1// SPDX-License-Identifier: GPL-2.0
2/*
3 * A memslot-related performance benchmark.
4 *
5 * Copyright (C) 2021 Oracle and/or its affiliates.
6 *
7 * Basic guest setup / host vCPU thread code lifted from set_memory_region_test.
8 */
9#include <pthread.h>
10#include <sched.h>
11#include <semaphore.h>
12#include <stdatomic.h>
13#include <stdbool.h>
14#include <stdint.h>
15#include <stdio.h>
16#include <stdlib.h>
17#include <string.h>
18#include <sys/mman.h>
19#include <time.h>
20#include <unistd.h>
21
22#include <linux/compiler.h>
23#include <linux/sizes.h>
24
25#include <test_util.h>
26#include <kvm_util.h>
27#include <processor.h>
28
29#define MEM_EXTRA_SIZE SZ_64K
30
31#define MEM_SIZE (SZ_512M + MEM_EXTRA_SIZE)
32#define MEM_GPA SZ_256M
33#define MEM_AUX_GPA MEM_GPA
34#define MEM_SYNC_GPA MEM_AUX_GPA
35#define MEM_TEST_GPA (MEM_AUX_GPA + MEM_EXTRA_SIZE)
36#define MEM_TEST_SIZE (MEM_SIZE - MEM_EXTRA_SIZE)
37
38/*
39 * 32 MiB is max size that gets well over 100 iterations on 509 slots.
40 * Considering that each slot needs to have at least one page up to
41 * 8194 slots in use can then be tested (although with slightly
42 * limited resolution).
43 */
44#define MEM_SIZE_MAP (SZ_32M + MEM_EXTRA_SIZE)
45#define MEM_TEST_MAP_SIZE (MEM_SIZE_MAP - MEM_EXTRA_SIZE)
46
47/*
48 * 128 MiB is min size that fills 32k slots with at least one page in each
49 * while at the same time gets 100+ iterations in such test
50 *
51 * 2 MiB chunk size like a typical huge page
52 */
53#define MEM_TEST_UNMAP_SIZE SZ_128M
54#define MEM_TEST_UNMAP_CHUNK_SIZE SZ_2M
55
56/*
57 * For the move active test the middle of the test area is placed on
58 * a memslot boundary: half lies in the memslot being moved, half in
59 * other memslot(s).
60 *
61 * We have different number of memory slots, excluding the reserved
62 * memory slot 0, on various architectures and configurations. The
63 * memory size in this test is calculated by picking the maximal
64 * last memory slot's memory size, with alignment to the largest
65 * supported page size (64KB). In this way, the selected memory
66 * size for this test is compatible with test_memslot_move_prepare().
67 *
68 * architecture slots memory-per-slot memory-on-last-slot
69 * --------------------------------------------------------------
70 * x86-4KB 32763 16KB 160KB
71 * arm64-4KB 32766 16KB 112KB
72 * arm64-16KB 32766 16KB 112KB
73 * arm64-64KB 8192 64KB 128KB
74 */
75#define MEM_TEST_MOVE_SIZE (3 * SZ_64K)
76#define MEM_TEST_MOVE_GPA_DEST (MEM_GPA + MEM_SIZE)
77static_assert(MEM_TEST_MOVE_SIZE <= MEM_TEST_SIZE,
78 "invalid move test region size");
79
80#define MEM_TEST_VAL_1 0x1122334455667788
81#define MEM_TEST_VAL_2 0x99AABBCCDDEEFF00
82
83struct vm_data {
84 struct kvm_vm *vm;
85 struct kvm_vcpu *vcpu;
86 pthread_t vcpu_thread;
87 uint32_t nslots;
88 uint64_t npages;
89 uint64_t pages_per_slot;
90 void **hva_slots;
91 bool mmio_ok;
92 uint64_t mmio_gpa_min;
93 uint64_t mmio_gpa_max;
94};
95
96struct sync_area {
97 uint32_t guest_page_size;
98 atomic_bool start_flag;
99 atomic_bool exit_flag;
100 atomic_bool sync_flag;
101 void *move_area_ptr;
102};
103
104/*
105 * Technically, we need also for the atomic bool to be address-free, which
106 * is recommended, but not strictly required, by C11 for lockless
107 * implementations.
108 * However, in practice both GCC and Clang fulfill this requirement on
109 * all KVM-supported platforms.
