| 1 | /* |
| 2 | * Virtio Balloon Device |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2008 |
| 5 | * Copyright (C) 2011 Red Hat, Inc. |
| 6 | * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com> |
| 7 | * |
| 8 | * Authors: |
| 9 | * Anthony Liguori <aliguori@us.ibm.com> |
| 10 | * |
| 11 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 12 | * the COPYING file in the top-level directory. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include "qemu/osdep.h" |
| 17 | #include "qemu/iov.h" |
| 18 | #include "qemu/module.h" |
| 19 | #include "qemu/timer.h" |
| 20 | #include "qemu/madvise.h" |
| 21 | #include "hw/virtio/virtio.h" |
| 22 | #include "hw/mem/pc-dimm.h" |
| 23 | #include "hw/core/qdev-properties.h" |
| 24 | #include "hw/core/boards.h" |
| 25 | #include "system/balloon.h" |
| 26 | #include "system/ramblock.h" |
| 27 | #include "hw/virtio/virtio-balloon.h" |
| 28 | #include "system/address-spaces.h" |
| 29 | #include "qapi/error.h" |
| 30 | #include "qapi/qapi-events-machine.h" |
| 31 | #include "qapi/visitor.h" |
| 32 | #include "trace.h" |
| 33 | #include "qemu/error-report.h" |
| 34 | #include "migration/misc.h" |
| 35 | #include "system/reset.h" |
| 36 | #include "hw/virtio/virtio-bus.h" |
| 37 | #include "hw/virtio/virtio-access.h" |
| 38 | |
| 39 | #define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT) |
| 40 | |
| 41 | typedef struct PartiallyBalloonedPage { |
| 42 | ram_addr_t base_gpa; |
| 43 | unsigned long *bitmap; |
| 44 | } PartiallyBalloonedPage; |
| 45 | |
| 46 | static void virtio_balloon_pbp_free(PartiallyBalloonedPage *pbp) |
| 47 | { |
| 48 | if (!pbp->bitmap) { |
| 49 | return; |
| 50 | } |
| 51 | g_free(pbp->bitmap); |
| 52 | pbp->bitmap = NULL; |
| 53 | } |
| 54 | |
| 55 | static void virtio_balloon_pbp_alloc(PartiallyBalloonedPage *pbp, |
| 56 | ram_addr_t base_gpa, |
| 57 | long subpages) |
| 58 | { |
| 59 | pbp->base_gpa = base_gpa; |
| 60 | pbp->bitmap = bitmap_new(subpages); |
| 61 | } |
| 62 | |
| 63 | static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp, |
| 64 | ram_addr_t base_gpa) |
| 65 | { |
| 66 | return pbp->base_gpa == base_gpa; |
| 67 | } |
| 68 | |
| 69 | static bool virtio_balloon_inhibited(void) |
| 70 | { |
| 71 | /* |
| 72 | * Postcopy cannot deal with concurrent discards, |
| 73 | * so it's special, as well as background snapshots. |
| 74 | */ |
| 75 | return ram_block_discard_is_disabled() || migration_in_incoming_postcopy() || |
| 76 | migration_in_bg_snapshot(); |
| 77 | } |
| 78 | |
| 79 | static void balloon_inflate_page(VirtIOBalloon *balloon, |
| 80 | MemoryRegion *mr, hwaddr mr_offset, |
| 81 | PartiallyBalloonedPage *pbp) |
| 82 | { |
| 83 | void *addr = memory_region_get_ram_ptr(mr) + mr_offset; |
| 84 | ram_addr_t rb_offset, rb_aligned_offset, base_gpa; |
| 85 | RAMBlock *rb; |
| 86 | size_t rb_page_size; |
| 87 | int subpages; |
| 88 | |
| 89 | /* XXX is there a better way to get to the RAMBlock than via a |
| 90 | * host address? */ |
| 91 | rb = qemu_ram_block_from_host(addr, false, &rb_offset); |
| 92 | rb_page_size = qemu_ram_pagesize(rb); |
| 93 | |
| 94 | if (rb_page_size == BALLOON_PAGE_SIZE) { |
| 95 | /* Easy case */ |
| 96 | |
| 97 | ram_block_discard_range(rb, rb_offset, rb_page_size); |
| 98 | /* We ignore errors from ram_block_discard_range(), because it |
| 99 | * has already reported them, and failing to discard a balloon |
| 100 | * page is not fatal */ |
| 101 | return; |
| 102 | } |
| 103 | |
| 104 | /* Hard case |
| 105 | * |
| 106 | * We've put a piece of a larger host page into the balloon - we |
| 107 | * need to keep track until we have a whole host page to |
| 108 | * discard |
| 109 | */ |
| 110 | warn_report_once( |
| 111 | "Balloon used with backing page size > 4kiB, this may not be reliable"); |
| 112 | |
| 113 | rb_aligned_offset = QEMU_ALIGN_DOWN(rb_offset, rb_page_size); |
| 114 | subpages = rb_page_size / BALLOON_PAGE_SIZE; |
| 115 | base_gpa = memory_region_get_ram_addr(mr) + mr_offset - |
| 116 | (rb_offset - rb_aligned_offset); |
| 117 | |
| 118 | if (pbp->bitmap && !virtio_balloon_pbp_matches(pbp, base_gpa)) { |
| 119 | /* We've partially ballooned part of a host page, but now |
| 120 | * we're trying to balloon part of a different one. Too hard, |
| 121 | * give up on the old partial page */ |
| 122 | virtio_balloon_pbp_free(pbp); |
| 123 | } |
| 124 | |
| 125 | if (!pbp->bitmap) { |
| 126 | virtio_balloon_pbp_alloc(pbp, base_gpa, subpages); |
| 127 | } |
| 128 | |
| 129 | set_bit((rb_offset - rb_aligned_offset) / BALLOON_PAGE_SIZE, |
| 130 | pbp->bitmap); |
| 131 | |
| 132 | if (bitmap_full(pbp->bitmap, subpages)) { |
| 133 | /* We've accumulated a full host page, we can actually discard |
| 134 | * it now */ |
| 135 | |
| 136 | ram_block_discard_range(rb, rb_aligned_offset, rb_page_size); |
| 137 | /* We ignore errors from ram_block_discard_range(), because it |
| 138 | * has already reported them, and failing to discard a balloon |
| 139 | * page is not fatal */ |
