1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * KVM dirty page logging test
  4 *
  5 * Copyright (C) 2018, Red Hat, Inc.
  6 */
  7
  8#define _GNU_SOURCE /* for program_invocation_name */
  9
 10#include <stdio.h>
 11#include <stdlib.h>
 12#include <pthread.h>
 13#include <semaphore.h>
 14#include <sys/types.h>
 15#include <signal.h>
 16#include <errno.h>
 17#include <linux/bitmap.h>
 18#include <linux/bitops.h>
 19#include <linux/atomic.h>
 20#include <asm/barrier.h>
 21
 22#include "kvm_util.h"
 23#include "test_util.h"
 24#include "guest_modes.h"
 25#include "processor.h"
 26
 27#define DIRTY_MEM_BITS 30 /* 1G */
 28#define PAGE_SHIFT_4K  12
 29
 30/* The memory slot index to track dirty pages */
 31#define TEST_MEM_SLOT_INDEX		1
 32
 33/* Default guest test virtual memory offset */
 34#define DEFAULT_GUEST_TEST_MEM		0xc0000000
 35
 36/* How many pages to dirty for each guest loop */
 37#define TEST_PAGES_PER_LOOP		1024
 38
 39/* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
 40#define TEST_HOST_LOOP_N		32UL
 41
 42/* Interval for each host loop (ms) */
 43#define TEST_HOST_LOOP_INTERVAL		10UL
 44
 45/* Dirty bitmaps are always little endian, so we need to swap on big endian */
 46#if defined(__s390x__)
 47# define BITOP_LE_SWIZZLE	((BITS_PER_LONG-1) & ~0x7)
 48# define test_bit_le(nr, addr) \
 49	test_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
 50# define __set_bit_le(nr, addr) \
 51	__set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
 52# define __clear_bit_le(nr, addr) \
 53	__clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
 54# define __test_and_set_bit_le(nr, addr) \
 55	__test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
 56# define __test_and_clear_bit_le(nr, addr) \
 57	__test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
 58#else
 59# define test_bit_le			test_bit
 60# define __set_bit_le			__set_bit
 61# define __clear_bit_le			__clear_bit
 62# define __test_and_set_bit_le		__test_and_set_bit
 63# define __test_and_clear_bit_le	__test_and_clear_bit
 64#endif
 65
 66#define TEST_DIRTY_RING_COUNT		65536
 67
 68#define SIG_IPI SIGUSR1
 69
 70/*
 71 * Guest/Host shared variables. Ensure addr_gva2hva() and/or
 72 * sync_global_to/from_guest() are used when accessing from
 73 * the host. READ/WRITE_ONCE() should also be used with anything
 74 * that may change.
 75 */
 76static uint64_t host_page_size;
 77static uint64_t guest_page_size;
 78static uint64_t guest_num_pages;
 79static uint64_t random_array[TEST_PAGES_PER_LOOP];
 80static uint64_t iteration;
 81
 82/*
 83 * Guest physical memory offset of the testing memory slot.
 84 * This will be set to the topmost valid physical address minus
 85 * the test memory size.
 86 */
 87static uint64_t guest_test_phys_mem;
 88
 89/*
 90 * Guest virtual memory offset of the testing memory slot.
 91 * Must not conflict with identity mapped test code.
 92 */
 93static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
 94
 95/*
 96 * Continuously write to the first 8 bytes of a random pages within
 97 * the testing memory region.
 98 */
 99static void guest_code(void)
100{
101	uint64_t addr;
102	int i;
103
104	/*
105	 * On s390x, all pages of a 1M segment are initially marked as dirty
106	 * when a page of the segment is written to for the very first time.
107	 * To compensate this specialty in this test, we need to touch all
108	 * pages during the first iteration.
