| 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/iov.h" |
| 15 | #include "qemu/cutils.h" |
| 16 | #include "qemu/error-report.h" |
| 17 | #include "qemu/units.h" |
| 18 | #include "qemu/target-info-qapi.h" |
| 19 | #include "system/memory.h" |
| 20 | #include "system/numa.h" |
| 21 | #include "system/system.h" |
| 22 | #include "system/ramblock.h" |
| 23 | #include "system/reset.h" |
| 24 | #include "system/runstate.h" |
| 25 | #include "hw/virtio/virtio.h" |
| 26 | #include "hw/virtio/virtio-bus.h" |
| 27 | #include "hw/virtio/virtio-mem.h" |
| 28 | #include "qapi/error.h" |
| 29 | #include "qapi/visitor.h" |
| 30 | #include "migration/misc.h" |
| 31 | #include "hw/core/boards.h" |
| 32 | #include "hw/core/qdev-properties.h" |
| 33 | #include "hw/acpi/acpi.h" |
| 34 | #include "trace.h" |
| 35 | |
| 36 | static const VMStateDescription vmstate_virtio_mem_device_early; |
| 37 | |
| 38 | static bool virtio_mem_has_legacy_guests(void) |
| 39 | { |
| 40 | /* |
| 41 | * We only had legacy x86 guests that did not support |
| 42 | * VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE. Other targets don't have |
| 43 | * legacy guests. |
| 44 | */ |
| 45 | switch (target_arch()) { |
| 46 | case SYS_EMU_TARGET_I386: |
| 47 | case SYS_EMU_TARGET_X86_64: |
| 48 | return true; |
| 49 | default: |
| 50 | return false; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | /* |
| 55 | * Let's not allow blocks smaller than 1 MiB, for example, to keep the tracking |
| 56 | * bitmap small. |
| 57 | */ |
| 58 | #define VIRTIO_MEM_MIN_BLOCK_SIZE ((uint32_t)(1 * MiB)) |
| 59 | |
| 60 | static uint32_t virtio_mem_default_thp_size(void) |
| 61 | { |
| 62 | uint32_t default_thp_size = VIRTIO_MEM_MIN_BLOCK_SIZE; |
| 63 | |
| 64 | #if defined(__x86_64__) || defined(__powerpc64__) |
| 65 | default_thp_size = 2 * MiB; |
| 66 | #elif defined(__aarch64__) |
| 67 | if (qemu_real_host_page_size() == 4 * KiB) { |
| 68 | default_thp_size = 2 * MiB; |
| 69 | } else if (qemu_real_host_page_size() == 16 * KiB) { |
| 70 | default_thp_size = 32 * MiB; |
| 71 | } else if (qemu_real_host_page_size() == 64 * KiB) { |
| 72 | default_thp_size = 512 * MiB; |
| 73 | } |
| 74 | #elif defined(__s390x__) |
| 75 | default_thp_size = 1 * MiB; |
| 76 | #endif |
| 77 | |
| 78 | return default_thp_size; |
| 79 | } |
| 80 | |
| 81 | /* |
| 82 | * The minimum memslot size depends on this setting ("sane default"), the |
| 83 | * device block size, and the memory backend page size. The last (or single) |
| 84 | * memslot might be smaller than this constant. |
| 85 | */ |
| 86 | #define VIRTIO_MEM_MIN_MEMSLOT_SIZE (1 * GiB) |
| 87 | |
| 88 | /* |
| 89 | * We want to have a reasonable default block size such that |
| 90 | * 1. We avoid splitting THPs when unplugging memory, which degrades |
| 91 | * performance. |
| 92 | * 2. We avoid placing THPs for plugged blocks that also cover unplugged |
| 93 | * blocks. |
| 94 | * |
| 95 | * The actual THP size might differ between Linux kernels, so we try to probe |
| 96 | * it. In the future (if we ever run into issues regarding 2.), we might want |
| 97 | * to disable THP in case we fail to properly probe the THP size, or if the |
| 98 | * block size is configured smaller than the THP size. |
| 99 | */ |
| 100 | static uint32_t thp_size; |
| 101 | |
| 102 | #define HPAGE_PMD_SIZE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" |
| 103 | #define HPAGE_PATH "/sys/kernel/mm/transparent_hugepage/" |
| 104 | static uint32_t virtio_mem_thp_size(void) |
| 105 | { |
| 106 | gchar *content = NULL; |
| 107 | const char *endptr; |
| 108 | uint64_t tmp; |
| 109 | |
| 110 | if (thp_size) { |
| 111 | return thp_size; |
| 112 | } |
| 113 | |
| 114 | /* No THP -> no restrictions. */ |
| 115 | if (!g_file_test(HPAGE_PATH, G_FILE_TEST_EXISTS)) { |
| 116 | thp_size = VIRTIO_MEM_MIN_BLOCK_SIZE; |
| 117 | return thp_size; |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * Try to probe the actual THP size, fallback to (sane but eventually |
| 122 | * incorrect) default sizes. |
| 123 | */ |
| 124 | if (g_file_get_contents(HPAGE_PMD_SIZE_PATH, &content, NULL, NULL) && |
| 125 | !qemu_strtou64(content, &endptr, 0, &tmp) && |
| 126 | (!endptr || *endptr == '\n')) { |
| 127 | /* Sanity-check the value and fallback to something reasonable. */ |
| 128 | if (!tmp || !is_power_of_2(tmp)) { |
| 129 | warn_report("Read unsupported THP size: %" PRIx64, tmp); |
| 130 | } else { |
| 131 | thp_size = tmp; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | if (!thp_size) { |
| 136 | thp_size = virtio_mem_default_thp_size(); |
| 137 | warn_report("Could not detect THP size, falling back to %" PRIx64 |
| 138 | " MiB.", thp_size / MiB); |
| 139 | } |
| 140 | |
| 141 | g_free(content); |
| 142 | return thp_size; |
| 143 | } |
| 144 | |
| 145 | static uint64_t virtio_mem_default_block_size(RAMBlock *rb) |
| 146 | { |
| 147 | const uint64_t page_size = qemu_ram_pagesize(rb); |
| 148 | |
| 149 | /* We can have hugetlbfs with a page size smaller than the THP size. */ |
| 150 | if (page_size == qemu_real_host_page_size()) { |
| 151 | return MAX(page_size, virtio_mem_thp_size()); |
| 152 | } |
| 153 | return MAX(page_size, VIRTIO_MEM_MIN_BLOCK_SIZE); |
| 154 | } |
| 155 | |
| 156 | static bool virtio_mem_has_shared_zeropage(RAMBlock *rb) |
| 157 | { |
| 158 | /* |
| 159 | * We only have a guaranteed shared zeropage on ordinary MAP_PRIVATE |
| 160 | * anonymous RAM. In any other case, reading unplugged *can* populate a |
| 161 | * fresh page, consuming actual memory. |
| 162 | */ |
| 163 | return !qemu_ram_is_shared(rb) && qemu_ram_get_fd(rb) < 0 && |
| 164 | qemu_ram_pagesize(rb) == qemu_real_host_page_size(); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * Size the usable region bigger than the requested size if possible. Esp. |
| 169 | * Linux guests will only add (aligned) memory blocks in case they fully |
| 170 | * fit into the usable region, but plug+online only a subset of the pages. |
| 171 | * The memory block size corresponds mostly to the section size. |
| 172 | * |
| 173 | * This allows e.g., to add 20MB with a section size of 128MB on x86_64, and |
| 174 | * a section size of 512MB on arm64 (as long as the start address is properly |
| 175 | * aligned, similar to ordinary DIMMs). |
| 176 | * |
| 177 | * We can change this at any time and maybe even make it configurable if |
| 178 | * necessary (as the section size can change). But it's more likely that the |
| 179 | * section size will rather get smaller and not bigger over time. |
| 180 | */ |
| 181 | static uint64_t virtio_mem_usable_extent_size(void) |
| 182 | { |
| 183 | switch (target_arch()) { |
| 184 | case SYS_EMU_TARGET_I386: |
| 185 | case SYS_EMU_TARGET_X86_64: |
| 186 | case SYS_EMU_TARGET_S390X: |
| 187 | return 2 * 128 * MiB; |
| 188 | case SYS_EMU_TARGET_AARCH64: |
| 189 | case SYS_EMU_TARGET_ARM: |
| 190 | return 2 * 512 * MiB; |
| 191 | default: |
| 192 | g_assert_not_reached(); |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | static bool virtio_mem_is_busy(void) |
| 197 | { |
| 198 | /* |
| 199 | * Postcopy cannot handle concurrent discards and we don't want to migrate |
| 200 | * pages on-demand with stale content when plugging new blocks. |
| 201 | * |
| 202 | * For precopy, we don't want unplugged blocks in our migration stream, and |
| 203 | * when plugging new blocks, the page content might differ between source |
| 204 | * and destination (observable by the guest when not initializing pages |
| 205 | * after plugging them) until we're running on the destination (as we didn't |
| 206 | * migrate these blocks when they were unplugged). |
| 207 | */ |
| 208 | return migration_in_incoming_postcopy() || migration_is_running(); |
| 209 | } |
| 210 | |
| 211 | typedef int (*virtio_mem_range_cb)(VirtIOMEM *vmem, void *arg, |
| 212 | uint64_t offset, uint64_t size); |
| 213 | |
| 214 | static int virtio_mem_for_each_unplugged_range(VirtIOMEM *vmem, void *arg, |
| 215 | virtio_mem_range_cb cb) |
| 216 | { |
| 217 | unsigned long first_zero_bit, last_zero_bit; |
| 218 | uint64_t offset, size; |
| 219 | int ret = 0; |
| 220 | |
| 221 | first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size); |
| 222 | while (first_zero_bit < vmem->bitmap_size) { |
| 223 | offset = first_zero_bit * vmem->block_size; |
| 224 | last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size, |
| 225 | first_zero_bit + 1) - 1; |