| 140 | virtio_balloon_pbp_free(pbp); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | static void balloon_deflate_page(VirtIOBalloon *balloon, |
| 145 | MemoryRegion *mr, hwaddr mr_offset) |
| 146 | { |
| 147 | void *addr = memory_region_get_ram_ptr(mr) + mr_offset; |
| 148 | ram_addr_t rb_offset; |
| 149 | RAMBlock *rb; |
| 150 | size_t rb_page_size; |
| 151 | void *host_addr; |
| 152 | int ret; |
| 153 | |
| 154 | /* XXX is there a better way to get to the RAMBlock than via a |
| 155 | * host address? */ |
| 156 | rb = qemu_ram_block_from_host(addr, false, &rb_offset); |
| 157 | rb_page_size = qemu_ram_pagesize(rb); |
| 158 | |
| 159 | host_addr = (void *)((uintptr_t)addr & ~(rb_page_size - 1)); |
| 160 | |
| 161 | /* When a page is deflated, we hint the whole host page it lives |
| 162 | * on, since we can't do anything smaller */ |
| 163 | ret = qemu_madvise(host_addr, rb_page_size, QEMU_MADV_WILLNEED); |
| 164 | if (ret != 0) { |
| 165 | warn_report("Couldn't MADV_WILLNEED on balloon deflate: %s", |
| 166 | strerror(errno)); |
| 167 | /* Otherwise ignore, failing to page hint shouldn't be fatal */ |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * All stats upto VIRTIO_BALLOON_S_NR /must/ have a |
| 173 | * non-NULL name declared here, since these are used |
| 174 | * as keys for populating the QDict with stats |
| 175 | */ |
| 176 | static const char *balloon_stat_names[] = { |
| 177 | [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in", |
| 178 | [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out", |
| 179 | [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults", |
| 180 | [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults", |
| 181 | [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory", |
| 182 | |
| 183 | [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory", |
| 184 | [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory", |
| 185 | [VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches", |
| 186 | [VIRTIO_BALLOON_S_HTLB_PGALLOC] = "stat-htlb-pgalloc", |
| 187 | [VIRTIO_BALLOON_S_HTLB_PGFAIL] = "stat-htlb-pgfail", |
| 188 | |
| 189 | [VIRTIO_BALLOON_S_OOM_KILL] = "stat-oom-kills", |
| 190 | [VIRTIO_BALLOON_S_ALLOC_STALL] = "stat-alloc-stalls", |
| 191 | [VIRTIO_BALLOON_S_ASYNC_SCAN] = "stat-async-scans", |
| 192 | [VIRTIO_BALLOON_S_DIRECT_SCAN] = "stat-direct-scans", |
| 193 | [VIRTIO_BALLOON_S_ASYNC_RECLAIM] = "stat-async-reclaims", |
| 194 | |
| 195 | [VIRTIO_BALLOON_S_DIRECT_RECLAIM] = "stat-direct-reclaims", |
| 196 | }; |
| 197 | G_STATIC_ASSERT(G_N_ELEMENTS(balloon_stat_names) == VIRTIO_BALLOON_S_NR); |
| 198 | |
| 199 | /* |
| 200 | * reset_stats - Mark all items in the stats array as unset |
| 201 | * |
| 202 | * This function needs to be called at device initialization and before |
| 203 | * updating to a set of newly-generated stats. This will ensure that no |
| 204 | * stale values stick around in case the guest reports a subset of the supported |
| 205 | * statistics. |
| 206 | */ |
| 207 | static inline void reset_stats(VirtIOBalloon *dev) |
| 208 | { |
| 209 | int i; |
| 210 | for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); |
| 211 | } |
| 212 | |
| 213 | static bool balloon_stats_supported(const VirtIOBalloon *s) |
| 214 | { |
| 215 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 216 | return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ); |
| 217 | } |
| 218 | |
| 219 | static bool balloon_stats_enabled(const VirtIOBalloon *s) |
| 220 | { |
| 221 | return s->stats_poll_interval > 0; |
| 222 | } |
| 223 | |
| 224 | static void balloon_stats_destroy_timer(VirtIOBalloon *s) |
| 225 | { |
| 226 | if (balloon_stats_enabled(s)) { |
| 227 | timer_free(s->stats_timer); |
| 228 | s->stats_timer = NULL; |
| 229 | s->stats_poll_interval = 0; |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs) |
| 234 | { |
| 235 | timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000); |
| 236 | } |
| 237 | |
| 238 | static void balloon_stats_poll_cb(void *opaque) |
| 239 | { |
| 240 | VirtIOBalloon *s = opaque; |
| 241 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 242 | |
| 243 | if (s->stats_vq_elem == NULL || !balloon_stats_supported(s)) { |
| 244 | /* re-schedule */ |
| 245 | balloon_stats_change_timer(s, s->stats_poll_interval); |
| 246 | return; |
| 247 | } |
| 248 | |
| 249 | virtqueue_push(s->svq, s->stats_vq_elem, 0); |
| 250 | virtio_notify(vdev, s->svq); |
| 251 | g_free(s->stats_vq_elem); |
| 252 | s->stats_vq_elem = NULL; |
| 253 | } |
| 254 | |
| 255 | static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name, |
| 256 | void *opaque, Error **errp) |
| 257 | { |
| 258 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 259 | bool ok = false; |
| 260 | int i; |
| 261 | |
| 262 | if (!visit_start_struct(v, name, NULL, 0, errp)) { |
| 263 | return; |
| 264 | } |
| 265 | if (!visit_type_int(v, "last-update", &s->stats_last_update, errp)) { |
| 266 | goto out_end; |
| 267 | } |
| 268 | |
| 269 | if (!visit_start_struct(v, "stats", NULL, 0, errp)) { |