109	 */
110	for (i = 0; i < guest_num_pages; i++) {
111		addr = guest_test_virt_mem + i * guest_page_size;
112		*(uint64_t *)addr = READ_ONCE(iteration);
113	}
114
115	while (true) {
116		for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
117			addr = guest_test_virt_mem;
118			addr += (READ_ONCE(random_array[i]) % guest_num_pages)
119				* guest_page_size;
120			addr = align_down(addr, host_page_size);
121			*(uint64_t *)addr = READ_ONCE(iteration);
122		}
123
124		/* Tell the host that we need more random numbers */
125		GUEST_SYNC(1);
126	}
127}
128
129/* Host variables */
130static bool host_quit;
131
132/* Points to the test VM memory region on which we track dirty logs */
133static void *host_test_mem;
134static uint64_t host_num_pages;
135
136/* For statistics only */
137static uint64_t host_dirty_count;
138static uint64_t host_clear_count;
139static uint64_t host_track_next_count;
140
141/* Whether dirty ring reset is requested, or finished */
142static sem_t sem_vcpu_stop;
143static sem_t sem_vcpu_cont;
144/*
145 * This is only set by main thread, and only cleared by vcpu thread.  It is
146 * used to request vcpu thread to stop at the next GUEST_SYNC, since GUEST_SYNC
147 * is the only place that we'll guarantee both "dirty bit" and "dirty data"
148 * will match.  E.g., SIG_IPI won't guarantee that if the vcpu is interrupted
149 * after setting dirty bit but before the data is written.
150 */
151static atomic_t vcpu_sync_stop_requested;
152/*
153 * This is updated by the vcpu thread to tell the host whether it's a
154 * ring-full event.  It should only be read until a sem_wait() of
155 * sem_vcpu_stop and before vcpu continues to run.
156 */
157static bool dirty_ring_vcpu_ring_full;
158/*
159 * This is only used for verifying the dirty pages.  Dirty ring has a very
160 * tricky case when the ring just got full, kvm will do userspace exit due to
161 * ring full.  When that happens, the very last PFN is set but actually the
162 * data is not changed (the guest WRITE is not really applied yet), because
163 * we found that the dirty ring is full, refused to continue the vcpu, and
164 * recorded the dirty gfn with the old contents.
165 *
166 * For this specific case, it's safe to skip checking this pfn for this
167 * bit, because it's a redundant bit, and when the write happens later the bit
168 * will be set again.  We use this variable to always keep track of the latest
169 * dirty gfn we've collected, so that if a mismatch of data found later in the
170 * verifying process, we let it pass.
171 */
172static uint64_t dirty_ring_last_page;
173
174enum log_mode_t {
175	/* Only use KVM_GET_DIRTY_LOG for logging */
176	LOG_MODE_DIRTY_LOG = 0,
177
178	/* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */
179	LOG_MODE_CLEAR_LOG = 1,
180
181	/* Use dirty ring for logging */
182	LOG_MODE_DIRTY_RING = 2,
183
184	LOG_MODE_NUM,
185
186	/* Run all supported modes */
187	LOG_MODE_ALL = LOG_MODE_NUM,
188};
189
190/* Mode of logging to test.  Default is to run all supported modes */
191static enum log_mode_t host_log_mode_option = LOG_MODE_ALL;
192/* Logging mode for current run */
193static enum log_mode_t host_log_mode;
194static pthread_t vcpu_thread;
195static uint32_t test_dirty_ring_count = TEST_DIRTY_RING_COUNT;
196
197static void vcpu_kick(void)
198{
199	pthread_kill(vcpu_thread, SIG_IPI);
200}
201
202/*
203 * In our test we do signal tricks, let's use a better version of
204 * sem_wait to avoid signal interrupts
205 */
206static void sem_wait_until(sem_t *sem)
207{
208	int ret;
209
210	do
211		ret = sem_wait(sem);
212	while (ret == -1 && errno == EINTR);
213}
214
215static bool clear_log_supported(void)
216{
217	return kvm_has_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
218}
219
220static void clear_log_create_vm_done(struct kvm_vm *vm)
221{
222	u64 manual_caps;
223
224	manual_caps = kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