| 226 | size = (last_zero_bit - first_zero_bit + 1) * vmem->block_size; |
| 227 | |
| 228 | ret = cb(vmem, arg, offset, size); |
| 229 | if (ret) { |
| 230 | break; |
| 231 | } |
| 232 | first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size, |
| 233 | last_zero_bit + 2); |
| 234 | } |
| 235 | return ret; |
| 236 | } |
| 237 | |
| 238 | static int virtio_mem_for_each_plugged_range(VirtIOMEM *vmem, void *arg, |
| 239 | virtio_mem_range_cb cb) |
| 240 | { |
| 241 | unsigned long first_bit, last_bit; |
| 242 | uint64_t offset, size; |
| 243 | int ret = 0; |
| 244 | |
| 245 | first_bit = find_first_bit(vmem->bitmap, vmem->bitmap_size); |
| 246 | while (first_bit < vmem->bitmap_size) { |
| 247 | offset = first_bit * vmem->block_size; |
| 248 | last_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size, |
| 249 | first_bit + 1) - 1; |
| 250 | size = (last_bit - first_bit + 1) * vmem->block_size; |
| 251 | |
| 252 | ret = cb(vmem, arg, offset, size); |
| 253 | if (ret) { |
| 254 | break; |
| 255 | } |
| 256 | first_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size, |
| 257 | last_bit + 2); |
| 258 | } |
| 259 | return ret; |
| 260 | } |
| 261 | |
| 262 | static void virtio_mem_notify_unplug(VirtIOMEM *vmem, uint64_t offset, |
| 263 | uint64_t size) |
| 264 | { |
| 265 | RamDiscardManager *rdm = memory_region_get_ram_discard_manager(&vmem->memdev->mr); |
| 266 | |
| 267 | ram_discard_manager_notify_discard(rdm, RAM_DISCARD_SOURCE(vmem), |
| 268 | offset, size); |
| 269 | } |
| 270 | |
| 271 | static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset, |
| 272 | uint64_t size) |
| 273 | { |
| 274 | RamDiscardManager *rdm = memory_region_get_ram_discard_manager(&vmem->memdev->mr); |
| 275 | |
| 276 | return ram_discard_manager_notify_populate(rdm, RAM_DISCARD_SOURCE(vmem), |
| 277 | offset, size); |
| 278 | } |
| 279 | |
| 280 | static void virtio_mem_notify_unplug_all(VirtIOMEM *vmem) |
| 281 | { |
| 282 | RamDiscardManager *rdm = memory_region_get_ram_discard_manager(&vmem->memdev->mr); |
| 283 | |
| 284 | if (!vmem->size) { |
| 285 | return; |
| 286 | } |
| 287 | |
| 288 | ram_discard_manager_notify_discard_all(rdm, RAM_DISCARD_SOURCE(vmem)); |
| 289 | } |
| 290 | |
| 291 | static bool virtio_mem_is_range_plugged(const VirtIOMEM *vmem, |
| 292 | uint64_t start_gpa, uint64_t size) |
| 293 | { |
| 294 | const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size; |
| 295 | const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1; |
| 296 | unsigned long found_bit; |
| 297 | |
| 298 | /* We fake a shorter bitmap to avoid searching too far. */ |
| 299 | found_bit = find_next_zero_bit(vmem->bitmap, last_bit + 1, first_bit); |
| 300 | return found_bit > last_bit; |
| 301 | } |
| 302 | |
| 303 | static bool virtio_mem_is_range_unplugged(const VirtIOMEM *vmem, |
| 304 | uint64_t start_gpa, uint64_t size) |
| 305 | { |
| 306 | const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size; |
| 307 | const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1; |
| 308 | unsigned long found_bit; |
| 309 | |
| 310 | /* We fake a shorter bitmap to avoid searching too far. */ |
| 311 | found_bit = find_next_bit(vmem->bitmap, last_bit + 1, first_bit); |
| 312 | return found_bit > last_bit; |
| 313 | } |
| 314 | |
| 315 | static void virtio_mem_set_range_plugged(VirtIOMEM *vmem, uint64_t start_gpa, |
| 316 | uint64_t size) |
| 317 | { |
| 318 | const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size; |
| 319 | const unsigned long nbits = size / vmem->block_size; |
| 320 | |
| 321 | bitmap_set(vmem->bitmap, bit, nbits); |
| 322 | } |
| 323 | |
| 324 | static void virtio_mem_set_range_unplugged(VirtIOMEM *vmem, uint64_t start_gpa, |
| 325 | uint64_t size) |
| 326 | { |
| 327 | const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size; |
| 328 | const unsigned long nbits = size / vmem->block_size; |
| 329 | |
| 330 | bitmap_clear(vmem->bitmap, bit, nbits); |
| 331 | } |
| 332 | |
| 333 | static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem, |
| 334 | struct virtio_mem_resp *resp) |
| 335 | { |
| 336 | VirtIODevice *vdev = VIRTIO_DEVICE(vmem); |
| 337 | VirtQueue *vq = vmem->vq; |
| 338 | |
| 339 | trace_virtio_mem_send_response(le16_to_cpu(resp->type)); |
| 340 | iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp)); |
| 341 | |
| 342 | virtqueue_push(vq, elem, sizeof(*resp)); |
| 343 | virtio_notify(vdev, vq); |
| 344 | } |
| 345 | |
| 346 | static void virtio_mem_send_response_simple(VirtIOMEM *vmem, |
| 347 | VirtQueueElement *elem, |
| 348 | uint16_t type) |
| 349 | { |
| 350 | struct virtio_mem_resp resp = { |
| 351 | .type = cpu_to_le16(type), |
| 352 | }; |
| 353 | |
| 354 | virtio_mem_send_response(vmem, elem, &resp); |
| 355 | } |
| 356 | |
| 357 | static bool virtio_mem_valid_range(const VirtIOMEM *vmem, uint64_t gpa, |
| 358 | uint64_t size) |
| 359 | { |
| 360 | if (!QEMU_IS_ALIGNED(gpa, vmem->block_size)) { |
| 361 | return false; |
| 362 | } |
| 363 | if (gpa + size < gpa || !size) { |
| 364 | return false; |
| 365 | } |
| 366 | if (gpa < vmem->addr || gpa >= vmem->addr + vmem->usable_region_size) { |
| 367 | return false; |
| 368 | } |
| 369 | if (gpa + size > vmem->addr + vmem->usable_region_size) { |
| 370 | return false; |
| 371 | } |
| 372 | return true; |
| 373 | } |
| 374 | |
| 375 | static void virtio_mem_activate_memslot(VirtIOMEM *vmem, unsigned int idx) |
| 376 | { |
| 377 | const uint64_t memslot_offset = idx * vmem->memslot_size; |
| 378 | |
| 379 | assert(vmem->memslots); |
| 380 | |
| 381 | /* |
| 382 | * Instead of enabling/disabling memslots, we add/remove them. This should |
| 383 | * make address space updates faster, because we don't have to loop over |
| 384 | * many disabled subregions. |
| 385 | */ |
| 386 | if (memory_region_is_mapped(&vmem->memslots[idx])) { |
| 387 | return; |
| 388 | } |
| 389 | memory_region_add_subregion(vmem->mr, memslot_offset, &vmem->memslots[idx]); |
| 390 | } |
| 391 | |
| 392 | static void virtio_mem_deactivate_memslot(VirtIOMEM *vmem, unsigned int idx) |
| 393 | { |
| 394 | assert(vmem->memslots); |
| 395 | |
| 396 | if (!memory_region_is_mapped(&vmem->memslots[idx])) { |
| 397 | return; |
| 398 | } |
| 399 | memory_region_del_subregion(vmem->mr, &vmem->memslots[idx]); |
| 400 | } |
| 401 | |
| 402 | static void virtio_mem_activate_memslots_to_plug(VirtIOMEM *vmem, |
| 403 | uint64_t offset, uint64_t size) |
| 404 | { |
| 405 | const unsigned int start_idx = offset / vmem->memslot_size; |
| 406 | const unsigned int end_idx = (offset + size + vmem->memslot_size - 1) / |
| 407 | vmem->memslot_size; |
| 408 | unsigned int idx; |
| 409 | |
| 410 | assert(vmem->dynamic_memslots); |
| 411 | |
| 412 | /* Activate all involved memslots in a single transaction. */ |
| 413 | memory_region_transaction_begin(); |
| 414 | for (idx = start_idx; idx < end_idx; idx++) { |
| 415 | virtio_mem_activate_memslot(vmem, idx); |
| 416 | } |
| 417 | memory_region_transaction_commit(); |
| 418 | } |
| 419 | |
| 420 | static void virtio_mem_deactivate_unplugged_memslots(VirtIOMEM *vmem, |
| 421 | uint64_t offset, |
| 422 | uint64_t size) |
| 423 | { |
| 424 | const uint64_t region_size = memory_region_size(&vmem->memdev->mr); |
| 425 | const unsigned int start_idx = offset / vmem->memslot_size; |
| 426 | const unsigned int end_idx = (offset + size + vmem->memslot_size - 1) / |
| 427 | vmem->memslot_size; |
| 428 | unsigned int idx; |
| 429 | |
| 430 | assert(vmem->dynamic_memslots); |
| 431 | |
| 432 | /* Deactivate all memslots with unplugged blocks in a single transaction. */ |
| 433 | memory_region_transaction_begin(); |
| 434 | for (idx = start_idx; idx < end_idx; idx++) { |
| 435 | const uint64_t memslot_offset = idx * vmem->memslot_size; |
| 436 | uint64_t memslot_size = vmem->memslot_size; |
| 437 | |
| 438 | /* The size of the last memslot might be smaller. */ |
| 439 | if (idx == vmem->nb_memslots - 1) { |
| 440 | memslot_size = region_size - memslot_offset; |
| 441 | } |
| 442 | |
| 443 | /* |
| 444 | * Partially covered memslots might still have some blocks plugged and |
| 445 | * have to remain active if that's the case. |
| 446 | */ |
| 447 | if (offset > memslot_offset || |
| 448 | offset + size < memslot_offset + memslot_size) { |
| 449 | const uint64_t gpa = vmem->addr + memslot_offset; |
| 450 | |
| 451 | if (!virtio_mem_is_range_unplugged(vmem, gpa, memslot_size)) { |