110 */
111static_assert(ATOMIC_BOOL_LOCK_FREE == 2, "atomic bool is not lockless");
112
113static sem_t vcpu_ready;
114
115static bool map_unmap_verify;
116
117static bool verbose;
118#define pr_info_v(...) \
119 do { \
120 if (verbose) \
121 pr_info(__VA_ARGS__); \
122 } while (0)
123
124static void check_mmio_access(struct vm_data *data, struct kvm_run *run)
125{
126 TEST_ASSERT(data->mmio_ok, "Unexpected mmio exit");
127 TEST_ASSERT(run->mmio.is_write, "Unexpected mmio read");
128 TEST_ASSERT(run->mmio.len == 8,
129 "Unexpected exit mmio size = %u", run->mmio.len);
130 TEST_ASSERT(run->mmio.phys_addr >= data->mmio_gpa_min &&
131 run->mmio.phys_addr <= data->mmio_gpa_max,
132 "Unexpected exit mmio address = 0x%llx",
133 run->mmio.phys_addr);
134}
135
136static void *vcpu_worker(void *__data)
137{
138 struct vm_data *data = __data;
139 struct kvm_vcpu *vcpu = data->vcpu;
140 struct kvm_run *run = vcpu->run;
141 struct ucall uc;
142
143 while (1) {
144 vcpu_run(vcpu);
145
146 switch (get_ucall(vcpu, &uc)) {
147 case UCALL_SYNC:
148 TEST_ASSERT(uc.args[1] == 0,
149 "Unexpected sync ucall, got %lx",
150 (ulong)uc.args[1]);
151 sem_post(&vcpu_ready);
152 continue;
153 case UCALL_NONE:
154 if (run->exit_reason == KVM_EXIT_MMIO)
155 check_mmio_access(data, run);
156 else
157 goto done;
158 break;
159 case UCALL_ABORT:
160 REPORT_GUEST_ASSERT(uc);
161 break;
162 case UCALL_DONE:
163 goto done;
164 default:
165 TEST_FAIL("Unknown ucall %lu", uc.cmd);
166 }
167 }
168
169done:
170 return NULL;
171}
172
173static void wait_for_vcpu(void)
174{
175 struct timespec ts;
176
177 TEST_ASSERT(!clock_gettime(CLOCK_REALTIME, &ts),
178 "clock_gettime() failed: %d", errno);
179
180 ts.tv_sec += 2;
181 TEST_ASSERT(!sem_timedwait(&vcpu_ready, &ts),
182 "sem_timedwait() failed: %d", errno);
183}
184
185static void *vm_gpa2hva(struct vm_data *data, uint64_t gpa, uint64_t *rempages)
186{
187 uint64_t gpage, pgoffs;
188 uint32_t slot, slotoffs;
189 void *base;
190 uint32_t guest_page_size = data->vm->page_size;
191
192 TEST_ASSERT(gpa >= MEM_GPA, "Too low gpa to translate");
193 TEST_ASSERT(gpa < MEM_GPA + data->npages * guest_page_size,
194 "Too high gpa to translate");
195 gpa -= MEM_GPA;
196
197 gpage = gpa / guest_page_size;
198 pgoffs = gpa % guest_page_size;
199 slot = min(gpage / data->pages_per_slot, (uint64_t)data->nslots - 1);
200 slotoffs = gpage - (slot * data->pages_per_slot);
201
202 if (rempages) {
203 uint64_t slotpages;
204
205 if (slot == data->nslots - 1)
206 slotpages = data->npages - slot * data->pages_per_slot;
207 else
208 slotpages = data->pages_per_slot;
209
210 TEST_ASSERT(!pgoffs,
211 "Asking for remaining pages in slot but gpa not page aligned");
212 *rempages = slotpages - slotoffs;
213 }
214
215 base = data->hva_slots[slot];
216 return (uint8_t *)base + slotoffs * guest_page_size + pgoffs;
217}
218
219static uint64_t vm_slot2gpa(struct vm_data *data, uint32_t slot)
220{
221 uint32_t guest_page_size = data->vm->page_size;
222
223 TEST_ASSERT(slot < data->nslots, "Too high slot number");
224
225 return MEM_GPA + slot * data->pages_per_slot * guest_page_size;
226}
227
228static struct vm_data *alloc_vm(void)
229{
230 struct vm_data *data;
231
232 data = malloc(sizeof(*data));
233 TEST_ASSERT(data, "malloc(vmdata) failed");
234
235 data->vm = NULL;
236 data->vcpu = NULL;
237 data->hva_slots = NULL;
238
239 return data;
240}
241
242static bool check_slot_pages(uint32_t host_page_size, uint32_t guest_page_size,
243 uint64_t pages_per_slot, uint64_t rempages)
244{
245 if (!pages_per_slot)
246 return false;
247
248 if ((pages_per_slot * guest_page_size) % host_page_size)
249 return false;
250
251 if ((rempages * guest_page_size) % host_page_size)
252 return false;
253
254 return true;
255}
256
257
258static uint64_t get_max_slots(struct vm_data *data, uint32_t host_page_size)
259{
260 uint32_t guest_page_size = data->vm->page_size;
261 uint64_t mempages, pages_per_slot, rempages;
262 uint64_t slots;
263
264 mempages = data->npages;
265 slots = data->nslots;
266 while (--slots > 1) {
267 pages_per_slot = mempages / slots;
268 if (!pages_per_slot)
269 continue;
270
271 rempages = mempages % pages_per_slot;
272 if (check_slot_pages(host_page_size, guest_page_size,
