1eb59db53SDr. David Alan Gilbert /*
2eb59db53SDr. David Alan Gilbert * Postcopy migration for RAM
3eb59db53SDr. David Alan Gilbert *
4eb59db53SDr. David Alan Gilbert * Copyright 2013-2015 Red Hat, Inc. and/or its affiliates
5eb59db53SDr. David Alan Gilbert *
6eb59db53SDr. David Alan Gilbert * Authors:
7eb59db53SDr. David Alan Gilbert * Dave Gilbert <dgilbert@redhat.com>
8eb59db53SDr. David Alan Gilbert *
9eb59db53SDr. David Alan Gilbert * This work is licensed under the terms of the GNU GPL, version 2 or later.
10eb59db53SDr. David Alan Gilbert * See the COPYING file in the top-level directory.
11eb59db53SDr. David Alan Gilbert *
12eb59db53SDr. David Alan Gilbert */
13eb59db53SDr. David Alan Gilbert
14eb59db53SDr. David Alan Gilbert /*
15eb59db53SDr. David Alan Gilbert * Postcopy is a migration technique where the execution flips from the
16eb59db53SDr. David Alan Gilbert * source to the destination before all the data has been copied.
17eb59db53SDr. David Alan Gilbert */
18eb59db53SDr. David Alan Gilbert
191393a485SPeter Maydell #include "qemu/osdep.h"
20b85ea5faSPeter Maydell #include "qemu/madvise.h"
2151180423SJuan Quintela #include "exec/target_page.h"
226666c96aSJuan Quintela #include "migration.h"
2308a0aee1SJuan Quintela #include "qemu-file.h"
2420a519a0SJuan Quintela #include "savevm.h"
25be07b0acSJuan Quintela #include "postcopy-ram.h"
267b1e1a22SJuan Quintela #include "ram.h"
271693c64cSDr. David Alan Gilbert #include "qapi/error.h"
281693c64cSDr. David Alan Gilbert #include "qemu/notify.h"
29d4842052SMarkus Armbruster #include "qemu/rcu.h"
30eb59db53SDr. David Alan Gilbert #include "sysemu/sysemu.h"
31eb59db53SDr. David Alan Gilbert #include "qemu/error-report.h"
32eb59db53SDr. David Alan Gilbert #include "trace.h"
335cc8767dSLike Xu #include "hw/boards.h"
34898ba906SDavid Hildenbrand #include "exec/ramblock.h"
3536f62f11SPeter Xu #include "socket.h"
3636f62f11SPeter Xu #include "yank_functions.h"
37f0afaf6cSPeter Xu #include "tls.h"
38d5890ea0SPeter Xu #include "qemu/userfaultfd.h"
39ae30b9b2SPeter Xu #include "qemu/mmap-alloc.h"
401f0776f1SJuan Quintela #include "options.h"
41eb59db53SDr. David Alan Gilbert
42e0b266f0SDr. David Alan Gilbert /* Arbitrary limit on size of each discard command,
43e0b266f0SDr. David Alan Gilbert * keeps them around ~200 bytes
44e0b266f0SDr. David Alan Gilbert */
45e0b266f0SDr. David Alan Gilbert #define MAX_DISCARDS_PER_COMMAND 12
46e0b266f0SDr. David Alan Gilbert
47e0b266f0SDr. David Alan Gilbert struct PostcopyDiscardState {
48e0b266f0SDr. David Alan Gilbert const char *ramblock_name;
49e0b266f0SDr. David Alan Gilbert uint16_t cur_entry;
50e0b266f0SDr. David Alan Gilbert /*
51e0b266f0SDr. David Alan Gilbert * Start and length of a discard range (bytes)
52e0b266f0SDr. David Alan Gilbert */
53e0b266f0SDr. David Alan Gilbert uint64_t start_list[MAX_DISCARDS_PER_COMMAND];
54e0b266f0SDr. David Alan Gilbert uint64_t length_list[MAX_DISCARDS_PER_COMMAND];
55e0b266f0SDr. David Alan Gilbert unsigned int nsentwords;
56e0b266f0SDr. David Alan Gilbert unsigned int nsentcmds;
57e0b266f0SDr. David Alan Gilbert };
58e0b266f0SDr. David Alan Gilbert
591693c64cSDr. David Alan Gilbert static NotifierWithReturnList postcopy_notifier_list;
601693c64cSDr. David Alan Gilbert
postcopy_infrastructure_init(void)611693c64cSDr. David Alan Gilbert void postcopy_infrastructure_init(void)
621693c64cSDr. David Alan Gilbert {
631693c64cSDr. David Alan Gilbert notifier_with_return_list_init(&postcopy_notifier_list);
641693c64cSDr. David Alan Gilbert }
651693c64cSDr. David Alan Gilbert
postcopy_add_notifier(NotifierWithReturn * nn)661693c64cSDr. David Alan Gilbert void postcopy_add_notifier(NotifierWithReturn *nn)
671693c64cSDr. David Alan Gilbert {
681693c64cSDr. David Alan Gilbert notifier_with_return_list_add(&postcopy_notifier_list, nn);
691693c64cSDr. David Alan Gilbert }
701693c64cSDr. David Alan Gilbert
postcopy_remove_notifier(NotifierWithReturn * n)711693c64cSDr. David Alan Gilbert void postcopy_remove_notifier(NotifierWithReturn *n)
721693c64cSDr. David Alan Gilbert {
731693c64cSDr. David Alan Gilbert notifier_with_return_remove(n);
741693c64cSDr. David Alan Gilbert }
751693c64cSDr. David Alan Gilbert
postcopy_notify(enum PostcopyNotifyReason reason,Error ** errp)761693c64cSDr. David Alan Gilbert int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp)
771693c64cSDr. David Alan Gilbert {
781693c64cSDr. David Alan Gilbert struct PostcopyNotifyData pnd;
791693c64cSDr. David Alan Gilbert pnd.reason = reason;
801693c64cSDr. David Alan Gilbert
811693c64cSDr. David Alan Gilbert return notifier_with_return_list_notify(&postcopy_notifier_list,
82be19d836SSteve Sistare &pnd, errp);
831693c64cSDr. David Alan Gilbert }
841693c64cSDr. David Alan Gilbert
85095c12a4SPeter Xu /*
86095c12a4SPeter Xu * NOTE: this routine is not thread safe, we can't call it concurrently. But it
87095c12a4SPeter Xu * should be good enough for migration's purposes.
88095c12a4SPeter Xu */
postcopy_thread_create(MigrationIncomingState * mis,QemuThread * thread,const char * name,void * (* fn)(void *),int joinable)89095c12a4SPeter Xu void postcopy_thread_create(MigrationIncomingState *mis,
90095c12a4SPeter Xu QemuThread *thread, const char *name,
91095c12a4SPeter Xu void *(*fn)(void *), int joinable)
92095c12a4SPeter Xu {
93095c12a4SPeter Xu qemu_sem_init(&mis->thread_sync_sem, 0);
94095c12a4SPeter Xu qemu_thread_create(thread, name, fn, mis, joinable);
95095c12a4SPeter Xu qemu_sem_wait(&mis->thread_sync_sem);
96095c12a4SPeter Xu qemu_sem_destroy(&mis->thread_sync_sem);
97095c12a4SPeter Xu }
98095c12a4SPeter Xu
99eb59db53SDr. David Alan Gilbert /* Postcopy needs to detect accesses to pages that haven't yet been copied
100eb59db53SDr. David Alan Gilbert * across, and efficiently map new pages in, the techniques for doing this
101eb59db53SDr. David Alan Gilbert * are target OS specific.
102eb59db53SDr. David Alan Gilbert */
103eb59db53SDr. David Alan Gilbert #if defined(__linux__)
104c4faeed2SDr. David Alan Gilbert #include <poll.h>
105eb59db53SDr. David Alan Gilbert #include <sys/ioctl.h>
106eb59db53SDr. David Alan Gilbert #include <sys/syscall.h>
107eb59db53SDr. David Alan Gilbert #endif
108eb59db53SDr. David Alan Gilbert
109d8b9d771SMatthew Fortune #if defined(__linux__) && defined(__NR_userfaultfd) && defined(CONFIG_EVENTFD)
110d8b9d771SMatthew Fortune #include <sys/eventfd.h>
111eb59db53SDr. David Alan Gilbert #include <linux/userfaultfd.h>
112eb59db53SDr. David Alan Gilbert
1132a4c42f1SAlexey Perevalov typedef struct PostcopyBlocktimeContext {
1142a4c42f1SAlexey Perevalov /* time when page fault initiated per vCPU */
1152a4c42f1SAlexey Perevalov uint32_t *page_fault_vcpu_time;
1162a4c42f1SAlexey Perevalov /* page address per vCPU */
1172a4c42f1SAlexey Perevalov uintptr_t *vcpu_addr;
1182a4c42f1SAlexey Perevalov uint32_t total_blocktime;
1192a4c42f1SAlexey Perevalov /* blocktime per vCPU */
1202a4c42f1SAlexey Perevalov uint32_t *vcpu_blocktime;
1212a4c42f1SAlexey Perevalov /* point in time when last page fault was initiated */
1222a4c42f1SAlexey Perevalov uint32_t last_begin;
1232a4c42f1SAlexey Perevalov /* number of vCPU are suspended */
1242a4c42f1SAlexey Perevalov int smp_cpus_down;
1252a4c42f1SAlexey Perevalov uint64_t start_time;
1262a4c42f1SAlexey Perevalov
1272a4c42f1SAlexey Perevalov /*
1282a4c42f1SAlexey Perevalov * Handler for exit event, necessary for
1292a4c42f1SAlexey Perevalov * releasing whole blocktime_ctx
1302a4c42f1SAlexey Perevalov */
1312a4c42f1SAlexey Perevalov Notifier exit_notifier;
1322a4c42f1SAlexey Perevalov } PostcopyBlocktimeContext;
1332a4c42f1SAlexey Perevalov
destroy_blocktime_context(struct PostcopyBlocktimeContext * ctx)1342a4c42f1SAlexey Perevalov static void destroy_blocktime_context(struct PostcopyBlocktimeContext *ctx)
1352a4c42f1SAlexey Perevalov {
1362a4c42f1SAlexey Perevalov g_free(ctx->page_fault_vcpu_time);
1372a4c42f1SAlexey Perevalov g_free(ctx->vcpu_addr);
1382a4c42f1SAlexey Perevalov g_free(ctx->vcpu_blocktime);
1392a4c42f1SAlexey Perevalov g_free(ctx);
1402a4c42f1SAlexey Perevalov }
1412a4c42f1SAlexey Perevalov
migration_exit_cb(Notifier * n,void * data)1422a4c42f1SAlexey Perevalov static void migration_exit_cb(Notifier *n, void *data)
1432a4c42f1SAlexey Perevalov {
1442a4c42f1SAlexey Perevalov PostcopyBlocktimeContext *ctx = container_of(n, PostcopyBlocktimeContext,
1452a4c42f1SAlexey Perevalov exit_notifier);
1462a4c42f1SAlexey Perevalov destroy_blocktime_context(ctx);
1472a4c42f1SAlexey Perevalov }
1482a4c42f1SAlexey Perevalov
blocktime_context_new(void)1492a4c42f1SAlexey Perevalov static struct PostcopyBlocktimeContext *blocktime_context_new(void)
1502a4c42f1SAlexey Perevalov {
1515cc8767dSLike Xu MachineState *ms = MACHINE(qdev_get_machine());
1525cc8767dSLike Xu unsigned int smp_cpus = ms->smp.cpus;
1532a4c42f1SAlexey Perevalov PostcopyBlocktimeContext *ctx = g_new0(PostcopyBlocktimeContext, 1);
1542a4c42f1SAlexey Perevalov ctx->page_fault_vcpu_time = g_new0(uint32_t, smp_cpus);
1552a4c42f1SAlexey Perevalov ctx->vcpu_addr = g_new0(uintptr_t, smp_cpus);
1562a4c42f1SAlexey Perevalov ctx->vcpu_blocktime = g_new0(uint32_t, smp_cpus);
1572a4c42f1SAlexey Perevalov
1582a4c42f1SAlexey Perevalov ctx->exit_notifier.notify = migration_exit_cb;
1592a4c42f1SAlexey Perevalov ctx->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
1602a4c42f1SAlexey Perevalov qemu_add_exit_notifier(&ctx->exit_notifier);
1612a4c42f1SAlexey Perevalov return ctx;
1622a4c42f1SAlexey Perevalov }
163ca6011c2SAlexey Perevalov
get_vcpu_blocktime_list(PostcopyBlocktimeContext * ctx)16465ace060SAlexey Perevalov static uint32List *get_vcpu_blocktime_list(PostcopyBlocktimeContext *ctx)
16565ace060SAlexey Perevalov {
1665cc8767dSLike Xu MachineState *ms = MACHINE(qdev_get_machine());
16754aa3de7SEric Blake uint32List *list = NULL;
16865ace060SAlexey Perevalov int i;
16965ace060SAlexey Perevalov
1705cc8767dSLike Xu for (i = ms->smp.cpus - 1; i >= 0; i--) {
17154aa3de7SEric Blake QAPI_LIST_PREPEND(list, ctx->vcpu_blocktime[i]);
17265ace060SAlexey Perevalov }
17365ace060SAlexey Perevalov
17465ace060SAlexey Perevalov return list;
17565ace060SAlexey Perevalov }
17665ace060SAlexey Perevalov
17765ace060SAlexey Perevalov /*
17865ace060SAlexey Perevalov * This function just populates MigrationInfo from postcopy's
17965ace060SAlexey Perevalov * blocktime context. It will not populate MigrationInfo,
18065ace060SAlexey Perevalov * unless postcopy-blocktime capability was set.
18165ace060SAlexey Perevalov *
18265ace060SAlexey Perevalov * @info: pointer to MigrationInfo to populate
18365ace060SAlexey Perevalov */
fill_destination_postcopy_migration_info(MigrationInfo * info)18465ace060SAlexey Perevalov void fill_destination_postcopy_migration_info(MigrationInfo *info)
18565ace060SAlexey Perevalov {
18665ace060SAlexey Perevalov MigrationIncomingState *mis = migration_incoming_get_current();
18765ace060SAlexey Perevalov PostcopyBlocktimeContext *bc = mis->blocktime_ctx;
18865ace060SAlexey Perevalov
18965ace060SAlexey Perevalov if (!bc) {
19065ace060SAlexey Perevalov return;
19165ace060SAlexey Perevalov }
19265ace060SAlexey Perevalov
19365ace060SAlexey Perevalov info->has_postcopy_blocktime = true;
19465ace060SAlexey Perevalov info->postcopy_blocktime = bc->total_blocktime;
19565ace060SAlexey Perevalov info->has_postcopy_vcpu_blocktime = true;
19665ace060SAlexey Perevalov info->postcopy_vcpu_blocktime = get_vcpu_blocktime_list(bc);
19765ace060SAlexey Perevalov }
19865ace060SAlexey Perevalov
get_postcopy_total_blocktime(void)19965ace060SAlexey Perevalov static uint32_t get_postcopy_total_blocktime(void)
20065ace060SAlexey Perevalov {
20165ace060SAlexey Perevalov MigrationIncomingState *mis = migration_incoming_get_current();
20265ace060SAlexey Perevalov PostcopyBlocktimeContext *bc = mis->blocktime_ctx;
20365ace060SAlexey Perevalov
20465ace060SAlexey Perevalov if (!bc) {
20565ace060SAlexey Perevalov return 0;
20665ace060SAlexey Perevalov }
20765ace060SAlexey Perevalov
20865ace060SAlexey Perevalov return bc->total_blocktime;
20965ace060SAlexey Perevalov }
21065ace060SAlexey Perevalov
21154ae0886SAlexey Perevalov /**
21254ae0886SAlexey Perevalov * receive_ufd_features: check userfault fd features, to request only supported
21354ae0886SAlexey Perevalov * features in the future.