225	TEST_ASSERT(manual_caps, "MANUAL_CAPS is zero!");
226	manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
227			KVM_DIRTY_LOG_INITIALLY_SET);
228	vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, manual_caps);
229}
230
231static void dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
232					  void *bitmap, uint32_t num_pages,
233					  uint32_t *unused)
234{
235	kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
236}
237
238static void clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
239					  void *bitmap, uint32_t num_pages,
240					  uint32_t *unused)
241{
242	kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
243	kvm_vm_clear_dirty_log(vcpu->vm, slot, bitmap, 0, num_pages);
244}
245
246/* Should only be called after a GUEST_SYNC */
247static void vcpu_handle_sync_stop(void)
248{
249	if (atomic_read(&vcpu_sync_stop_requested)) {
250		/* It means main thread is sleeping waiting */
251		atomic_set(&vcpu_sync_stop_requested, false);
252		sem_post(&sem_vcpu_stop);
253		sem_wait_until(&sem_vcpu_cont);
254	}
255}
256
257static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
258{
259	struct kvm_run *run = vcpu->run;
260
261	TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR),
262		    "vcpu run failed: errno=%d", err);
263
264	TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC,
265		    "Invalid guest sync status: exit_reason=%s\n",
266		    exit_reason_str(run->exit_reason));
267
268	vcpu_handle_sync_stop();
269}
270
271static bool dirty_ring_supported(void)
272{
273	return (kvm_has_cap(KVM_CAP_DIRTY_LOG_RING) ||
274		kvm_has_cap(KVM_CAP_DIRTY_LOG_RING_ACQ_REL));
275}
276
277static void dirty_ring_create_vm_done(struct kvm_vm *vm)
278{
279	uint64_t pages;
280	uint32_t limit;
281
282	/*
283	 * We rely on vcpu exit due to full dirty ring state. Adjust
284	 * the ring buffer size to ensure we're able to reach the
285	 * full dirty ring state.
286	 */
287	pages = (1ul << (DIRTY_MEM_BITS - vm->page_shift)) + 3;
288	pages = vm_adjust_num_guest_pages(vm->mode, pages);
289	if (vm->page_size < getpagesize())
290		pages = vm_num_host_pages(vm->mode, pages);
291
292	limit = 1 << (31 - __builtin_clz(pages));
293	test_dirty_ring_count = 1 << (31 - __builtin_clz(test_dirty_ring_count));
294	test_dirty_ring_count = min(limit, test_dirty_ring_count);
295	pr_info("dirty ring count: 0x%x\n", test_dirty_ring_count);
296
297	/*
298	 * Switch to dirty ring mode after VM creation but before any
299	 * of the vcpu creation.
300	 */
301	vm_enable_dirty_ring(vm, test_dirty_ring_count *
302			     sizeof(struct kvm_dirty_gfn));
303}
304
305static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
306{
307	return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY;
308}
309
310static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
311{
312	smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET);
313}
314
315static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
316				       int slot, void *bitmap,
317				       uint32_t num_pages, uint32_t *fetch_index)
318{
319	struct kvm_dirty_gfn *cur;
320	uint32_t count = 0;
321
322	while (true) {
323		cur = &dirty_gfns[*fetch_index % test_dirty_ring_count];
324		if (!dirty_gfn_is_dirtied(cur))
325			break;
326		TEST_ASSERT(cur->slot == slot, "Slot number didn't match: "
327			    "%u != %u", cur->slot, slot);
328		TEST_ASSERT(cur->offset < num_pages, "Offset overflow: "
329			    "0x%llx >= 0x%x", cur->offset, num_pages);
330		//pr_info("fetch 0x%x page %llu\n", *fetch_index, cur->offset);
331		__set_bit_le(cur->offset, bitmap);
332		dirty_ring_last_page = cur->offset;
333		dirty_gfn_set_collected(cur);
334		(*fetch_index)++;
335		count++;
336	}
337
338	return count;
339}
340
341static void dirty_ring_wait_vcpu(void)
342{
343	/* This makes sure that hardware PML cache flushed */
344	vcpu_kick();
345	sem_wait_until(&sem_vcpu_stop);
346}
347
348static void dirty_ring_continue_vcpu(void)
