tests/acpi: add microvm test
[qemu.git] / hw / virtio / virtio-mem.c
1 /*
2 * Virtio MEM device
3 *
4 * Copyright (C) 2020 Red Hat, Inc.
5 *
6 * Authors:
7 * David Hildenbrand <david@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2.
10 * See the COPYING file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu-common.h"
15 #include "qemu/iov.h"
16 #include "qemu/cutils.h"
17 #include "qemu/error-report.h"
18 #include "qemu/units.h"
19 #include "sysemu/numa.h"
20 #include "sysemu/sysemu.h"
21 #include "sysemu/reset.h"
22 #include "hw/virtio/virtio.h"
23 #include "hw/virtio/virtio-bus.h"
24 #include "hw/virtio/virtio-access.h"
25 #include "hw/virtio/virtio-mem.h"
26 #include "qapi/error.h"
27 #include "qapi/visitor.h"
28 #include "exec/ram_addr.h"
29 #include "migration/misc.h"
30 #include "hw/boards.h"
31 #include "hw/qdev-properties.h"
32 #include CONFIG_DEVICES
33 #include "trace.h"
34
35 /*
36 * Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
37 * memory (e.g., 2MB on x86_64).
38 */
39 #define VIRTIO_MEM_MIN_BLOCK_SIZE ((uint32_t)QEMU_VMALLOC_ALIGN)
40 /*
41 * Size the usable region bigger than the requested size if possible. Esp.
42 * Linux guests will only add (aligned) memory blocks in case they fully
43 * fit into the usable region, but plug+online only a subset of the pages.
44 * The memory block size corresponds mostly to the section size.
45 *
46 * This allows e.g., to add 20MB with a section size of 128MB on x86_64, and
47 * a section size of 1GB on arm64 (as long as the start address is properly
48 * aligned, similar to ordinary DIMMs).
49 *
50 * We can change this at any time and maybe even make it configurable if
51 * necessary (as the section size can change). But it's more likely that the
52 * section size will rather get smaller and not bigger over time.
53 */
54 #if defined(TARGET_X86_64) || defined(TARGET_I386)
55 #define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
56 #else
57 #error VIRTIO_MEM_USABLE_EXTENT not defined
58 #endif
59
60 static bool virtio_mem_is_busy(void)
61 {
62 /*
63 * Postcopy cannot handle concurrent discards and we don't want to migrate
64 * pages on-demand with stale content when plugging new blocks.
65 *
66 * For precopy, we don't want unplugged blocks in our migration stream, and
67 * when plugging new blocks, the page content might differ between source
68 * and destination (observable by the guest when not initializing pages
69 * after plugging them) until we're running on the destination (as we didn't
70 * migrate these blocks when they were unplugged).
71 */
72 return migration_in_incoming_postcopy() || !migration_is_idle();
73 }
74
75 static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
76 uint64_t size, bool plugged)
77 {
78 const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size;
79 const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1;
80 unsigned long found_bit;
81
82 /* We fake a shorter bitmap to avoid searching too far. */
83 if (plugged) {
84 found_bit = find_next_zero_bit(vmem->bitmap, last_bit + 1, first_bit);
85 } else {
86 found_bit = find_next_bit(vmem->bitmap, last_bit + 1, first_bit);
87 }
88 return found_bit > last_bit;
89 }
90
91 static void virtio_mem_set_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
92 uint64_t size, bool plugged)
93 {
94 const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size;
95 const unsigned long nbits = size / vmem->block_size;
96
97 if (plugged) {
98 bitmap_set(vmem->bitmap, bit, nbits);
99 } else {
100 bitmap_clear(vmem->bitmap, bit, nbits);
101 }
102 }
103
104 static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
105 struct virtio_mem_resp *resp)
106 {
107 VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
108 VirtQueue *vq = vmem->vq;
109