| 452 | continue; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | virtio_mem_deactivate_memslot(vmem, idx); |
| 457 | } |
| 458 | memory_region_transaction_commit(); |
| 459 | } |
| 460 | |
| 461 | static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa, |
| 462 | uint64_t size, bool plug) |
| 463 | { |
| 464 | const uint64_t offset = start_gpa - vmem->addr; |
| 465 | RAMBlock *rb = vmem->memdev->mr.ram_block; |
| 466 | int ret = 0; |
| 467 | |
| 468 | if (virtio_mem_is_busy()) { |
| 469 | return -EBUSY; |
| 470 | } |
| 471 | |
| 472 | if (!plug) { |
| 473 | if (ram_block_discard_range(rb, offset, size)) { |
| 474 | return -EBUSY; |
| 475 | } |
| 476 | virtio_mem_notify_unplug(vmem, offset, size); |
| 477 | virtio_mem_set_range_unplugged(vmem, start_gpa, size); |
| 478 | /* Deactivate completely unplugged memslots after updating the state. */ |
| 479 | if (vmem->dynamic_memslots) { |
| 480 | virtio_mem_deactivate_unplugged_memslots(vmem, offset, size); |
| 481 | } |
| 482 | return 0; |
| 483 | } |
| 484 | |
| 485 | if (vmem->prealloc) { |
| 486 | void *area = memory_region_get_ram_ptr(&vmem->memdev->mr) + offset; |
| 487 | int fd = memory_region_get_fd(&vmem->memdev->mr); |
| 488 | Error *local_err = NULL; |
| 489 | |
| 490 | if (!qemu_prealloc_mem(fd, area, size, 1, NULL, false, &local_err)) { |
| 491 | warn_report_err_once(local_err); |
| 492 | ret = -EBUSY; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | if (!ret) { |
| 497 | /* |
| 498 | * Activate before notifying and rollback in case of any errors. |
| 499 | * |
| 500 | * When activating a yet inactive memslot, memory notifiers will get |
| 501 | * notified about the added memory region and can register with the |
| 502 | * RamDiscardManager; this will traverse all plugged blocks and skip the |
| 503 | * blocks we are plugging here. The following notification will inform |
| 504 | * registered listeners about the blocks we're plugging. |
| 505 | */ |
| 506 | if (vmem->dynamic_memslots) { |
| 507 | virtio_mem_activate_memslots_to_plug(vmem, offset, size); |
| 508 | } |
| 509 | ret = virtio_mem_notify_plug(vmem, offset, size); |
| 510 | if (ret && vmem->dynamic_memslots) { |
| 511 | virtio_mem_deactivate_unplugged_memslots(vmem, offset, size); |
| 512 | } |
| 513 | } |
| 514 | if (ret) { |
| 515 | /* Could be preallocation or a notifier populated memory. */ |
| 516 | ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size); |
| 517 | return -EBUSY; |
| 518 | } |
| 519 | |
| 520 | virtio_mem_set_range_plugged(vmem, start_gpa, size); |
| 521 | return 0; |
| 522 | } |
| 523 | |
| 524 | static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa, |
| 525 | uint16_t nb_blocks, bool plug) |
| 526 | { |
| 527 | const uint64_t size = nb_blocks * vmem->block_size; |
| 528 | int ret; |
| 529 | |
| 530 | if (!virtio_mem_valid_range(vmem, gpa, size)) { |
| 531 | return VIRTIO_MEM_RESP_ERROR; |
| 532 | } |
| 533 | |
| 534 | if (plug && (vmem->size + size > vmem->requested_size)) { |
| 535 | return VIRTIO_MEM_RESP_NACK; |
| 536 | } |
| 537 | |
| 538 | /* test if really all blocks are in the opposite state */ |
| 539 | if ((plug && !virtio_mem_is_range_unplugged(vmem, gpa, size)) || |
| 540 | (!plug && !virtio_mem_is_range_plugged(vmem, gpa, size))) { |
| 541 | return VIRTIO_MEM_RESP_ERROR; |
| 542 | } |
| 543 | |
| 544 | ret = virtio_mem_set_block_state(vmem, gpa, size, plug); |
| 545 | if (ret) { |
| 546 | return VIRTIO_MEM_RESP_BUSY; |
| 547 | } |
| 548 | if (plug) { |
| 549 | vmem->size += size; |
| 550 | } else { |
| 551 | vmem->size -= size; |
| 552 | } |
| 553 | notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); |
| 554 | return VIRTIO_MEM_RESP_ACK; |
| 555 | } |
| 556 | |
| 557 | static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem, |
| 558 | struct virtio_mem_req *req) |
| 559 | { |
| 560 | const uint64_t gpa = le64_to_cpu(req->u.plug.addr); |
| 561 | const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks); |
| 562 | uint16_t type; |
| 563 | |
| 564 | trace_virtio_mem_plug_request(gpa, nb_blocks); |
| 565 | type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true); |
| 566 | virtio_mem_send_response_simple(vmem, elem, type); |
| 567 | } |
| 568 | |
| 569 | static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem, |
| 570 | struct virtio_mem_req *req) |
| 571 | { |
| 572 | const uint64_t gpa = le64_to_cpu(req->u.unplug.addr); |
| 573 | const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks); |
| 574 | uint16_t type; |
| 575 | |
| 576 | trace_virtio_mem_unplug_request(gpa, nb_blocks); |
| 577 | type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false); |
| 578 | virtio_mem_send_response_simple(vmem, elem, type); |
| 579 | } |
| 580 | |
| 581 | static void virtio_mem_resize_usable_region(VirtIOMEM *vmem, |
| 582 | uint64_t requested_size, |
| 583 | bool can_shrink) |
| 584 | { |
| 585 | uint64_t newsize = MIN(memory_region_size(&vmem->memdev->mr), |
| 586 | requested_size + virtio_mem_usable_extent_size()); |
| 587 | |
| 588 | /* The usable region size always has to be multiples of the block size. */ |
| 589 | newsize = QEMU_ALIGN_UP(newsize, vmem->block_size); |
| 590 | |
| 591 | if (!requested_size) { |
| 592 | newsize = 0; |
| 593 | } |
| 594 | |
| 595 | if (newsize < vmem->usable_region_size && !can_shrink) { |
| 596 | return; |
| 597 | } |
| 598 | |
| 599 | trace_virtio_mem_resized_usable_region(vmem->usable_region_size, newsize); |
| 600 | vmem->usable_region_size = newsize; |
| 601 | } |
| 602 | |
| 603 | static int virtio_mem_unplug_all(VirtIOMEM *vmem) |
| 604 | { |
| 605 | const uint64_t region_size = memory_region_size(&vmem->memdev->mr); |
| 606 | RAMBlock *rb = vmem->memdev->mr.ram_block; |
| 607 | |
| 608 | if (vmem->size) { |
| 609 | if (virtio_mem_is_busy()) { |
| 610 | return -EBUSY; |
| 611 | } |
| 612 | if (ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb))) { |
| 613 | return -EBUSY; |
| 614 | } |
| 615 | virtio_mem_notify_unplug_all(vmem); |
| 616 | |
| 617 | bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size); |
| 618 | vmem->size = 0; |
| 619 | notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); |
| 620 | |
| 621 | /* Deactivate all memslots after updating the state. */ |
| 622 | if (vmem->dynamic_memslots) { |
| 623 | virtio_mem_deactivate_unplugged_memslots(vmem, 0, region_size); |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | trace_virtio_mem_unplugged_all(); |
| 628 | virtio_mem_resize_usable_region(vmem, vmem->requested_size, true); |
| 629 | return 0; |
| 630 | } |
| 631 | |
| 632 | static void virtio_mem_unplug_all_request(VirtIOMEM *vmem, |
| 633 | VirtQueueElement *elem) |
| 634 | { |
| 635 | trace_virtio_mem_unplug_all_request(); |
| 636 | if (virtio_mem_unplug_all(vmem)) { |
| 637 | virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY); |
| 638 | } else { |
| 639 | virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ACK); |
| 640 | } |
| 641 | } |
| 642 | |
| 643 | static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem, |
| 644 | struct virtio_mem_req *req) |
| 645 | { |
| 646 | const uint16_t nb_blocks = le16_to_cpu(req->u.state.nb_blocks); |
| 647 | const uint64_t gpa = le64_to_cpu(req->u.state.addr); |
| 648 | const uint64_t size = nb_blocks * vmem->block_size; |
| 649 | struct virtio_mem_resp resp = { |
| 650 | .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK), |
| 651 | }; |
| 652 | |
| 653 | trace_virtio_mem_state_request(gpa, nb_blocks); |
| 654 | if (!virtio_mem_valid_range(vmem, gpa, size)) { |
| 655 | virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR); |
| 656 | return; |
| 657 | } |
| 658 | |
| 659 | if (virtio_mem_is_range_plugged(vmem, gpa, size)) { |
| 660 | resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_PLUGGED); |
| 661 | } else if (virtio_mem_is_range_unplugged(vmem, gpa, size)) { |
| 662 | resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_UNPLUGGED); |
| 663 | } else { |
| 664 | resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED); |
| 665 | } |
| 666 | trace_virtio_mem_state_response(le16_to_cpu(resp.u.state.state)); |
| 667 | virtio_mem_send_response(vmem, elem, &resp); |
| 668 | } |
| 669 | |
| 670 | static void virtio_mem_handle_request(VirtIODevice *vdev, VirtQueue *vq) |
| 671 | { |
| 672 | const int len = sizeof(struct virtio_mem_req); |
| 673 | VirtIOMEM *vmem = VIRTIO_MEM(vdev); |
| 674 | VirtQueueElement *elem; |