21454ae0886SAlexey Perevalov *
21554ae0886SAlexey Perevalov * Returns: true on success
21654ae0886SAlexey Perevalov *
21754ae0886SAlexey Perevalov * __NR_userfaultfd - should be checked before
21854ae0886SAlexey Perevalov * @features: out parameter will contain uffdio_api.features provided by kernel
21954ae0886SAlexey Perevalov * in case of success
22054ae0886SAlexey Perevalov */
receive_ufd_features(uint64_t * features)22154ae0886SAlexey Perevalov static bool receive_ufd_features(uint64_t *features)
22254ae0886SAlexey Perevalov {
22354ae0886SAlexey Perevalov struct uffdio_api api_struct = {0};
22454ae0886SAlexey Perevalov int ufd;
22554ae0886SAlexey Perevalov bool ret = true;
22654ae0886SAlexey Perevalov
227d5890ea0SPeter Xu ufd = uffd_open(O_CLOEXEC);
22854ae0886SAlexey Perevalov if (ufd == -1) {
229d5890ea0SPeter Xu error_report("%s: uffd_open() failed: %s", __func__, strerror(errno));
23054ae0886SAlexey Perevalov return false;
23154ae0886SAlexey Perevalov }
23254ae0886SAlexey Perevalov
23354ae0886SAlexey Perevalov /* ask features */
234eb59db53SDr. David Alan Gilbert api_struct.api = UFFD_API;
235eb59db53SDr. David Alan Gilbert api_struct.features = 0;
236eb59db53SDr. David Alan Gilbert if (ioctl(ufd, UFFDIO_API, &api_struct)) {
2375553499fSAlexey Perevalov error_report("%s: UFFDIO_API failed: %s", __func__,
238eb59db53SDr. David Alan Gilbert strerror(errno));
23954ae0886SAlexey Perevalov ret = false;
24054ae0886SAlexey Perevalov goto release_ufd;
24154ae0886SAlexey Perevalov }
24254ae0886SAlexey Perevalov
24354ae0886SAlexey Perevalov *features = api_struct.features;
24454ae0886SAlexey Perevalov
24554ae0886SAlexey Perevalov release_ufd:
24654ae0886SAlexey Perevalov close(ufd);
24754ae0886SAlexey Perevalov return ret;
24854ae0886SAlexey Perevalov }
24954ae0886SAlexey Perevalov
25054ae0886SAlexey Perevalov /**
25154ae0886SAlexey Perevalov * request_ufd_features: this function should be called only once on a newly
25254ae0886SAlexey Perevalov * opened ufd, subsequent calls will lead to error.
25354ae0886SAlexey Perevalov *
2543a4452d8Szhaolichang * Returns: true on success
25554ae0886SAlexey Perevalov *
25654ae0886SAlexey Perevalov * @ufd: fd obtained from userfaultfd syscall
25754ae0886SAlexey Perevalov * @features: bit mask see UFFD_API_FEATURES
25854ae0886SAlexey Perevalov */
request_ufd_features(int ufd,uint64_t features)25954ae0886SAlexey Perevalov static bool request_ufd_features(int ufd, uint64_t features)
26054ae0886SAlexey Perevalov {
26154ae0886SAlexey Perevalov struct uffdio_api api_struct = {0};
26254ae0886SAlexey Perevalov uint64_t ioctl_mask;
26354ae0886SAlexey Perevalov
26454ae0886SAlexey Perevalov api_struct.api = UFFD_API;
26554ae0886SAlexey Perevalov api_struct.features = features;
26654ae0886SAlexey Perevalov if (ioctl(ufd, UFFDIO_API, &api_struct)) {
26754ae0886SAlexey Perevalov error_report("%s failed: UFFDIO_API failed: %s", __func__,
26854ae0886SAlexey Perevalov strerror(errno));
269eb59db53SDr. David Alan Gilbert return false;
270eb59db53SDr. David Alan Gilbert }
271eb59db53SDr. David Alan Gilbert
27273b49878SPaolo Bonzini ioctl_mask = 1ULL << _UFFDIO_REGISTER |
27373b49878SPaolo Bonzini 1ULL << _UFFDIO_UNREGISTER;
274eb59db53SDr. David Alan Gilbert if ((api_struct.ioctls & ioctl_mask) != ioctl_mask) {
275eb59db53SDr. David Alan Gilbert error_report("Missing userfault features: %" PRIx64,
276eb59db53SDr. David Alan Gilbert (uint64_t)(~api_struct.ioctls & ioctl_mask));
277eb59db53SDr. David Alan Gilbert return false;
278eb59db53SDr. David Alan Gilbert }
279eb59db53SDr. David Alan Gilbert
28054ae0886SAlexey Perevalov return true;
28154ae0886SAlexey Perevalov }
28254ae0886SAlexey Perevalov
ufd_check_and_apply(int ufd,MigrationIncomingState * mis,Error ** errp)28374c38cf7SPeter Xu static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis,
28474c38cf7SPeter Xu Error **errp)
28554ae0886SAlexey Perevalov {
28646ff64a8SZhao Liu ERRP_GUARD();
28754ae0886SAlexey Perevalov uint64_t asked_features = 0;
28854ae0886SAlexey Perevalov static uint64_t supported_features;
28954ae0886SAlexey Perevalov
29054ae0886SAlexey Perevalov /*
29154ae0886SAlexey Perevalov * it's not possible to
29254ae0886SAlexey Perevalov * request UFFD_API twice per one fd
29354ae0886SAlexey Perevalov * userfault fd features is persistent
29454ae0886SAlexey Perevalov */
29554ae0886SAlexey Perevalov if (!supported_features) {
29654ae0886SAlexey Perevalov if (!receive_ufd_features(&supported_features)) {
29774c38cf7SPeter Xu error_setg(errp, "Userfault feature detection failed");
29854ae0886SAlexey Perevalov return false;
29954ae0886SAlexey Perevalov }
30054ae0886SAlexey Perevalov }
30154ae0886SAlexey Perevalov
3022a4c42f1SAlexey Perevalov #ifdef UFFD_FEATURE_THREAD_ID
3032d1c37c6SPeter Xu if (UFFD_FEATURE_THREAD_ID & supported_features) {
3042d1c37c6SPeter Xu asked_features |= UFFD_FEATURE_THREAD_ID;
3052d1c37c6SPeter Xu if (migrate_postcopy_blocktime()) {
3062a4c42f1SAlexey Perevalov if (!mis->blocktime_ctx) {
3072a4c42f1SAlexey Perevalov mis->blocktime_ctx = blocktime_context_new();
3082a4c42f1SAlexey Perevalov }
3092d1c37c6SPeter Xu }
3102a4c42f1SAlexey Perevalov }
3112a4c42f1SAlexey Perevalov #endif
3122a4c42f1SAlexey Perevalov
31354ae0886SAlexey Perevalov /*
31454ae0886SAlexey Perevalov * request features, even if asked_features is 0, due to
31554ae0886SAlexey Perevalov * kernel expects UFFD_API before UFFDIO_REGISTER, per
31654ae0886SAlexey Perevalov * userfault file descriptor
31754ae0886SAlexey Perevalov */
31854ae0886SAlexey Perevalov if (!request_ufd_features(ufd, asked_features)) {
31974c38cf7SPeter Xu error_setg(errp, "Failed features %" PRIu64, asked_features);
32054ae0886SAlexey Perevalov return false;
32154ae0886SAlexey Perevalov }
32254ae0886SAlexey Perevalov
3238e3b0cbbSMarc-André Lureau if (qemu_real_host_page_size() != ram_pagesize_summary()) {
3247e8cafb7SDr. David Alan Gilbert bool have_hp = false;
3257e8cafb7SDr. David Alan Gilbert /* We've got a huge page */
3267e8cafb7SDr. David Alan Gilbert #ifdef UFFD_FEATURE_MISSING_HUGETLBFS
32754ae0886SAlexey Perevalov have_hp = supported_features & UFFD_FEATURE_MISSING_HUGETLBFS;
3287e8cafb7SDr. David Alan Gilbert #endif
3297e8cafb7SDr. David Alan Gilbert if (!have_hp) {
33074c38cf7SPeter Xu error_setg(errp,
33174c38cf7SPeter Xu "Userfault on this host does not support huge pages");
3327e8cafb7SDr. David Alan Gilbert return false;
3337e8cafb7SDr. David Alan Gilbert }
3347e8cafb7SDr. David Alan Gilbert }
335eb59db53SDr. David Alan Gilbert return true;
336eb59db53SDr. David Alan Gilbert }
337eb59db53SDr. David Alan Gilbert
3388679638bSDr. David Alan Gilbert /* Callback from postcopy_ram_supported_by_host block iterator.
3398679638bSDr. David Alan Gilbert */
test_ramblock_postcopiable(RAMBlock * rb,Error ** errp)34074c38cf7SPeter Xu static int test_ramblock_postcopiable(RAMBlock *rb, Error **errp)
3418679638bSDr. David Alan Gilbert {
342754cb9c0SYury Kotov const char *block_name = qemu_ram_get_idstr(rb);
343754cb9c0SYury Kotov ram_addr_t length = qemu_ram_get_used_length(rb);
3445d214a92SDr. David Alan Gilbert size_t pagesize = qemu_ram_pagesize(rb);
345ae30b9b2SPeter Xu QemuFsType fs;
3465d214a92SDr. David Alan Gilbert
3475d214a92SDr. David Alan Gilbert if (length % pagesize) {
34874c38cf7SPeter Xu error_setg(errp,
34974c38cf7SPeter Xu "Postcopy requires RAM blocks to be a page size multiple,"
3505d214a92SDr. David Alan Gilbert " block %s is 0x" RAM_ADDR_FMT " bytes with a "
3515d214a92SDr. David Alan Gilbert "page size of 0x%zx", block_name, length, pagesize);
3525d214a92SDr. David Alan Gilbert return 1;
3535d214a92SDr. David Alan Gilbert }
354ae30b9b2SPeter Xu
355ae30b9b2SPeter Xu if (rb->fd >= 0) {
356ae30b9b2SPeter Xu fs = qemu_fd_getfs(rb->fd);
357ae30b9b2SPeter Xu if (fs != QEMU_FS_TYPE_TMPFS && fs != QEMU_FS_TYPE_HUGETLBFS) {
35874c38cf7SPeter Xu error_setg(errp,
35974c38cf7SPeter Xu "Host backend files need to be TMPFS or HUGETLBFS only");
360ae30b9b2SPeter Xu return 1;
361ae30b9b2SPeter Xu }
362ae30b9b2SPeter Xu }
363ae30b9b2SPeter Xu
3648679638bSDr. David Alan Gilbert return 0;
3658679638bSDr. David Alan Gilbert }
3668679638bSDr. David Alan Gilbert
36758b7c17eSDr. David Alan Gilbert /*
36858b7c17eSDr. David Alan Gilbert * Note: This has the side effect of munlock'ing all of RAM, that's
36958b7c17eSDr. David Alan Gilbert * normally fine since if the postcopy succeeds it gets turned back on at the
37058b7c17eSDr. David Alan Gilbert * end.
37158b7c17eSDr. David Alan Gilbert */
postcopy_ram_supported_by_host(MigrationIncomingState * mis,Error ** errp)37274c38cf7SPeter Xu bool postcopy_ram_supported_by_host(MigrationIncomingState *mis, Error **errp)
373eb59db53SDr. David Alan Gilbert {
37446ff64a8SZhao Liu ERRP_GUARD();
3758e3b0cbbSMarc-André Lureau long pagesize = qemu_real_host_page_size();
376eb59db53SDr. David Alan Gilbert int ufd = -1;
377eb59db53SDr. David Alan Gilbert bool ret = false; /* Error unless we change it */
378eb59db53SDr. David Alan Gilbert void *testarea = NULL;
379eb59db53SDr. David Alan Gilbert struct uffdio_register reg_struct;
380eb59db53SDr. David Alan Gilbert struct uffdio_range range_struct;
381eb59db53SDr. David Alan Gilbert uint64_t feature_mask;
382ae30b9b2SPeter Xu RAMBlock *block;
383eb59db53SDr. David Alan Gilbert
38420afaed9SJuan Quintela if (qemu_target_page_size() > pagesize) {
38574c38cf7SPeter Xu error_setg(errp, "Target page size bigger than host page size");
386eb59db53SDr. David Alan Gilbert goto out;
387eb59db53SDr. David Alan Gilbert }
388eb59db53SDr. David Alan Gilbert
389d5890ea0SPeter Xu ufd = uffd_open(O_CLOEXEC);
390eb59db53SDr. David Alan Gilbert if (ufd == -1) {
39174c38cf7SPeter Xu error_setg(errp, "Userfaultfd not available: %s", strerror(errno));
392eb59db53SDr. David Alan Gilbert goto out;
393eb59db53SDr. David Alan Gilbert }
394eb59db53SDr. David Alan Gilbert
3951693c64cSDr. David Alan Gilbert /* Give devices a chance to object */
39674c38cf7SPeter Xu if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, errp)) {
3971693c64cSDr. David Alan Gilbert goto out;
3981693c64cSDr. David Alan Gilbert }
3991693c64cSDr. David Alan Gilbert
400eb59db53SDr. David Alan Gilbert /* Version and features check */
40174c38cf7SPeter Xu if (!ufd_check_and_apply(ufd, mis, errp)) {
402eb59db53SDr. David Alan Gilbert goto out;
403eb59db53SDr. David Alan Gilbert }
404eb59db53SDr. David Alan Gilbert
405ae30b9b2SPeter Xu /*
406ae30b9b2SPeter Xu * We don't support postcopy with some type of ramblocks.
407ae30b9b2SPeter Xu *
408f161c88aSDavid Hildenbrand * NOTE: we explicitly ignored migrate_ram_is_ignored() instead we checked
409ae30b9b2SPeter Xu * all possible ramblocks. This is because this function can be called
410ae30b9b2SPeter Xu * when creating the migration object, during the phase RAM_MIGRATABLE
411ae30b9b2SPeter Xu * is not even properly set for all the ramblocks.
412ae30b9b2SPeter Xu *
413ae30b9b2SPeter Xu * A side effect of this is we'll also check against RAM_SHARED
414ae30b9b2SPeter Xu * ramblocks even if migrate_ignore_shared() is set (in which case
415ae30b9b2SPeter Xu * we'll never migrate RAM_SHARED at all), but normally this shouldn't
416ae30b9b2SPeter Xu * affect in reality, or we can revisit.