110 trace_virtio_mem_send_response(le16_to_cpu(resp->type));
111 iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
112
113 virtqueue_push(vq, elem, sizeof(*resp));
114 virtio_notify(vdev, vq);
115 }
116
117 static void virtio_mem_send_response_simple(VirtIOMEM *vmem,
118 VirtQueueElement *elem,
119 uint16_t type)
120 {
121 struct virtio_mem_resp resp = {
122 .type = cpu_to_le16(type),
123 };
124
125 virtio_mem_send_response(vmem, elem, &resp);
126 }
127
128 static bool virtio_mem_valid_range(VirtIOMEM *vmem, uint64_t gpa, uint64_t size)
129 {
130 if (!QEMU_IS_ALIGNED(gpa, vmem->block_size)) {
131 return false;
132 }
133 if (gpa + size < gpa || !size) {
134 return false;
135 }
136 if (gpa < vmem->addr || gpa >= vmem->addr + vmem->usable_region_size) {
137 return false;
138 }
139 if (gpa + size > vmem->addr + vmem->usable_region_size) {
140 return false;
141 }
142 return true;
143 }
144
145 static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
146 uint64_t size, bool plug)
147 {
148 const uint64_t offset = start_gpa - vmem->addr;
149 int ret;
150
151 if (virtio_mem_is_busy()) {
152 return -EBUSY;
153 }
154
155 if (!plug) {
156 ret = ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size);
157 if (ret) {
158 error_report("Unexpected error discarding RAM: %s",
159 strerror(-ret));
160 return -EBUSY;
161 }
162 }
163 virtio_mem_set_bitmap(vmem, start_gpa, size, plug);
164 return 0;
165 }
166
167 static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa,
168 uint16_t nb_blocks, bool plug)
169 {
170 const uint64_t size = nb_blocks * vmem->block_size;
171 int ret;
172
173 if (!virtio_mem_valid_range(vmem, gpa, size)) {
174 return VIRTIO_MEM_RESP_ERROR;
175 }
176
177 if (plug && (vmem->size + size > vmem->requested_size)) {
178 return VIRTIO_MEM_RESP_NACK;
179 }
180
181 /* test if really all blocks are in the opposite state */
182 if (!virtio_mem_test_bitmap(vmem, gpa, size, !plug)) {
183 return VIRTIO_MEM_RESP_ERROR;
184 }
185
186 ret = virtio_mem_set_block_state(vmem, gpa, size, plug);
187 if (ret) {
188 return VIRTIO_MEM_RESP_BUSY;
189 }
190 if (plug) {
191 vmem->size += size;
192 } else {
193 vmem->size -= size;
194 }
195 notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
196 return VIRTIO_MEM_RESP_ACK;
197 }
198
199 static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
200 struct virtio_mem_req *req)
201 {
202 const uint64_t gpa = le64_to_cpu(req->u.plug.addr);
203 const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
204 uint16_t type;
205
206 trace_virtio_mem_plug_request(gpa, nb_blocks);
207 type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
208 virtio_mem_send_response_simple(vmem, elem, type);
209 }
210
211 static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
212 struct virtio_mem_req *req)
213 {
214 const uint64_t gpa = le64_to_cpu(req->u.unplug.addr);
215 const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
216 uint16_t type;
217
218 trace_virtio_mem_unplug_request(gpa, nb_blocks);
219 type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
220 virtio_mem_send_response_simple(vmem, elem, type);
221 }
222
223 static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
224 uint64_t requested_size,
225 bool can_shrink)
226 {
227 uint64_t newsize = MIN(memory_region_size(&vmem->memdev->mr),
228 requested_size + VIRTIO_MEM_USABLE_EXTENT);
229
230 if (!requested_size) {
231 newsize = 0;
232 }
233
234 if (newsize < vmem->usable_region_size && !can_shrink) {
235 return;
236 }
237
238 trace_virtio_mem_resized_usable_region(vmem->usable_region_size, newsize);
239 vmem->usable_region_size = newsize;
240 }
241
242 static int virtio_mem_unplug_all(VirtIOMEM *vmem)
243 {
244 RAMBlock *rb = vmem->memdev->mr.ram_block;
245 int ret;
246
247 if (virtio_mem_is_busy()) {
248 return -EBUSY;