273 pages_per_slot, rempages))
274 return slots + 1; /* slot 0 is reserved */
275 }
276
277 return 0;
278}
279
280static bool prepare_vm(struct vm_data *data, int nslots, uint64_t *maxslots,
281 void *guest_code, uint64_t mem_size,
282 struct timespec *slot_runtime)
283{
284 uint64_t mempages, rempages;
285 uint64_t guest_addr;
286 uint32_t slot, host_page_size, guest_page_size;
287 struct timespec tstart;
288 struct sync_area *sync;
289
290 host_page_size = getpagesize();
291 guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size;
292 mempages = mem_size / guest_page_size;
293
294 data->vm = __vm_create_with_one_vcpu(&data->vcpu, mempages, guest_code);
295 TEST_ASSERT(data->vm->page_size == guest_page_size, "Invalid VM page size");
296
297 data->npages = mempages;
298 TEST_ASSERT(data->npages > 1, "Can't test without any memory");
299 data->nslots = nslots;
300 data->pages_per_slot = data->npages / data->nslots;
301 rempages = data->npages % data->nslots;
302 if (!check_slot_pages(host_page_size, guest_page_size,
303 pages_per_slot: data->pages_per_slot, rempages)) {
304 *maxslots = get_max_slots(data, host_page_size);
305 return false;
306 }
307
308 data->hva_slots = malloc(sizeof(*data->hva_slots) * data->nslots);
309 TEST_ASSERT(data->hva_slots, "malloc() fail");
310
311 pr_info_v("Adding slots 1..%i, each slot with %"PRIu64" pages + %"PRIu64" extra pages last\n",
312 data->nslots, data->pages_per_slot, rempages);
313
314 clock_gettime(CLOCK_MONOTONIC, &tstart);
315 for (slot = 1, guest_addr = MEM_GPA; slot <= data->nslots; slot++) {
316 uint64_t npages;
317
318 npages = data->pages_per_slot;
319 if (slot == data->nslots)
320 npages += rempages;
321
322 vm_userspace_mem_region_add(data->vm, VM_MEM_SRC_ANONYMOUS,
323 guest_addr, slot, npages,
324 0);
325 guest_addr += npages * guest_page_size;
326 }
327 *slot_runtime = timespec_elapsed(tstart);
328
329 for (slot = 1, guest_addr = MEM_GPA; slot <= data->nslots; slot++) {
330 uint64_t npages;
331 uint64_t gpa;
332
333 npages = data->pages_per_slot;
334 if (slot == data->nslots)
335 npages += rempages;
336
337 gpa = vm_phy_pages_alloc(data->vm, npages, guest_addr, slot);
338 TEST_ASSERT(gpa == guest_addr,
339 "vm_phy_pages_alloc() failed");
340
341 data->hva_slots[slot - 1] = addr_gpa2hva(data->vm, guest_addr);
342 memset(data->hva_slots[slot - 1], 0, npages * guest_page_size);
343
344 guest_addr += npages * guest_page_size;
345 }
346
347 virt_map(data->vm, MEM_GPA, MEM_GPA, data->npages);
348
349 sync = (typeof(sync))vm_gpa2hva(data, MEM_SYNC_GPA, NULL);
350 sync->guest_page_size = data->vm->page_size;
351 atomic_init(&sync->start_flag, false);
352 atomic_init(&sync->exit_flag, false);
353 atomic_init(&sync->sync_flag, false);
354
355 data->mmio_ok = false;
356
357 return true;
358}
359
360static void launch_vm(struct vm_data *data)
361{
362 pr_info_v("Launching the test VM\n");
363
364 pthread_create(&data->vcpu_thread, NULL, vcpu_worker, data);
365
366 /* Ensure the guest thread is spun up. */
367 wait_for_vcpu();
368}
369
370static void free_vm(struct vm_data *data)
371{
372 kvm_vm_free(data->vm);
373 free(data->hva_slots);
374 free(data);
375}
376
377static void wait_guest_exit(struct vm_data *data)
378{
379 pthread_join(data->vcpu_thread, NULL);
380}
381
382static void let_guest_run(struct sync_area *sync)
383{
384 atomic_store_explicit(&sync->start_flag, true, memory_order_release);
385}
386
387static void guest_spin_until_start(void)
388{
389 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
390
391 while (!atomic_load_explicit(&sync->start_flag, memory_order_acquire))
392 ;
393}
394
395static void make_guest_exit(struct sync_area *sync)
396{
397 atomic_store_explicit(&sync->exit_flag, true, memory_order_release);
398}
399
400static bool _guest_should_exit(void)
401{
402 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
403
404 return atomic_load_explicit(&sync->exit_flag, memory_order_acquire);
405}
406
407#define guest_should_exit() unlikely(_guest_should_exit())
408
409/*
410 * noinline so we can easily see how much time the host spends waiting
411 * for the guest.
412 * For the same reason use alarm() instead of polling clock_gettime()
413 * to implement a wait timeout.