417ae30b9b2SPeter Xu */
418ae30b9b2SPeter Xu RAMBLOCK_FOREACH(block) {
41974c38cf7SPeter Xu if (test_ramblock_postcopiable(block, errp)) {
4208679638bSDr. David Alan Gilbert goto out;
4218679638bSDr. David Alan Gilbert }
422ae30b9b2SPeter Xu }
4238679638bSDr. David Alan Gilbert
424eb59db53SDr. David Alan Gilbert /*
42558b7c17eSDr. David Alan Gilbert * userfault and mlock don't go together; we'll put it back later if
42658b7c17eSDr. David Alan Gilbert * it was enabled.
42758b7c17eSDr. David Alan Gilbert */
42858b7c17eSDr. David Alan Gilbert if (munlockall()) {
42974c38cf7SPeter Xu error_setg(errp, "munlockall() failed: %s", strerror(errno));
430617a32f5SDr. David Alan Gilbert goto out;
43158b7c17eSDr. David Alan Gilbert }
43258b7c17eSDr. David Alan Gilbert
43358b7c17eSDr. David Alan Gilbert /*
434eb59db53SDr. David Alan Gilbert * We need to check that the ops we need are supported on anon memory
435eb59db53SDr. David Alan Gilbert * To do that we need to register a chunk and see the flags that
436eb59db53SDr. David Alan Gilbert * are returned.
437eb59db53SDr. David Alan Gilbert */
438eb59db53SDr. David Alan Gilbert testarea = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE |
439eb59db53SDr. David Alan Gilbert MAP_ANONYMOUS, -1, 0);
440eb59db53SDr. David Alan Gilbert if (testarea == MAP_FAILED) {
44174c38cf7SPeter Xu error_setg(errp, "Failed to map test area: %s", strerror(errno));
442eb59db53SDr. David Alan Gilbert goto out;
443eb59db53SDr. David Alan Gilbert }
4447648297dSDavid Hildenbrand g_assert(QEMU_PTR_IS_ALIGNED(testarea, pagesize));
445eb59db53SDr. David Alan Gilbert
446eb59db53SDr. David Alan Gilbert reg_struct.range.start = (uintptr_t)testarea;
447eb59db53SDr. David Alan Gilbert reg_struct.range.len = pagesize;
448eb59db53SDr. David Alan Gilbert reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
449eb59db53SDr. David Alan Gilbert
450eb59db53SDr. David Alan Gilbert if (ioctl(ufd, UFFDIO_REGISTER, ®_struct)) {
45174c38cf7SPeter Xu error_setg(errp, "UFFDIO_REGISTER failed: %s", strerror(errno));
452eb59db53SDr. David Alan Gilbert goto out;
453eb59db53SDr. David Alan Gilbert }
454eb59db53SDr. David Alan Gilbert
455eb59db53SDr. David Alan Gilbert range_struct.start = (uintptr_t)testarea;
456eb59db53SDr. David Alan Gilbert range_struct.len = pagesize;
457eb59db53SDr. David Alan Gilbert if (ioctl(ufd, UFFDIO_UNREGISTER, &range_struct)) {
45874c38cf7SPeter Xu error_setg(errp, "UFFDIO_UNREGISTER failed: %s", strerror(errno));
459eb59db53SDr. David Alan Gilbert goto out;
460eb59db53SDr. David Alan Gilbert }
461eb59db53SDr. David Alan Gilbert
46273b49878SPaolo Bonzini feature_mask = 1ULL << _UFFDIO_WAKE |
46373b49878SPaolo Bonzini 1ULL << _UFFDIO_COPY |
46473b49878SPaolo Bonzini 1ULL << _UFFDIO_ZEROPAGE;
465eb59db53SDr. David Alan Gilbert if ((reg_struct.ioctls & feature_mask) != feature_mask) {
46674c38cf7SPeter Xu error_setg(errp, "Missing userfault map features: %" PRIx64,
467eb59db53SDr. David Alan Gilbert (uint64_t)(~reg_struct.ioctls & feature_mask));
468eb59db53SDr. David Alan Gilbert goto out;
469eb59db53SDr. David Alan Gilbert }
470eb59db53SDr. David Alan Gilbert
471eb59db53SDr. David Alan Gilbert /* Success! */
472eb59db53SDr. David Alan Gilbert ret = true;
473eb59db53SDr. David Alan Gilbert out:
474eb59db53SDr. David Alan Gilbert if (testarea) {
475eb59db53SDr. David Alan Gilbert munmap(testarea, pagesize);
476eb59db53SDr. David Alan Gilbert }
477eb59db53SDr. David Alan Gilbert if (ufd != -1) {
478eb59db53SDr. David Alan Gilbert close(ufd);
479eb59db53SDr. David Alan Gilbert }
480eb59db53SDr. David Alan Gilbert return ret;
481eb59db53SDr. David Alan Gilbert }
482eb59db53SDr. David Alan Gilbert
4831caddf8aSDr. David Alan Gilbert /*
4841caddf8aSDr. David Alan Gilbert * Setup an area of RAM so that it *can* be used for postcopy later; this
4851caddf8aSDr. David Alan Gilbert * must be done right at the start prior to pre-copy.
4861caddf8aSDr. David Alan Gilbert * opaque should be the MIS.
4871caddf8aSDr. David Alan Gilbert */
init_range(RAMBlock * rb,void * opaque)488754cb9c0SYury Kotov static int init_range(RAMBlock *rb, void *opaque)
4891caddf8aSDr. David Alan Gilbert {
490754cb9c0SYury Kotov const char *block_name = qemu_ram_get_idstr(rb);
491754cb9c0SYury Kotov void *host_addr = qemu_ram_get_host_addr(rb);
492754cb9c0SYury Kotov ram_addr_t offset = qemu_ram_get_offset(rb);
493754cb9c0SYury Kotov ram_addr_t length = qemu_ram_get_used_length(rb);
4941caddf8aSDr. David Alan Gilbert trace_postcopy_init_range(block_name, host_addr, offset, length);
4951caddf8aSDr. David Alan Gilbert
4961caddf8aSDr. David Alan Gilbert /*
497898ba906SDavid Hildenbrand * Save the used_length before running the guest. In case we have to
498898ba906SDavid Hildenbrand * resize RAM blocks when syncing RAM block sizes from the source during
499898ba906SDavid Hildenbrand * precopy, we'll update it manually via the ram block notifier.
500898ba906SDavid Hildenbrand */
501898ba906SDavid Hildenbrand rb->postcopy_length = length;
502898ba906SDavid Hildenbrand
503898ba906SDavid Hildenbrand /*
5041caddf8aSDr. David Alan Gilbert * We need the whole of RAM to be truly empty for postcopy, so things
5051caddf8aSDr. David Alan Gilbert * like ROMs and any data tables built during init must be zero'd
5061caddf8aSDr. David Alan Gilbert * - we're going to get the copy from the source anyway.
5071caddf8aSDr. David Alan Gilbert * (Precopy will just overwrite this data, so doesn't need the discard)
5081caddf8aSDr. David Alan Gilbert */
509aaa2064cSJuan Quintela if (ram_discard_range(block_name, 0, length)) {
5101caddf8aSDr. David Alan Gilbert return -1;
5111caddf8aSDr. David Alan Gilbert }
5121caddf8aSDr. David Alan Gilbert
5131caddf8aSDr. David Alan Gilbert return 0;
5141caddf8aSDr. David Alan Gilbert }
5151caddf8aSDr. David Alan Gilbert
5161caddf8aSDr. David Alan Gilbert /*
5171caddf8aSDr. David Alan Gilbert * At the end of migration, undo the effects of init_range
5181caddf8aSDr. David Alan Gilbert * opaque should be the MIS.
5191caddf8aSDr. David Alan Gilbert */
cleanup_range(RAMBlock * rb,void * opaque)520754cb9c0SYury Kotov static int cleanup_range(RAMBlock *rb, void *opaque)
5211caddf8aSDr. David Alan Gilbert {
522754cb9c0SYury Kotov const char *block_name = qemu_ram_get_idstr(rb);
523754cb9c0SYury Kotov void *host_addr = qemu_ram_get_host_addr(rb);
524754cb9c0SYury Kotov ram_addr_t offset = qemu_ram_get_offset(rb);
525898ba906SDavid Hildenbrand ram_addr_t length = rb->postcopy_length;
5261caddf8aSDr. David Alan Gilbert MigrationIncomingState *mis = opaque;
5271caddf8aSDr. David Alan Gilbert struct uffdio_range range_struct;
5281caddf8aSDr. David Alan Gilbert trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
5291caddf8aSDr. David Alan Gilbert
5301caddf8aSDr. David Alan Gilbert /*
5311caddf8aSDr. David Alan Gilbert * We turned off hugepage for the precopy stage with postcopy enabled
5321caddf8aSDr. David Alan Gilbert * we can turn it back on now.
5331caddf8aSDr. David Alan Gilbert */
5341d741439SDr. David Alan Gilbert qemu_madvise(host_addr, length, QEMU_MADV_HUGEPAGE);
5351caddf8aSDr. David Alan Gilbert
5361caddf8aSDr. David Alan Gilbert /*
5371caddf8aSDr. David Alan Gilbert * We can also turn off userfault now since we should have all the
5381caddf8aSDr. David Alan Gilbert * pages. It can be useful to leave it on to debug postcopy
5391caddf8aSDr. David Alan Gilbert * if you're not sure it's always getting every page.
5401caddf8aSDr. David Alan Gilbert */
5411caddf8aSDr. David Alan Gilbert range_struct.start = (uintptr_t)host_addr;
5421caddf8aSDr. David Alan Gilbert range_struct.len = length;
5431caddf8aSDr. David Alan Gilbert
5441caddf8aSDr. David Alan Gilbert if (ioctl(mis->userfault_fd, UFFDIO_UNREGISTER, &range_struct)) {
5451caddf8aSDr. David Alan Gilbert error_report("%s: userfault unregister %s", __func__, strerror(errno));
5461caddf8aSDr. David Alan Gilbert
5471caddf8aSDr. David Alan Gilbert return -1;
5481caddf8aSDr. David Alan Gilbert }
5491caddf8aSDr. David Alan Gilbert
5501caddf8aSDr. David Alan Gilbert return 0;
5511caddf8aSDr. David Alan Gilbert }
5521caddf8aSDr. David Alan Gilbert
5531caddf8aSDr. David Alan Gilbert /*
5541caddf8aSDr. David Alan Gilbert * Initialise postcopy-ram, setting the RAM to a state where we can go into
5551caddf8aSDr. David Alan Gilbert * postcopy later; must be called prior to any precopy.
5561caddf8aSDr. David Alan Gilbert * called from arch_init's similarly named ram_postcopy_incoming_init
5571caddf8aSDr. David Alan Gilbert */
postcopy_ram_incoming_init(MigrationIncomingState * mis)558c136180cSDavid Hildenbrand int postcopy_ram_incoming_init(MigrationIncomingState *mis)
5591caddf8aSDr. David Alan Gilbert {
560fbd162e6SYury Kotov if (foreach_not_ignored_block(init_range, NULL)) {
5611caddf8aSDr. David Alan Gilbert return -1;
5621caddf8aSDr. David Alan Gilbert }
5631caddf8aSDr. David Alan Gilbert
5641caddf8aSDr. David Alan Gilbert return 0;
5651caddf8aSDr. David Alan Gilbert }
5661caddf8aSDr. David Alan Gilbert
postcopy_temp_pages_cleanup(MigrationIncomingState * mis)567476ebf77SPeter Xu static void postcopy_temp_pages_cleanup(MigrationIncomingState *mis)
568476ebf77SPeter Xu {
56977dadc3fSPeter Xu int i;
57077dadc3fSPeter Xu
57177dadc3fSPeter Xu if (mis->postcopy_tmp_pages) {
57277dadc3fSPeter Xu for (i = 0; i < mis->postcopy_channels; i++) {
57377dadc3fSPeter Xu if (mis->postcopy_tmp_pages[i].tmp_huge_page) {
57477dadc3fSPeter Xu munmap(mis->postcopy_tmp_pages[i].tmp_huge_page,
57577dadc3fSPeter Xu mis->largest_page_size);
57677dadc3fSPeter Xu mis->postcopy_tmp_pages[i].tmp_huge_page = NULL;
57777dadc3fSPeter Xu }
57877dadc3fSPeter Xu }
57977dadc3fSPeter Xu g_free(mis->postcopy_tmp_pages);
58077dadc3fSPeter Xu mis->postcopy_tmp_pages = NULL;
581476ebf77SPeter Xu }
582476ebf77SPeter Xu
583476ebf77SPeter Xu if (mis->postcopy_tmp_zero_page) {
584476ebf77SPeter Xu munmap(mis->postcopy_tmp_zero_page, mis->largest_page_size);
585476ebf77SPeter Xu mis->postcopy_tmp_zero_page = NULL;
586476ebf77SPeter Xu }
587476ebf77SPeter Xu }
588476ebf77SPeter Xu
5891caddf8aSDr. David Alan Gilbert /*
5901caddf8aSDr. David Alan Gilbert * At the end of a migration where postcopy_ram_incoming_init was called.
5911caddf8aSDr. David Alan Gilbert */
postcopy_ram_incoming_cleanup(MigrationIncomingState * mis)5921caddf8aSDr. David Alan Gilbert int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
5931caddf8aSDr. David Alan Gilbert {
594c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_incoming_cleanup_entry();
595c4faeed2SDr. David Alan Gilbert
5966621883fSPeter Xu if (mis->preempt_thread_status == PREEMPT_THREAD_CREATED) {
5976621883fSPeter Xu /* Notify the fast load thread to quit */
5986621883fSPeter Xu mis->preempt_thread_status = PREEMPT_THREAD_QUIT;
599cf02f29eSPeter Xu /*
600cf02f29eSPeter Xu * Update preempt_thread_status before reading count. Note: mutex
601cf02f29eSPeter Xu * lock only provide ACQUIRE semantic, and it doesn't stops this
602cf02f29eSPeter Xu * write to be reordered after reading the count.
603cf02f29eSPeter Xu */
604cf02f29eSPeter Xu smp_mb();
605cf02f29eSPeter Xu /*
606cf02f29eSPeter Xu * It's possible that the preempt thread is still handling the last
607cf02f29eSPeter Xu * pages to arrive which were requested by guest page faults.
608cf02f29eSPeter Xu * Making sure nothing is left behind by waiting on the condvar if
609cf02f29eSPeter Xu * that unlikely case happened.
610cf02f29eSPeter Xu */
611cf02f29eSPeter Xu WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
612cf02f29eSPeter Xu if (qatomic_read(&mis->page_requested_count)) {
613cf02f29eSPeter Xu /*
614cf02f29eSPeter Xu * It is guaranteed to receive a signal later, because the
615cf02f29eSPeter Xu * count>0 now, so it's destined to be decreased to zero
616cf02f29eSPeter Xu * very soon by the preempt thread.