249 }
250
251 ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
252 if (ret) {
253 error_report("Unexpected error discarding RAM: %s", strerror(-ret));
254 return -EBUSY;
255 }
256 bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size);
257 if (vmem->size) {
258 vmem->size = 0;
259 notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
260 }
261 trace_virtio_mem_unplugged_all();
262 virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
263 return 0;
264 }
265
266 static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
267 VirtQueueElement *elem)
268 {
269 trace_virtio_mem_unplug_all_request();
270 if (virtio_mem_unplug_all(vmem)) {
271 virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
272 } else {
273 virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ACK);
274 }
275 }
276
277 static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
278 struct virtio_mem_req *req)
279 {
280 const uint16_t nb_blocks = le16_to_cpu(req->u.state.nb_blocks);
281 const uint64_t gpa = le64_to_cpu(req->u.state.addr);
282 const uint64_t size = nb_blocks * vmem->block_size;
283 struct virtio_mem_resp resp = {
284 .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
285 };
286
287 trace_virtio_mem_state_request(gpa, nb_blocks);
288 if (!virtio_mem_valid_range(vmem, gpa, size)) {
289 virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
290 return;
291 }
292
293 if (virtio_mem_test_bitmap(vmem, gpa, size, true)) {
294 resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_PLUGGED);
295 } else if (virtio_mem_test_bitmap(vmem, gpa, size, false)) {
296 resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_UNPLUGGED);
297 } else {
298 resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
299 }
300 trace_virtio_mem_state_response(le16_to_cpu(resp.u.state.state));
301 virtio_mem_send_response(vmem, elem, &resp);
302 }
303
304 static void virtio_mem_handle_request(VirtIODevice *vdev, VirtQueue *vq)
305 {
306 const int len = sizeof(struct virtio_mem_req);
307 VirtIOMEM *vmem = VIRTIO_MEM(vdev);
308 VirtQueueElement *elem;
309 struct virtio_mem_req req;
310 uint16_t type;
311
312 while (true) {
313 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
314 if (!elem) {
315 return;
316 }
317
318 if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) {
319 virtio_error(vdev, "virtio-mem protocol violation: invalid request"
320 " size: %d", len);
321 g_free(elem);
322 return;
323 }
324
325 if (iov_size(elem->in_sg, elem->in_num) <
326 sizeof(struct virtio_mem_resp)) {
327 virtio_error(vdev, "virtio-mem protocol violation: not enough space"
328 " for response: %zu",
329 iov_size(elem->in_sg, elem->in_num));
330 g_free(elem);
331 return;
332 }
333
334 type = le16_to_cpu(req.type);
335 switch (type) {
336 case VIRTIO_MEM_REQ_PLUG:
337 virtio_mem_plug_request(vmem, elem, &req);
338 break;
339 case VIRTIO_MEM_REQ_UNPLUG:
340 virtio_mem_unplug_request(vmem, elem, &req);
341 break;
342 case VIRTIO_MEM_REQ_UNPLUG_ALL:
343 virtio_mem_unplug_all_request(vmem, elem);
344 break;
345 case VIRTIO_MEM_REQ_STATE:
346 virtio_mem_state_request(vmem, elem, &req);
347 break;
348 default:
349 virtio_error(vdev, "virtio-mem protocol violation: unknown request"
350 " type: %d", type);
351 g_free(elem);
352 return;
353 }
354
355 g_free(elem);
356 }
357 }
358
359 static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data)
360 {
361 VirtIOMEM *vmem = VIRTIO_MEM(vdev);
362 struct virtio_mem_config *config = (void *) config_data;
363
364 config->block_size = cpu_to_le64(vmem->block_size);
365 config->node_id = cpu_to_le16(vmem->node);
366 config->requested_size = cpu_to_le64(vmem->requested_size);
367 config->plugged_size = cpu_to_le64(vmem->size);
368 config->addr = cpu_to_le64(vmem->addr);