| 675 | struct virtio_mem_req req; |
| 676 | uint16_t type; |
| 677 | |
| 678 | while (true) { |
| 679 | elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); |
| 680 | if (!elem) { |
| 681 | return; |
| 682 | } |
| 683 | |
| 684 | if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) { |
| 685 | virtio_error(vdev, "virtio-mem protocol violation: invalid request" |
| 686 | " size: %d", len); |
| 687 | virtqueue_detach_element(vq, elem, 0); |
| 688 | g_free(elem); |
| 689 | return; |
| 690 | } |
| 691 | |
| 692 | if (iov_size(elem->in_sg, elem->in_num) < |
| 693 | sizeof(struct virtio_mem_resp)) { |
| 694 | virtio_error(vdev, "virtio-mem protocol violation: not enough space" |
| 695 | " for response: %zu", |
| 696 | iov_size(elem->in_sg, elem->in_num)); |
| 697 | virtqueue_detach_element(vq, elem, 0); |
| 698 | g_free(elem); |
| 699 | return; |
| 700 | } |
| 701 | |
| 702 | type = le16_to_cpu(req.type); |
| 703 | switch (type) { |
| 704 | case VIRTIO_MEM_REQ_PLUG: |
| 705 | virtio_mem_plug_request(vmem, elem, &req); |
| 706 | break; |
| 707 | case VIRTIO_MEM_REQ_UNPLUG: |
| 708 | virtio_mem_unplug_request(vmem, elem, &req); |
| 709 | break; |
| 710 | case VIRTIO_MEM_REQ_UNPLUG_ALL: |
| 711 | virtio_mem_unplug_all_request(vmem, elem); |
| 712 | break; |
| 713 | case VIRTIO_MEM_REQ_STATE: |
| 714 | virtio_mem_state_request(vmem, elem, &req); |
| 715 | break; |
| 716 | default: |
| 717 | virtio_error(vdev, "virtio-mem protocol violation: unknown request" |
| 718 | " type: %d", type); |
| 719 | virtqueue_detach_element(vq, elem, 0); |
| 720 | g_free(elem); |
| 721 | return; |
| 722 | } |
| 723 | |
| 724 | g_free(elem); |
| 725 | } |
| 726 | } |
| 727 | |
| 728 | static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data) |
| 729 | { |
| 730 | VirtIOMEM *vmem = VIRTIO_MEM(vdev); |
| 731 | struct virtio_mem_config *config = (void *) config_data; |
| 732 | |
| 733 | config->block_size = cpu_to_le64(vmem->block_size); |
| 734 | config->node_id = cpu_to_le16(vmem->node); |
| 735 | config->requested_size = cpu_to_le64(vmem->requested_size); |
| 736 | config->plugged_size = cpu_to_le64(vmem->size); |
| 737 | config->addr = cpu_to_le64(vmem->addr); |
| 738 | config->region_size = cpu_to_le64(memory_region_size(&vmem->memdev->mr)); |
| 739 | config->usable_region_size = cpu_to_le64(vmem->usable_region_size); |
| 740 | } |
| 741 | |
| 742 | static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features, |
| 743 | Error **errp) |
| 744 | { |
| 745 | MachineState *ms = MACHINE(qdev_get_machine()); |
| 746 | VirtIOMEM *vmem = VIRTIO_MEM(vdev); |
| 747 | |
| 748 | if (ms->numa_state && acpi_builtin()) { |
| 749 | virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM); |
| 750 | } |
| 751 | assert(vmem->unplugged_inaccessible != ON_OFF_AUTO_AUTO); |
| 752 | if (vmem->unplugged_inaccessible == ON_OFF_AUTO_ON) { |
| 753 | virtio_add_feature(&features, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE); |
| 754 | } |
| 755 | if (qemu_wakeup_suspend_enabled()) { |
| 756 | virtio_add_feature(&features, VIRTIO_MEM_F_PERSISTENT_SUSPEND); |
| 757 | } |
| 758 | return features; |
| 759 | } |
| 760 | |
| 761 | static int virtio_mem_validate_features(VirtIODevice *vdev) |
| 762 | { |
| 763 | if (virtio_host_has_feature(vdev, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE) && |
| 764 | !virtio_vdev_has_feature(vdev, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE)) { |
| 765 | return -EFAULT; |
| 766 | } |
| 767 | return 0; |
| 768 | } |
| 769 | |
| 770 | static void virtio_mem_prepare_mr(VirtIOMEM *vmem) |
| 771 | { |
| 772 | const uint64_t region_size = memory_region_size(&vmem->memdev->mr); |
| 773 | |
| 774 | assert(!vmem->mr && vmem->dynamic_memslots); |
| 775 | vmem->mr = g_new0(MemoryRegion, 1); |
| 776 | memory_region_init(vmem->mr, OBJECT(vmem), "virtio-mem", |
| 777 | region_size); |
| 778 | vmem->mr->align = memory_region_get_alignment(&vmem->memdev->mr); |
| 779 | } |
| 780 | |
| 781 | static void virtio_mem_prepare_memslots(VirtIOMEM *vmem) |
| 782 | { |
| 783 | const uint64_t region_size = memory_region_size(&vmem->memdev->mr); |
| 784 | unsigned int idx; |
| 785 | |
| 786 | g_assert(!vmem->memslots && vmem->nb_memslots && vmem->dynamic_memslots); |
| 787 | vmem->memslots = g_new0(MemoryRegion, vmem->nb_memslots); |
| 788 | |
| 789 | /* Initialize our memslots, but don't map them yet. */ |
| 790 | for (idx = 0; idx < vmem->nb_memslots; idx++) { |
| 791 | const uint64_t memslot_offset = idx * vmem->memslot_size; |
| 792 | uint64_t memslot_size = vmem->memslot_size; |
| 793 | char name[20]; |
| 794 | |
| 795 | /* The size of the last memslot might be smaller. */ |
| 796 | if (idx == vmem->nb_memslots - 1) { |
| 797 | memslot_size = region_size - memslot_offset; |
| 798 | } |
| 799 | |
| 800 | snprintf(name, sizeof(name), "memslot-%u", idx); |
| 801 | memory_region_init_alias(&vmem->memslots[idx], OBJECT(vmem), name, |
| 802 | &vmem->memdev->mr, memslot_offset, |
| 803 | memslot_size); |
| 804 | /* |
| 805 | * We want to be able to atomically and efficiently activate/deactivate |
| 806 | * individual memslots without affecting adjacent memslots in memory |
| 807 | * notifiers. |
| 808 | */ |
| 809 | memory_region_set_unmergeable(&vmem->memslots[idx], true); |
| 810 | } |
| 811 | } |
| 812 | |
| 813 | static void virtio_mem_device_realize(DeviceState *dev, Error **errp) |
| 814 | { |
| 815 | MachineState *ms = MACHINE(qdev_get_machine()); |
| 816 | int nb_numa_nodes = ms->numa_state ? ms->numa_state->num_nodes : 0; |
| 817 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 818 | VirtIOMEM *vmem = VIRTIO_MEM(dev); |
| 819 | uint64_t page_size; |
| 820 | RAMBlock *rb; |
| 821 | Object *obj; |
| 822 | int ret; |
| 823 | |
| 824 | if (!vmem->memdev) { |
| 825 | error_setg(errp, "'%s' property is not set", VIRTIO_MEM_MEMDEV_PROP); |
| 826 | return; |
| 827 | } else if (host_memory_backend_is_mapped(vmem->memdev)) { |
| 828 | error_setg(errp, "'%s' property specifies a busy memdev: %s", |
| 829 | VIRTIO_MEM_MEMDEV_PROP, |
| 830 | object_get_canonical_path_component(OBJECT(vmem->memdev))); |
| 831 | return; |
| 832 | } else if (!memory_region_is_ram(&vmem->memdev->mr) || |
| 833 | memory_region_is_rom(&vmem->memdev->mr) || |
| 834 | !vmem->memdev->mr.ram_block) { |
| 835 | error_setg(errp, "'%s' property specifies an unsupported memdev", |
| 836 | VIRTIO_MEM_MEMDEV_PROP); |
| 837 | return; |
| 838 | } else if (vmem->memdev->prealloc) { |
| 839 | error_setg(errp, "'%s' property specifies a memdev with preallocation" |
| 840 | " enabled: %s. Instead, specify 'prealloc=on' for the" |
| 841 | " virtio-mem device. ", VIRTIO_MEM_MEMDEV_PROP, |
| 842 | object_get_canonical_path_component(OBJECT(vmem->memdev))); |
| 843 | return; |
| 844 | } |
| 845 | |
| 846 | if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) || |
| 847 | (!nb_numa_nodes && vmem->node)) { |
| 848 | error_setg(errp, "'%s' property has value '%" PRIu32 "', which exceeds" |
| 849 | "the number of numa nodes: %d", VIRTIO_MEM_NODE_PROP, |
| 850 | vmem->node, nb_numa_nodes ? nb_numa_nodes : 1); |
| 851 | return; |
| 852 | } |
| 853 | |
| 854 | if (should_mlock(mlock_state)) { |
| 855 | error_setg(errp, "Incompatible with mlock"); |
| 856 | return; |
| 857 | } |
| 858 | |
| 859 | rb = vmem->memdev->mr.ram_block; |
| 860 | page_size = qemu_ram_pagesize(rb); |
| 861 | |
| 862 | if (virtio_mem_has_legacy_guests()) { |
| 863 | switch (vmem->unplugged_inaccessible) { |
| 864 | case ON_OFF_AUTO_AUTO: |
| 865 | if (virtio_mem_has_shared_zeropage(rb)) { |
| 866 | vmem->unplugged_inaccessible = ON_OFF_AUTO_OFF; |
| 867 | } else { |
| 868 | vmem->unplugged_inaccessible = ON_OFF_AUTO_ON; |
| 869 | } |
| 870 | break; |
| 871 | case ON_OFF_AUTO_OFF: |
| 872 | if (!virtio_mem_has_shared_zeropage(rb)) { |
| 873 | warn_report("'%s' property set to 'off' with a memdev that does" |
| 874 | " not support the shared zeropage.", |
| 875 | VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP); |
| 876 | } |
| 877 | break; |
| 878 | default: |
| 879 | break; |
| 880 | } |
| 881 | } else { |
| 882 | vmem->unplugged_inaccessible = ON_OFF_AUTO_ON; |
| 883 | } |
| 884 | |
| 885 | if (vmem->dynamic_memslots && |
| 886 | vmem->unplugged_inaccessible != ON_OFF_AUTO_ON) { |
| 887 | error_setg(errp, "'%s' property set to 'on' requires '%s' to be 'on'", |
| 888 | VIRTIO_MEM_DYNAMIC_MEMSLOTS_PROP, |