617cf02f29eSPeter Xu */
618cf02f29eSPeter Xu qemu_cond_wait(&mis->page_request_cond,
619cf02f29eSPeter Xu &mis->page_request_mutex);
620cf02f29eSPeter Xu }
621cf02f29eSPeter Xu }
622cf02f29eSPeter Xu /* Notify the fast load thread to quit */
6236621883fSPeter Xu if (mis->postcopy_qemufile_dst) {
6246621883fSPeter Xu qemu_file_shutdown(mis->postcopy_qemufile_dst);
6256621883fSPeter Xu }
62636f62f11SPeter Xu qemu_thread_join(&mis->postcopy_prio_thread);
6276621883fSPeter Xu mis->preempt_thread_status = PREEMPT_THREAD_NONE;
62836f62f11SPeter Xu }
62936f62f11SPeter Xu
630c4faeed2SDr. David Alan Gilbert if (mis->have_fault_thread) {
63146343570SDr. David Alan Gilbert Error *local_err = NULL;
63246343570SDr. David Alan Gilbert
63355d0fe82SIlya Maximets /* Let the fault thread quit */
634d73415a3SStefan Hajnoczi qatomic_set(&mis->fault_thread_quit, 1);
63555d0fe82SIlya Maximets postcopy_fault_thread_notify(mis);
63655d0fe82SIlya Maximets trace_postcopy_ram_incoming_cleanup_join();
63755d0fe82SIlya Maximets qemu_thread_join(&mis->fault_thread);
63855d0fe82SIlya Maximets
63946343570SDr. David Alan Gilbert if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_END, &local_err)) {
64046343570SDr. David Alan Gilbert error_report_err(local_err);
64146343570SDr. David Alan Gilbert return -1;
64246343570SDr. David Alan Gilbert }
64346343570SDr. David Alan Gilbert
644fbd162e6SYury Kotov if (foreach_not_ignored_block(cleanup_range, mis)) {
6451caddf8aSDr. David Alan Gilbert return -1;
6461caddf8aSDr. David Alan Gilbert }
6479ab7ef9bSPeter Xu
648c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_incoming_cleanup_closeuf();
649c4faeed2SDr. David Alan Gilbert close(mis->userfault_fd);
65064f615feSPeter Xu close(mis->userfault_event_fd);
651c4faeed2SDr. David Alan Gilbert mis->have_fault_thread = false;
652c4faeed2SDr. David Alan Gilbert }
653c4faeed2SDr. David Alan Gilbert
65458b7c17eSDr. David Alan Gilbert if (enable_mlock) {
65558b7c17eSDr. David Alan Gilbert if (os_mlock() < 0) {
65658b7c17eSDr. David Alan Gilbert error_report("mlock: %s", strerror(errno));
65758b7c17eSDr. David Alan Gilbert /*
65858b7c17eSDr. David Alan Gilbert * It doesn't feel right to fail at this point, we have a valid
65958b7c17eSDr. David Alan Gilbert * VM state.
66058b7c17eSDr. David Alan Gilbert */
66158b7c17eSDr. David Alan Gilbert }
66258b7c17eSDr. David Alan Gilbert }
66358b7c17eSDr. David Alan Gilbert
664476ebf77SPeter Xu postcopy_temp_pages_cleanup(mis);
665476ebf77SPeter Xu
66665ace060SAlexey Perevalov trace_postcopy_ram_incoming_cleanup_blocktime(
66765ace060SAlexey Perevalov get_postcopy_total_blocktime());
66865ace060SAlexey Perevalov
669c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_incoming_cleanup_exit();
6701caddf8aSDr. David Alan Gilbert return 0;
6711caddf8aSDr. David Alan Gilbert }
6721caddf8aSDr. David Alan Gilbert
673f0a227adSDr. David Alan Gilbert /*
674f9527107SDr. David Alan Gilbert * Disable huge pages on an area
675f9527107SDr. David Alan Gilbert */
nhp_range(RAMBlock * rb,void * opaque)676754cb9c0SYury Kotov static int nhp_range(RAMBlock *rb, void *opaque)
677f9527107SDr. David Alan Gilbert {
678754cb9c0SYury Kotov const char *block_name = qemu_ram_get_idstr(rb);
679754cb9c0SYury Kotov void *host_addr = qemu_ram_get_host_addr(rb);
680754cb9c0SYury Kotov ram_addr_t offset = qemu_ram_get_offset(rb);
681898ba906SDavid Hildenbrand ram_addr_t length = rb->postcopy_length;
682f9527107SDr. David Alan Gilbert trace_postcopy_nhp_range(block_name, host_addr, offset, length);
683f9527107SDr. David Alan Gilbert
684f9527107SDr. David Alan Gilbert /*
685f9527107SDr. David Alan Gilbert * Before we do discards we need to ensure those discards really
686f9527107SDr. David Alan Gilbert * do delete areas of the page, even if THP thinks a hugepage would
687f9527107SDr. David Alan Gilbert * be a good idea, so force hugepages off.
688f9527107SDr. David Alan Gilbert */
6891d741439SDr. David Alan Gilbert qemu_madvise(host_addr, length, QEMU_MADV_NOHUGEPAGE);
690f9527107SDr. David Alan Gilbert
691f9527107SDr. David Alan Gilbert return 0;
692f9527107SDr. David Alan Gilbert }
693f9527107SDr. David Alan Gilbert
694f9527107SDr. David Alan Gilbert /*
695f9527107SDr. David Alan Gilbert * Userfault requires us to mark RAM as NOHUGEPAGE prior to discard
696f9527107SDr. David Alan Gilbert * however leaving it until after precopy means that most of the precopy
697f9527107SDr. David Alan Gilbert * data is still THPd
698f9527107SDr. David Alan Gilbert */
postcopy_ram_prepare_discard(MigrationIncomingState * mis)699f9527107SDr. David Alan Gilbert int postcopy_ram_prepare_discard(MigrationIncomingState *mis)
700f9527107SDr. David Alan Gilbert {
701fbd162e6SYury Kotov if (foreach_not_ignored_block(nhp_range, mis)) {
702f9527107SDr. David Alan Gilbert return -1;
703f9527107SDr. David Alan Gilbert }
704f9527107SDr. David Alan Gilbert
705f9527107SDr. David Alan Gilbert postcopy_state_set(POSTCOPY_INCOMING_DISCARD);
706f9527107SDr. David Alan Gilbert
707f9527107SDr. David Alan Gilbert return 0;
708f9527107SDr. David Alan Gilbert }
709f9527107SDr. David Alan Gilbert
710f9527107SDr. David Alan Gilbert /*
711f0a227adSDr. David Alan Gilbert * Mark the given area of RAM as requiring notification to unwritten areas
712fbd162e6SYury Kotov * Used as a callback on foreach_not_ignored_block.
713f0a227adSDr. David Alan Gilbert * host_addr: Base of area to mark
714f0a227adSDr. David Alan Gilbert * offset: Offset in the whole ram arena
715f0a227adSDr. David Alan Gilbert * length: Length of the section
716f0a227adSDr. David Alan Gilbert * opaque: MigrationIncomingState pointer
717f0a227adSDr. David Alan Gilbert * Returns 0 on success
718f0a227adSDr. David Alan Gilbert */
ram_block_enable_notify(RAMBlock * rb,void * opaque)719754cb9c0SYury Kotov static int ram_block_enable_notify(RAMBlock *rb, void *opaque)
720f0a227adSDr. David Alan Gilbert {
721f0a227adSDr. David Alan Gilbert MigrationIncomingState *mis = opaque;
722f0a227adSDr. David Alan Gilbert struct uffdio_register reg_struct;
723f0a227adSDr. David Alan Gilbert
724754cb9c0SYury Kotov reg_struct.range.start = (uintptr_t)qemu_ram_get_host_addr(rb);
725898ba906SDavid Hildenbrand reg_struct.range.len = rb->postcopy_length;
726f0a227adSDr. David Alan Gilbert reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
727f0a227adSDr. David Alan Gilbert
728f0a227adSDr. David Alan Gilbert /* Now tell our userfault_fd that it's responsible for this area */
729f0a227adSDr. David Alan Gilbert if (ioctl(mis->userfault_fd, UFFDIO_REGISTER, ®_struct)) {
730f0a227adSDr. David Alan Gilbert error_report("%s userfault register: %s", __func__, strerror(errno));
731f0a227adSDr. David Alan Gilbert return -1;
732f0a227adSDr. David Alan Gilbert }
73373b49878SPaolo Bonzini if (!(reg_struct.ioctls & (1ULL << _UFFDIO_COPY))) {
734665414adSDr. David Alan Gilbert error_report("%s userfault: Region doesn't support COPY", __func__);
735665414adSDr. David Alan Gilbert return -1;
736665414adSDr. David Alan Gilbert }
73773b49878SPaolo Bonzini if (reg_struct.ioctls & (1ULL << _UFFDIO_ZEROPAGE)) {
7382ce16640SDr. David Alan Gilbert qemu_ram_set_uf_zeroable(rb);
7392ce16640SDr. David Alan Gilbert }
740f0a227adSDr. David Alan Gilbert
741f0a227adSDr. David Alan Gilbert return 0;
742f0a227adSDr. David Alan Gilbert }
743f0a227adSDr. David Alan Gilbert
postcopy_wake_shared(struct PostCopyFD * pcfd,uint64_t client_addr,RAMBlock * rb)7445efc3564SDr. David Alan Gilbert int postcopy_wake_shared(struct PostCopyFD *pcfd,
7455efc3564SDr. David Alan Gilbert uint64_t client_addr,
7465efc3564SDr. David Alan Gilbert RAMBlock *rb)
7475efc3564SDr. David Alan Gilbert {
7485efc3564SDr. David Alan Gilbert size_t pagesize = qemu_ram_pagesize(rb);
7495efc3564SDr. David Alan Gilbert struct uffdio_range range;
7505efc3564SDr. David Alan Gilbert int ret;
7515efc3564SDr. David Alan Gilbert trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
7527648297dSDavid Hildenbrand range.start = ROUND_DOWN(client_addr, pagesize);
7535efc3564SDr. David Alan Gilbert range.len = pagesize;
7545efc3564SDr. David Alan Gilbert ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
7555efc3564SDr. David Alan Gilbert if (ret) {
7565efc3564SDr. David Alan Gilbert error_report("%s: Failed to wake: %zx in %s (%s)",
7575efc3564SDr. David Alan Gilbert __func__, (size_t)client_addr, qemu_ram_get_idstr(rb),
7585efc3564SDr. David Alan Gilbert strerror(errno));
7595efc3564SDr. David Alan Gilbert }
7605efc3564SDr. David Alan Gilbert return ret;
7615efc3564SDr. David Alan Gilbert }
7625efc3564SDr. David Alan Gilbert
postcopy_request_page(MigrationIncomingState * mis,RAMBlock * rb,ram_addr_t start,uint64_t haddr)7639470c5e0SDavid Hildenbrand static int postcopy_request_page(MigrationIncomingState *mis, RAMBlock *rb,
7649470c5e0SDavid Hildenbrand ram_addr_t start, uint64_t haddr)
7659470c5e0SDavid Hildenbrand {
7669470c5e0SDavid Hildenbrand void *aligned = (void *)(uintptr_t)ROUND_DOWN(haddr, qemu_ram_pagesize(rb));
7679470c5e0SDavid Hildenbrand
7689470c5e0SDavid Hildenbrand /*
7699470c5e0SDavid Hildenbrand * Discarded pages (via RamDiscardManager) are never migrated. On unlikely
7709470c5e0SDavid Hildenbrand * access, place a zeropage, which will also set the relevant bits in the
7719470c5e0SDavid Hildenbrand * recv_bitmap accordingly, so we won't try placing a zeropage twice.
7729470c5e0SDavid Hildenbrand *
7739470c5e0SDavid Hildenbrand * Checking a single bit is sufficient to handle pagesize > TPS as either
7749470c5e0SDavid Hildenbrand * all relevant bits are set or not.
7759470c5e0SDavid Hildenbrand */
7769470c5e0SDavid Hildenbrand assert(QEMU_IS_ALIGNED(start, qemu_ram_pagesize(rb)));
7779470c5e0SDavid Hildenbrand if (ramblock_page_is_discarded(rb, start)) {
7789470c5e0SDavid Hildenbrand bool received = ramblock_recv_bitmap_test_byte_offset(rb, start);
7799470c5e0SDavid Hildenbrand
7809470c5e0SDavid Hildenbrand return received ? 0 : postcopy_place_page_zero(mis, aligned, rb);
7819470c5e0SDavid Hildenbrand }
7829470c5e0SDavid Hildenbrand
7839470c5e0SDavid Hildenbrand return migrate_send_rp_req_pages(mis, rb, start, haddr);
7849470c5e0SDavid Hildenbrand }
7859470c5e0SDavid Hildenbrand
786f0a227adSDr. David Alan Gilbert /*
787096bf4c8SDr. David Alan Gilbert * Callback from shared fault handlers to ask for a page,
788096bf4c8SDr. David Alan Gilbert * the page must be specified by a RAMBlock and an offset in that rb
789096bf4c8SDr. David Alan Gilbert * Note: Only for use by shared fault handlers (in fault thread)
790096bf4c8SDr. David Alan Gilbert */
postcopy_request_shared_page(struct PostCopyFD * pcfd,RAMBlock * rb,uint64_t client_addr,uint64_t rb_offset)791096bf4c8SDr. David Alan Gilbert int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
792096bf4c8SDr. David Alan Gilbert uint64_t client_addr, uint64_t rb_offset)
793096bf4c8SDr. David Alan Gilbert {
7947648297dSDavid Hildenbrand uint64_t aligned_rbo = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb));
795096bf4c8SDr. David Alan Gilbert MigrationIncomingState *mis = migration_incoming_get_current();
796096bf4c8SDr. David Alan Gilbert
797096bf4c8SDr. David Alan Gilbert trace_postcopy_request_shared_page(pcfd->idstr, qemu_ram_get_idstr(rb),
798096bf4c8SDr. David Alan Gilbert rb_offset);
799dedfb4b2SDr. David Alan Gilbert if (ramblock_recv_bitmap_test_byte_offset(rb, aligned_rbo)) {
800dedfb4b2SDr. David Alan Gilbert trace_postcopy_request_shared_page_present(pcfd->idstr,
801dedfb4b2SDr. David Alan Gilbert qemu_ram_get_idstr(rb), rb_offset);
802dedfb4b2SDr. David Alan Gilbert return postcopy_wake_shared(pcfd, client_addr, rb);
803dedfb4b2SDr. David Alan Gilbert }
8049470c5e0SDavid Hildenbrand postcopy_request_page(mis, rb, aligned_rbo, client_addr);
805096bf4c8SDr. David Alan Gilbert return 0;
806096bf4c8SDr. David Alan Gilbert }
807096bf4c8SDr. David Alan Gilbert
get_mem_fault_cpu_index(uint32_t pid)808575b0b33SAlexey Perevalov static int get_mem_fault_cpu_index(uint32_t pid)
809575b0b33SAlexey Perevalov {
810575b0b33SAlexey Perevalov CPUState *cpu_iter;
811575b0b33SAlexey Perevalov
812575b0b33SAlexey Perevalov CPU_FOREACH(cpu_iter) {
813575b0b33SAlexey Perevalov if (cpu_iter->thread_id == pid) {
814575b0b33SAlexey Perevalov trace_get_mem_fault_cpu_index(cpu_iter->cpu_index, pid);
815575b0b33SAlexey Perevalov return cpu_iter->cpu_index;
816575b0b33SAlexey Perevalov }
817575b0b33SAlexey Perevalov }
818575b0b33SAlexey Perevalov trace_get_mem_fault_cpu_index(-1, pid);
819575b0b33SAlexey Perevalov return -1;
820575b0b33SAlexey Perevalov }
821575b0b33SAlexey Perevalov
get_low_time_offset(PostcopyBlocktimeContext * dc)822575b0b33SAlexey Perevalov static uint32_t get_low_time_offset(PostcopyBlocktimeContext *dc)
823575b0b33SAlexey Perevalov {
824575b0b33SAlexey Perevalov int64_t start_time_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
825575b0b33SAlexey Perevalov dc->start_time;
826575b0b33SAlexey Perevalov return start_time_offset < 1 ? 1 : start_time_offset & UINT32_MAX;
827575b0b33SAlexey Perevalov }
828575b0b33SAlexey Perevalov
829575b0b33SAlexey Perevalov /*
830575b0b33SAlexey Perevalov * This function is being called when pagefault occurs. It
831575b0b33SAlexey Perevalov * tracks down vCPU blocking time.