414 */
415static noinline void host_perform_sync(struct sync_area *sync)
416{
417 alarm(2);
418
419 atomic_store_explicit(&sync->sync_flag, true, memory_order_release);
420 while (atomic_load_explicit(&sync->sync_flag, memory_order_acquire))
421 ;
422
423 alarm(0);
424}
425
426static bool guest_perform_sync(void)
427{
428 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
429 bool expected;
430
431 do {
432 if (guest_should_exit())
433 return false;
434
435 expected = true;
436 } while (!atomic_compare_exchange_weak_explicit(&sync->sync_flag,
437 &expected, false,
438 memory_order_acq_rel,
439 memory_order_relaxed));
440
441 return true;
442}
443
444static void guest_code_test_memslot_move(void)
445{
446 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
447 uint32_t page_size = (typeof(page_size))READ_ONCE(sync->guest_page_size);
448 uintptr_t base = (typeof(base))READ_ONCE(sync->move_area_ptr);
449
450 GUEST_SYNC(0);
451
452 guest_spin_until_start();
453
454 while (!guest_should_exit()) {
455 uintptr_t ptr;
456
457 for (ptr = base; ptr < base + MEM_TEST_MOVE_SIZE;
458 ptr += page_size)
459 *(uint64_t *)ptr = MEM_TEST_VAL_1;
460
461 /*
462 * No host sync here since the MMIO exits are so expensive
463 * that the host would spend most of its time waiting for
464 * the guest and so instead of measuring memslot move
465 * performance we would measure the performance and
466 * likelihood of MMIO exits
467 */
468 }
469
470 GUEST_DONE();
471}
472
473static void guest_code_test_memslot_map(void)
474{
475 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
476 uint32_t page_size = (typeof(page_size))READ_ONCE(sync->guest_page_size);
477
478 GUEST_SYNC(0);
479
480 guest_spin_until_start();
481
482 while (1) {
483 uintptr_t ptr;
484
485 for (ptr = MEM_TEST_GPA;
486 ptr < MEM_TEST_GPA + MEM_TEST_MAP_SIZE / 2;
487 ptr += page_size)
488 *(uint64_t *)ptr = MEM_TEST_VAL_1;
489
490 if (!guest_perform_sync())
491 break;
492
493 for (ptr = MEM_TEST_GPA + MEM_TEST_MAP_SIZE / 2;
494 ptr < MEM_TEST_GPA + MEM_TEST_MAP_SIZE;
495 ptr += page_size)
496 *(uint64_t *)ptr = MEM_TEST_VAL_2;
497
498 if (!guest_perform_sync())
499 break;
500 }
501
502 GUEST_DONE();
503}
504
505static void guest_code_test_memslot_unmap(void)
506{
507 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
508
509 GUEST_SYNC(0);
510
511 guest_spin_until_start();
512
513 while (1) {
514 uintptr_t ptr = MEM_TEST_GPA;
515
516 /*
517 * We can afford to access (map) just a small number of pages
518 * per host sync as otherwise the host will spend
519 * a significant amount of its time waiting for the guest
520 * (instead of doing unmap operations), so this will
521 * effectively turn this test into a map performance test.
522 *
523 * Just access a single page to be on the safe side.
524 */
525 *(uint64_t *)ptr = MEM_TEST_VAL_1;
526
527 if (!guest_perform_sync())
528 break;
529
530 ptr += MEM_TEST_UNMAP_SIZE / 2;
531 *(uint64_t *)ptr = MEM_TEST_VAL_2;
532
533 if (!guest_perform_sync())
534 break;
535 }
536
537 GUEST_DONE();
538}
539
540static void guest_code_test_memslot_rw(void)
541{
542 struct sync_area *sync = (typeof(sync))MEM_SYNC_GPA;
543 uint32_t page_size = (typeof(page_size))READ_ONCE(sync->guest_page_size);
544
545 GUEST_SYNC(0);
546
547 guest_spin_until_start();
548
549 while (1) {
550 uintptr_t ptr;
551
552 for (ptr = MEM_TEST_GPA;
553 ptr < MEM_TEST_GPA + MEM_TEST_SIZE; ptr += page_size)
554 *(uint64_t *)ptr = MEM_TEST_VAL_1;
555
556 if (!guest_perform_sync())
557 break;
558
559 for (ptr = MEM_TEST_GPA + page_size / 2;
560 ptr < MEM_TEST_GPA + MEM_TEST_SIZE; ptr += page_size) {
561 uint64_t val = *(uint64_t *)ptr;
562
563 GUEST_ASSERT_EQ(val, MEM_TEST_VAL_2);
564 *(uint64_t *)ptr = 0;
565 }
566
567 if (!guest_perform_sync())
568 break;
569 }
570
571 GUEST_DONE();
572}
573
574static bool test_memslot_move_prepare(struct vm_data *data,
575 struct sync_area *sync,
576 uint64_t *maxslots, bool isactive)
577{
578 uint32_t guest_page_size = data->vm->page_size;
579 uint64_t movesrcgpa, movetestgpa;
580
581 movesrcgpa = vm_slot2gpa(data, slot: data->nslots - 1);
582
583 if (isactive) {
584 uint64_t lastpages;
585
586 vm_gpa2hva(data, gpa: movesrcgpa, rempages: &lastpages);
587 if (lastpages * guest_page_size < MEM_TEST_MOVE_SIZE / 2) {
588 *maxslots = 0;
589 return false;
590 }
591 }
592
593 movetestgpa = movesrcgpa - (MEM_TEST_MOVE_SIZE / (isactive ? 2 : 1));