| 270 | goto out_end; |
| 271 | } |
| 272 | for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) { |
| 273 | if (!visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], errp)) { |
| 274 | goto out_nested; |
| 275 | } |
| 276 | } |
| 277 | ok = visit_check_struct(v, errp); |
| 278 | out_nested: |
| 279 | visit_end_struct(v, NULL); |
| 280 | |
| 281 | if (ok) { |
| 282 | visit_check_struct(v, errp); |
| 283 | } |
| 284 | out_end: |
| 285 | visit_end_struct(v, NULL); |
| 286 | } |
| 287 | |
| 288 | static void balloon_stats_get_poll_interval(Object *obj, Visitor *v, |
| 289 | const char *name, void *opaque, |
| 290 | Error **errp) |
| 291 | { |
| 292 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 293 | visit_type_int(v, name, &s->stats_poll_interval, errp); |
| 294 | } |
| 295 | |
| 296 | static void balloon_stats_set_poll_interval(Object *obj, Visitor *v, |
| 297 | const char *name, void *opaque, |
| 298 | Error **errp) |
| 299 | { |
| 300 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 301 | int64_t value; |
| 302 | |
| 303 | if (!visit_type_int(v, name, &value, errp)) { |
| 304 | return; |
| 305 | } |
| 306 | |
| 307 | if (value < 0) { |
| 308 | error_setg(errp, "timer value must be greater than zero"); |
| 309 | return; |
| 310 | } |
| 311 | |
| 312 | if (value > UINT32_MAX) { |
| 313 | error_setg(errp, "timer value is too big"); |
| 314 | return; |
| 315 | } |
| 316 | |
| 317 | if (value == s->stats_poll_interval) { |
| 318 | return; |
| 319 | } |
| 320 | |
| 321 | if (value == 0) { |
| 322 | /* timer=0 disables the timer */ |
| 323 | balloon_stats_destroy_timer(s); |
| 324 | return; |
| 325 | } |
| 326 | |
| 327 | if (balloon_stats_enabled(s)) { |
| 328 | /* timer interval change */ |
| 329 | s->stats_poll_interval = value; |
| 330 | balloon_stats_change_timer(s, value); |
| 331 | return; |
| 332 | } |
| 333 | |
| 334 | /* create a new timer */ |
| 335 | g_assert(s->stats_timer == NULL); |
| 336 | s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s); |
| 337 | s->stats_poll_interval = value; |
| 338 | balloon_stats_change_timer(s, 0); |
| 339 | } |
| 340 | |
| 341 | static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq) |
| 342 | { |
| 343 | VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); |
| 344 | VirtQueueElement *elem; |
| 345 | |
| 346 | while ((elem = virtqueue_pop(vq, sizeof(VirtQueueElement)))) { |
| 347 | unsigned int i; |
| 348 | |
| 349 | /* |
| 350 | * When we discard the page it has the effect of removing the page |
| 351 | * from the hypervisor itself and causing it to be zeroed when it |
| 352 | * is returned to us. So we must not discard the page if it is |
| 353 | * accessible by another device or process, or if the guest is |
| 354 | * expecting it to retain a non-zero value. |
| 355 | */ |
| 356 | if (virtio_balloon_inhibited() || dev->poison_val) { |
| 357 | goto skip_element; |
| 358 | } |
| 359 | |
| 360 | for (i = 0; i < elem->in_num; i++) { |
| 361 | void *addr = elem->in_sg[i].iov_base; |
| 362 | size_t size = elem->in_sg[i].iov_len; |
| 363 | ram_addr_t ram_offset; |
| 364 | RAMBlock *rb; |
| 365 | |
| 366 | /* |
| 367 | * There is no need to check the memory section to see if |
| 368 | * it is ram/readonly/romd like there is for handle_output |
| 369 | * below. If the region is not meant to be written to then |
| 370 | * address_space_map will have allocated a bounce buffer |
| 371 | * and it will be freed in address_space_unmap and trigger |
| 372 | * and unassigned_mem_write before failing to copy over the |
| 373 | * buffer. If more than one bad descriptor is provided it |
| 374 | * will return NULL after the first bounce buffer and fail |
| 375 | * to map any resources. |
| 376 | */ |
| 377 | rb = qemu_ram_block_from_host(addr, false, &ram_offset); |
| 378 | if (!rb) { |
| 379 | trace_virtio_balloon_bad_addr(elem->in_addr[i]); |
| 380 | continue; |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * For now we will simply ignore unaligned memory regions, or |
| 385 | * regions that overrun the end of the RAMBlock. |
| 386 | */ |
| 387 | if (!QEMU_IS_ALIGNED(ram_offset | size, qemu_ram_pagesize(rb)) || |
| 388 | (ram_offset + size) > qemu_ram_get_used_length(rb)) { |
| 389 | continue; |
| 390 | } |
| 391 | |
| 392 | ram_block_discard_range(rb, ram_offset, size); |
| 393 | } |
| 394 | |
| 395 | skip_element: |
| 396 | virtqueue_push(vq, elem, 0); |
| 397 | virtio_notify(vdev, vq); |
| 398 | g_free(elem); |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| 403 | { |
| 404 | VirtIOBalloon *s = VIRTIO_BALLOON(vdev); |
| 405 | VirtQueueElement *elem; |
| 406 | MemoryRegionSection section; |
| 407 | |
| 408 | for (;;) { |
| 409 | PartiallyBalloonedPage pbp = {}; |
| 410 | size_t offset = 0; |
| 411 | uint32_t pfn; |
| 412 | |
| 413 | elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); |
| 414 | if (!elem) { |
| 415 | break; |
| 416 | } |
| 417 | |
| 418 | while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) { |
| 419 | unsigned int p = virtio_ldl_p(vdev, &pfn); |