832575b0b33SAlexey Perevalov *
833575b0b33SAlexey Perevalov * @addr: faulted host virtual address
834575b0b33SAlexey Perevalov * @ptid: faulted process thread id
835575b0b33SAlexey Perevalov * @rb: ramblock appropriate to addr
836575b0b33SAlexey Perevalov */
mark_postcopy_blocktime_begin(uintptr_t addr,uint32_t ptid,RAMBlock * rb)837575b0b33SAlexey Perevalov static void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid,
838575b0b33SAlexey Perevalov RAMBlock *rb)
839575b0b33SAlexey Perevalov {
840575b0b33SAlexey Perevalov int cpu, already_received;
841575b0b33SAlexey Perevalov MigrationIncomingState *mis = migration_incoming_get_current();
842575b0b33SAlexey Perevalov PostcopyBlocktimeContext *dc = mis->blocktime_ctx;
843575b0b33SAlexey Perevalov uint32_t low_time_offset;
844575b0b33SAlexey Perevalov
845575b0b33SAlexey Perevalov if (!dc || ptid == 0) {
846575b0b33SAlexey Perevalov return;
847575b0b33SAlexey Perevalov }
848575b0b33SAlexey Perevalov cpu = get_mem_fault_cpu_index(ptid);
849575b0b33SAlexey Perevalov if (cpu < 0) {
850575b0b33SAlexey Perevalov return;
851575b0b33SAlexey Perevalov }
852575b0b33SAlexey Perevalov
853575b0b33SAlexey Perevalov low_time_offset = get_low_time_offset(dc);
854575b0b33SAlexey Perevalov if (dc->vcpu_addr[cpu] == 0) {
855d73415a3SStefan Hajnoczi qatomic_inc(&dc->smp_cpus_down);
856575b0b33SAlexey Perevalov }
857575b0b33SAlexey Perevalov
858d73415a3SStefan Hajnoczi qatomic_xchg(&dc->last_begin, low_time_offset);
859d73415a3SStefan Hajnoczi qatomic_xchg(&dc->page_fault_vcpu_time[cpu], low_time_offset);
860d73415a3SStefan Hajnoczi qatomic_xchg(&dc->vcpu_addr[cpu], addr);
861575b0b33SAlexey Perevalov
862da1725d3SWei Yang /*
863da1725d3SWei Yang * check it here, not at the beginning of the function,
864da1725d3SWei Yang * due to, check could occur early than bitmap_set in
865da1725d3SWei Yang * qemu_ufd_copy_ioctl
866da1725d3SWei Yang */
867575b0b33SAlexey Perevalov already_received = ramblock_recv_bitmap_test(rb, (void *)addr);
868575b0b33SAlexey Perevalov if (already_received) {
869d73415a3SStefan Hajnoczi qatomic_xchg(&dc->vcpu_addr[cpu], 0);
870d73415a3SStefan Hajnoczi qatomic_xchg(&dc->page_fault_vcpu_time[cpu], 0);
871d73415a3SStefan Hajnoczi qatomic_dec(&dc->smp_cpus_down);
872575b0b33SAlexey Perevalov }
873575b0b33SAlexey Perevalov trace_mark_postcopy_blocktime_begin(addr, dc, dc->page_fault_vcpu_time[cpu],
874575b0b33SAlexey Perevalov cpu, already_received);
875575b0b33SAlexey Perevalov }
876575b0b33SAlexey Perevalov
877575b0b33SAlexey Perevalov /*
878575b0b33SAlexey Perevalov * This function just provide calculated blocktime per cpu and trace it.
879575b0b33SAlexey Perevalov * Total blocktime is calculated in mark_postcopy_blocktime_end.
880575b0b33SAlexey Perevalov *
881575b0b33SAlexey Perevalov *
882575b0b33SAlexey Perevalov * Assume we have 3 CPU
883575b0b33SAlexey Perevalov *
884575b0b33SAlexey Perevalov * S1 E1 S1 E1
885575b0b33SAlexey Perevalov * -----***********------------xxx***************------------------------> CPU1
886575b0b33SAlexey Perevalov *
887575b0b33SAlexey Perevalov * S2 E2
888575b0b33SAlexey Perevalov * ------------****************xxx---------------------------------------> CPU2
889575b0b33SAlexey Perevalov *
890575b0b33SAlexey Perevalov * S3 E3
891575b0b33SAlexey Perevalov * ------------------------****xxx********-------------------------------> CPU3
892575b0b33SAlexey Perevalov *
893575b0b33SAlexey Perevalov * We have sequence S1,S2,E1,S3,S1,E2,E3,E1
894575b0b33SAlexey Perevalov * S2,E1 - doesn't match condition due to sequence S1,S2,E1 doesn't include CPU3
895575b0b33SAlexey Perevalov * S3,S1,E2 - sequence includes all CPUs, in this case overlap will be S1,E2 -
896575b0b33SAlexey Perevalov * it's a part of total blocktime.
897575b0b33SAlexey Perevalov * S1 - here is last_begin
898575b0b33SAlexey Perevalov * Legend of the picture is following:
899575b0b33SAlexey Perevalov * * - means blocktime per vCPU
900575b0b33SAlexey Perevalov * x - means overlapped blocktime (total blocktime)
901575b0b33SAlexey Perevalov *
902575b0b33SAlexey Perevalov * @addr: host virtual address
903575b0b33SAlexey Perevalov */
mark_postcopy_blocktime_end(uintptr_t addr)904575b0b33SAlexey Perevalov static void mark_postcopy_blocktime_end(uintptr_t addr)
905575b0b33SAlexey Perevalov {
906575b0b33SAlexey Perevalov MigrationIncomingState *mis = migration_incoming_get_current();
907575b0b33SAlexey Perevalov PostcopyBlocktimeContext *dc = mis->blocktime_ctx;
9085cc8767dSLike Xu MachineState *ms = MACHINE(qdev_get_machine());
9095cc8767dSLike Xu unsigned int smp_cpus = ms->smp.cpus;
910575b0b33SAlexey Perevalov int i, affected_cpu = 0;
911575b0b33SAlexey Perevalov bool vcpu_total_blocktime = false;
912575b0b33SAlexey Perevalov uint32_t read_vcpu_time, low_time_offset;
913575b0b33SAlexey Perevalov
914575b0b33SAlexey Perevalov if (!dc) {
915575b0b33SAlexey Perevalov return;
916575b0b33SAlexey Perevalov }
917575b0b33SAlexey Perevalov
918575b0b33SAlexey Perevalov low_time_offset = get_low_time_offset(dc);
919575b0b33SAlexey Perevalov /* lookup cpu, to clear it,
9203a4452d8Szhaolichang * that algorithm looks straightforward, but it's not
921575b0b33SAlexey Perevalov * optimal, more optimal algorithm is keeping tree or hash
922575b0b33SAlexey Perevalov * where key is address value is a list of */
923575b0b33SAlexey Perevalov for (i = 0; i < smp_cpus; i++) {
924575b0b33SAlexey Perevalov uint32_t vcpu_blocktime = 0;
925575b0b33SAlexey Perevalov
926d73415a3SStefan Hajnoczi read_vcpu_time = qatomic_fetch_add(&dc->page_fault_vcpu_time[i], 0);
927d73415a3SStefan Hajnoczi if (qatomic_fetch_add(&dc->vcpu_addr[i], 0) != addr ||
928575b0b33SAlexey Perevalov read_vcpu_time == 0) {
929575b0b33SAlexey Perevalov continue;
930575b0b33SAlexey Perevalov }
931d73415a3SStefan Hajnoczi qatomic_xchg(&dc->vcpu_addr[i], 0);
932575b0b33SAlexey Perevalov vcpu_blocktime = low_time_offset - read_vcpu_time;
933575b0b33SAlexey Perevalov affected_cpu += 1;
934575b0b33SAlexey Perevalov /* we need to know is that mark_postcopy_end was due to
935575b0b33SAlexey Perevalov * faulted page, another possible case it's prefetched
936575b0b33SAlexey Perevalov * page and in that case we shouldn't be here */
937575b0b33SAlexey Perevalov if (!vcpu_total_blocktime &&
938d73415a3SStefan Hajnoczi qatomic_fetch_add(&dc->smp_cpus_down, 0) == smp_cpus) {
939575b0b33SAlexey Perevalov vcpu_total_blocktime = true;
940575b0b33SAlexey Perevalov }
941575b0b33SAlexey Perevalov /* continue cycle, due to one page could affect several vCPUs */
942575b0b33SAlexey Perevalov dc->vcpu_blocktime[i] += vcpu_blocktime;
943575b0b33SAlexey Perevalov }
944575b0b33SAlexey Perevalov
945d73415a3SStefan Hajnoczi qatomic_sub(&dc->smp_cpus_down, affected_cpu);
946575b0b33SAlexey Perevalov if (vcpu_total_blocktime) {
947d73415a3SStefan Hajnoczi dc->total_blocktime += low_time_offset - qatomic_fetch_add(
948575b0b33SAlexey Perevalov &dc->last_begin, 0);
949575b0b33SAlexey Perevalov }
950575b0b33SAlexey Perevalov trace_mark_postcopy_blocktime_end(addr, dc, dc->total_blocktime,
951575b0b33SAlexey Perevalov affected_cpu);
952575b0b33SAlexey Perevalov }
953575b0b33SAlexey Perevalov
postcopy_pause_fault_thread(MigrationIncomingState * mis)95427dd21b4SPeter Xu static void postcopy_pause_fault_thread(MigrationIncomingState *mis)
9553a7804c3SPeter Xu {
9563a7804c3SPeter Xu trace_postcopy_pause_fault_thread();
9573a7804c3SPeter Xu qemu_sem_wait(&mis->postcopy_pause_sem_fault);
9583a7804c3SPeter Xu trace_postcopy_pause_fault_thread_continued();
9593a7804c3SPeter Xu }
9603a7804c3SPeter Xu
961096bf4c8SDr. David Alan Gilbert /*
962f0a227adSDr. David Alan Gilbert * Handle faults detected by the USERFAULT markings
963f0a227adSDr. David Alan Gilbert */
postcopy_ram_fault_thread(void * opaque)964f0a227adSDr. David Alan Gilbert static void *postcopy_ram_fault_thread(void *opaque)
965f0a227adSDr. David Alan Gilbert {
966f0a227adSDr. David Alan Gilbert MigrationIncomingState *mis = opaque;
967c4faeed2SDr. David Alan Gilbert struct uffd_msg msg;
968c4faeed2SDr. David Alan Gilbert int ret;
96900fa4fc8SDr. David Alan Gilbert size_t index;
970c4faeed2SDr. David Alan Gilbert RAMBlock *rb = NULL;
971f0a227adSDr. David Alan Gilbert
972c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_entry();
97374637e6fSLidong Chen rcu_register_thread();
974096bf4c8SDr. David Alan Gilbert mis->last_rb = NULL; /* last RAMBlock we sent part of */
975095c12a4SPeter Xu qemu_sem_post(&mis->thread_sync_sem);
976c4faeed2SDr. David Alan Gilbert
97700fa4fc8SDr. David Alan Gilbert struct pollfd *pfd;
97800fa4fc8SDr. David Alan Gilbert size_t pfd_len = 2 + mis->postcopy_remote_fds->len;
97900fa4fc8SDr. David Alan Gilbert
98000fa4fc8SDr. David Alan Gilbert pfd = g_new0(struct pollfd, pfd_len);
98100fa4fc8SDr. David Alan Gilbert
98200fa4fc8SDr. David Alan Gilbert pfd[0].fd = mis->userfault_fd;
98300fa4fc8SDr. David Alan Gilbert pfd[0].events = POLLIN;
98400fa4fc8SDr. David Alan Gilbert pfd[1].fd = mis->userfault_event_fd;
98500fa4fc8SDr. David Alan Gilbert pfd[1].events = POLLIN; /* Waiting for eventfd to go positive */
98600fa4fc8SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_fds_core(pfd[0].fd, pfd[1].fd);
98700fa4fc8SDr. David Alan Gilbert for (index = 0; index < mis->postcopy_remote_fds->len; index++) {
98800fa4fc8SDr. David Alan Gilbert struct PostCopyFD *pcfd = &g_array_index(mis->postcopy_remote_fds,
98900fa4fc8SDr. David Alan Gilbert struct PostCopyFD, index);
99000fa4fc8SDr. David Alan Gilbert pfd[2 + index].fd = pcfd->fd;
99100fa4fc8SDr. David Alan Gilbert pfd[2 + index].events = POLLIN;
99200fa4fc8SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_fds_extra(2 + index, pcfd->idstr,
99300fa4fc8SDr. David Alan Gilbert pcfd->fd);
99400fa4fc8SDr. David Alan Gilbert }
99500fa4fc8SDr. David Alan Gilbert
996c4faeed2SDr. David Alan Gilbert while (true) {
997c4faeed2SDr. David Alan Gilbert ram_addr_t rb_offset;
99800fa4fc8SDr. David Alan Gilbert int poll_result;
999c4faeed2SDr. David Alan Gilbert
1000c4faeed2SDr. David Alan Gilbert /*
1001c4faeed2SDr. David Alan Gilbert * We're mainly waiting for the kernel to give us a faulting HVA,
1002c4faeed2SDr. David Alan Gilbert * however we can be told to quit via userfault_quit_fd which is
1003c4faeed2SDr. David Alan Gilbert * an eventfd
1004c4faeed2SDr. David Alan Gilbert */
1005c4faeed2SDr. David Alan Gilbert
100600fa4fc8SDr. David Alan Gilbert poll_result = poll(pfd, pfd_len, -1 /* Wait forever */);
100700fa4fc8SDr. David Alan Gilbert if (poll_result == -1) {
1008c4faeed2SDr. David Alan Gilbert error_report("%s: userfault poll: %s", __func__, strerror(errno));
1009c4faeed2SDr. David Alan Gilbert break;
1010f0a227adSDr. David Alan Gilbert }
1011f0a227adSDr. David Alan Gilbert
10123a7804c3SPeter Xu if (!mis->to_src_file) {
10133a7804c3SPeter Xu /*
10143a7804c3SPeter Xu * Possibly someone tells us that the return path is
10153a7804c3SPeter Xu * broken already using the event. We should hold until
10163a7804c3SPeter Xu * the channel is rebuilt.