594 sync->move_area_ptr = (void *)movetestgpa;
595
596 if (isactive) {
597 data->mmio_ok = true;
598 data->mmio_gpa_min = movesrcgpa;
599 data->mmio_gpa_max = movesrcgpa + MEM_TEST_MOVE_SIZE / 2 - 1;
600 }
601
602 return true;
603}
604
605static bool test_memslot_move_prepare_active(struct vm_data *data,
606 struct sync_area *sync,
607 uint64_t *maxslots)
608{
609 return test_memslot_move_prepare(data, sync, maxslots, isactive: true);
610}
611
612static bool test_memslot_move_prepare_inactive(struct vm_data *data,
613 struct sync_area *sync,
614 uint64_t *maxslots)
615{
616 return test_memslot_move_prepare(data, sync, maxslots, isactive: false);
617}
618
619static void test_memslot_move_loop(struct vm_data *data, struct sync_area *sync)
620{
621 uint64_t movesrcgpa;
622
623 movesrcgpa = vm_slot2gpa(data, slot: data->nslots - 1);
624 vm_mem_region_move(data->vm, data->nslots - 1 + 1,
625 MEM_TEST_MOVE_GPA_DEST);
626 vm_mem_region_move(data->vm, data->nslots - 1 + 1, movesrcgpa);
627}
628
629static void test_memslot_do_unmap(struct vm_data *data,
630 uint64_t offsp, uint64_t count)
631{
632 uint64_t gpa, ctr;
633 uint32_t guest_page_size = data->vm->page_size;
634
635 for (gpa = MEM_TEST_GPA + offsp * guest_page_size, ctr = 0; ctr < count; ) {
636 uint64_t npages;
637 void *hva;
638 int ret;
639
640 hva = vm_gpa2hva(data, gpa, rempages: &npages);
641 TEST_ASSERT(npages, "Empty memory slot at gptr 0x%"PRIx64, gpa);
642 npages = min(npages, count - ctr);
643 ret = madvise(hva, npages * guest_page_size, MADV_DONTNEED);
644 TEST_ASSERT(!ret,
645 "madvise(%p, MADV_DONTNEED) on VM memory should not fail for gptr 0x%"PRIx64,
646 hva, gpa);
647 ctr += npages;
648 gpa += npages * guest_page_size;
649 }
650 TEST_ASSERT(ctr == count,
651 "madvise(MADV_DONTNEED) should exactly cover all of the requested area");
652}
653
654static void test_memslot_map_unmap_check(struct vm_data *data,
655 uint64_t offsp, uint64_t valexp)
656{
657 uint64_t gpa;
658 uint64_t *val;
659 uint32_t guest_page_size = data->vm->page_size;
660
661 if (!map_unmap_verify)
662 return;
663
664 gpa = MEM_TEST_GPA + offsp * guest_page_size;
665 val = (typeof(val))vm_gpa2hva(data, gpa, NULL);
666 TEST_ASSERT(*val == valexp,
667 "Guest written values should read back correctly before unmap (%"PRIu64" vs %"PRIu64" @ %"PRIx64")",
668 *val, valexp, gpa);
669 *val = 0;
670}
671
672static void test_memslot_map_loop(struct vm_data *data, struct sync_area *sync)
673{
674 uint32_t guest_page_size = data->vm->page_size;
675 uint64_t guest_pages = MEM_TEST_MAP_SIZE / guest_page_size;
676
677 /*
678 * Unmap the second half of the test area while guest writes to (maps)
679 * the first half.
680 */
681 test_memslot_do_unmap(data, offsp: guest_pages / 2, count: guest_pages / 2);
682
683 /*
684 * Wait for the guest to finish writing the first half of the test
685 * area, verify the written value on the first and the last page of
686 * this area and then unmap it.
687 * Meanwhile, the guest is writing to (mapping) the second half of
688 * the test area.
689 */
690 host_perform_sync(sync);
691 test_memslot_map_unmap_check(data, offsp: 0, MEM_TEST_VAL_1);
692 test_memslot_map_unmap_check(data, offsp: guest_pages / 2 - 1, MEM_TEST_VAL_1);
693 test_memslot_do_unmap(data, offsp: 0, count: guest_pages / 2);
694
695
696 /*
697 * Wait for the guest to finish writing the second half of the test
698 * area and verify the written value on the first and the last page
699 * of this area.
700 * The area will be unmapped at the beginning of the next loop
701 * iteration.
702 * Meanwhile, the guest is writing to (mapping) the first half of
703 * the test area.
704 */
705 host_perform_sync(sync);
706 test_memslot_map_unmap_check(data, offsp: guest_pages / 2, MEM_TEST_VAL_2);
707 test_memslot_map_unmap_check(data, offsp: guest_pages - 1, MEM_TEST_VAL_2);
708}
709
710static void test_memslot_unmap_loop_common(struct vm_data *data,
711 struct sync_area *sync,
712 uint64_t chunk)
713{
714 uint32_t guest_page_size = data->vm->page_size;
715 uint64_t guest_pages = MEM_TEST_UNMAP_SIZE / guest_page_size;
716 uint64_t ctr;
717
718 /*
719 * Wait for the guest to finish mapping page(s) in the first half
720 * of the test area, verify the written value and then perform unmap
721 * of this area.
722 * Meanwhile, the guest is writing to (mapping) page(s) in the second
723 * half of the test area.