369 config->region_size = cpu_to_le64(memory_region_size(&vmem->memdev->mr));
370 config->usable_region_size = cpu_to_le64(vmem->usable_region_size);
371 }
372
373 static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features,
374 Error **errp)
375 {
376 MachineState *ms = MACHINE(qdev_get_machine());
377
378 if (ms->numa_state) {
379 #if defined(CONFIG_ACPI)
380 virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM);
381 #endif
382 }
383 return features;
384 }
385
386 static void virtio_mem_system_reset(void *opaque)
387 {
388 VirtIOMEM *vmem = VIRTIO_MEM(opaque);
389
390 /*
391 * During usual resets, we will unplug all memory and shrink the usable
392 * region size. This is, however, not possible in all scenarios. Then,
393 * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
394 */
395 virtio_mem_unplug_all(vmem);
396 }
397
398 static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
399 {
400 MachineState *ms = MACHINE(qdev_get_machine());
401 int nb_numa_nodes = ms->numa_state ? ms->numa_state->num_nodes : 0;
402 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
403 VirtIOMEM *vmem = VIRTIO_MEM(dev);
404 uint64_t page_size;
405 RAMBlock *rb;
406 int ret;
407
408 if (!vmem->memdev) {
409 error_setg(errp, "'%s' property is not set", VIRTIO_MEM_MEMDEV_PROP);
410 return;
411 } else if (host_memory_backend_is_mapped(vmem->memdev)) {
412 error_setg(errp, "'%s' property specifies a busy memdev: %s",
413 VIRTIO_MEM_MEMDEV_PROP,
414 object_get_canonical_path_component(OBJECT(vmem->memdev)));
415 return;
416 } else if (!memory_region_is_ram(&vmem->memdev->mr) ||
417 memory_region_is_rom(&vmem->memdev->mr) ||
418 !vmem->memdev->mr.ram_block) {
419 error_setg(errp, "'%s' property specifies an unsupported memdev",
420 VIRTIO_MEM_MEMDEV_PROP);
421 return;
422 }
423
424 if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) ||
425 (!nb_numa_nodes && vmem->node)) {
426 error_setg(errp, "'%s' property has value '%" PRIu32 "', which exceeds"
427 "the number of numa nodes: %d", VIRTIO_MEM_NODE_PROP,
428 vmem->node, nb_numa_nodes ? nb_numa_nodes : 1);
429 return;
430 }
431
432 if (enable_mlock) {
433 error_setg(errp, "Incompatible with mlock");
434 return;
435 }
436
437 rb = vmem->memdev->mr.ram_block;
438 page_size = qemu_ram_pagesize(rb);
439
440 if (vmem->block_size < page_size) {
441 error_setg(errp, "'%s' property has to be at least the page size (0x%"
442 PRIx64 ")", VIRTIO_MEM_BLOCK_SIZE_PROP, page_size);
443 return;
444 } else if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) {
445 error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64
446 ")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
447 VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
448 return;
449 } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
450 vmem->block_size)) {
451 error_setg(errp, "'%s' property memdev size has to be multiples of"
452 "'%s' (0x%" PRIx64 ")", VIRTIO_MEM_MEMDEV_PROP,
453 VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
454 return;
455 }
456
457 if (ram_block_discard_require(true)) {
458 error_setg(errp, "Discarding RAM is disabled");
459 return;
460 }
461
462 ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
463 if (ret) {
464 error_setg_errno(errp, -ret, "Unexpected error discarding RAM");
465 ram_block_discard_require(false);
466 return;
467 }
468
469 virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
470
471 vmem->bitmap_size = memory_region_size(&vmem->memdev->mr) /
472 vmem->block_size;
473 vmem->bitmap = bitmap_new(vmem->bitmap_size);
474
475 virtio_init(vdev, TYPE_VIRTIO_MEM, VIRTIO_ID_MEM,
476 sizeof(struct virtio_mem_config));
477 vmem->vq = virtio_add_queue(vdev, 128, virtio_mem_handle_request);
478
479 host_memory_backend_set_mapped(vmem->memdev, true);
480 vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem));