| 420 | hwaddr pa; |
| 421 | |
| 422 | pa = (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT; |
| 423 | offset += 4; |
| 424 | |
| 425 | section = memory_region_find(get_system_memory(), pa, |
| 426 | BALLOON_PAGE_SIZE); |
| 427 | if (!section.mr) { |
| 428 | trace_virtio_balloon_bad_addr(pa); |
| 429 | continue; |
| 430 | } |
| 431 | if (!memory_region_is_ram(section.mr) || |
| 432 | memory_region_is_rom(section.mr) || |
| 433 | memory_region_is_romd(section.mr)) { |
| 434 | trace_virtio_balloon_bad_addr(pa); |
| 435 | memory_region_unref(section.mr); |
| 436 | continue; |
| 437 | } |
| 438 | |
| 439 | trace_virtio_balloon_handle_output(memory_region_name(section.mr), |
| 440 | pa); |
| 441 | if (!virtio_balloon_inhibited()) { |
| 442 | if (vq == s->ivq) { |
| 443 | balloon_inflate_page(s, section.mr, |
| 444 | section.offset_within_region, &pbp); |
| 445 | } else if (vq == s->dvq) { |
| 446 | balloon_deflate_page(s, section.mr, section.offset_within_region); |
| 447 | } else { |
| 448 | g_assert_not_reached(); |
| 449 | } |
| 450 | } |
| 451 | memory_region_unref(section.mr); |
| 452 | } |
| 453 | |
| 454 | virtqueue_push(vq, elem, 0); |
| 455 | virtio_notify(vdev, vq); |
| 456 | g_free(elem); |
| 457 | virtio_balloon_pbp_free(&pbp); |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) |
| 462 | { |
| 463 | VirtIOBalloon *s = VIRTIO_BALLOON(vdev); |
| 464 | VirtQueueElement *elem; |
| 465 | VirtIOBalloonStat stat; |
| 466 | size_t offset = 0; |
| 467 | |
| 468 | elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); |
| 469 | if (!elem) { |
| 470 | goto out; |
| 471 | } |
| 472 | |
| 473 | if (s->stats_vq_elem != NULL) { |
| 474 | /* This should never happen if the driver follows the spec. */ |
| 475 | virtqueue_push(vq, s->stats_vq_elem, 0); |
| 476 | virtio_notify(vdev, vq); |
| 477 | g_free(s->stats_vq_elem); |
| 478 | } |
| 479 | |
| 480 | s->stats_vq_elem = elem; |
| 481 | |
| 482 | /* Initialize the stats to get rid of any stale values. This is only |
| 483 | * needed to handle the case where a guest supports fewer stats than it |
| 484 | * used to (ie. it has booted into an old kernel). |
| 485 | */ |
| 486 | reset_stats(s); |
| 487 | |
| 488 | while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat)) |
| 489 | == sizeof(stat)) { |
| 490 | uint16_t tag = virtio_tswap16(vdev, stat.tag); |
| 491 | uint64_t val = virtio_tswap64(vdev, stat.val); |
| 492 | |
| 493 | offset += sizeof(stat); |
| 494 | if (tag < VIRTIO_BALLOON_S_NR) |
| 495 | s->stats[tag] = val; |
| 496 | } |
| 497 | s->stats_vq_offset = offset; |
| 498 | s->stats_last_update = g_get_real_time() / G_USEC_PER_SEC; |
| 499 | |
| 500 | out: |
| 501 | if (balloon_stats_enabled(s)) { |
| 502 | balloon_stats_change_timer(s, s->stats_poll_interval); |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | static void virtio_balloon_handle_free_page_vq(VirtIODevice *vdev, |
| 507 | VirtQueue *vq) |
| 508 | { |
| 509 | VirtIOBalloon *s = VIRTIO_BALLOON(vdev); |
| 510 | qemu_bh_schedule(s->free_page_bh); |
| 511 | } |
| 512 | |
| 513 | static bool get_free_page_hints(VirtIOBalloon *dev) |
| 514 | { |
| 515 | VirtQueueElement *elem; |
| 516 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 517 | VirtQueue *vq = dev->free_page_vq; |
| 518 | bool ret = true; |
| 519 | int i; |
| 520 | |
| 521 | while (dev->block_iothread) { |
| 522 | qemu_cond_wait(&dev->free_page_cond, &dev->free_page_lock); |
| 523 | } |
| 524 | |
| 525 | elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); |
| 526 | if (!elem) { |
| 527 | return false; |
| 528 | } |
| 529 | |
| 530 | if (elem->out_num) { |
| 531 | uint32_t id; |
| 532 | size_t size = iov_to_buf(elem->out_sg, elem->out_num, 0, |
| 533 | &id, sizeof(id)); |
| 534 | |
| 535 | virtio_tswap32s(vdev, &id); |
| 536 | if (unlikely(size != sizeof(id))) { |
| 537 | virtio_error(vdev, "received an incorrect cmd id"); |
| 538 | ret = false; |
| 539 | goto out; |
| 540 | } |
| 541 | if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED && |
| 542 | id == dev->free_page_hint_cmd_id) { |
| 543 | dev->free_page_hint_status = FREE_PAGE_HINT_S_START; |
| 544 | } else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_START) { |
| 545 | /* |
| 546 | * Stop the optimization only when it has started. This |
| 547 | * avoids a stale stop sign for the previous command. |
| 548 | */ |
| 549 | dev->free_page_hint_status = FREE_PAGE_HINT_S_STOP; |
| 550 | } |
| 551 | } |
| 552 | |
| 553 | if (elem->in_num && dev->free_page_hint_status == FREE_PAGE_HINT_S_START) { |
| 554 | for (i = 0; i < elem->in_num; i++) { |
| 555 | qemu_guest_free_page_hint(elem->in_sg[i].iov_base, |
| 556 | elem->in_sg[i].iov_len); |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | out: |
| 561 | virtqueue_push(vq, elem, 0); |
| 562 | g_free(elem); |
| 563 | return ret; |
| 564 | } |
| 565 | |
| 566 | static void virtio_ballloon_get_free_page_hints(void *opaque) |
| 567 | { |
| 568 | VirtIOBalloon *dev = opaque; |