| 889 | VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP); |
| 890 | return; |
| 891 | } |
| 892 | |
| 893 | /* |
| 894 | * If the block size wasn't configured by the user, use a sane default. This |
| 895 | * allows using hugetlbfs backends of any page size without manual |
| 896 | * intervention. |
| 897 | */ |
| 898 | if (!vmem->block_size) { |
| 899 | vmem->block_size = virtio_mem_default_block_size(rb); |
| 900 | } |
| 901 | |
| 902 | if (vmem->block_size < page_size) { |
| 903 | error_setg(errp, "'%s' property has to be at least the page size (0x%" |
| 904 | PRIx64 ")", VIRTIO_MEM_BLOCK_SIZE_PROP, page_size); |
| 905 | return; |
| 906 | } else if (vmem->block_size < virtio_mem_default_block_size(rb)) { |
| 907 | warn_report("'%s' property is smaller than the default block size (%" |
| 908 | PRIx64 " MiB)", VIRTIO_MEM_BLOCK_SIZE_PROP, |
| 909 | virtio_mem_default_block_size(rb) / MiB); |
| 910 | } |
| 911 | if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) { |
| 912 | error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64 |
| 913 | ")", VIRTIO_MEM_REQUESTED_SIZE_PROP, |
| 914 | VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size); |
| 915 | return; |
| 916 | } else if (!QEMU_IS_ALIGNED(vmem->addr, vmem->block_size)) { |
| 917 | error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64 |
| 918 | ")", VIRTIO_MEM_ADDR_PROP, VIRTIO_MEM_BLOCK_SIZE_PROP, |
| 919 | vmem->block_size); |
| 920 | return; |
| 921 | } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr), |
| 922 | vmem->block_size)) { |
| 923 | error_setg(errp, "'%s' property memdev size has to be multiples of" |
| 924 | "'%s' (0x%" PRIx64 ")", VIRTIO_MEM_MEMDEV_PROP, |
| 925 | VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size); |
| 926 | return; |
| 927 | } |
| 928 | |
| 929 | if (ram_block_coordinated_discard_require(true)) { |
| 930 | error_setg(errp, "Discarding RAM is disabled"); |
| 931 | return; |
| 932 | } |
| 933 | |
| 934 | if (memory_region_add_ram_discard_source(&vmem->memdev->mr, |
| 935 | RAM_DISCARD_SOURCE(vmem))) { |
| 936 | error_setg(errp, "Failed to add RAM discard source"); |
| 937 | ram_block_coordinated_discard_require(false); |
| 938 | return; |
| 939 | } |
| 940 | |
| 941 | /* |
| 942 | * We don't know at this point whether shared RAM is migrated using |
| 943 | * QEMU or migrated using the file content. "x-ignore-shared" will be |
| 944 | * configured after realizing the device. So in case we have an |
| 945 | * incoming migration, simply always skip the discard step. |
| 946 | * |
| 947 | * Otherwise, make sure that we start with a clean slate: either the |
| 948 | * memory backend might get reused or the shared file might still have |
| 949 | * memory allocated. |
| 950 | */ |
| 951 | if (!runstate_check(RUN_STATE_INMIGRATE)) { |
| 952 | ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb)); |
| 953 | if (ret) { |
| 954 | error_setg_errno(errp, -ret, "Unexpected error discarding RAM"); |
| 955 | memory_region_del_ram_discard_source(&vmem->memdev->mr, |
| 956 | RAM_DISCARD_SOURCE(vmem)); |
| 957 | ram_block_coordinated_discard_require(false); |
| 958 | return; |
| 959 | } |
| 960 | } |
| 961 | |
| 962 | virtio_mem_resize_usable_region(vmem, vmem->requested_size, true); |
| 963 | |
| 964 | vmem->bitmap_size = memory_region_size(&vmem->memdev->mr) / |
| 965 | vmem->block_size; |
| 966 | vmem->bitmap = bitmap_new(vmem->bitmap_size); |
| 967 | |
| 968 | virtio_init(vdev, VIRTIO_ID_MEM, sizeof(struct virtio_mem_config)); |
| 969 | vmem->vq = virtio_add_queue(vdev, 128, virtio_mem_handle_request); |
| 970 | |
| 971 | /* |
| 972 | * With "dynamic-memslots=off" (old behavior) we always map the whole |
| 973 | * RAM memory region directly. |
| 974 | */ |
| 975 | if (vmem->dynamic_memslots) { |
| 976 | if (!vmem->mr) { |
| 977 | virtio_mem_prepare_mr(vmem); |
| 978 | } |
| 979 | if (vmem->nb_memslots <= 1) { |
| 980 | vmem->nb_memslots = 1; |
| 981 | vmem->memslot_size = memory_region_size(&vmem->memdev->mr); |
| 982 | } |
| 983 | if (!vmem->memslots) { |
| 984 | virtio_mem_prepare_memslots(vmem); |
| 985 | } |
| 986 | } else { |
| 987 | assert(!vmem->mr && !vmem->nb_memslots && !vmem->memslots); |
| 988 | } |
| 989 | |
| 990 | host_memory_backend_set_mapped(vmem->memdev, true); |
| 991 | vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem)); |
| 992 | if (vmem->early_migration) { |
| 993 | vmstate_register_any(VMSTATE_IF(vmem), |
| 994 | &vmstate_virtio_mem_device_early, vmem); |
| 995 | } |
| 996 | |
| 997 | /* |
| 998 | * We only want to unplug all memory to start with a clean slate when |
| 999 | * it is safe for the guest -- during system resets that call |
| 1000 | * qemu_devices_reset(). |
| 1001 | * |
| 1002 | * We'll filter out selected qemu_devices_reset() calls used for other |
| 1003 | * purposes, like resetting all devices during wakeup from suspend on |
| 1004 | * x86 based on the reset type passed to qemu_devices_reset(). |
| 1005 | * |
| 1006 | * Unplugging all memory during simple device resets can result in the VM |
| 1007 | * unexpectedly losing RAM, corrupting VM state. |
| 1008 | * |
| 1009 | * Simple device resets (or resets triggered by getting a parent device |
| 1010 | * reset) must not change the state of plugged memory blocks. Therefore, |
| 1011 | * we need a dedicated reset object that only gets called during |
| 1012 | * qemu_devices_reset(). |
| 1013 | */ |
| 1014 | obj = object_new(TYPE_VIRTIO_MEM_SYSTEM_RESET); |
| 1015 | vmem->system_reset = VIRTIO_MEM_SYSTEM_RESET(obj); |
| 1016 | vmem->system_reset->vmem = vmem; |
| 1017 | qemu_register_resettable(obj); |
| 1018 | } |
| 1019 | |
| 1020 | static void virtio_mem_device_unrealize(DeviceState *dev) |
| 1021 | { |
| 1022 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 1023 | VirtIOMEM *vmem = VIRTIO_MEM(dev); |
| 1024 | |
| 1025 | qemu_unregister_resettable(OBJECT(vmem->system_reset)); |
| 1026 | object_unref(OBJECT(vmem->system_reset)); |
| 1027 | |
| 1028 | if (vmem->early_migration) { |
| 1029 | vmstate_unregister(VMSTATE_IF(vmem), &vmstate_virtio_mem_device_early, |
| 1030 | vmem); |
| 1031 | } |
| 1032 | vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem)); |
| 1033 | host_memory_backend_set_mapped(vmem->memdev, false); |
| 1034 | virtio_del_queue(vdev, 0); |
| 1035 | virtio_cleanup(vdev); |
| 1036 | g_free(vmem->bitmap); |
| 1037 | /* |
| 1038 | * The unplug handler unmapped the memory region, it cannot be |
| 1039 | * found via an address space anymore. Unset ourselves. |
| 1040 | */ |
| 1041 | memory_region_del_ram_discard_source(&vmem->memdev->mr, RAM_DISCARD_SOURCE(vmem)); |
| 1042 | ram_block_coordinated_discard_require(false); |
| 1043 | } |
| 1044 | |
| 1045 | static int virtio_mem_discard_range_cb(VirtIOMEM *vmem, void *arg, |
| 1046 | uint64_t offset, uint64_t size) |
| 1047 | { |
| 1048 | RAMBlock *rb = vmem->memdev->mr.ram_block; |
| 1049 | |
| 1050 | return ram_block_discard_range(rb, offset, size) ? -EINVAL : 0; |
| 1051 | } |
| 1052 | |
| 1053 | static int virtio_mem_restore_unplugged(VirtIOMEM *vmem) |
| 1054 | { |
| 1055 | /* Make sure all memory is really discarded after migration. */ |
| 1056 | return virtio_mem_for_each_unplugged_range(vmem, NULL, |
| 1057 | virtio_mem_discard_range_cb); |
| 1058 | } |
| 1059 | |
| 1060 | static int virtio_mem_activate_memslot_range_cb(VirtIOMEM *vmem, void *arg, |
| 1061 | uint64_t offset, uint64_t size) |
| 1062 | { |
| 1063 | virtio_mem_activate_memslots_to_plug(vmem, offset, size); |
| 1064 | return 0; |
| 1065 | } |
| 1066 | |
| 1067 | static int virtio_mem_post_load_bitmap(VirtIOMEM *vmem) |
| 1068 | { |
| 1069 | RamDiscardManager *rdm = memory_region_get_ram_discard_manager(&vmem->memdev->mr); |
| 1070 | /* |
| 1071 | * We restored the bitmap and updated the requested size; activate all |
| 1072 | * memslots (so listeners register) before notifying about plugged blocks. |
| 1073 | */ |
| 1074 | if (vmem->dynamic_memslots) { |
| 1075 | /* |
| 1076 | * We don't expect any active memslots at this point to deactivate: no |
| 1077 | * memory was plugged on the migration destination. |
| 1078 | */ |
| 1079 | virtio_mem_for_each_plugged_range(vmem, NULL, |
| 1080 | virtio_mem_activate_memslot_range_cb); |
| 1081 | } |
| 1082 | |
| 1083 | /* |
| 1084 | * We started out with all memory discarded and our memory region is mapped |
| 1085 | * into an address space. Replay, now that we updated the bitmap. |
| 1086 | */ |