481 qemu_register_reset(virtio_mem_system_reset, vmem);
482 precopy_add_notifier(&vmem->precopy_notifier);
483 }
484
485 static void virtio_mem_device_unrealize(DeviceState *dev)
486 {
487 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
488 VirtIOMEM *vmem = VIRTIO_MEM(dev);
489
490 precopy_remove_notifier(&vmem->precopy_notifier);
491 qemu_unregister_reset(virtio_mem_system_reset, vmem);
492 vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem));
493 host_memory_backend_set_mapped(vmem->memdev, false);
494 virtio_del_queue(vdev, 0);
495 virtio_cleanup(vdev);
496 g_free(vmem->bitmap);
497 ram_block_discard_require(false);
498 }
499
500 static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
501 {
502 RAMBlock *rb = vmem->memdev->mr.ram_block;
503 unsigned long first_zero_bit, last_zero_bit;
504 uint64_t offset, length;
505 int ret;
506
507 /* Find consecutive unplugged blocks and discard the consecutive range. */
508 first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
509 while (first_zero_bit < vmem->bitmap_size) {
510 offset = first_zero_bit * vmem->block_size;
511 last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
512 first_zero_bit + 1) - 1;
513 length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
514
515 ret = ram_block_discard_range(rb, offset, length);
516 if (ret) {
517 error_report("Unexpected error discarding RAM: %s",
518 strerror(-ret));
519 return -EINVAL;
520 }
521 first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
522 last_zero_bit + 2);
523 }
524 return 0;
525 }
526
527 static int virtio_mem_post_load(void *opaque, int version_id)
528 {
529 if (migration_in_incoming_postcopy()) {
530 return 0;
531 }
532
533 return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));
534 }
535
536 typedef struct VirtIOMEMMigSanityChecks {
537 VirtIOMEM *parent;
538 uint64_t addr;
539 uint64_t region_size;
540 uint64_t block_size;
541 uint32_t node;
542 } VirtIOMEMMigSanityChecks;
543
544 static int virtio_mem_mig_sanity_checks_pre_save(void *opaque)
545 {
546 VirtIOMEMMigSanityChecks *tmp = opaque;
547 VirtIOMEM *vmem = tmp->parent;
548
549 tmp->addr = vmem->addr;
550 tmp->region_size = memory_region_size(&vmem->memdev->mr);
551 tmp->block_size = vmem->block_size;
552 tmp->node = vmem->node;
553 return 0;
554 }
555
556 static int virtio_mem_mig_sanity_checks_post_load(void *opaque, int version_id)
557 {
558 VirtIOMEMMigSanityChecks *tmp = opaque;
559 VirtIOMEM *vmem = tmp->parent;
560 const uint64_t new_region_size = memory_region_size(&vmem->memdev->mr);
561
562 if (tmp->addr != vmem->addr) {
563 error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
564 VIRTIO_MEM_ADDR_PROP, tmp->addr, vmem->addr);
565 return -EINVAL;
566 }
567 /*
568 * Note: Preparation for resizeable memory regions. The maximum size
569 * of the memory region must not change during migration.
570 */
571 if (tmp->region_size != new_region_size) {
572 error_report("Property '%s' size changed from 0x%" PRIx64 " to 0x%"
573 PRIx64, VIRTIO_MEM_MEMDEV_PROP, tmp->region_size,
574 new_region_size);
575 return -EINVAL;
576 }
577 if (tmp->block_size != vmem->block_size) {
578 error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
579 VIRTIO_MEM_BLOCK_SIZE_PROP, tmp->block_size,
580 vmem->block_size);
581 return -EINVAL;
582 }
583 if (tmp->node != vmem->node) {
584 error_report("Property '%s' changed from %" PRIu32 " to %" PRIu32,
585 VIRTIO_MEM_NODE_PROP, tmp->node, vmem->node);
586 return -EINVAL;
587 }
588 return 0;
589 }
590
591 static const VMStateDescription vmstate_virtio_mem_sanity_checks = {
592 .name = "virtio-mem-device/sanity-checks",
593 .pre_save = virtio_mem_mig_sanity_checks_pre_save,
594 .post_load = virtio_mem_mig_sanity_checks_post_load,
595 .fields = (VMStateField[]) {