| 569 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 570 | VirtQueue *vq = dev->free_page_vq; |
| 571 | bool continue_to_get_hints; |
| 572 | |
| 573 | do { |
| 574 | qemu_mutex_lock(&dev->free_page_lock); |
| 575 | virtio_queue_set_notification(vq, 0); |
| 576 | continue_to_get_hints = get_free_page_hints(dev); |
| 577 | qemu_mutex_unlock(&dev->free_page_lock); |
| 578 | virtio_notify(vdev, vq); |
| 579 | /* |
| 580 | * Start to poll the vq once the hinting started. Otherwise, continue |
| 581 | * only when there are entries on the vq, which need to be given back. |
| 582 | */ |
| 583 | } while (continue_to_get_hints || |
| 584 | dev->free_page_hint_status == FREE_PAGE_HINT_S_START); |
| 585 | virtio_queue_set_notification(vq, 1); |
| 586 | } |
| 587 | |
| 588 | static bool virtio_balloon_free_page_support(void *opaque) |
| 589 | { |
| 590 | VirtIOBalloon *s = opaque; |
| 591 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 592 | |
| 593 | return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT); |
| 594 | } |
| 595 | |
| 596 | static void virtio_balloon_free_page_start(VirtIOBalloon *s) |
| 597 | { |
| 598 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 599 | |
| 600 | qemu_mutex_lock(&s->free_page_lock); |
| 601 | |
| 602 | if (s->free_page_hint_cmd_id == UINT_MAX) { |
| 603 | s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN; |
| 604 | } else { |
| 605 | s->free_page_hint_cmd_id++; |
| 606 | } |
| 607 | |
| 608 | s->free_page_hint_status = FREE_PAGE_HINT_S_REQUESTED; |
| 609 | qemu_mutex_unlock(&s->free_page_lock); |
| 610 | |
| 611 | virtio_notify_config(vdev); |
| 612 | } |
| 613 | |
| 614 | static void virtio_balloon_free_page_stop(VirtIOBalloon *s) |
| 615 | { |
| 616 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 617 | |
| 618 | if (s->free_page_hint_status != FREE_PAGE_HINT_S_STOP) { |
| 619 | /* |
| 620 | * The lock also guarantees us that the |
| 621 | * virtio_ballloon_get_free_page_hints exits after the |
| 622 | * free_page_hint_status is set to S_STOP. |
| 623 | */ |
| 624 | qemu_mutex_lock(&s->free_page_lock); |
| 625 | /* |
| 626 | * The guest isn't done hinting, so send a notification |
| 627 | * to the guest to actively stop the hinting. |
| 628 | */ |
| 629 | s->free_page_hint_status = FREE_PAGE_HINT_S_STOP; |
| 630 | qemu_mutex_unlock(&s->free_page_lock); |
| 631 | virtio_notify_config(vdev); |
| 632 | } |
| 633 | } |
| 634 | |
| 635 | static void virtio_balloon_free_page_done(VirtIOBalloon *s) |
| 636 | { |
| 637 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 638 | |
| 639 | if (s->free_page_hint_status != FREE_PAGE_HINT_S_DONE) { |
| 640 | /* See virtio_balloon_free_page_stop() */ |
| 641 | qemu_mutex_lock(&s->free_page_lock); |
| 642 | s->free_page_hint_status = FREE_PAGE_HINT_S_DONE; |
| 643 | qemu_mutex_unlock(&s->free_page_lock); |
| 644 | virtio_notify_config(vdev); |
| 645 | } |
| 646 | } |
| 647 | |
| 648 | static int |
| 649 | virtio_balloon_free_page_hint_notify(NotifierWithReturn *n, void *data, |
| 650 | Error **errp) |
| 651 | { |
| 652 | VirtIOBalloon *dev = container_of(n, VirtIOBalloon, free_page_hint_notify); |
| 653 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 654 | PrecopyNotifyData *pnd = data; |
| 655 | |
| 656 | if (!virtio_balloon_free_page_support(dev)) { |
| 657 | /* |
| 658 | * This is an optimization provided to migration, so just return 0 to |
| 659 | * have the normal migration process not affected when this feature is |
| 660 | * not supported. |
| 661 | */ |
| 662 | return 0; |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | * Pages hinted via qemu_guest_free_page_hint() are cleared from the dirty |
| 667 | * bitmap and will not get migrated, especially also not when the postcopy |
| 668 | * destination starts using them and requests migration from the source; the |
| 669 | * faulting thread will stall until postcopy migration finishes and |
| 670 | * all threads are woken up. Let's not start free page hinting if postcopy |
| 671 | * is possible. |
| 672 | */ |
| 673 | if (migrate_postcopy_ram()) { |
| 674 | return 0; |
| 675 | } |
| 676 | |
| 677 | switch (pnd->reason) { |
| 678 | case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC: |
| 679 | virtio_balloon_free_page_stop(dev); |
| 680 | break; |
| 681 | case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC: |
| 682 | if (vdev->vm_running) { |
| 683 | virtio_balloon_free_page_start(dev); |
| 684 | break; |
| 685 | } |
| 686 | /* |
| 687 | * Set S_DONE before migrating the vmstate, so the guest will reuse |
| 688 | * all hinted pages once running on the destination. Fall through. |
| 689 | */ |
| 690 | case PRECOPY_NOTIFY_CLEANUP: |
| 691 | /* |
| 692 | * Especially, if something goes wrong during precopy or if migration |
| 693 | * is canceled, we have to properly communicate S_DONE to the VM. |
| 694 | */ |
| 695 | virtio_balloon_free_page_done(dev); |
| 696 | break; |
| 697 | case PRECOPY_NOTIFY_SETUP: |
| 698 | case PRECOPY_NOTIFY_COMPLETE: |
| 699 | break; |
| 700 | default: |