724 */
725 host_perform_sync(sync);
726 test_memslot_map_unmap_check(data, offsp: 0, MEM_TEST_VAL_1);
727 for (ctr = 0; ctr < guest_pages / 2; ctr += chunk)
728 test_memslot_do_unmap(data, offsp: ctr, count: chunk);
729
730 /* Likewise, but for the opposite host / guest areas */
731 host_perform_sync(sync);
732 test_memslot_map_unmap_check(data, offsp: guest_pages / 2, MEM_TEST_VAL_2);
733 for (ctr = guest_pages / 2; ctr < guest_pages; ctr += chunk)
734 test_memslot_do_unmap(data, offsp: ctr, count: chunk);
735}
736
737static void test_memslot_unmap_loop(struct vm_data *data,
738 struct sync_area *sync)
739{
740 uint32_t host_page_size = getpagesize();
741 uint32_t guest_page_size = data->vm->page_size;
742 uint64_t guest_chunk_pages = guest_page_size >= host_page_size ?
743 1 : host_page_size / guest_page_size;
744
745 test_memslot_unmap_loop_common(data, sync, chunk: guest_chunk_pages);
746}
747
748static void test_memslot_unmap_loop_chunked(struct vm_data *data,
749 struct sync_area *sync)
750{
751 uint32_t guest_page_size = data->vm->page_size;
752 uint64_t guest_chunk_pages = MEM_TEST_UNMAP_CHUNK_SIZE / guest_page_size;
753
754 test_memslot_unmap_loop_common(data, sync, chunk: guest_chunk_pages);
755}
756
757static void test_memslot_rw_loop(struct vm_data *data, struct sync_area *sync)
758{
759 uint64_t gptr;
760 uint32_t guest_page_size = data->vm->page_size;
761
762 for (gptr = MEM_TEST_GPA + guest_page_size / 2;
763 gptr < MEM_TEST_GPA + MEM_TEST_SIZE; gptr += guest_page_size)
764 *(uint64_t *)vm_gpa2hva(data, gpa: gptr, NULL) = MEM_TEST_VAL_2;
765
766 host_perform_sync(sync);
767
768 for (gptr = MEM_TEST_GPA;
769 gptr < MEM_TEST_GPA + MEM_TEST_SIZE; gptr += guest_page_size) {
770 uint64_t *vptr = (typeof(vptr))vm_gpa2hva(data, gpa: gptr, NULL);
771 uint64_t val = *vptr;
772
773 TEST_ASSERT(val == MEM_TEST_VAL_1,
774 "Guest written values should read back correctly (is %"PRIu64" @ %"PRIx64")",
775 val, gptr);
776 *vptr = 0;
777 }
778
779 host_perform_sync(sync);
780}
781
782struct test_data {
783 const char *name;
784 uint64_t mem_size;
785 void (*guest_code)(void);
786 bool (*prepare)(struct vm_data *data, struct sync_area *sync,
787 uint64_t *maxslots);
788 void (*loop)(struct vm_data *data, struct sync_area *sync);
789};
790
791static bool test_execute(int nslots, uint64_t *maxslots,
792 unsigned int maxtime,
793 const struct test_data *tdata,
794 uint64_t *nloops,
795 struct timespec *slot_runtime,
796 struct timespec *guest_runtime)
797{
798 uint64_t mem_size = tdata->mem_size ? : MEM_SIZE;
799 struct vm_data *data;
800 struct sync_area *sync;
801 struct timespec tstart;
802 bool ret = true;
803
804 data = alloc_vm();
805 if (!prepare_vm(data, nslots, maxslots, guest_code: tdata->guest_code,
806 mem_size, slot_runtime)) {
807 ret = false;
808 goto exit_free;
809 }
810
811 sync = (typeof(sync))vm_gpa2hva(data, MEM_SYNC_GPA, NULL);
812 if (tdata->prepare &&
813 !tdata->prepare(data, sync, maxslots)) {
814 ret = false;
815 goto exit_free;
816 }
817
818 launch_vm(data);
819
820 clock_gettime(CLOCK_MONOTONIC, &tstart);
821 let_guest_run(sync);
822
823 while (1) {
824 *guest_runtime = timespec_elapsed(tstart);
825 if (guest_runtime->tv_sec >= maxtime)
826 break;
827
828 tdata->loop(data, sync);
829
830 (*nloops)++;
831 }
832
833 make_guest_exit(sync);
834 wait_guest_exit(data);
835
836exit_free:
837 free_vm(data);
838
839 return ret;
840}
841
842static const struct test_data tests[] = {
843 {
844 .name = "map",
845 .mem_size = MEM_SIZE_MAP,
846 .guest_code = guest_code_test_memslot_map,
847 .loop = test_memslot_map_loop,
848 },
849 {
850 .name = "unmap",
851 .mem_size = MEM_TEST_UNMAP_SIZE + MEM_EXTRA_SIZE,
852 .guest_code = guest_code_test_memslot_unmap,
853 .loop = test_memslot_unmap_loop,
854 },
855 {
856 .name = "unmap chunked",
857 .mem_size = MEM_TEST_UNMAP_SIZE + MEM_EXTRA_SIZE,
858 .guest_code = guest_code_test_memslot_unmap,
859 .loop = test_memslot_unmap_loop_chunked,
860 },
861 {
862 .name = "move active area",