349{
350	pr_info("Notifying vcpu to continue\n");
351	sem_post(&sem_vcpu_cont);
352}
353
354static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
355					   void *bitmap, uint32_t num_pages,
356					   uint32_t *ring_buf_idx)
357{
358	uint32_t count = 0, cleared;
359	bool continued_vcpu = false;
360
361	dirty_ring_wait_vcpu();
362
363	if (!dirty_ring_vcpu_ring_full) {
364		/*
365		 * This is not a ring-full event, it's safe to allow
366		 * vcpu to continue
367		 */
368		dirty_ring_continue_vcpu();
369		continued_vcpu = true;
370	}
371
372	/* Only have one vcpu */
373	count = dirty_ring_collect_one(vcpu_map_dirty_ring(vcpu),
374				       slot, bitmap, num_pages,
375				       ring_buf_idx);
376
377	cleared = kvm_vm_reset_dirty_ring(vcpu->vm);
378
379	/* Cleared pages should be the same as collected */
380	TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch "
381		    "with collected (%u)", cleared, count);
382
383	if (!continued_vcpu) {
384		TEST_ASSERT(dirty_ring_vcpu_ring_full,
385			    "Didn't continue vcpu even without ring full");
386		dirty_ring_continue_vcpu();
387	}
388
389	pr_info("Iteration %ld collected %u pages\n", iteration, count);
390}
391
392static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
393{
394	struct kvm_run *run = vcpu->run;
395
396	/* A ucall-sync or ring-full event is allowed */
397	if (get_ucall(vcpu, NULL) == UCALL_SYNC) {
398		/* We should allow this to continue */
399		;
400	} else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL ||
401		   (ret == -1 && err == EINTR)) {
402		/* Update the flag first before pause */
403		WRITE_ONCE(dirty_ring_vcpu_ring_full,
404			   run->exit_reason == KVM_EXIT_DIRTY_RING_FULL);
405		sem_post(&sem_vcpu_stop);
406		pr_info("vcpu stops because %s...\n",
407			dirty_ring_vcpu_ring_full ?
408			"dirty ring is full" : "vcpu is kicked out");
409		sem_wait_until(&sem_vcpu_cont);
410		pr_info("vcpu continues now.\n");
411	} else {
412		TEST_ASSERT(false, "Invalid guest sync status: "
413			    "exit_reason=%s\n",
414			    exit_reason_str(run->exit_reason));
415	}
416}
417
418static void dirty_ring_before_vcpu_join(void)
419{
420	/* Kick another round of vcpu just to make sure it will quit */
421	sem_post(&sem_vcpu_cont);
422}
423
424struct log_mode {
425	const char *name;
426	/* Return true if this mode is supported, otherwise false */
427	bool (*supported)(void);
428	/* Hook when the vm creation is done (before vcpu creation) */
429	void (*create_vm_done)(struct kvm_vm *vm);
430	/* Hook to collect the dirty pages into the bitmap provided */
431	void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot,
432				     void *bitmap, uint32_t num_pages,
433				     uint32_t *ring_buf_idx);
434	/* Hook to call when after each vcpu run */
435	void (*after_vcpu_run)(struct kvm_vcpu *vcpu, int ret, int err);
436	void (*before_vcpu_join) (void);
437} log_modes[LOG_MODE_NUM] = {
438	{
439		.name = "dirty-log",
440		.collect_dirty_pages = dirty_log_collect_dirty_pages,
441		.after_vcpu_run = default_after_vcpu_run,
442	},
443	{
444		.name = "clear-log",
445		.supported = clear_log_supported,
446		.create_vm_done = clear_log_create_vm_done,
447		.collect_dirty_pages = clear_log_collect_dirty_pages,
448		.after_vcpu_run = default_after_vcpu_run,
449	},
450	{
451		.name = "dirty-ring",
452		.supported = dirty_ring_supported,
453		.create_vm_done = dirty_ring_create_vm_done,
454		.collect_dirty_pages = dirty_ring_collect_dirty_pages,
455		.before_vcpu_join = dirty_ring_before_vcpu_join,
456		.after_vcpu_run = dirty_ring_after_vcpu_run,
457	},
458};
459
460/*
461 * We use this bitmap to track some pages that should have its dirty
462 * bit set in the _next_ iteration.  For example, if we detected the
463 * page value changed to current iteration but at the same time the
464 * page bit is cleared in the latest bitmap, then the system must
465 * report that write in the next get dirty log call.