| 701 | virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason); |
| 702 | } |
| 703 | |
| 704 | return 0; |
| 705 | } |
| 706 | |
| 707 | static size_t virtio_balloon_config_size(VirtIOBalloon *s) |
| 708 | { |
| 709 | uint64_t features = s->host_features; |
| 710 | |
| 711 | if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON)) { |
| 712 | return sizeof(struct virtio_balloon_config); |
| 713 | } |
| 714 | if (virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { |
| 715 | return offsetof(struct virtio_balloon_config, poison_val); |
| 716 | } |
| 717 | return offsetof(struct virtio_balloon_config, free_page_hint_cmd_id); |
| 718 | } |
| 719 | |
| 720 | static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
| 721 | { |
| 722 | VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); |
| 723 | struct virtio_balloon_config config = {}; |
| 724 | |
| 725 | config.num_pages = cpu_to_le32(dev->num_pages); |
| 726 | config.actual = cpu_to_le32(dev->actual); |
| 727 | config.poison_val = cpu_to_le32(dev->poison_val); |
| 728 | |
| 729 | if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED) { |
| 730 | config.free_page_hint_cmd_id = |
| 731 | cpu_to_le32(dev->free_page_hint_cmd_id); |
| 732 | } else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_STOP) { |
| 733 | config.free_page_hint_cmd_id = |
| 734 | cpu_to_le32(VIRTIO_BALLOON_CMD_ID_STOP); |
| 735 | } else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_DONE) { |
| 736 | config.free_page_hint_cmd_id = |
| 737 | cpu_to_le32(VIRTIO_BALLOON_CMD_ID_DONE); |
| 738 | } |
| 739 | |
| 740 | trace_virtio_balloon_get_config(config.num_pages, config.actual); |
| 741 | memcpy(config_data, &config, virtio_balloon_config_size(dev)); |
| 742 | } |
| 743 | |
| 744 | static ram_addr_t get_current_ram_size(void) |
| 745 | { |
| 746 | MachineState *machine = MACHINE(qdev_get_machine()); |
| 747 | if (machine->device_memory) { |
| 748 | return machine->ram_size + machine->device_memory->dimm_size; |
| 749 | } else { |
| 750 | return machine->ram_size; |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | static bool virtio_balloon_page_poison_support(void *opaque) |
| 755 | { |
| 756 | VirtIOBalloon *s = opaque; |
| 757 | VirtIODevice *vdev = VIRTIO_DEVICE(s); |
| 758 | |
| 759 | return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON); |
| 760 | } |
| 761 | |
| 762 | static void virtio_balloon_set_config(VirtIODevice *vdev, |
| 763 | const uint8_t *config_data) |
| 764 | { |
| 765 | VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); |
| 766 | struct virtio_balloon_config config; |
| 767 | uint32_t oldactual = dev->actual; |
| 768 | ram_addr_t vm_ram_size = get_current_ram_size(); |
| 769 | |
| 770 | memcpy(&config, config_data, virtio_balloon_config_size(dev)); |
| 771 | dev->actual = le32_to_cpu(config.actual); |
| 772 | if (dev->actual != oldactual) { |
| 773 | qapi_event_send_balloon_change(vm_ram_size - |
| 774 | ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT)); |
| 775 | } |
| 776 | dev->poison_val = 0; |
| 777 | if (virtio_balloon_page_poison_support(dev)) { |
| 778 | dev->poison_val = le32_to_cpu(config.poison_val); |
| 779 | } |
| 780 | trace_virtio_balloon_set_config(dev->actual, oldactual); |
| 781 | } |
| 782 | |
| 783 | static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f, |
| 784 | Error **errp) |
| 785 | { |
| 786 | VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); |
| 787 | f |= dev->host_features; |
| 788 | virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ); |
| 789 | |
| 790 | return f; |
| 791 | } |
| 792 | |
| 793 | static void virtio_balloon_stat(void *opaque, BalloonInfo *info) |
| 794 | { |
| 795 | VirtIOBalloon *dev = opaque; |
| 796 | info->actual = get_current_ram_size() - ((uint64_t) dev->actual << |
| 797 | VIRTIO_BALLOON_PFN_SHIFT); |
| 798 | } |
| 799 | |
| 800 | static void virtio_balloon_to_target(void *opaque, ram_addr_t target) |
| 801 | { |
| 802 | VirtIOBalloon *dev = VIRTIO_BALLOON(opaque); |
| 803 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 804 | ram_addr_t vm_ram_size = get_current_ram_size(); |
| 805 | |
| 806 | if (target > vm_ram_size) { |
| 807 | target = vm_ram_size; |
| 808 | } |
| 809 | if (target) { |
| 810 | dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; |
| 811 | virtio_notify_config(vdev); |
| 812 | } |
| 813 | trace_virtio_balloon_to_target(target, dev->num_pages); |
| 814 | } |
| 815 | |
| 816 | static int virtio_balloon_post_load_device(void *opaque, int version_id) |
| 817 | { |
| 818 | VirtIOBalloon *s = VIRTIO_BALLOON(opaque); |
| 819 | |
| 820 | if (balloon_stats_enabled(s)) { |
| 821 | balloon_stats_change_timer(s, s->stats_poll_interval); |
| 822 | } |
| 823 | return 0; |
| 824 | } |
| 825 | |
| 826 | static const VMStateDescription vmstate_virtio_balloon_free_page_hint = { |
| 827 | .name = "virtio-balloon-device/free-page-report", |
| 828 | .version_id = 1, |
| 829 | .minimum_version_id = 1, |
| 830 | .needed = virtio_balloon_free_page_support, |