863 .guest_code = guest_code_test_memslot_move,
864 .prepare = test_memslot_move_prepare_active,
865 .loop = test_memslot_move_loop,
866 },
867 {
868 .name = "move inactive area",
869 .guest_code = guest_code_test_memslot_move,
870 .prepare = test_memslot_move_prepare_inactive,
871 .loop = test_memslot_move_loop,
872 },
873 {
874 .name = "RW",
875 .guest_code = guest_code_test_memslot_rw,
876 .loop = test_memslot_rw_loop
877 },
878};
879
880#define NTESTS ARRAY_SIZE(tests)
881
882struct test_args {
883 int tfirst;
884 int tlast;
885 int nslots;
886 int seconds;
887 int runs;
888};
889
890static void help(char *name, struct test_args *targs)
891{
892 int ctr;
893
894 pr_info("usage: %s [-h] [-v] [-d] [-s slots] [-f first_test] [-e last_test] [-l test_length] [-r run_count]\n",
895 name);
896 pr_info(" -h: print this help screen.\n");
897 pr_info(" -v: enable verbose mode (not for benchmarking).\n");
898 pr_info(" -d: enable extra debug checks.\n");
899 pr_info(" -s: specify memslot count cap (-1 means no cap; currently: %i)\n",
900 targs->nslots);
901 pr_info(" -f: specify the first test to run (currently: %i; max %zu)\n",
902 targs->tfirst, NTESTS - 1);
903 pr_info(" -e: specify the last test to run (currently: %i; max %zu)\n",
904 targs->tlast, NTESTS - 1);
905 pr_info(" -l: specify the test length in seconds (currently: %i)\n",
906 targs->seconds);
907 pr_info(" -r: specify the number of runs per test (currently: %i)\n",
908 targs->runs);
909
910 pr_info("\nAvailable tests:\n");
911 for (ctr = 0; ctr < NTESTS; ctr++)
912 pr_info("%d: %s\n", ctr, tests[ctr].name);
913}
914
915static bool check_memory_sizes(void)
916{
917 uint32_t host_page_size = getpagesize();
918 uint32_t guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size;
919
920 if (host_page_size > SZ_64K || guest_page_size > SZ_64K) {
921 pr_info("Unsupported page size on host (0x%x) or guest (0x%x)\n",
922 host_page_size, guest_page_size);
923 return false;
924 }
925
926 if (MEM_SIZE % guest_page_size ||
927 MEM_TEST_SIZE % guest_page_size) {
928 pr_info("invalid MEM_SIZE or MEM_TEST_SIZE\n");
929 return false;
930 }
931
932 if (MEM_SIZE_MAP % guest_page_size ||
933 MEM_TEST_MAP_SIZE % guest_page_size ||
934 (MEM_TEST_MAP_SIZE / guest_page_size) <= 2 ||
935 (MEM_TEST_MAP_SIZE / guest_page_size) % 2) {
936 pr_info("invalid MEM_SIZE_MAP or MEM_TEST_MAP_SIZE\n");
937 return false;
938 }
939
940 if (MEM_TEST_UNMAP_SIZE > MEM_TEST_SIZE ||
941 MEM_TEST_UNMAP_SIZE % guest_page_size ||
942 (MEM_TEST_UNMAP_SIZE / guest_page_size) %
943 (2 * MEM_TEST_UNMAP_CHUNK_SIZE / guest_page_size)) {
944 pr_info("invalid MEM_TEST_UNMAP_SIZE or MEM_TEST_UNMAP_CHUNK_SIZE\n");
945 return false;
946 }
947
948 return true;
949}
950
951static bool parse_args(int argc, char *argv[],
952 struct test_args *targs)
953{
954 uint32_t max_mem_slots;
955 int opt;
956
957 while ((opt = getopt(argc, argv, "hvds:f:e:l:r:")) != -1) {
958 switch (opt) {
959 case 'h':
960 default:
961 help(name: argv[0], targs);
962 return false;
963 case 'v':
964 verbose = true;
965 break;
966 case 'd':
967 map_unmap_verify = true;
968 break;
969 case 's':
970 targs->nslots = atoi_paranoid(optarg);
971 if (targs->nslots <= 1 && targs->nslots != -1) {
972 pr_info("Slot count cap must be larger than 1 or -1 for no cap\n");
973 return false;
974 }
975 break;
976 case 'f':
977 targs->tfirst = atoi_non_negative("First test", optarg);
978 break;
979 case 'e':
980 targs->tlast = atoi_non_negative("Last test", optarg);
981 if (targs->tlast >= NTESTS) {
982 pr_info("Last test to run has to be non-negative and less than %zu\n",
983 NTESTS);
984 return false;
985 }
986 break;
987 case 'l':
988 targs->seconds = atoi_non_negative("Test length", optarg);
989 break;
990 case 'r':
991 targs->runs = atoi_positive("Runs per test", optarg);
992 break;
993 }
994 }
995
996 if (optind < argc) {
997 help(name: argv[0], targs);
998 return false;
999 }
1000
1001 if (targs->tfirst > targs->tlast) {
1002 pr_info("First test to run cannot be greater than the last test to run\n");