466 */
467static unsigned long *host_bmap_track;
468
469static void log_modes_dump(void)
470{
471	int i;
472
473	printf("all");
474	for (i = 0; i < LOG_MODE_NUM; i++)
475		printf(", %s", log_modes[i].name);
476	printf("\n");
477}
478
479static bool log_mode_supported(void)
480{
481	struct log_mode *mode = &log_modes[host_log_mode];
482
483	if (mode->supported)
484		return mode->supported();
485
486	return true;
487}
488
489static void log_mode_create_vm_done(struct kvm_vm *vm)
490{
491	struct log_mode *mode = &log_modes[host_log_mode];
492
493	if (mode->create_vm_done)
494		mode->create_vm_done(vm);
495}
496
497static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
498					 void *bitmap, uint32_t num_pages,
499					 uint32_t *ring_buf_idx)
500{
501	struct log_mode *mode = &log_modes[host_log_mode];
502
503	TEST_ASSERT(mode->collect_dirty_pages != NULL,
504		    "collect_dirty_pages() is required for any log mode!");
505	mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx);
506}
507
508static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
509{
510	struct log_mode *mode = &log_modes[host_log_mode];
511
512	if (mode->after_vcpu_run)
513		mode->after_vcpu_run(vcpu, ret, err);
514}
515
516static void log_mode_before_vcpu_join(void)
517{
518	struct log_mode *mode = &log_modes[host_log_mode];
519
520	if (mode->before_vcpu_join)
521		mode->before_vcpu_join();
522}
523
524static void generate_random_array(uint64_t *guest_array, uint64_t size)
525{
526	uint64_t i;
527
528	for (i = 0; i < size; i++)
529		guest_array[i] = random();
530}
531
532static void *vcpu_worker(void *data)
533{
534	int ret;
535	struct kvm_vcpu *vcpu = data;
536	struct kvm_vm *vm = vcpu->vm;
537	uint64_t *guest_array;
538	uint64_t pages_count = 0;
539	struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset)
540						 + sizeof(sigset_t));
541	sigset_t *sigset = (sigset_t *) &sigmask->sigset;
542
543	/*
544	 * SIG_IPI is unblocked atomically while in KVM_RUN.  It causes the
545	 * ioctl to return with -EINTR, but it is still pending and we need
546	 * to accept it with the sigwait.
547	 */
548	sigmask->len = 8;
549	pthread_sigmask(0, NULL, sigset);
550	sigdelset(sigset, SIG_IPI);
551	vcpu_ioctl(vcpu, KVM_SET_SIGNAL_MASK, sigmask);
552
553	sigemptyset(sigset);
554	sigaddset(sigset, SIG_IPI);
555
556	guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
557
558	while (!READ_ONCE(host_quit)) {
559		/* Clear any existing kick signals */
560		generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
561		pages_count += TEST_PAGES_PER_LOOP;
562		/* Let the guest dirty the random pages */
563		ret = __vcpu_run(vcpu);
564		if (ret == -1 && errno == EINTR) {
565			int sig = -1;
566			sigwait(sigset, &sig);
567			assert(sig == SIG_IPI);
568		}
569		log_mode_after_vcpu_run(vcpu, ret, errno);
570	}
571
572	pr_info("Dirtied %"PRIu64" pages\n", pages_count);
573
574	return NULL;
575}
576
577static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap)
578{
579	uint64_t step = vm_num_host_pages(mode, 1);
580	uint64_t page;
581	uint64_t *value_ptr;
582	uint64_t min_iter = 0;
583
584	for (page = 0; page < host_num_pages; page += step) {
585		value_ptr = host_test_mem + page * host_page_size;
586
587		/* If this is a special page that we were tracking... */
588		if (__test_and_clear_bit_le(page, host_bmap_track)) {
589			host_track_next_count++;
590			TEST_ASSERT(test_bit_le(page, bmap),
591				    "Page %"PRIu64" should have its dirty bit "
592				    "set in this iteration but it is missing",
593				    page);
594		}
595
596		if (__test_and_clear_bit_le(page, bmap)) {
597			bool matched;
598
599			host_dirty_count++;
600
601			/*
602			 * If the bit is set, the value written onto
603			 * the corresponding page should be either the
604			 * previous iteration number or the current one.