10173a7804c3SPeter Xu */
101827dd21b4SPeter Xu postcopy_pause_fault_thread(mis);
10193a7804c3SPeter Xu }
10203a7804c3SPeter Xu
1021c4faeed2SDr. David Alan Gilbert if (pfd[1].revents) {
102264f615feSPeter Xu uint64_t tmp64 = 0;
102364f615feSPeter Xu
102464f615feSPeter Xu /* Consume the signal */
102564f615feSPeter Xu if (read(mis->userfault_event_fd, &tmp64, 8) != 8) {
102664f615feSPeter Xu /* Nothing obviously nicer than posting this error. */
102764f615feSPeter Xu error_report("%s: read() failed", __func__);
102864f615feSPeter Xu }
102964f615feSPeter Xu
1030d73415a3SStefan Hajnoczi if (qatomic_read(&mis->fault_thread_quit)) {
1031c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_quit();
1032c4faeed2SDr. David Alan Gilbert break;
1033c4faeed2SDr. David Alan Gilbert }
103464f615feSPeter Xu }
1035c4faeed2SDr. David Alan Gilbert
103600fa4fc8SDr. David Alan Gilbert if (pfd[0].revents) {
103700fa4fc8SDr. David Alan Gilbert poll_result--;
1038c4faeed2SDr. David Alan Gilbert ret = read(mis->userfault_fd, &msg, sizeof(msg));
1039c4faeed2SDr. David Alan Gilbert if (ret != sizeof(msg)) {
1040c4faeed2SDr. David Alan Gilbert if (errno == EAGAIN) {
1041c4faeed2SDr. David Alan Gilbert /*
1042c4faeed2SDr. David Alan Gilbert * if a wake up happens on the other thread just after
1043c4faeed2SDr. David Alan Gilbert * the poll, there is nothing to read.
1044c4faeed2SDr. David Alan Gilbert */
1045c4faeed2SDr. David Alan Gilbert continue;
1046c4faeed2SDr. David Alan Gilbert }
1047c4faeed2SDr. David Alan Gilbert if (ret < 0) {
104800fa4fc8SDr. David Alan Gilbert error_report("%s: Failed to read full userfault "
104900fa4fc8SDr. David Alan Gilbert "message: %s",
1050c4faeed2SDr. David Alan Gilbert __func__, strerror(errno));
1051c4faeed2SDr. David Alan Gilbert break;
1052c4faeed2SDr. David Alan Gilbert } else {
105300fa4fc8SDr. David Alan Gilbert error_report("%s: Read %d bytes from userfaultfd "
105400fa4fc8SDr. David Alan Gilbert "expected %zd",
1055c4faeed2SDr. David Alan Gilbert __func__, ret, sizeof(msg));
1056c4faeed2SDr. David Alan Gilbert break; /* Lost alignment, don't know what we'd read next */
1057c4faeed2SDr. David Alan Gilbert }
1058c4faeed2SDr. David Alan Gilbert }
1059c4faeed2SDr. David Alan Gilbert if (msg.event != UFFD_EVENT_PAGEFAULT) {
1060c4faeed2SDr. David Alan Gilbert error_report("%s: Read unexpected event %ud from userfaultfd",
1061c4faeed2SDr. David Alan Gilbert __func__, msg.event);
1062c4faeed2SDr. David Alan Gilbert continue; /* It's not a page fault, shouldn't happen */
1063c4faeed2SDr. David Alan Gilbert }
1064c4faeed2SDr. David Alan Gilbert
1065c4faeed2SDr. David Alan Gilbert rb = qemu_ram_block_from_host(
1066c4faeed2SDr. David Alan Gilbert (void *)(uintptr_t)msg.arg.pagefault.address,
1067f615f396SPaolo Bonzini true, &rb_offset);
1068c4faeed2SDr. David Alan Gilbert if (!rb) {
1069c4faeed2SDr. David Alan Gilbert error_report("postcopy_ram_fault_thread: Fault outside guest: %"
1070c4faeed2SDr. David Alan Gilbert PRIx64, (uint64_t)msg.arg.pagefault.address);
1071c4faeed2SDr. David Alan Gilbert break;
1072c4faeed2SDr. David Alan Gilbert }
1073c4faeed2SDr. David Alan Gilbert
10747648297dSDavid Hildenbrand rb_offset = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb));
1075c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
1076c4faeed2SDr. David Alan Gilbert qemu_ram_get_idstr(rb),
1077575b0b33SAlexey Perevalov rb_offset,
1078575b0b33SAlexey Perevalov msg.arg.pagefault.feat.ptid);
1079575b0b33SAlexey Perevalov mark_postcopy_blocktime_begin(
1080575b0b33SAlexey Perevalov (uintptr_t)(msg.arg.pagefault.address),
1081575b0b33SAlexey Perevalov msg.arg.pagefault.feat.ptid, rb);
1082575b0b33SAlexey Perevalov
10833a7804c3SPeter Xu retry:
1084c4faeed2SDr. David Alan Gilbert /*
1085c4faeed2SDr. David Alan Gilbert * Send the request to the source - we want to request one
1086c4faeed2SDr. David Alan Gilbert * of our host page sizes (which is >= TPS)
1087c4faeed2SDr. David Alan Gilbert */
10889470c5e0SDavid Hildenbrand ret = postcopy_request_page(mis, rb, rb_offset,
10898f8bfffcSPeter Xu msg.arg.pagefault.address);
10903a7804c3SPeter Xu if (ret) {
10913a7804c3SPeter Xu /* May be network failure, try to wait for recovery */
109227dd21b4SPeter Xu postcopy_pause_fault_thread(mis);
10933a7804c3SPeter Xu goto retry;
1094c4faeed2SDr. David Alan Gilbert }
1095c4faeed2SDr. David Alan Gilbert }
109600fa4fc8SDr. David Alan Gilbert
109700fa4fc8SDr. David Alan Gilbert /* Now handle any requests from external processes on shared memory */
109800fa4fc8SDr. David Alan Gilbert /* TODO: May need to handle devices deregistering during postcopy */
109900fa4fc8SDr. David Alan Gilbert for (index = 2; index < pfd_len && poll_result; index++) {
110000fa4fc8SDr. David Alan Gilbert if (pfd[index].revents) {
110100fa4fc8SDr. David Alan Gilbert struct PostCopyFD *pcfd =
110200fa4fc8SDr. David Alan Gilbert &g_array_index(mis->postcopy_remote_fds,
110300fa4fc8SDr. David Alan Gilbert struct PostCopyFD, index - 2);
110400fa4fc8SDr. David Alan Gilbert
110500fa4fc8SDr. David Alan Gilbert poll_result--;
110600fa4fc8SDr. David Alan Gilbert if (pfd[index].revents & POLLERR) {
110700fa4fc8SDr. David Alan Gilbert error_report("%s: POLLERR on poll %zd fd=%d",
110800fa4fc8SDr. David Alan Gilbert __func__, index, pcfd->fd);
110900fa4fc8SDr. David Alan Gilbert pfd[index].events = 0;
111000fa4fc8SDr. David Alan Gilbert continue;
111100fa4fc8SDr. David Alan Gilbert }
111200fa4fc8SDr. David Alan Gilbert
111300fa4fc8SDr. David Alan Gilbert ret = read(pcfd->fd, &msg, sizeof(msg));
111400fa4fc8SDr. David Alan Gilbert if (ret != sizeof(msg)) {
111500fa4fc8SDr. David Alan Gilbert if (errno == EAGAIN) {
111600fa4fc8SDr. David Alan Gilbert /*
111700fa4fc8SDr. David Alan Gilbert * if a wake up happens on the other thread just after
111800fa4fc8SDr. David Alan Gilbert * the poll, there is nothing to read.
111900fa4fc8SDr. David Alan Gilbert */
112000fa4fc8SDr. David Alan Gilbert continue;
112100fa4fc8SDr. David Alan Gilbert }
112200fa4fc8SDr. David Alan Gilbert if (ret < 0) {
112300fa4fc8SDr. David Alan Gilbert error_report("%s: Failed to read full userfault "
112400fa4fc8SDr. David Alan Gilbert "message: %s (shared) revents=%d",
112500fa4fc8SDr. David Alan Gilbert __func__, strerror(errno),
112600fa4fc8SDr. David Alan Gilbert pfd[index].revents);
112700fa4fc8SDr. David Alan Gilbert /*TODO: Could just disable this sharer */
112800fa4fc8SDr. David Alan Gilbert break;
112900fa4fc8SDr. David Alan Gilbert } else {
113000fa4fc8SDr. David Alan Gilbert error_report("%s: Read %d bytes from userfaultfd "
113100fa4fc8SDr. David Alan Gilbert "expected %zd (shared)",
113200fa4fc8SDr. David Alan Gilbert __func__, ret, sizeof(msg));
113300fa4fc8SDr. David Alan Gilbert /*TODO: Could just disable this sharer */
113400fa4fc8SDr. David Alan Gilbert break; /*Lost alignment,don't know what we'd read next*/
113500fa4fc8SDr. David Alan Gilbert }
113600fa4fc8SDr. David Alan Gilbert }
113700fa4fc8SDr. David Alan Gilbert if (msg.event != UFFD_EVENT_PAGEFAULT) {
113800fa4fc8SDr. David Alan Gilbert error_report("%s: Read unexpected event %ud "
113900fa4fc8SDr. David Alan Gilbert "from userfaultfd (shared)",
114000fa4fc8SDr. David Alan Gilbert __func__, msg.event);
114100fa4fc8SDr. David Alan Gilbert continue; /* It's not a page fault, shouldn't happen */
114200fa4fc8SDr. David Alan Gilbert }
114300fa4fc8SDr. David Alan Gilbert /* Call the device handler registered with us */
114400fa4fc8SDr. David Alan Gilbert ret = pcfd->handler(pcfd, &msg);
114500fa4fc8SDr. David Alan Gilbert if (ret) {
114600fa4fc8SDr. David Alan Gilbert error_report("%s: Failed to resolve shared fault on %zd/%s",
114700fa4fc8SDr. David Alan Gilbert __func__, index, pcfd->idstr);
114800fa4fc8SDr. David Alan Gilbert /* TODO: Fail? Disable this sharer? */
114900fa4fc8SDr. David Alan Gilbert }
115000fa4fc8SDr. David Alan Gilbert }
115100fa4fc8SDr. David Alan Gilbert }
115200fa4fc8SDr. David Alan Gilbert }
115374637e6fSLidong Chen rcu_unregister_thread();
1154c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_fault_thread_exit();
1155fc6008f3SMarc-André Lureau g_free(pfd);
1156f0a227adSDr. David Alan Gilbert return NULL;
1157f0a227adSDr. David Alan Gilbert }
1158f0a227adSDr. David Alan Gilbert
postcopy_temp_pages_setup(MigrationIncomingState * mis)1159476ebf77SPeter Xu static int postcopy_temp_pages_setup(MigrationIncomingState *mis)
1160476ebf77SPeter Xu {
116177dadc3fSPeter Xu PostcopyTmpPage *tmp_page;
116277dadc3fSPeter Xu int err, i, channels;
116377dadc3fSPeter Xu void *temp_page;
1164476ebf77SPeter Xu
116536f62f11SPeter Xu if (migrate_postcopy_preempt()) {
116636f62f11SPeter Xu /* If preemption enabled, need extra channel for urgent requests */
116736f62f11SPeter Xu mis->postcopy_channels = RAM_CHANNEL_MAX;
116836f62f11SPeter Xu } else {
116936f62f11SPeter Xu /* Both precopy/postcopy on the same channel */
117077dadc3fSPeter Xu mis->postcopy_channels = 1;
117136f62f11SPeter Xu }
117277dadc3fSPeter Xu
117377dadc3fSPeter Xu channels = mis->postcopy_channels;
117477dadc3fSPeter Xu mis->postcopy_tmp_pages = g_malloc0_n(sizeof(PostcopyTmpPage), channels);
117577dadc3fSPeter Xu
117677dadc3fSPeter Xu for (i = 0; i < channels; i++) {
117777dadc3fSPeter Xu tmp_page = &mis->postcopy_tmp_pages[i];
117877dadc3fSPeter Xu temp_page = mmap(NULL, mis->largest_page_size, PROT_READ | PROT_WRITE,
1179476ebf77SPeter Xu MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
118077dadc3fSPeter Xu if (temp_page == MAP_FAILED) {
1181476ebf77SPeter Xu err = errno;
118277dadc3fSPeter Xu error_report("%s: Failed to map postcopy_tmp_pages[%d]: %s",
118377dadc3fSPeter Xu __func__, i, strerror(err));
118477dadc3fSPeter Xu /* Clean up will be done later */
1185476ebf77SPeter Xu return -err;
1186476ebf77SPeter Xu }
118777dadc3fSPeter Xu tmp_page->tmp_huge_page = temp_page;
118877dadc3fSPeter Xu /* Initialize default states for each tmp page */
118977dadc3fSPeter Xu postcopy_temp_page_reset(tmp_page);
119077dadc3fSPeter Xu }
1191476ebf77SPeter Xu
1192476ebf77SPeter Xu /*
1193476ebf77SPeter Xu * Map large zero page when kernel can't use UFFDIO_ZEROPAGE for hugepages
1194476ebf77SPeter Xu */
1195476ebf77SPeter Xu mis->postcopy_tmp_zero_page = mmap(NULL, mis->largest_page_size,
1196476ebf77SPeter Xu PROT_READ | PROT_WRITE,
1197476ebf77SPeter Xu MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
1198476ebf77SPeter Xu if (mis->postcopy_tmp_zero_page == MAP_FAILED) {
1199476ebf77SPeter Xu err = errno;
1200476ebf77SPeter Xu mis->postcopy_tmp_zero_page = NULL;
1201476ebf77SPeter Xu error_report("%s: Failed to map large zero page %s",
1202476ebf77SPeter Xu __func__, strerror(err));
1203476ebf77SPeter Xu return -err;
1204476ebf77SPeter Xu }
1205476ebf77SPeter Xu
1206476ebf77SPeter Xu memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size);
1207476ebf77SPeter Xu
1208476ebf77SPeter Xu return 0;
1209476ebf77SPeter Xu }
1210476ebf77SPeter Xu
postcopy_ram_incoming_setup(MigrationIncomingState * mis)12112a7eb148SWei Yang int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
1212f0a227adSDr. David Alan Gilbert {
121374c38cf7SPeter Xu Error *local_err = NULL;
121474c38cf7SPeter Xu
1215c4faeed2SDr. David Alan Gilbert /* Open the fd for the kernel to give us userfaults */
1216d5890ea0SPeter Xu mis->userfault_fd = uffd_open(O_CLOEXEC | O_NONBLOCK);
1217c4faeed2SDr. David Alan Gilbert if (mis->userfault_fd == -1) {
1218c4faeed2SDr. David Alan Gilbert error_report("%s: Failed to open userfault fd: %s", __func__,
1219c4faeed2SDr. David Alan Gilbert strerror(errno));
1220c4faeed2SDr. David Alan Gilbert return -1;
1221c4faeed2SDr. David Alan Gilbert }
1222c4faeed2SDr. David Alan Gilbert
1223c4faeed2SDr. David Alan Gilbert /*
1224c4faeed2SDr. David Alan Gilbert * Although the host check already tested the API, we need to
1225c4faeed2SDr. David Alan Gilbert * do the check again as an ABI handshake on the new fd.