1003 return false;
1004 }
1005
1006 max_mem_slots = kvm_check_cap(KVM_CAP_NR_MEMSLOTS);
1007 if (max_mem_slots <= 1) {
1008 pr_info("KVM_CAP_NR_MEMSLOTS should be greater than 1\n");
1009 return false;
1010 }
1011
1012 /* Memory slot 0 is reserved */
1013 if (targs->nslots == -1)
1014 targs->nslots = max_mem_slots - 1;
1015 else
1016 targs->nslots = min_t(int, targs->nslots, max_mem_slots) - 1;
1017
1018 pr_info_v("Allowed Number of memory slots: %"PRIu32"\n",
1019 targs->nslots + 1);
1020
1021 return true;
1022}
1023
1024struct test_result {
1025 struct timespec slot_runtime, guest_runtime, iter_runtime;
1026 int64_t slottimens, runtimens;
1027 uint64_t nloops;
1028};
1029
1030static bool test_loop(const struct test_data *data,
1031 const struct test_args *targs,
1032 struct test_result *rbestslottime,
1033 struct test_result *rbestruntime)
1034{
1035 uint64_t maxslots;
1036 struct test_result result = {};
1037
1038 if (!test_execute(nslots: targs->nslots, maxslots: &maxslots, maxtime: targs->seconds, tdata: data,
1039 nloops: &result.nloops,
1040 slot_runtime: &result.slot_runtime, guest_runtime: &result.guest_runtime)) {
1041 if (maxslots)
1042 pr_info("Memslot count too high for this test, decrease the cap (max is %"PRIu64")\n",
1043 maxslots);
1044 else
1045 pr_info("Memslot count may be too high for this test, try adjusting the cap\n");
1046
1047 return false;
1048 }
1049
1050 pr_info("Test took %ld.%.9lds for slot setup + %ld.%.9lds all iterations\n",
1051 result.slot_runtime.tv_sec, result.slot_runtime.tv_nsec,
1052 result.guest_runtime.tv_sec, result.guest_runtime.tv_nsec);
1053 if (!result.nloops) {
1054 pr_info("No full loops done - too short test time or system too loaded?\n");
1055 return true;
1056 }
1057
1058 result.iter_runtime = timespec_div(result.guest_runtime,
1059 result.nloops);
1060 pr_info("Done %"PRIu64" iterations, avg %ld.%.9lds each\n",
1061 result.nloops,
1062 result.iter_runtime.tv_sec,
1063 result.iter_runtime.tv_nsec);
1064 result.slottimens = timespec_to_ns(result.slot_runtime);
1065 result.runtimens = timespec_to_ns(result.iter_runtime);
1066
1067 /*
1068 * Only rank the slot setup time for tests using the whole test memory
1069 * area so they are comparable
1070 */
1071 if (!data->mem_size &&
1072 (!rbestslottime->slottimens ||
1073 result.slottimens < rbestslottime->slottimens))
1074 *rbestslottime = result;
1075 if (!rbestruntime->runtimens ||
1076 result.runtimens < rbestruntime->runtimens)
1077 *rbestruntime = result;
1078
1079 return true;
1080}
1081
1082int main(int argc, char *argv[])
1083{
1084 struct test_args targs = {
1085 .tfirst = 0,
1086 .tlast = NTESTS - 1,
1087 .nslots = -1,
1088 .seconds = 5,
1089 .runs = 1,
1090 };
1091 struct test_result rbestslottime = {};
1092 int tctr;
1093
1094 if (!check_memory_sizes())
1095 return -1;
1096
1097 if (!parse_args(argc, argv, targs: &targs))
1098 return -1;
1099
1100 for (tctr = targs.tfirst; tctr <= targs.tlast; tctr++) {
1101 const struct test_data *data = &tests[tctr];
1102 unsigned int runctr;
1103 struct test_result rbestruntime = {};
1104
1105 if (tctr > targs.tfirst)
1106 pr_info("\n");
1107
1108 pr_info("Testing %s performance with %i runs, %d seconds each\n",
1109 data->name, targs.runs, targs.seconds);
1110
1111 for (runctr = 0; runctr < targs.runs; runctr++)
1112 if (!test_loop(data, targs: &targs,
1113 rbestslottime: &rbestslottime, rbestruntime: &rbestruntime))
1114 break;
1115
1116 if (rbestruntime.runtimens)
1117 pr_info("Best runtime result was %ld.%.9lds per iteration (with %"PRIu64" iterations)\n",
1118 rbestruntime.iter_runtime.tv_sec,
1119 rbestruntime.iter_runtime.tv_nsec,
1120 rbestruntime.nloops);
1121 }
1122
1123 if (rbestslottime.slottimens)
1124 pr_info("Best slot setup time for the whole test area was %ld.%.9lds\n",
1125 rbestslottime.slot_runtime.tv_sec,
1126 rbestslottime.slot_runtime.tv_nsec);
1127
1128 return 0;
1129}
1130

source code of linux/tools/testing/selftests/kvm/memslot_perf_test.c