605			 */
606			matched = (*value_ptr == iteration ||
607				   *value_ptr == iteration - 1);
608
609			if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) {
610				if (*value_ptr == iteration - 2 && min_iter <= iteration - 2) {
611					/*
612					 * Short answer: this case is special
613					 * only for dirty ring test where the
614					 * page is the last page before a kvm
615					 * dirty ring full in iteration N-2.
616					 *
617					 * Long answer: Assuming ring size R,
618					 * one possible condition is:
619					 *
620					 *      main thr       vcpu thr
621					 *      --------       --------
622					 *    iter=1
623					 *                   write 1 to page 0~(R-1)
624					 *                   full, vmexit
625					 *    collect 0~(R-1)
626					 *    kick vcpu
627					 *                   write 1 to (R-1)~(2R-2)
628					 *                   full, vmexit
629					 *    iter=2
630					 *    collect (R-1)~(2R-2)
631					 *    kick vcpu
632					 *                   write 1 to (2R-2)
633					 *                   (NOTE!!! "1" cached in cpu reg)
634					 *                   write 2 to (2R-1)~(3R-3)
635					 *                   full, vmexit
636					 *    iter=3
637					 *    collect (2R-2)~(3R-3)
638					 *    (here if we read value on page
639					 *     "2R-2" is 1, while iter=3!!!)
640					 *
641					 * This however can only happen once per iteration.
642					 */
643					min_iter = iteration - 1;
644					continue;
645				} else if (page == dirty_ring_last_page) {
646					/*
647					 * Please refer to comments in
648					 * dirty_ring_last_page.
649					 */
650					continue;
651				}
652			}
653
654			TEST_ASSERT(matched,
655				    "Set page %"PRIu64" value %"PRIu64
656				    " incorrect (iteration=%"PRIu64")",
657				    page, *value_ptr, iteration);
658		} else {
659			host_clear_count++;
660			/*
661			 * If cleared, the value written can be any
662			 * value smaller or equals to the iteration
663			 * number.  Note that the value can be exactly
664			 * (iteration-1) if that write can happen
665			 * like this:
666			 *
667			 * (1) increase loop count to "iteration-1"
668			 * (2) write to page P happens (with value
669			 *     "iteration-1")
670			 * (3) get dirty log for "iteration-1"; we'll
671			 *     see that page P bit is set (dirtied),
672			 *     and not set the bit in host_bmap_track
673			 * (4) increase loop count to "iteration"
674			 *     (which is current iteration)
675			 * (5) get dirty log for current iteration,
676			 *     we'll see that page P is cleared, with
677			 *     value "iteration-1".
678			 */
679			TEST_ASSERT(*value_ptr <= iteration,
680				    "Clear page %"PRIu64" value %"PRIu64
681				    " incorrect (iteration=%"PRIu64")",
682				    page, *value_ptr, iteration);
683			if (*value_ptr == iteration) {
684				/*
685				 * This page is _just_ modified; it
686				 * should report its dirtyness in the
687				 * next run
688				 */
689				__set_bit_le(page, host_bmap_track);
690			}
691		}
692	}
693}
694
695static struct kvm_vm *create_vm(enum vm_guest_mode mode, struct kvm_vcpu **vcpu,
696				uint64_t extra_mem_pages, void *guest_code)
697{
698	struct kvm_vm *vm;
699
700	pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
701
702	vm = __vm_create(mode, 1, extra_mem_pages);
703
704	log_mode_create_vm_done(vm);
705	*vcpu = vm_vcpu_add(vm, 0, guest_code);
706	return vm;
707}
708
709struct test_params {
710	unsigned long iterations;
711	unsigned long interval;
712	uint64_t phys_offset;
713};
714
715static void run_test(enum vm_guest_mode mode, void *arg)
716{
717	struct test_params *p = arg;
718	struct kvm_vcpu *vcpu;
719	struct kvm_vm *vm;
720	unsigned long *bmap;
721	uint32_t ring_buf_idx = 0;
722
723	if (!log_mode_supported()) {
724		print_skip("Log mode '%s' not supported",
725			   log_modes[host_log_mode].name);
726		return;
727	}
728
729	/*
730	 * We reserve page table for 2 times of extra dirty mem which
731	 * will definitely cover the original (1G+) test range.  Here
732	 * we do the calculation with 4K page size which is the
733	 * smallest so the page number will be enough for all archs
734	 * (e.g., 64K page size guest will need even less memory for
735	 * page tables).