1226c4faeed2SDr. David Alan Gilbert */
122774c38cf7SPeter Xu if (!ufd_check_and_apply(mis->userfault_fd, mis, &local_err)) {
122874c38cf7SPeter Xu error_report_err(local_err);
1229c4faeed2SDr. David Alan Gilbert return -1;
1230c4faeed2SDr. David Alan Gilbert }
1231c4faeed2SDr. David Alan Gilbert
1232c4faeed2SDr. David Alan Gilbert /* Now an eventfd we use to tell the fault-thread to quit */
123364f615feSPeter Xu mis->userfault_event_fd = eventfd(0, EFD_CLOEXEC);
123464f615feSPeter Xu if (mis->userfault_event_fd == -1) {
123564f615feSPeter Xu error_report("%s: Opening userfault_event_fd: %s", __func__,
1236c4faeed2SDr. David Alan Gilbert strerror(errno));
1237c4faeed2SDr. David Alan Gilbert close(mis->userfault_fd);
1238c4faeed2SDr. David Alan Gilbert return -1;
1239c4faeed2SDr. David Alan Gilbert }
1240c4faeed2SDr. David Alan Gilbert
124136f62f11SPeter Xu postcopy_thread_create(mis, &mis->fault_thread, "fault-default",
1242095c12a4SPeter Xu postcopy_ram_fault_thread, QEMU_THREAD_JOINABLE);
1243c4faeed2SDr. David Alan Gilbert mis->have_fault_thread = true;
1244f0a227adSDr. David Alan Gilbert
1245f0a227adSDr. David Alan Gilbert /* Mark so that we get notified of accesses to unwritten areas */
1246fbd162e6SYury Kotov if (foreach_not_ignored_block(ram_block_enable_notify, mis)) {
124791b02dc7SFei Li error_report("ram_block_enable_notify failed");
1248f0a227adSDr. David Alan Gilbert return -1;
1249f0a227adSDr. David Alan Gilbert }
1250f0a227adSDr. David Alan Gilbert
1251476ebf77SPeter Xu if (postcopy_temp_pages_setup(mis)) {
1252476ebf77SPeter Xu /* Error dumped in the sub-function */
12533414322aSWei Yang return -1;
12543414322aSWei Yang }
12553414322aSWei Yang
125636f62f11SPeter Xu if (migrate_postcopy_preempt()) {
125736f62f11SPeter Xu /*
125836f62f11SPeter Xu * This thread needs to be created after the temp pages because
125936f62f11SPeter Xu * it'll fetch RAM_CHANNEL_POSTCOPY PostcopyTmpPage immediately.
126036f62f11SPeter Xu */
126136f62f11SPeter Xu postcopy_thread_create(mis, &mis->postcopy_prio_thread, "fault-fast",
126236f62f11SPeter Xu postcopy_preempt_thread, QEMU_THREAD_JOINABLE);
12636621883fSPeter Xu mis->preempt_thread_status = PREEMPT_THREAD_CREATED;
126436f62f11SPeter Xu }
126536f62f11SPeter Xu
1266c4faeed2SDr. David Alan Gilbert trace_postcopy_ram_enable_notify();
1267c4faeed2SDr. David Alan Gilbert
1268f0a227adSDr. David Alan Gilbert return 0;
1269f0a227adSDr. David Alan Gilbert }
1270f0a227adSDr. David Alan Gilbert
qemu_ufd_copy_ioctl(MigrationIncomingState * mis,void * host_addr,void * from_addr,uint64_t pagesize,RAMBlock * rb)1271eef621c4SPeter Xu static int qemu_ufd_copy_ioctl(MigrationIncomingState *mis, void *host_addr,
1272f9494614SAlexey Perevalov void *from_addr, uint64_t pagesize, RAMBlock *rb)
1273727b9d7eSAlexey Perevalov {
1274eef621c4SPeter Xu int userfault_fd = mis->userfault_fd;
1275f9494614SAlexey Perevalov int ret;
1276eef621c4SPeter Xu
1277727b9d7eSAlexey Perevalov if (from_addr) {
1278727b9d7eSAlexey Perevalov struct uffdio_copy copy_struct;
1279727b9d7eSAlexey Perevalov copy_struct.dst = (uint64_t)(uintptr_t)host_addr;
1280727b9d7eSAlexey Perevalov copy_struct.src = (uint64_t)(uintptr_t)from_addr;
1281727b9d7eSAlexey Perevalov copy_struct.len = pagesize;
1282727b9d7eSAlexey Perevalov copy_struct.mode = 0;
1283f9494614SAlexey Perevalov ret = ioctl(userfault_fd, UFFDIO_COPY, ©_struct);
1284727b9d7eSAlexey Perevalov } else {
1285727b9d7eSAlexey Perevalov struct uffdio_zeropage zero_struct;
1286727b9d7eSAlexey Perevalov zero_struct.range.start = (uint64_t)(uintptr_t)host_addr;
1287727b9d7eSAlexey Perevalov zero_struct.range.len = pagesize;
1288727b9d7eSAlexey Perevalov zero_struct.mode = 0;
1289f9494614SAlexey Perevalov ret = ioctl(userfault_fd, UFFDIO_ZEROPAGE, &zero_struct);
1290727b9d7eSAlexey Perevalov }
1291f9494614SAlexey Perevalov if (!ret) {
12928f8bfffcSPeter Xu qemu_mutex_lock(&mis->page_request_mutex);
1293f9494614SAlexey Perevalov ramblock_recv_bitmap_set_range(rb, host_addr,
1294f9494614SAlexey Perevalov pagesize / qemu_target_page_size());
12958f8bfffcSPeter Xu /*
12968f8bfffcSPeter Xu * If this page resolves a page fault for a previous recorded faulted
12978f8bfffcSPeter Xu * address, take a special note to maintain the requested page list.
12988f8bfffcSPeter Xu */
12998f8bfffcSPeter Xu if (g_tree_lookup(mis->page_requested, host_addr)) {
13008f8bfffcSPeter Xu g_tree_remove(mis->page_requested, host_addr);
1301cf02f29eSPeter Xu int left_pages = qatomic_dec_fetch(&mis->page_requested_count);
1302cf02f29eSPeter Xu
13038f8bfffcSPeter Xu trace_postcopy_page_req_del(host_addr, mis->page_requested_count);
1304cf02f29eSPeter Xu /* Order the update of count and read of preempt status */
1305cf02f29eSPeter Xu smp_mb();
1306cf02f29eSPeter Xu if (mis->preempt_thread_status == PREEMPT_THREAD_QUIT &&
1307cf02f29eSPeter Xu left_pages == 0) {
1308cf02f29eSPeter Xu /*
1309cf02f29eSPeter Xu * This probably means the main thread is waiting for us.
1310cf02f29eSPeter Xu * Notify that we've finished receiving the last requested
1311cf02f29eSPeter Xu * page.
1312cf02f29eSPeter Xu */
1313cf02f29eSPeter Xu qemu_cond_signal(&mis->page_request_cond);
1314cf02f29eSPeter Xu }
13158f8bfffcSPeter Xu }
13168f8bfffcSPeter Xu qemu_mutex_unlock(&mis->page_request_mutex);
1317575b0b33SAlexey Perevalov mark_postcopy_blocktime_end((uintptr_t)host_addr);
1318f9494614SAlexey Perevalov }
1319f9494614SAlexey Perevalov return ret;
1320727b9d7eSAlexey Perevalov }
1321727b9d7eSAlexey Perevalov
postcopy_notify_shared_wake(RAMBlock * rb,uint64_t offset)1322d488b349SDr. David Alan Gilbert int postcopy_notify_shared_wake(RAMBlock *rb, uint64_t offset)
1323d488b349SDr. David Alan Gilbert {
1324d488b349SDr. David Alan Gilbert int i;
1325d488b349SDr. David Alan Gilbert MigrationIncomingState *mis = migration_incoming_get_current();
1326d488b349SDr. David Alan Gilbert GArray *pcrfds = mis->postcopy_remote_fds;
1327d488b349SDr. David Alan Gilbert
1328d488b349SDr. David Alan Gilbert for (i = 0; i < pcrfds->len; i++) {
1329d488b349SDr. David Alan Gilbert struct PostCopyFD *cur = &g_array_index(pcrfds, struct PostCopyFD, i);
1330d488b349SDr. David Alan Gilbert int ret = cur->waker(cur, rb, offset);
1331d488b349SDr. David Alan Gilbert if (ret) {
1332d488b349SDr. David Alan Gilbert return ret;
1333d488b349SDr. David Alan Gilbert }
1334d488b349SDr. David Alan Gilbert }
1335d488b349SDr. David Alan Gilbert return 0;
1336d488b349SDr. David Alan Gilbert }
1337d488b349SDr. David Alan Gilbert
1338696ed9a9SDr. David Alan Gilbert /*
1339696ed9a9SDr. David Alan Gilbert * Place a host page (from) at (host) atomically
1340696ed9a9SDr. David Alan Gilbert * returns 0 on success
1341696ed9a9SDr. David Alan Gilbert */
postcopy_place_page(MigrationIncomingState * mis,void * host,void * from,RAMBlock * rb)1342df9ff5e1SDr. David Alan Gilbert int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
13438be4620bSAlexey Perevalov RAMBlock *rb)
1344696ed9a9SDr. David Alan Gilbert {
13458be4620bSAlexey Perevalov size_t pagesize = qemu_ram_pagesize(rb);
1346696ed9a9SDr. David Alan Gilbert
1347696ed9a9SDr. David Alan Gilbert /* copy also acks to the kernel waking the stalled thread up
1348696ed9a9SDr. David Alan Gilbert * TODO: We can inhibit that ack and only do it if it was requested
1349696ed9a9SDr. David Alan Gilbert * which would be slightly cheaper, but we'd have to be careful
1350696ed9a9SDr. David Alan Gilbert * of the order of updating our page state.
1351696ed9a9SDr. David Alan Gilbert */
1352eef621c4SPeter Xu if (qemu_ufd_copy_ioctl(mis, host, from, pagesize, rb)) {
1353696ed9a9SDr. David Alan Gilbert int e = errno;
1354df9ff5e1SDr. David Alan Gilbert error_report("%s: %s copy host: %p from: %p (size: %zd)",
1355df9ff5e1SDr. David Alan Gilbert __func__, strerror(e), host, from, pagesize);
1356696ed9a9SDr. David Alan Gilbert
1357696ed9a9SDr. David Alan Gilbert return -e;
1358696ed9a9SDr. David Alan Gilbert }
1359696ed9a9SDr. David Alan Gilbert
1360696ed9a9SDr. David Alan Gilbert trace_postcopy_place_page(host);
1361dedfb4b2SDr. David Alan Gilbert return postcopy_notify_shared_wake(rb,
1362dedfb4b2SDr. David Alan Gilbert qemu_ram_block_host_offset(rb, host));
1363696ed9a9SDr. David Alan Gilbert }
1364696ed9a9SDr. David Alan Gilbert
1365696ed9a9SDr. David Alan Gilbert /*
1366696ed9a9SDr. David Alan Gilbert * Place a zero page at (host) atomically
1367696ed9a9SDr. David Alan Gilbert * returns 0 on success
1368696ed9a9SDr. David Alan Gilbert */
postcopy_place_page_zero(MigrationIncomingState * mis,void * host,RAMBlock * rb)1369df9ff5e1SDr. David Alan Gilbert int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
13708be4620bSAlexey Perevalov RAMBlock *rb)
1371696ed9a9SDr. David Alan Gilbert {
13722ce16640SDr. David Alan Gilbert size_t pagesize = qemu_ram_pagesize(rb);
1373df9ff5e1SDr. David Alan Gilbert trace_postcopy_place_page_zero(host);
1374696ed9a9SDr. David Alan Gilbert
13752ce16640SDr. David Alan Gilbert /* Normal RAMBlocks can zero a page using UFFDIO_ZEROPAGE
13762ce16640SDr. David Alan Gilbert * but it's not available for everything (e.g. hugetlbpages)
13772ce16640SDr. David Alan Gilbert */
13782ce16640SDr. David Alan Gilbert if (qemu_ram_is_uf_zeroable(rb)) {
1379eef621c4SPeter Xu if (qemu_ufd_copy_ioctl(mis, host, NULL, pagesize, rb)) {
1380696ed9a9SDr. David Alan Gilbert int e = errno;
1381696ed9a9SDr. David Alan Gilbert error_report("%s: %s zero host: %p",
1382696ed9a9SDr. David Alan Gilbert __func__, strerror(e), host);
1383696ed9a9SDr. David Alan Gilbert
1384696ed9a9SDr. David Alan Gilbert return -e;
1385696ed9a9SDr. David Alan Gilbert }
1386dedfb4b2SDr. David Alan Gilbert return postcopy_notify_shared_wake(rb,
1387dedfb4b2SDr. David Alan Gilbert qemu_ram_block_host_offset(rb,
1388dedfb4b2SDr. David Alan Gilbert host));
1389df9ff5e1SDr. David Alan Gilbert } else {
13906629890dSWei Yang return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, rb);
1391df9ff5e1SDr. David Alan Gilbert }
1392696ed9a9SDr. David Alan Gilbert }
1393696ed9a9SDr. David Alan Gilbert
1394eb59db53SDr. David Alan Gilbert #else
1395eb59db53SDr. David Alan Gilbert /* No target OS support, stubs just fail */
fill_destination_postcopy_migration_info(MigrationInfo * info)139665ace060SAlexey Perevalov void fill_destination_postcopy_migration_info(MigrationInfo *info)
139765ace060SAlexey Perevalov {
139865ace060SAlexey Perevalov }
139965ace060SAlexey Perevalov
postcopy_ram_supported_by_host(MigrationIncomingState * mis,Error ** errp)140074c38cf7SPeter Xu bool postcopy_ram_supported_by_host(MigrationIncomingState *mis, Error **errp)
1401eb59db53SDr. David Alan Gilbert {
1402eb59db53SDr. David Alan Gilbert error_report("%s: No OS support", __func__);
1403eb59db53SDr. David Alan Gilbert return false;
1404eb59db53SDr. David Alan Gilbert }
1405eb59db53SDr. David Alan Gilbert
postcopy_ram_incoming_init(MigrationIncomingState * mis)1406c136180cSDavid Hildenbrand int postcopy_ram_incoming_init(MigrationIncomingState *mis)
14071caddf8aSDr. David Alan Gilbert {
14081caddf8aSDr. David Alan Gilbert error_report("postcopy_ram_incoming_init: No OS support");
14091caddf8aSDr. David Alan Gilbert return -1;
14101caddf8aSDr. David Alan Gilbert }
14111caddf8aSDr. David Alan Gilbert
postcopy_ram_incoming_cleanup(MigrationIncomingState * mis)14121caddf8aSDr. David Alan Gilbert int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
14131caddf8aSDr. David Alan Gilbert {
14141caddf8aSDr. David Alan Gilbert assert(0);
14151caddf8aSDr. David Alan Gilbert return -1;
14161caddf8aSDr. David Alan Gilbert }
14171caddf8aSDr. David Alan Gilbert
postcopy_ram_prepare_discard(MigrationIncomingState * mis)1418f9527107SDr. David Alan Gilbert int postcopy_ram_prepare_discard(MigrationIncomingState *mis)
1419f9527107SDr. David Alan Gilbert {
1420f9527107SDr. David Alan Gilbert assert(0);
1421f9527107SDr. David Alan Gilbert return -1;
1422f9527107SDr. David Alan Gilbert }
1423f9527107SDr. David Alan Gilbert
postcopy_request_shared_page(struct PostCopyFD * pcfd,RAMBlock * rb,uint64_t client_addr,uint64_t rb_offset)1424c188c539SMichael S. Tsirkin int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
1425c188c539SMichael S. Tsirkin uint64_t client_addr, uint64_t rb_offset)
1426c188c539SMichael S. Tsirkin {
1427c188c539SMichael S. Tsirkin assert(0);
1428c188c539SMichael S. Tsirkin return -1;
1429c188c539SMichael S. Tsirkin }
1430c188c539SMichael S. Tsirkin
postcopy_ram_incoming_setup(MigrationIncomingState * mis)14312a7eb148SWei Yang int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
1432f0a227adSDr. David Alan Gilbert {
1433f0a227adSDr. David Alan Gilbert assert(0);
1434f0a227adSDr. David Alan Gilbert return -1;
1435f0a227adSDr. David Alan Gilbert }
1436696ed9a9SDr. David Alan Gilbert
postcopy_place_page(MigrationIncomingState * mis,void * host,void * from,RAMBlock * rb)1437df9ff5e1SDr. David Alan Gilbert int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
14388be4620bSAlexey Perevalov RAMBlock *rb)
1439696ed9a9SDr. David Alan Gilbert {
1440696ed9a9SDr. David Alan Gilbert assert(0);
1441696ed9a9SDr. David Alan Gilbert return -1;
1442696ed9a9SDr. David Alan Gilbert }
1443696ed9a9SDr. David Alan Gilbert
postcopy_place_page_zero(MigrationIncomingState * mis,void * host,RAMBlock * rb)1444df9ff5e1SDr. David Alan Gilbert int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
14458be4620bSAlexey Perevalov RAMBlock *rb)
1446696ed9a9SDr. David Alan Gilbert {
1447696ed9a9SDr. David Alan Gilbert assert(0);
1448696ed9a9SDr. David Alan Gilbert return -1;
1449696ed9a9SDr. David Alan Gilbert }
1450696ed9a9SDr. David Alan Gilbert
postcopy_wake_shared(struct PostCopyFD * pcfd,uint64_t client_addr,RAMBlock * rb)14515efc3564SDr. David Alan Gilbert int postcopy_wake_shared(struct PostCopyFD *pcfd,
14525efc3564SDr. David Alan Gilbert uint64_t client_addr,
14535efc3564SDr. David Alan Gilbert RAMBlock *rb)
14545efc3564SDr. David Alan Gilbert {
14555efc3564SDr. David Alan Gilbert assert(0);
14565efc3564SDr. David Alan Gilbert return -1;
14575efc3564SDr. David Alan Gilbert }
1458eb59db53SDr. David Alan Gilbert #endif
1459eb59db53SDr. David Alan Gilbert
1460e0b266f0SDr. David Alan Gilbert /* ------------------------------------------------------------------------- */
postcopy_temp_page_reset(PostcopyTmpPage * tmp_page)146177dadc3fSPeter Xu void postcopy_temp_page_reset(PostcopyTmpPage *tmp_page)
146277dadc3fSPeter Xu {
146377dadc3fSPeter Xu tmp_page->target_pages = 0;
146477dadc3fSPeter Xu tmp_page->host_addr = NULL;
146577dadc3fSPeter Xu /*
146677dadc3fSPeter Xu * This is set to true when reset, and cleared as long as we received any
146777dadc3fSPeter Xu * of the non-zero small page within this huge page.