596 VMSTATE_UINT64(addr, VirtIOMEMMigSanityChecks),
597 VMSTATE_UINT64(region_size, VirtIOMEMMigSanityChecks),
598 VMSTATE_UINT64(block_size, VirtIOMEMMigSanityChecks),
599 VMSTATE_UINT32(node, VirtIOMEMMigSanityChecks),
600 VMSTATE_END_OF_LIST(),
601 },
602 };
603
604 static const VMStateDescription vmstate_virtio_mem_device = {
605 .name = "virtio-mem-device",
606 .minimum_version_id = 1,
607 .version_id = 1,
608 .post_load = virtio_mem_post_load,
609 .fields = (VMStateField[]) {
610 VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks,
611 vmstate_virtio_mem_sanity_checks),
612 VMSTATE_UINT64(usable_region_size, VirtIOMEM),
613 VMSTATE_UINT64(size, VirtIOMEM),
614 VMSTATE_UINT64(requested_size, VirtIOMEM),
615 VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size),
616 VMSTATE_END_OF_LIST()
617 },
618 };
619
620 static const VMStateDescription vmstate_virtio_mem = {
621 .name = "virtio-mem",
622 .minimum_version_id = 1,
623 .version_id = 1,
624 .fields = (VMStateField[]) {
625 VMSTATE_VIRTIO_DEVICE,
626 VMSTATE_END_OF_LIST()
627 },
628 };
629
630 static void virtio_mem_fill_device_info(const VirtIOMEM *vmem,
631 VirtioMEMDeviceInfo *vi)
632 {
633 vi->memaddr = vmem->addr;
634 vi->node = vmem->node;
635 vi->requested_size = vmem->requested_size;
636 vi->size = vmem->size;
637 vi->max_size = memory_region_size(&vmem->memdev->mr);
638 vi->block_size = vmem->block_size;
639 vi->memdev = object_get_canonical_path(OBJECT(vmem->memdev));
640 }
641
642 static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp)
643 {
644 if (!vmem->memdev) {
645 error_setg(errp, "'%s' property must be set", VIRTIO_MEM_MEMDEV_PROP);
646 return NULL;
647 }
648
649 return &vmem->memdev->mr;
650 }
651
652 static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem,
653 Notifier *notifier)
654 {
655 notifier_list_add(&vmem->size_change_notifiers, notifier);
656 }
657
658 static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem,
659 Notifier *notifier)
660 {
661 notifier_remove(notifier);
662 }
663
664 static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name,
665 void *opaque, Error **errp)
666 {
667 const VirtIOMEM *vmem = VIRTIO_MEM(obj);
668 uint64_t value = vmem->size;
669
670 visit_type_size(v, name, &value, errp);
671 }
672
673 static void virtio_mem_get_requested_size(Object *obj, Visitor *v,
674 const char *name, void *opaque,
675 Error **errp)
676 {
677 const VirtIOMEM *vmem = VIRTIO_MEM(obj);
678 uint64_t value = vmem->requested_size;
679
680 visit_type_size(v, name, &value, errp);
681 }
682
683 static void virtio_mem_set_requested_size(Object *obj, Visitor *v,
684 const char *name, void *opaque,
685 Error **errp)
686 {
687 VirtIOMEM *vmem = VIRTIO_MEM(obj);
688 Error *err = NULL;
689 uint64_t value;
690
691 visit_type_size(v, name, &value, &err);
692 if (err) {
693 error_propagate(errp, err);
694 return;
695 }
696
697 /*
698 * The block size and memory backend are not fixed until the device was
699 * realized. realize() will verify these properties then.
700 */
701 if (DEVICE(obj)->realized) {
702 if (!QEMU_IS_ALIGNED(value, vmem->block_size)) {
703 error_setg(errp, "'%s' has to be multiples of '%s' (0x%" PRIx64
704 ")", name, VIRTIO_MEM_BLOCK_SIZE_PROP,
705 vmem->block_size);
706 return;
707 } else if (value > memory_region_size(&vmem->memdev->mr)) {
708 error_setg(errp, "'%s' cannot exceed the memory backend size"
709 "(0x%" PRIx64 ")", name,
710 memory_region_size(&vmem->memdev->mr));
711 return;
712 }
713
714 if (value != vmem->requested_size) {
715 virtio_mem_resize_usable_region(vmem, value, false);
716 vmem->requested_size = value;
717 }
718 /*
719 * Trigger a config update so the guest gets notified. We trigger
720 * even if the size didn't change (especially helpful for debugging).