736	 */
737	vm = create_vm(mode, &vcpu,
738		       2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), guest_code);
739
740	guest_page_size = vm->page_size;
741	/*
742	 * A little more than 1G of guest page sized pages.  Cover the
743	 * case where the size is not aligned to 64 pages.
744	 */
745	guest_num_pages = (1ul << (DIRTY_MEM_BITS - vm->page_shift)) + 3;
746	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
747
748	host_page_size = getpagesize();
749	host_num_pages = vm_num_host_pages(mode, guest_num_pages);
750
751	if (!p->phys_offset) {
752		guest_test_phys_mem = (vm->max_gfn - guest_num_pages) *
753				      guest_page_size;
754		guest_test_phys_mem = align_down(guest_test_phys_mem, host_page_size);
755	} else {
756		guest_test_phys_mem = p->phys_offset;
757	}
758
759#ifdef __s390x__
760	/* Align to 1M (segment size) */
761	guest_test_phys_mem = align_down(guest_test_phys_mem, 1 << 20);
762#endif
763
764	pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
765
766	bmap = bitmap_zalloc(host_num_pages);
767	host_bmap_track = bitmap_zalloc(host_num_pages);
768
769	/* Add an extra memory slot for testing dirty logging */
770	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
771				    guest_test_phys_mem,
772				    TEST_MEM_SLOT_INDEX,
773				    guest_num_pages,
774				    KVM_MEM_LOG_DIRTY_PAGES);
775
776	/* Do mapping for the dirty track memory slot */
777	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages);
778
779	/* Cache the HVA pointer of the region */
780	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
781
782	/* Export the shared variables to the guest */
783	sync_global_to_guest(vm, host_page_size);
784	sync_global_to_guest(vm, guest_page_size);
785	sync_global_to_guest(vm, guest_test_virt_mem);
786	sync_global_to_guest(vm, guest_num_pages);
787
788	/* Start the iterations */
789	iteration = 1;
790	sync_global_to_guest(vm, iteration);
791	host_quit = false;
792	host_dirty_count = 0;
793	host_clear_count = 0;
794	host_track_next_count = 0;
795	WRITE_ONCE(dirty_ring_vcpu_ring_full, false);
796
797	pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu);
798
799	while (iteration < p->iterations) {
800		/* Give the vcpu thread some time to dirty some pages */
801		usleep(p->interval * 1000);
802		log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,
803					     bmap, host_num_pages,
804					     &ring_buf_idx);
805
806		/*
807		 * See vcpu_sync_stop_requested definition for details on why
808		 * we need to stop vcpu when verify data.
809		 */
810		atomic_set(&vcpu_sync_stop_requested, true);
811		sem_wait_until(&sem_vcpu_stop);
812		/*
813		 * NOTE: for dirty ring, it's possible that we didn't stop at
814		 * GUEST_SYNC but instead we stopped because ring is full;
815		 * that's okay too because ring full means we're only missing
816		 * the flush of the last page, and since we handle the last
817		 * page specially verification will succeed anyway.