| 831 | .fields = (const VMStateField[]) { |
| 832 | VMSTATE_UINT32(free_page_hint_cmd_id, VirtIOBalloon), |
| 833 | VMSTATE_UINT32(free_page_hint_status, VirtIOBalloon), |
| 834 | VMSTATE_END_OF_LIST() |
| 835 | } |
| 836 | }; |
| 837 | |
| 838 | static const VMStateDescription vmstate_virtio_balloon_page_poison = { |
| 839 | .name = "virtio-balloon-device/page-poison", |
| 840 | .version_id = 1, |
| 841 | .minimum_version_id = 1, |
| 842 | .needed = virtio_balloon_page_poison_support, |
| 843 | .fields = (const VMStateField[]) { |
| 844 | VMSTATE_UINT32(poison_val, VirtIOBalloon), |
| 845 | VMSTATE_END_OF_LIST() |
| 846 | } |
| 847 | }; |
| 848 | |
| 849 | static const VMStateDescription vmstate_virtio_balloon_device = { |
| 850 | .name = "virtio-balloon-device", |
| 851 | .version_id = 1, |
| 852 | .minimum_version_id = 1, |
| 853 | .post_load = virtio_balloon_post_load_device, |
| 854 | .fields = (const VMStateField[]) { |
| 855 | VMSTATE_UINT32(num_pages, VirtIOBalloon), |
| 856 | VMSTATE_UINT32(actual, VirtIOBalloon), |
| 857 | VMSTATE_END_OF_LIST() |
| 858 | }, |
| 859 | .subsections = (const VMStateDescription * const []) { |
| 860 | &vmstate_virtio_balloon_free_page_hint, |
| 861 | &vmstate_virtio_balloon_page_poison, |
| 862 | NULL |
| 863 | } |
| 864 | }; |
| 865 | |
| 866 | static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) |
| 867 | { |
| 868 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 869 | VirtIOBalloon *s = VIRTIO_BALLOON(dev); |
| 870 | int ret; |
| 871 | |
| 872 | virtio_init(vdev, VIRTIO_ID_BALLOON, virtio_balloon_config_size(s)); |
| 873 | |
| 874 | ret = qemu_add_balloon_handler(virtio_balloon_to_target, |
| 875 | virtio_balloon_stat, s); |
| 876 | |
| 877 | if (ret < 0) { |
| 878 | error_setg(errp, "Only one balloon device is supported"); |
| 879 | virtio_cleanup(vdev); |
| 880 | return; |
| 881 | } |
| 882 | |
| 883 | if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT) && |
| 884 | !s->iothread) { |
| 885 | error_setg(errp, "'free-page-hint' requires 'iothread' to be set"); |
| 886 | virtio_cleanup(vdev); |
| 887 | return; |
| 888 | } |
| 889 | |
| 890 | s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); |
| 891 | s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); |
| 892 | s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats); |
| 893 | |
| 894 | if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { |
| 895 | s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE, |
| 896 | virtio_balloon_handle_free_page_vq); |
| 897 | precopy_add_notifier(&s->free_page_hint_notify); |
| 898 | |
| 899 | object_ref(OBJECT(s->iothread)); |
| 900 | s->free_page_bh = aio_bh_new_guarded(iothread_get_aio_context(s->iothread), |
| 901 | virtio_ballloon_get_free_page_hints, s, |
| 902 | &dev->mem_reentrancy_guard); |
| 903 | } |
| 904 | |
| 905 | if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) { |
| 906 | s->reporting_vq = virtio_add_queue(vdev, 32, |
| 907 | virtio_balloon_handle_report); |
| 908 | } |
| 909 | |
| 910 | reset_stats(s); |
| 911 | s->stats_last_update = 0; |
| 912 | qemu_register_resettable(OBJECT(dev)); |
| 913 | } |
| 914 | |
| 915 | static void virtio_balloon_device_unrealize(DeviceState *dev) |
| 916 | { |
| 917 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 918 | VirtIOBalloon *s = VIRTIO_BALLOON(dev); |
| 919 | |
| 920 | qemu_unregister_resettable(OBJECT(dev)); |
| 921 | if (s->free_page_bh) { |
| 922 | qemu_bh_delete(s->free_page_bh); |
| 923 | object_unref(OBJECT(s->iothread)); |
| 924 | virtio_balloon_free_page_stop(s); |
| 925 | precopy_remove_notifier(&s->free_page_hint_notify); |
| 926 | } |
| 927 | balloon_stats_destroy_timer(s); |
| 928 | qemu_remove_balloon_handler(s); |
| 929 | |
| 930 | virtio_delete_queue(s->ivq); |
| 931 | virtio_delete_queue(s->dvq); |
| 932 | virtio_delete_queue(s->svq); |
| 933 | if (s->free_page_vq) { |
| 934 | virtio_delete_queue(s->free_page_vq); |
| 935 | } |
| 936 | if (s->reporting_vq) { |
| 937 | virtio_delete_queue(s->reporting_vq); |
| 938 | } |
| 939 | virtio_cleanup(vdev); |
| 940 | } |
| 941 | |
| 942 | static void virtio_balloon_device_reset(VirtIODevice *vdev) |
| 943 | { |
| 944 | VirtIOBalloon *s = VIRTIO_BALLOON(vdev); |
| 945 | |
| 946 | if (virtio_balloon_free_page_support(s)) { |
| 947 | virtio_balloon_free_page_stop(s); |
| 948 | } |
| 949 | |
| 950 | if (s->stats_vq_elem != NULL) { |
| 951 | virtqueue_unpop(s->svq, s->stats_vq_elem, 0); |
| 952 | g_free(s->stats_vq_elem); |
| 953 | s->stats_vq_elem = NULL; |
| 954 | } |
| 955 | |
| 956 | s->poison_val = 0; |
| 957 | } |
| 958 | |
| 959 | static int virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status) |
| 960 | { |
| 961 | VirtIOBalloon *s = VIRTIO_BALLOON(vdev); |
| 962 | |
| 963 | if (!s->stats_vq_elem && vdev->vm_running && |
| 964 | (status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq, 1)) { |
| 965 | /* poll stats queue for the element we have discarded when the VM |
| 966 | * was stopped */ |