721 */
722 virtio_notify_config(VIRTIO_DEVICE(vmem));
723 } else {
724 vmem->requested_size = value;
725 }
726 }
727
728 static void virtio_mem_get_block_size(Object *obj, Visitor *v, const char *name,
729 void *opaque, Error **errp)
730 {
731 const VirtIOMEM *vmem = VIRTIO_MEM(obj);
732 uint64_t value = vmem->block_size;
733
734 visit_type_size(v, name, &value, errp);
735 }
736
737 static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name,
738 void *opaque, Error **errp)
739 {
740 VirtIOMEM *vmem = VIRTIO_MEM(obj);
741 Error *err = NULL;
742 uint64_t value;
743
744 if (DEVICE(obj)->realized) {
745 error_setg(errp, "'%s' cannot be changed", name);
746 return;
747 }
748
749 visit_type_size(v, name, &value, &err);
750 if (err) {
751 error_propagate(errp, err);
752 return;
753 }
754
755 if (value < VIRTIO_MEM_MIN_BLOCK_SIZE) {
756 error_setg(errp, "'%s' property has to be at least 0x%" PRIx32, name,
757 VIRTIO_MEM_MIN_BLOCK_SIZE);
758 return;
759 } else if (!is_power_of_2(value)) {
760 error_setg(errp, "'%s' property has to be a power of two", name);
761 return;
762 }
763 vmem->block_size = value;
764 }
765
766 static void virtio_mem_precopy_exclude_unplugged(VirtIOMEM *vmem)
767 {
768 void * const host = qemu_ram_get_host_addr(vmem->memdev->mr.ram_block);
769 unsigned long first_zero_bit, last_zero_bit;
770 uint64_t offset, length;
771
772 /*
773 * Find consecutive unplugged blocks and exclude them from migration.
774 *
775 * Note: Blocks cannot get (un)plugged during precopy, no locking needed.
776 */
777 first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
778 while (first_zero_bit < vmem->bitmap_size) {
779 offset = first_zero_bit * vmem->block_size;
780 last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
781 first_zero_bit + 1) - 1;
782 length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
783
784 qemu_guest_free_page_hint(host + offset, length);
785 first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
786 last_zero_bit + 2);
787 }
788 }
789
790 static int virtio_mem_precopy_notify(NotifierWithReturn *n, void *data)
791 {
792 VirtIOMEM *vmem = container_of(n, VirtIOMEM, precopy_notifier);
793 PrecopyNotifyData *pnd = data;
794
795 switch (pnd->reason) {
796 case PRECOPY_NOTIFY_SETUP:
797 precopy_enable_free_page_optimization();
798 break;
799 case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
800 virtio_mem_precopy_exclude_unplugged(vmem);
801 break;
802 default:
803 break;
804 }
805
806 return 0;
807 }
808
809 static void virtio_mem_instance_init(Object *obj)
810 {
811 VirtIOMEM *vmem = VIRTIO_MEM(obj);
812
813 vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
814 notifier_list_init(&vmem->size_change_notifiers);
815 vmem->precopy_notifier.notify = virtio_mem_precopy_notify;
816
817 object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
818 NULL, NULL, NULL);
819 object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size",
820 virtio_mem_get_requested_size,
821 virtio_mem_set_requested_size, NULL, NULL);
822 object_property_add(obj, VIRTIO_MEM_BLOCK_SIZE_PROP, "size",
823 virtio_mem_get_block_size, virtio_mem_set_block_size,
824 NULL, NULL);
825 }
826
827 static Property virtio_mem_properties[] = {
828 DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0),
829 DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0),
830 DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev,
831 TYPE_MEMORY_BACKEND, HostMemoryBackend *),
832 DEFINE_PROP_END_OF_LIST(),
833 };
834
835 static void virtio_mem_class_init(ObjectClass *klass, void *data)
836 {
837 DeviceClass *dc = DEVICE_CLASS(klass);
838 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
839 VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass);
840
841 device_class_set_props(dc, virtio_mem_properties);
842 dc->vmsd = &vmstate_virtio_mem;
843
844 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
845 vdc->realize = virtio_mem_device_realize;
846 vdc->unrealize = virtio_mem_device_unrealize;
847 vdc->get_config = virtio_mem_get_config;
848 vdc->get_features = virtio_mem_get_features;
849 vdc->vmsd = &vmstate_virtio_mem_device;
850
851 vmc->fill_device_info = virtio_mem_fill_device_info;
852 vmc->get_memory_region = virtio_mem_get_memory_region;
853 vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier;
854 vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier;
855 }
856
857 static const TypeInfo virtio_mem_info = {
858 .name = TYPE_VIRTIO_MEM,
859 .parent = TYPE_VIRTIO_DEVICE,
860 .instance_size = sizeof(VirtIOMEM),
861 .instance_init = virtio_mem_instance_init,
862 .class_init = virtio_mem_class_init,
863 .class_size = sizeof(VirtIOMEMClass),
864 };
865
866 static void virtio_register_types(void)
867 {
868 type_register_static(&virtio_mem_info);
869 }
870
871 type_init(virtio_register_types)