| 1087 | return ram_discard_manager_replay_populated_to_listeners(rdm); |
| 1088 | } |
| 1089 | |
| 1090 | static int virtio_mem_post_load(void *opaque, int version_id) |
| 1091 | { |
| 1092 | VirtIOMEM *vmem = VIRTIO_MEM(opaque); |
| 1093 | int ret; |
| 1094 | |
| 1095 | if (!vmem->early_migration) { |
| 1096 | ret = virtio_mem_post_load_bitmap(vmem); |
| 1097 | if (ret) { |
| 1098 | return ret; |
| 1099 | } |
| 1100 | } |
| 1101 | |
| 1102 | /* |
| 1103 | * If shared RAM is migrated using the file content and not using QEMU, |
| 1104 | * don't mess with preallocation and postcopy. |
| 1105 | */ |
| 1106 | if (migrate_ram_is_ignored(vmem->memdev->mr.ram_block)) { |
| 1107 | return 0; |
| 1108 | } |
| 1109 | |
| 1110 | if (vmem->prealloc && !vmem->early_migration) { |
| 1111 | warn_report("Proper preallocation with migration requires a newer QEMU machine"); |
| 1112 | } |
| 1113 | |
| 1114 | if (migration_in_incoming_postcopy()) { |
| 1115 | return 0; |
| 1116 | } |
| 1117 | |
| 1118 | return virtio_mem_restore_unplugged(vmem); |
| 1119 | } |
| 1120 | |
| 1121 | static int virtio_mem_prealloc_range_cb(VirtIOMEM *vmem, void *arg, |
| 1122 | uint64_t offset, uint64_t size) |
| 1123 | { |
| 1124 | void *area = memory_region_get_ram_ptr(&vmem->memdev->mr) + offset; |
| 1125 | int fd = memory_region_get_fd(&vmem->memdev->mr); |
| 1126 | Error *local_err = NULL; |
| 1127 | |
| 1128 | if (!qemu_prealloc_mem(fd, area, size, 1, NULL, false, &local_err)) { |
| 1129 | error_report_err(local_err); |
| 1130 | return -ENOMEM; |
| 1131 | } |
| 1132 | return 0; |
| 1133 | } |
| 1134 | |
| 1135 | static int virtio_mem_post_load_early(void *opaque, int version_id) |
| 1136 | { |
| 1137 | VirtIOMEM *vmem = VIRTIO_MEM(opaque); |
| 1138 | RAMBlock *rb = vmem->memdev->mr.ram_block; |
| 1139 | int ret; |
| 1140 | |
| 1141 | if (!vmem->prealloc) { |
| 1142 | goto post_load_bitmap; |
| 1143 | } |
| 1144 | |
| 1145 | /* |
| 1146 | * If shared RAM is migrated using the file content and not using QEMU, |
| 1147 | * don't mess with preallocation and postcopy. |
| 1148 | */ |
| 1149 | if (migrate_ram_is_ignored(rb)) { |
| 1150 | goto post_load_bitmap; |
| 1151 | } |
| 1152 | |
| 1153 | /* |
| 1154 | * We restored the bitmap and verified that the basic properties |
| 1155 | * match on source and destination, so we can go ahead and preallocate |
| 1156 | * memory for all plugged memory blocks, before actual RAM migration starts |
| 1157 | * touching this memory. |
| 1158 | */ |
| 1159 | ret = virtio_mem_for_each_plugged_range(vmem, NULL, |
| 1160 | virtio_mem_prealloc_range_cb); |
| 1161 | if (ret) { |
| 1162 | return ret; |
| 1163 | } |
| 1164 | |
| 1165 | /* |
| 1166 | * This is tricky: postcopy wants to start with a clean slate. On |
| 1167 | * POSTCOPY_INCOMING_ADVISE, postcopy code discards all (ordinarily |
| 1168 | * preallocated) RAM such that postcopy will work as expected later. |
| 1169 | * |
| 1170 | * However, we run after POSTCOPY_INCOMING_ADVISE -- but before actual |
| 1171 | * RAM migration. So let's discard all memory again. This looks like an |
| 1172 | * expensive NOP, but actually serves a purpose: we made sure that we |
| 1173 | * were able to allocate all required backend memory once. We cannot |
| 1174 | * guarantee that the backend memory we will free will remain free |
| 1175 | * until we need it during postcopy, but at least we can catch the |
| 1176 | * obvious setup issues this way. |
| 1177 | */ |
| 1178 | if (migration_incoming_postcopy_advised()) { |
| 1179 | if (ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb))) { |
| 1180 | return -EBUSY; |
| 1181 | } |
| 1182 | } |
| 1183 | |
| 1184 | post_load_bitmap: |
| 1185 | /* Finally, update any other state to be consistent with the new bitmap. */ |
| 1186 | return virtio_mem_post_load_bitmap(vmem); |
| 1187 | } |
| 1188 | |
| 1189 | typedef struct VirtIOMEMMigSanityChecks { |
| 1190 | VirtIOMEM *parent; |
| 1191 | uint64_t addr; |
| 1192 | uint64_t region_size; |
| 1193 | uint64_t block_size; |
| 1194 | uint32_t node; |
| 1195 | } VirtIOMEMMigSanityChecks; |
| 1196 | |
| 1197 | static int virtio_mem_mig_sanity_checks_pre_save(void *opaque) |
| 1198 | { |
| 1199 | VirtIOMEMMigSanityChecks *tmp = opaque; |
| 1200 | VirtIOMEM *vmem = tmp->parent; |
| 1201 | |
| 1202 | tmp->addr = vmem->addr; |
| 1203 | tmp->region_size = memory_region_size(&vmem->memdev->mr); |
| 1204 | tmp->block_size = vmem->block_size; |
| 1205 | tmp->node = vmem->node; |
| 1206 | return 0; |
| 1207 | } |
| 1208 | |
| 1209 | static int virtio_mem_mig_sanity_checks_post_load(void *opaque, int version_id) |
| 1210 | { |
| 1211 | VirtIOMEMMigSanityChecks *tmp = opaque; |
| 1212 | VirtIOMEM *vmem = tmp->parent; |
| 1213 | const uint64_t new_region_size = memory_region_size(&vmem->memdev->mr); |
| 1214 | |
| 1215 | if (tmp->addr != vmem->addr) { |
| 1216 | error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64, |
| 1217 | VIRTIO_MEM_ADDR_PROP, tmp->addr, vmem->addr); |
| 1218 | return -EINVAL; |
| 1219 | } |
| 1220 | /* |
| 1221 | * Note: Preparation for resizable memory regions. The maximum size |
| 1222 | * of the memory region must not change during migration. |
| 1223 | */ |
| 1224 | if (tmp->region_size != new_region_size) { |
| 1225 | error_report("Property '%s' size changed from 0x%" PRIx64 " to 0x%" |
| 1226 | PRIx64, VIRTIO_MEM_MEMDEV_PROP, tmp->region_size, |
| 1227 | new_region_size); |
| 1228 | return -EINVAL; |
| 1229 | } |
| 1230 | if (tmp->block_size != vmem->block_size) { |
| 1231 | error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64, |
| 1232 | VIRTIO_MEM_BLOCK_SIZE_PROP, tmp->block_size, |
| 1233 | vmem->block_size); |
| 1234 | return -EINVAL; |
| 1235 | } |
| 1236 | if (tmp->node != vmem->node) { |
| 1237 | error_report("Property '%s' changed from %" PRIu32 " to %" PRIu32, |
| 1238 | VIRTIO_MEM_NODE_PROP, tmp->node, vmem->node); |
| 1239 | return -EINVAL; |
| 1240 | } |
| 1241 | return 0; |
| 1242 | } |
| 1243 | |
| 1244 | static const VMStateDescription vmstate_virtio_mem_sanity_checks = { |
| 1245 | .name = "virtio-mem-device/sanity-checks", |
| 1246 | .pre_save = virtio_mem_mig_sanity_checks_pre_save, |
| 1247 | .post_load = virtio_mem_mig_sanity_checks_post_load, |
| 1248 | .fields = (const VMStateField[]) { |
| 1249 | VMSTATE_UINT64(addr, VirtIOMEMMigSanityChecks), |
| 1250 | VMSTATE_UINT64(region_size, VirtIOMEMMigSanityChecks), |
| 1251 | VMSTATE_UINT64(block_size, VirtIOMEMMigSanityChecks), |
| 1252 | VMSTATE_UINT32(node, VirtIOMEMMigSanityChecks), |
| 1253 | VMSTATE_END_OF_LIST(), |
| 1254 | }, |
| 1255 | }; |
| 1256 | |
| 1257 | static bool virtio_mem_vmstate_field_exists(void *opaque, int version_id) |
| 1258 | { |
| 1259 | const VirtIOMEM *vmem = VIRTIO_MEM(opaque); |
| 1260 | |
| 1261 | /* With early migration, these fields were already migrated. */ |
| 1262 | return !vmem->early_migration; |
| 1263 | } |
| 1264 | |
| 1265 | static const VMStateDescription vmstate_virtio_mem_device = { |
| 1266 | .name = "virtio-mem-device", |
| 1267 | .minimum_version_id = 1, |
| 1268 | .version_id = 1, |
| 1269 | .priority = MIG_PRI_VIRTIO_MEM, |
| 1270 | .post_load = virtio_mem_post_load, |
| 1271 | .fields = (const VMStateField[]) { |
| 1272 | VMSTATE_WITH_TMP_TEST(VirtIOMEM, virtio_mem_vmstate_field_exists, |
| 1273 | VirtIOMEMMigSanityChecks, |
| 1274 | vmstate_virtio_mem_sanity_checks), |
| 1275 | VMSTATE_UINT64(usable_region_size, VirtIOMEM), |
| 1276 | VMSTATE_UINT64_TEST(size, VirtIOMEM, virtio_mem_vmstate_field_exists), |
| 1277 | VMSTATE_UINT64(requested_size, VirtIOMEM), |
| 1278 | VMSTATE_BITMAP_TEST(bitmap, VirtIOMEM, virtio_mem_vmstate_field_exists, |
| 1279 | 0, bitmap_size), |
| 1280 | VMSTATE_END_OF_LIST() |
| 1281 | }, |
| 1282 | }; |
| 1283 | |
| 1284 | /* |
| 1285 | * Transfer properties that are immutable while migration is active early, |
| 1286 | * such that we have have this information around before migrating any RAM |
| 1287 | * content. |
| 1288 | * |
| 1289 | * Note that virtio_mem_is_busy() makes sure these properties can no longer |
| 1290 | * change on the migration source until migration completed. |
| 1291 | * |
| 1292 | * With QEMU compat machines, we transmit these properties later, via |
| 1293 | * vmstate_virtio_mem_device instead -- see virtio_mem_vmstate_field_exists(). |
| 1294 | */ |
| 1295 | static const VMStateDescription vmstate_virtio_mem_device_early = { |
| 1296 | .name = "virtio-mem-device-early", |