| 967 | virtio_balloon_receive_stats(vdev, s->svq); |
| 968 | } |
| 969 | |
| 970 | if (virtio_balloon_free_page_support(s)) { |
| 971 | /* |
| 972 | * The VM is woken up and the iothread was blocked, so signal it to |
| 973 | * continue. |
| 974 | */ |
| 975 | if (vdev->vm_running && s->block_iothread) { |
| 976 | qemu_mutex_lock(&s->free_page_lock); |
| 977 | s->block_iothread = false; |
| 978 | qemu_cond_signal(&s->free_page_cond); |
| 979 | qemu_mutex_unlock(&s->free_page_lock); |
| 980 | } |
| 981 | |
| 982 | /* The VM is stopped, block the iothread. */ |
| 983 | if (!vdev->vm_running) { |
| 984 | qemu_mutex_lock(&s->free_page_lock); |
| 985 | s->block_iothread = true; |
| 986 | qemu_mutex_unlock(&s->free_page_lock); |
| 987 | } |
| 988 | } |
| 989 | return 0; |
| 990 | } |
| 991 | |
| 992 | static ResettableState *virtio_balloon_get_reset_state(Object *obj) |
| 993 | { |
| 994 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 995 | return &s->reset_state; |
| 996 | } |
| 997 | |
| 998 | static void virtio_balloon_reset_enter(Object *obj, ResetType type) |
| 999 | { |
| 1000 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 1001 | |
| 1002 | /* |
| 1003 | * When waking up from standby/suspend-to-ram, do not reset stats. |
| 1004 | */ |
| 1005 | if (type == RESET_TYPE_WAKEUP) { |
| 1006 | return; |
| 1007 | } |
| 1008 | |
| 1009 | reset_stats(s); |
| 1010 | s->stats_last_update = 0; |
| 1011 | } |
| 1012 | |
| 1013 | static void virtio_balloon_instance_init(Object *obj) |
| 1014 | { |
| 1015 | VirtIOBalloon *s = VIRTIO_BALLOON(obj); |
| 1016 | |
| 1017 | qemu_mutex_init(&s->free_page_lock); |
| 1018 | qemu_cond_init(&s->free_page_cond); |
| 1019 | s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN; |
| 1020 | s->free_page_hint_notify.notify = virtio_balloon_free_page_hint_notify; |
| 1021 | |
| 1022 | object_property_add(obj, "guest-stats", "guest statistics", |
| 1023 | balloon_stats_get_all, NULL, NULL, NULL); |
| 1024 | |
| 1025 | object_property_add(obj, "guest-stats-polling-interval", "int", |
| 1026 | balloon_stats_get_poll_interval, |
| 1027 | balloon_stats_set_poll_interval, |
| 1028 | NULL, NULL); |
| 1029 | } |
| 1030 | |
| 1031 | static const VMStateDescription vmstate_virtio_balloon = { |
| 1032 | .name = "virtio-balloon", |
| 1033 | .minimum_version_id = 1, |
| 1034 | .version_id = 1, |
| 1035 | .fields = (const VMStateField[]) { |
| 1036 | VMSTATE_VIRTIO_DEVICE, |
| 1037 | VMSTATE_END_OF_LIST() |
| 1038 | }, |
| 1039 | }; |
| 1040 | |
| 1041 | static const Property virtio_balloon_properties[] = { |
| 1042 | DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features, |
| 1043 | VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false), |
| 1044 | DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features, |
| 1045 | VIRTIO_BALLOON_F_FREE_PAGE_HINT, false), |
| 1046 | DEFINE_PROP_BIT("page-poison", VirtIOBalloon, host_features, |
| 1047 | VIRTIO_BALLOON_F_PAGE_POISON, true), |
| 1048 | DEFINE_PROP_BIT("free-page-reporting", VirtIOBalloon, host_features, |
| 1049 | VIRTIO_BALLOON_F_REPORTING, false), |
| 1050 | /* QEMU 4.0 accidentally changed the config size even when free-page-hint |
| 1051 | * is disabled, resulting in QEMU 3.1 migration incompatibility. This |
| 1052 | * property retains this quirk for QEMU 4.1 machine types. |
| 1053 | */ |
| 1054 | DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD, |
| 1055 | IOThread *), |
| 1056 | }; |
| 1057 | |
| 1058 | static void virtio_balloon_class_init(ObjectClass *klass, const void *data) |
| 1059 | { |
| 1060 | DeviceClass *dc = DEVICE_CLASS(klass); |
| 1061 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); |
| 1062 | ResettableClass *rc = RESETTABLE_CLASS(klass); |
| 1063 | |
| 1064 | device_class_set_props(dc, virtio_balloon_properties); |
| 1065 | dc->vmsd = &vmstate_virtio_balloon; |
| 1066 | set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
| 1067 | vdc->realize = virtio_balloon_device_realize; |
| 1068 | vdc->unrealize = virtio_balloon_device_unrealize; |
| 1069 | vdc->reset = virtio_balloon_device_reset; |
| 1070 | vdc->get_config = virtio_balloon_get_config; |
| 1071 | vdc->set_config = virtio_balloon_set_config; |
| 1072 | vdc->get_features = virtio_balloon_get_features; |
| 1073 | vdc->set_status = virtio_balloon_set_status; |
| 1074 | vdc->vmsd = &vmstate_virtio_balloon_device; |
| 1075 | |
| 1076 | rc->get_state = virtio_balloon_get_reset_state; |
| 1077 | rc->phases.enter = virtio_balloon_reset_enter; |
| 1078 | } |
| 1079 | |
| 1080 | static const TypeInfo virtio_balloon_info = { |
| 1081 | .name = TYPE_VIRTIO_BALLOON, |
| 1082 | .parent = TYPE_VIRTIO_DEVICE, |
| 1083 | .instance_size = sizeof(VirtIOBalloon), |
| 1084 | .instance_init = virtio_balloon_instance_init, |
| 1085 | .class_init = virtio_balloon_class_init, |
| 1086 | }; |
| 1087 | |
| 1088 | static void virtio_register_types(void) |
| 1089 | { |
| 1090 | type_register_static(&virtio_balloon_info); |
| 1091 | } |
| 1092 | |
| 1093 | type_init(virtio_register_types) |