iteration)
	{
	uint64_t page;
	uint64_t volatile *value_ptr;

	for (page = 0; page < TEST_MEM_PAGES; page++) {
	value_ptr = host_test_mem + page * getpagesize();

	/* 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);
	}
	}
	}
	}

	void help(char *name)
	{
	puts("");
	printf("usage: %s [-i iterations] [-I interval] [-h]\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);
	puts("");
	exit(0);
	}

	int main(int argc, char *argv[])
	{
	pthread_t vcpu_thread;
	struct kvm_vm *vm;
	uint64_t volatile psize, iteration;
	unsigned long *bmap, iterations = TEST_HOST_LOOP_N,
	interval = TEST_HOST_LOOP_INTERVAL;
	int opt;

	while ((opt = getopt(argc, argv, "hi:I:")) != -1) {
	switch (opt) {
	case 'i':
	iterations = strtol(optarg, NULL, 10);
	break;
	case 'I':
	interval = strtol(optarg, NULL, 10);
	break;
	case 'h':
	default:
	help(argv[0]);
	break;
	}
	}

	TEST_ASSERT(iterations > 2, "Iteration must be bigger than zero\n");
	TEST_ASSERT(interval > 0, "Interval must be bigger than zero");

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

	srandom(time(0));

	bmap = bitmap_alloc(TEST_MEM_PAGES);
	host_bmap_track = bitmap_alloc(TEST_MEM_PAGES);

	vm = vm_create_default(VCPU_ID, TEST_MEM_PAGES, guest_code);

	/* Add an extra memory slot for testing dirty logging */
	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
	TEST_MEM_OFFSET,
	TEST_MEM_SLOT_INDEX,
	TEST_MEM_PAGES,
	KVM_MEM_LOG_DIRTY_PAGES);
	/* Cache the HVA pointer of the region */
	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)TEST_MEM_OFFSET);

	/* Do 1:1 mapping for the dirty track memory slot */
	virt_map(vm, TEST_MEM_OFFSET, TEST_MEM_OFFSET,
	TEST_MEM_PAGES * getpagesize(), 0);

	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());

	/* Tell the guest about the page size on the system */
	psize = addr_gva2hva(vm, (vm_vaddr_t)&guest_page_size);
	*psize = getpagesize();

	/* Start the iterations */
	iteration = addr_gva2hva(vm, (vm_vaddr_t)&guest_iteration);
	*iteration = 1;

	/* Start dirtying pages */
	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);
	vm_dirty_log_verify(bmap, *iteration);
	(*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);
	kvm_vm_free(vm);

	return 0;
	}