| 1297 | .minimum_version_id = 1, |
| 1298 | .version_id = 1, |
| 1299 | .early_setup = true, |
| 1300 | .post_load = virtio_mem_post_load_early, |
| 1301 | .fields = (const VMStateField[]) { |
| 1302 | VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks, |
| 1303 | vmstate_virtio_mem_sanity_checks), |
| 1304 | VMSTATE_UINT64(size, VirtIOMEM), |
| 1305 | VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size), |
| 1306 | VMSTATE_END_OF_LIST() |
| 1307 | }, |
| 1308 | }; |
| 1309 | |
| 1310 | static const VMStateDescription vmstate_virtio_mem = { |
| 1311 | .name = "virtio-mem", |
| 1312 | .minimum_version_id = 1, |
| 1313 | .version_id = 1, |
| 1314 | .fields = (const VMStateField[]) { |
| 1315 | VMSTATE_VIRTIO_DEVICE, |
| 1316 | VMSTATE_END_OF_LIST() |
| 1317 | }, |
| 1318 | }; |
| 1319 | |
| 1320 | static void virtio_mem_fill_device_info(const VirtIOMEM *vmem, |
| 1321 | VirtioMEMDeviceInfo *vi) |
| 1322 | { |
| 1323 | vi->memaddr = vmem->addr; |
| 1324 | vi->node = vmem->node; |
| 1325 | vi->requested_size = vmem->requested_size; |
| 1326 | vi->size = vmem->size; |
| 1327 | vi->max_size = memory_region_size(&vmem->memdev->mr); |
| 1328 | vi->block_size = vmem->block_size; |
| 1329 | vi->memdev = object_get_canonical_path(OBJECT(vmem->memdev)); |
| 1330 | } |
| 1331 | |
| 1332 | static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp) |
| 1333 | { |
| 1334 | if (!vmem->memdev) { |
| 1335 | error_setg(errp, "'%s' property must be set", VIRTIO_MEM_MEMDEV_PROP); |
| 1336 | return NULL; |
| 1337 | } else if (vmem->dynamic_memslots) { |
| 1338 | if (!vmem->mr) { |
| 1339 | virtio_mem_prepare_mr(vmem); |
| 1340 | } |
| 1341 | return vmem->mr; |
| 1342 | } |
| 1343 | |
| 1344 | return &vmem->memdev->mr; |
| 1345 | } |
| 1346 | |
| 1347 | static void virtio_mem_decide_memslots(VirtIOMEM *vmem, unsigned int limit) |
| 1348 | { |
| 1349 | uint64_t region_size, memslot_size, min_memslot_size; |
| 1350 | unsigned int memslots; |
| 1351 | RAMBlock *rb; |
| 1352 | |
| 1353 | if (!vmem->dynamic_memslots) { |
| 1354 | return; |
| 1355 | } |
| 1356 | |
| 1357 | /* We're called exactly once, before realizing the device. */ |
| 1358 | assert(!vmem->nb_memslots); |
| 1359 | |
| 1360 | /* If realizing the device will fail, just assume a single memslot. */ |
| 1361 | if (limit <= 1 || !vmem->memdev || !vmem->memdev->mr.ram_block) { |
| 1362 | vmem->nb_memslots = 1; |
| 1363 | return; |
| 1364 | } |
| 1365 | |
| 1366 | rb = vmem->memdev->mr.ram_block; |
| 1367 | region_size = memory_region_size(&vmem->memdev->mr); |
| 1368 | |
| 1369 | /* |
| 1370 | * Determine the default block size now, to determine the minimum memslot |
| 1371 | * size. We want the minimum slot size to be at least the device block size. |
| 1372 | */ |
| 1373 | if (!vmem->block_size) { |
| 1374 | vmem->block_size = virtio_mem_default_block_size(rb); |
| 1375 | } |
| 1376 | /* If realizing the device will fail, just assume a single memslot. */ |
| 1377 | if (vmem->block_size < qemu_ram_pagesize(rb) || |
| 1378 | !QEMU_IS_ALIGNED(region_size, vmem->block_size)) { |
| 1379 | vmem->nb_memslots = 1; |
| 1380 | return; |
| 1381 | } |
| 1382 | |
| 1383 | /* |
| 1384 | * All memslots except the last one have a reasonable minimum size, and |
| 1385 | * and all memslot sizes are aligned to the device block size. |
| 1386 | */ |
| 1387 | memslot_size = QEMU_ALIGN_UP(region_size / limit, vmem->block_size); |
| 1388 | min_memslot_size = MAX(vmem->block_size, VIRTIO_MEM_MIN_MEMSLOT_SIZE); |
| 1389 | memslot_size = MAX(memslot_size, min_memslot_size); |
| 1390 | |
| 1391 | memslots = QEMU_ALIGN_UP(region_size, memslot_size) / memslot_size; |
| 1392 | if (memslots != 1) { |
| 1393 | vmem->memslot_size = memslot_size; |
| 1394 | } |
| 1395 | vmem->nb_memslots = memslots; |
| 1396 | } |
| 1397 | |
| 1398 | static unsigned int virtio_mem_get_memslots(VirtIOMEM *vmem) |
| 1399 | { |
| 1400 | if (!vmem->dynamic_memslots) { |
| 1401 | /* Exactly one static RAM memory region. */ |
| 1402 | return 1; |
| 1403 | } |
| 1404 | |
| 1405 | /* We're called after instructed to make a decision. */ |
| 1406 | g_assert(vmem->nb_memslots); |
| 1407 | return vmem->nb_memslots; |
| 1408 | } |
| 1409 | |
| 1410 | static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem, |
| 1411 | Notifier *notifier) |
| 1412 | { |
| 1413 | notifier_list_add(&vmem->size_change_notifiers, notifier); |
| 1414 | } |
| 1415 | |
| 1416 | static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem, |
| 1417 | Notifier *notifier) |
| 1418 | { |
| 1419 | notifier_remove(notifier); |
| 1420 | } |
| 1421 | |
| 1422 | static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name, |
| 1423 | void *opaque, Error **errp) |
| 1424 | { |
| 1425 | const VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1426 | uint64_t value = vmem->size; |
| 1427 | |
| 1428 | visit_type_size(v, name, &value, errp); |
| 1429 | } |
| 1430 | |
| 1431 | static void virtio_mem_get_requested_size(Object *obj, Visitor *v, |
| 1432 | const char *name, void *opaque, |
| 1433 | Error **errp) |
| 1434 | { |
| 1435 | const VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1436 | uint64_t value = vmem->requested_size; |
| 1437 | |
| 1438 | visit_type_size(v, name, &value, errp); |
| 1439 | } |
| 1440 | |
| 1441 | static void virtio_mem_set_requested_size(Object *obj, Visitor *v, |
| 1442 | const char *name, void *opaque, |
| 1443 | Error **errp) |
| 1444 | { |
| 1445 | VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1446 | uint64_t value; |
| 1447 | |
| 1448 | if (!visit_type_size(v, name, &value, errp)) { |
| 1449 | return; |
| 1450 | } |
| 1451 | |
| 1452 | /* |
| 1453 | * The block size and memory backend are not fixed until the device was |
| 1454 | * realized. realize() will verify these properties then. |
| 1455 | */ |
| 1456 | if (qdev_is_realized(DEVICE(obj))) { |
| 1457 | if (!QEMU_IS_ALIGNED(value, vmem->block_size)) { |
| 1458 | error_setg(errp, "'%s' has to be multiples of '%s' (0x%" PRIx64 |
| 1459 | ")", name, VIRTIO_MEM_BLOCK_SIZE_PROP, |
| 1460 | vmem->block_size); |
| 1461 | return; |
| 1462 | } else if (value > memory_region_size(&vmem->memdev->mr)) { |
| 1463 | error_setg(errp, "'%s' cannot exceed the memory backend size" |
| 1464 | "(0x%" PRIx64 ")", name, |
| 1465 | memory_region_size(&vmem->memdev->mr)); |
| 1466 | return; |
| 1467 | } |
| 1468 | |
| 1469 | if (value != vmem->requested_size) { |
| 1470 | virtio_mem_resize_usable_region(vmem, value, false); |
| 1471 | vmem->requested_size = value; |
| 1472 | } |
| 1473 | /* |
| 1474 | * Trigger a config update so the guest gets notified. We trigger |
| 1475 | * even if the size didn't change (especially helpful for debugging). |
| 1476 | */ |
| 1477 | virtio_notify_config(VIRTIO_DEVICE(vmem)); |
| 1478 | } else { |
| 1479 | vmem->requested_size = value; |
| 1480 | } |
| 1481 | } |
| 1482 | |
| 1483 | static void virtio_mem_get_block_size(Object *obj, Visitor *v, const char *name, |
| 1484 | void *opaque, Error **errp) |
| 1485 | { |
| 1486 | const VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1487 | uint64_t value = vmem->block_size; |
| 1488 | |
| 1489 | /* |
| 1490 | * If not configured by the user (and we're not realized yet), use the |
| 1491 | * default block size we would use with the current memory backend. |
| 1492 | */ |
| 1493 | if (!value) { |
| 1494 | if (vmem->memdev && memory_region_is_ram(&vmem->memdev->mr)) { |
| 1495 | value = virtio_mem_default_block_size(vmem->memdev->mr.ram_block); |
| 1496 | } else { |
| 1497 | value = virtio_mem_thp_size(); |
| 1498 | } |
| 1499 | } |
| 1500 | |
| 1501 | visit_type_size(v, name, &value, errp); |
| 1502 | } |
| 1503 | |
| 1504 | static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name, |
| 1505 | void *opaque, Error **errp) |
| 1506 | { |
| 1507 | VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1508 | uint64_t value; |
| 1509 | |
| 1510 | if (qdev_is_realized(DEVICE(obj))) { |
| 1511 | error_setg(errp, "'%s' cannot be changed", name); |
| 1512 | return; |
| 1513 | } |
| 1514 | |
| 1515 | if (!visit_type_size(v, name, &value, errp)) { |
| 1516 | return; |
| 1517 | } |
| 1518 | |
| 1519 | if (value < VIRTIO_MEM_MIN_BLOCK_SIZE) { |
| 1520 | error_setg(errp, "'%s' property has to be at least 0x%" PRIx32, name, |
| 1521 | VIRTIO_MEM_MIN_BLOCK_SIZE); |
| 1522 | return; |
| 1523 | } else if (!is_power_of_2(value)) { |