818		 */
819		assert(host_log_mode == LOG_MODE_DIRTY_RING ||
820		       atomic_read(&vcpu_sync_stop_requested) == false);
821		vm_dirty_log_verify(mode, bmap);
822		sem_post(&sem_vcpu_cont);
823
824		iteration++;
825		sync_global_to_guest(vm, iteration);
826	}
827
828	/* Tell the vcpu thread to quit */
829	host_quit = true;
830	log_mode_before_vcpu_join();
831	pthread_join(vcpu_thread, NULL);
832
833	pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
834		"track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
835		host_track_next_count);
836
837	free(bmap);
838	free(host_bmap_track);
839	kvm_vm_free(vm);
840}
841
842static void help(char *name)
843{
844	puts("");
845	printf("usage: %s [-h] [-i iterations] [-I interval] "
846	       "[-p offset] [-m mode]\n", name);
847	puts("");
848	printf(" -c: hint to dirty ring size, in number of entries\n");
849	printf("     (only useful for dirty-ring test; default: %"PRIu32")\n",
850	       TEST_DIRTY_RING_COUNT);
851	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
852	       TEST_HOST_LOOP_N);
853	printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
854	       TEST_HOST_LOOP_INTERVAL);
855	printf(" -p: specify guest physical test memory offset\n"
856	       "     Warning: a low offset can conflict with the loaded test code.\n");
857	printf(" -M: specify the host logging mode "
858	       "(default: run all log modes).  Supported modes: \n\t");
859	log_modes_dump();
860	guest_modes_help();
861	puts("");
862	exit(0);
863}
864
865int main(int argc, char *argv[])
866{
867	struct test_params p = {
868		.iterations = TEST_HOST_LOOP_N,
869		.interval = TEST_HOST_LOOP_INTERVAL,
870	};
871	int opt, i;
872	sigset_t sigset;
873
874	sem_init(&sem_vcpu_stop, 0, 0);
875	sem_init(&sem_vcpu_cont, 0, 0);
876
877	guest_modes_append_default();
878
879	while ((opt = getopt(argc, argv, "c:hi:I:p:m:M:")) != -1) {
880		switch (opt) {
881		case 'c':
882			test_dirty_ring_count = strtol(optarg, NULL, 10);
883			break;
884		case 'i':
885			p.iterations = strtol(optarg, NULL, 10);
886			break;
887		case 'I':
888			p.interval = strtol(optarg, NULL, 10);
889			break;
890		case 'p':
891			p.phys_offset = strtoull(optarg, NULL, 0);
892			break;
893		case 'm':
894			guest_modes_cmdline(optarg);
895			break;
896		case 'M':
897			if (!strcmp(optarg, "all")) {
898				host_log_mode_option = LOG_MODE_ALL;
899				break;
900			}
901			for (i = 0; i < LOG_MODE_NUM; i++) {
902				if (!strcmp(optarg, log_modes[i].name)) {
903					pr_info("Setting log mode to: '%s'\n",
904						optarg);
905					host_log_mode_option = i;
906					break;
907				}
908			}
909			if (i == LOG_MODE_NUM) {
910				printf("Log mode '%s' invalid. Please choose "
911				       "from: ", optarg);
912				log_modes_dump();
913				exit(1);
914			}
915			break;
916		case 'h':
917		default:
918			help(argv[0]);
919			break;
920		}
921	}
922
923	TEST_ASSERT(p.iterations > 2, "Iterations must be greater than two");
924	TEST_ASSERT(p.interval > 0, "Interval must be greater than zero");
925
926	pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
927		p.iterations, p.interval);
928
929	srandom(time(0));
930
931	/* Ensure that vCPU threads start with SIG_IPI blocked.  */
932	sigemptyset(&sigset);
933	sigaddset(&sigset, SIG_IPI);
934	pthread_sigmask(SIG_BLOCK, &sigset, NULL);
935
936	if (host_log_mode_option == LOG_MODE_ALL) {
937		/* Run each log mode */
938		for (i = 0; i < LOG_MODE_NUM; i++) {
939			pr_info("Testing Log Mode '%s'\n", log_modes[i].name);
940			host_log_mode = i;
941			for_each_guest_mode(run_test, &p);
942		}
943	} else {
944		host_log_mode = host_log_mode_option;
945		for_each_guest_mode(run_test, &p);
946	}
947
948	return 0;
949}