| 1524 | error_setg(errp, "'%s' property has to be a power of two", name); |
| 1525 | return; |
| 1526 | } |
| 1527 | vmem->block_size = value; |
| 1528 | } |
| 1529 | |
| 1530 | static void virtio_mem_instance_init(Object *obj) |
| 1531 | { |
| 1532 | VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1533 | |
| 1534 | notifier_list_init(&vmem->size_change_notifiers); |
| 1535 | |
| 1536 | object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size, |
| 1537 | NULL, NULL, NULL); |
| 1538 | object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size", |
| 1539 | virtio_mem_get_requested_size, |
| 1540 | virtio_mem_set_requested_size, NULL, NULL); |
| 1541 | object_property_add(obj, VIRTIO_MEM_BLOCK_SIZE_PROP, "size", |
| 1542 | virtio_mem_get_block_size, virtio_mem_set_block_size, |
| 1543 | NULL, NULL); |
| 1544 | } |
| 1545 | |
| 1546 | static void virtio_mem_instance_finalize(Object *obj) |
| 1547 | { |
| 1548 | VirtIOMEM *vmem = VIRTIO_MEM(obj); |
| 1549 | |
| 1550 | /* |
| 1551 | * Note: the core already dropped the references on all memory regions |
| 1552 | * (it's passed as the owner to memory_region_init_*()) and finalized |
| 1553 | * these objects. We can simply free the memory. |
| 1554 | */ |
| 1555 | g_free(vmem->memslots); |
| 1556 | vmem->memslots = NULL; |
| 1557 | g_free(vmem->mr); |
| 1558 | vmem->mr = NULL; |
| 1559 | } |
| 1560 | |
| 1561 | static const Property virtio_mem_properties[] = { |
| 1562 | DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0), |
| 1563 | DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0), |
| 1564 | DEFINE_PROP_BOOL(VIRTIO_MEM_PREALLOC_PROP, VirtIOMEM, prealloc, false), |
| 1565 | DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev, |
| 1566 | TYPE_MEMORY_BACKEND, HostMemoryBackend *), |
| 1567 | DEFINE_PROP_BOOL(VIRTIO_MEM_EARLY_MIGRATION_PROP, VirtIOMEM, |
| 1568 | early_migration, true), |
| 1569 | DEFINE_PROP_BOOL(VIRTIO_MEM_DYNAMIC_MEMSLOTS_PROP, VirtIOMEM, |
| 1570 | dynamic_memslots, false), |
| 1571 | }; |
| 1572 | |
| 1573 | static const Property virtio_mem_legacy_guests_properties[] = { |
| 1574 | DEFINE_PROP_ON_OFF_AUTO(VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP, VirtIOMEM, |
| 1575 | unplugged_inaccessible, ON_OFF_AUTO_ON), |
| 1576 | }; |
| 1577 | |
| 1578 | static uint64_t virtio_mem_rds_get_min_granularity(const RamDiscardSource *rds, |
| 1579 | const MemoryRegion *mr) |
| 1580 | { |
| 1581 | const VirtIOMEM *vmem = VIRTIO_MEM(rds); |
| 1582 | |
| 1583 | g_assert(mr == &vmem->memdev->mr); |
| 1584 | return vmem->block_size; |
| 1585 | } |
| 1586 | |
| 1587 | static bool virtio_mem_rds_is_populated(const RamDiscardSource *rds, |
| 1588 | const MemoryRegionSection *s) |
| 1589 | { |
| 1590 | const VirtIOMEM *vmem = VIRTIO_MEM(rds); |
| 1591 | uint64_t start_gpa = vmem->addr + s->offset_within_region; |
| 1592 | uint64_t end_gpa = start_gpa + int128_get64(s->size); |
| 1593 | |
| 1594 | g_assert(s->mr == &vmem->memdev->mr); |
| 1595 | |
| 1596 | start_gpa = QEMU_ALIGN_DOWN(start_gpa, vmem->block_size); |
| 1597 | end_gpa = QEMU_ALIGN_UP(end_gpa, vmem->block_size); |
| 1598 | |
| 1599 | if (!virtio_mem_valid_range(vmem, start_gpa, end_gpa - start_gpa)) { |
| 1600 | return false; |
| 1601 | } |
| 1602 | |
| 1603 | return virtio_mem_is_range_plugged(vmem, start_gpa, end_gpa - start_gpa); |
| 1604 | } |
| 1605 | |
| 1606 | static void virtio_mem_unplug_request_check(VirtIOMEM *vmem, Error **errp) |
| 1607 | { |
| 1608 | if (vmem->unplugged_inaccessible == ON_OFF_AUTO_OFF) { |
| 1609 | /* |
| 1610 | * We could allow it with a usable region size of 0, but let's just |
| 1611 | * not care about that legacy setting. |
| 1612 | */ |
| 1613 | error_setg(errp, "virtio-mem device cannot get unplugged while" |
| 1614 | " '" VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP "' != 'on'"); |
| 1615 | return; |
| 1616 | } |
| 1617 | |
| 1618 | if (vmem->size) { |
| 1619 | error_setg(errp, "virtio-mem device cannot get unplugged while some" |
| 1620 | " of its memory is still plugged"); |
| 1621 | return; |
| 1622 | } |
| 1623 | if (vmem->requested_size) { |
| 1624 | error_setg(errp, "virtio-mem device cannot get unplugged while" |
| 1625 | " '" VIRTIO_MEM_REQUESTED_SIZE_PROP "' != '0'"); |
| 1626 | return; |
| 1627 | } |
| 1628 | } |
| 1629 | |
| 1630 | static void virtio_mem_class_init(ObjectClass *klass, const void *data) |
| 1631 | { |
| 1632 | DeviceClass *dc = DEVICE_CLASS(klass); |
| 1633 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); |
| 1634 | VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass); |
| 1635 | RamDiscardSourceClass *rdsc = RAM_DISCARD_SOURCE_CLASS(klass); |
| 1636 | |
| 1637 | device_class_set_props(dc, virtio_mem_properties); |
| 1638 | if (virtio_mem_has_legacy_guests()) { |
| 1639 | device_class_set_props(dc, virtio_mem_legacy_guests_properties); |
| 1640 | } |
| 1641 | dc->vmsd = &vmstate_virtio_mem; |
| 1642 | |
| 1643 | set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
| 1644 | vdc->realize = virtio_mem_device_realize; |
| 1645 | vdc->unrealize = virtio_mem_device_unrealize; |
| 1646 | vdc->get_config = virtio_mem_get_config; |
| 1647 | vdc->get_features = virtio_mem_get_features; |
| 1648 | vdc->validate_features = virtio_mem_validate_features; |
| 1649 | vdc->vmsd = &vmstate_virtio_mem_device; |
| 1650 | |
| 1651 | vmc->fill_device_info = virtio_mem_fill_device_info; |
| 1652 | vmc->get_memory_region = virtio_mem_get_memory_region; |
| 1653 | vmc->decide_memslots = virtio_mem_decide_memslots; |
| 1654 | vmc->get_memslots = virtio_mem_get_memslots; |
| 1655 | vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier; |
| 1656 | vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier; |
| 1657 | vmc->unplug_request_check = virtio_mem_unplug_request_check; |
| 1658 | |
| 1659 | rdsc->get_min_granularity = virtio_mem_rds_get_min_granularity; |
| 1660 | rdsc->is_populated = virtio_mem_rds_is_populated; |
| 1661 | } |
| 1662 | |
| 1663 | static const TypeInfo virtio_mem_info = { |
| 1664 | .name = TYPE_VIRTIO_MEM, |
| 1665 | .parent = TYPE_VIRTIO_DEVICE, |
| 1666 | .instance_size = sizeof(VirtIOMEM), |
| 1667 | .instance_init = virtio_mem_instance_init, |
| 1668 | .instance_finalize = virtio_mem_instance_finalize, |
| 1669 | .class_init = virtio_mem_class_init, |
| 1670 | .class_size = sizeof(VirtIOMEMClass), |
| 1671 | .interfaces = (const InterfaceInfo[]) { |
| 1672 | { TYPE_RAM_DISCARD_SOURCE }, |
| 1673 | { } |
| 1674 | }, |
| 1675 | }; |
| 1676 | |
| 1677 | static void virtio_register_types(void) |
| 1678 | { |
| 1679 | type_register_static(&virtio_mem_info); |
| 1680 | } |
| 1681 | |
| 1682 | type_init(virtio_register_types) |
| 1683 | |
| 1684 | OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(VirtioMemSystemReset, virtio_mem_system_reset, VIRTIO_MEM_SYSTEM_RESET, OBJECT, { TYPE_RESETTABLE_INTERFACE }, { }) |
| 1685 | |
| 1686 | static void virtio_mem_system_reset_init(Object *obj) |
| 1687 | { |
| 1688 | } |
| 1689 | |
| 1690 | static void virtio_mem_system_reset_finalize(Object *obj) |
| 1691 | { |
| 1692 | } |
| 1693 | |
| 1694 | static ResettableState *virtio_mem_system_reset_get_state(Object *obj) |
| 1695 | { |
| 1696 | VirtioMemSystemReset *vmem_reset = VIRTIO_MEM_SYSTEM_RESET(obj); |
| 1697 | |
| 1698 | return &vmem_reset->reset_state; |
| 1699 | } |
| 1700 | |
| 1701 | static void virtio_mem_system_reset_hold(Object *obj, ResetType type) |
| 1702 | { |
| 1703 | VirtioMemSystemReset *vmem_reset = VIRTIO_MEM_SYSTEM_RESET(obj); |
| 1704 | VirtIOMEM *vmem = vmem_reset->vmem; |
| 1705 | |
| 1706 | /* |
| 1707 | * When waking up from standby/suspend-to-ram, do not unplug any memory. |
| 1708 | */ |
| 1709 | if (type == RESET_TYPE_WAKEUP) { |
| 1710 | return; |
| 1711 | } |
| 1712 | |
| 1713 | /* |
| 1714 | * During usual resets, we will unplug all memory and shrink the usable |
| 1715 | * region size. This is, however, not possible in all scenarios. Then, |
| 1716 | * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL). |
| 1717 | */ |
| 1718 | virtio_mem_unplug_all(vmem); |
| 1719 | } |
| 1720 | |
| 1721 | static void virtio_mem_system_reset_class_init(ObjectClass *klass, |
| 1722 | const void *data) |
| 1723 | { |
| 1724 | ResettableClass *rc = RESETTABLE_CLASS(klass); |
| 1725 | |
| 1726 | rc->get_state = virtio_mem_system_reset_get_state; |
| 1727 | rc->phases.hold = virtio_mem_system_reset_hold; |
| 1728 | } |