146877dadc3fSPeter Xu */
146977dadc3fSPeter Xu tmp_page->all_zero = true;
147077dadc3fSPeter Xu }
1471e0b266f0SDr. David Alan Gilbert
postcopy_fault_thread_notify(MigrationIncomingState * mis)14729ab7ef9bSPeter Xu void postcopy_fault_thread_notify(MigrationIncomingState *mis)
14739ab7ef9bSPeter Xu {
14749ab7ef9bSPeter Xu uint64_t tmp64 = 1;
14759ab7ef9bSPeter Xu
14769ab7ef9bSPeter Xu /*
14779ab7ef9bSPeter Xu * Wakeup the fault_thread. It's an eventfd that should currently
14789ab7ef9bSPeter Xu * be at 0, we're going to increment it to 1
14799ab7ef9bSPeter Xu */
14809ab7ef9bSPeter Xu if (write(mis->userfault_event_fd, &tmp64, 8) != 8) {
14819ab7ef9bSPeter Xu /* Not much we can do here, but may as well report it */
14829ab7ef9bSPeter Xu error_report("%s: incrementing failed: %s", __func__,
14839ab7ef9bSPeter Xu strerror(errno));
14849ab7ef9bSPeter Xu }
14859ab7ef9bSPeter Xu }
14869ab7ef9bSPeter Xu
1487e0b266f0SDr. David Alan Gilbert /**
1488e0b266f0SDr. David Alan Gilbert * postcopy_discard_send_init: Called at the start of each RAMBlock before
1489e0b266f0SDr. David Alan Gilbert * asking to discard individual ranges.
1490e0b266f0SDr. David Alan Gilbert *
1491e0b266f0SDr. David Alan Gilbert * @ms: The current migration state.
1492810cf2bbSWei Yang * @offset: the bitmap offset of the named RAMBlock in the migration bitmap.
1493e0b266f0SDr. David Alan Gilbert * @name: RAMBlock that discards will operate on.
1494e0b266f0SDr. David Alan Gilbert */
1495810cf2bbSWei Yang static PostcopyDiscardState pds = {0};
postcopy_discard_send_init(MigrationState * ms,const char * name)1496810cf2bbSWei Yang void postcopy_discard_send_init(MigrationState *ms, const char *name)
1497e0b266f0SDr. David Alan Gilbert {
1498810cf2bbSWei Yang pds.ramblock_name = name;
1499810cf2bbSWei Yang pds.cur_entry = 0;
1500810cf2bbSWei Yang pds.nsentwords = 0;
1501810cf2bbSWei Yang pds.nsentcmds = 0;
1502e0b266f0SDr. David Alan Gilbert }
1503e0b266f0SDr. David Alan Gilbert
1504e0b266f0SDr. David Alan Gilbert /**
1505e0b266f0SDr. David Alan Gilbert * postcopy_discard_send_range: Called by the bitmap code for each chunk to
1506e0b266f0SDr. David Alan Gilbert * discard. May send a discard message, may just leave it queued to
1507e0b266f0SDr. David Alan Gilbert * be sent later.
1508e0b266f0SDr. David Alan Gilbert *
1509e0b266f0SDr. David Alan Gilbert * @ms: Current migration state.
1510e0b266f0SDr. David Alan Gilbert * @start,@length: a range of pages in the migration bitmap in the
1511e0b266f0SDr. David Alan Gilbert * RAM block passed to postcopy_discard_send_init() (length=1 is one page)
1512e0b266f0SDr. David Alan Gilbert */
postcopy_discard_send_range(MigrationState * ms,unsigned long start,unsigned long length)1513810cf2bbSWei Yang void postcopy_discard_send_range(MigrationState *ms, unsigned long start,
1514810cf2bbSWei Yang unsigned long length)
1515e0b266f0SDr. David Alan Gilbert {
151620afaed9SJuan Quintela size_t tp_size = qemu_target_page_size();
1517e0b266f0SDr. David Alan Gilbert /* Convert to byte offsets within the RAM block */
1518810cf2bbSWei Yang pds.start_list[pds.cur_entry] = start * tp_size;
1519810cf2bbSWei Yang pds.length_list[pds.cur_entry] = length * tp_size;
1520810cf2bbSWei Yang trace_postcopy_discard_send_range(pds.ramblock_name, start, length);
1521810cf2bbSWei Yang pds.cur_entry++;
1522810cf2bbSWei Yang pds.nsentwords++;
1523e0b266f0SDr. David Alan Gilbert
1524810cf2bbSWei Yang if (pds.cur_entry == MAX_DISCARDS_PER_COMMAND) {
1525e0b266f0SDr. David Alan Gilbert /* Full set, ship it! */
152689a02a9fSzhanghailiang qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file,
1527810cf2bbSWei Yang pds.ramblock_name,
1528810cf2bbSWei Yang pds.cur_entry,
1529810cf2bbSWei Yang pds.start_list,
1530810cf2bbSWei Yang pds.length_list);
1531810cf2bbSWei Yang pds.nsentcmds++;
1532810cf2bbSWei Yang pds.cur_entry = 0;
1533e0b266f0SDr. David Alan Gilbert }
1534e0b266f0SDr. David Alan Gilbert }
1535e0b266f0SDr. David Alan Gilbert
1536e0b266f0SDr. David Alan Gilbert /**
1537e0b266f0SDr. David Alan Gilbert * postcopy_discard_send_finish: Called at the end of each RAMBlock by the
1538e0b266f0SDr. David Alan Gilbert * bitmap code. Sends any outstanding discard messages, frees the PDS
1539e0b266f0SDr. David Alan Gilbert *
1540e0b266f0SDr. David Alan Gilbert * @ms: Current migration state.
1541e0b266f0SDr. David Alan Gilbert */
postcopy_discard_send_finish(MigrationState * ms)1542810cf2bbSWei Yang void postcopy_discard_send_finish(MigrationState *ms)
1543e0b266f0SDr. David Alan Gilbert {
1544e0b266f0SDr. David Alan Gilbert /* Anything unsent? */
1545810cf2bbSWei Yang if (pds.cur_entry) {
154689a02a9fSzhanghailiang qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file,
1547810cf2bbSWei Yang pds.ramblock_name,
1548810cf2bbSWei Yang pds.cur_entry,
1549810cf2bbSWei Yang pds.start_list,
1550810cf2bbSWei Yang pds.length_list);
1551810cf2bbSWei Yang pds.nsentcmds++;
1552e0b266f0SDr. David Alan Gilbert }
1553e0b266f0SDr. David Alan Gilbert
1554810cf2bbSWei Yang trace_postcopy_discard_send_finish(pds.ramblock_name, pds.nsentwords,
1555810cf2bbSWei Yang pds.nsentcmds);
1556e0b266f0SDr. David Alan Gilbert }
1557bac3b212SJuan Quintela
1558bac3b212SJuan Quintela /*
1559bac3b212SJuan Quintela * Current state of incoming postcopy; note this is not part of
1560bac3b212SJuan Quintela * MigrationIncomingState since it's state is used during cleanup
1561bac3b212SJuan Quintela * at the end as MIS is being freed.
1562bac3b212SJuan Quintela */
1563bac3b212SJuan Quintela static PostcopyState incoming_postcopy_state;
1564bac3b212SJuan Quintela
postcopy_state_get(void)1565bac3b212SJuan Quintela PostcopyState postcopy_state_get(void)
1566bac3b212SJuan Quintela {
15674592eaf3SPaolo Bonzini return qatomic_load_acquire(&incoming_postcopy_state);
1568bac3b212SJuan Quintela }
1569bac3b212SJuan Quintela
1570bac3b212SJuan Quintela /* Set the state and return the old state */
postcopy_state_set(PostcopyState new_state)1571bac3b212SJuan Quintela PostcopyState postcopy_state_set(PostcopyState new_state)
1572bac3b212SJuan Quintela {
1573d73415a3SStefan Hajnoczi return qatomic_xchg(&incoming_postcopy_state, new_state);
1574bac3b212SJuan Quintela }
157500fa4fc8SDr. David Alan Gilbert
157600fa4fc8SDr. David Alan Gilbert /* Register a handler for external shared memory postcopy
157700fa4fc8SDr. David Alan Gilbert * called on the destination.
157800fa4fc8SDr. David Alan Gilbert */
postcopy_register_shared_ufd(struct PostCopyFD * pcfd)157900fa4fc8SDr. David Alan Gilbert void postcopy_register_shared_ufd(struct PostCopyFD *pcfd)
158000fa4fc8SDr. David Alan Gilbert {
158100fa4fc8SDr. David Alan Gilbert MigrationIncomingState *mis = migration_incoming_get_current();
158200fa4fc8SDr. David Alan Gilbert
158300fa4fc8SDr. David Alan Gilbert mis->postcopy_remote_fds = g_array_append_val(mis->postcopy_remote_fds,
158400fa4fc8SDr. David Alan Gilbert *pcfd);
158500fa4fc8SDr. David Alan Gilbert }
158600fa4fc8SDr. David Alan Gilbert
158700fa4fc8SDr. David Alan Gilbert /* Unregister a handler for external shared memory postcopy
158800fa4fc8SDr. David Alan Gilbert */
postcopy_unregister_shared_ufd(struct PostCopyFD * pcfd)158900fa4fc8SDr. David Alan Gilbert void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd)
159000fa4fc8SDr. David Alan Gilbert {
159100fa4fc8SDr. David Alan Gilbert guint i;
159200fa4fc8SDr. David Alan Gilbert MigrationIncomingState *mis = migration_incoming_get_current();
159300fa4fc8SDr. David Alan Gilbert GArray *pcrfds = mis->postcopy_remote_fds;
159400fa4fc8SDr. David Alan Gilbert
159556559980SJuan Quintela if (!pcrfds) {
159656559980SJuan Quintela /* migration has already finished and freed the array */
159756559980SJuan Quintela return;
159856559980SJuan Quintela }
159900fa4fc8SDr. David Alan Gilbert for (i = 0; i < pcrfds->len; i++) {
160000fa4fc8SDr. David Alan Gilbert struct PostCopyFD *cur = &g_array_index(pcrfds, struct PostCopyFD, i);
160100fa4fc8SDr. David Alan Gilbert if (cur->fd == pcfd->fd) {
160200fa4fc8SDr. David Alan Gilbert mis->postcopy_remote_fds = g_array_remove_index(pcrfds, i);
160300fa4fc8SDr. David Alan Gilbert return;
160400fa4fc8SDr. David Alan Gilbert }
160500fa4fc8SDr. David Alan Gilbert }
160600fa4fc8SDr. David Alan Gilbert }
160736f62f11SPeter Xu
postcopy_preempt_new_channel(MigrationIncomingState * mis,QEMUFile * file)16086720c2b3Smanish.mishra void postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file)
160936f62f11SPeter Xu {
161036f62f11SPeter Xu /*
161136f62f11SPeter Xu * The new loading channel has its own threads, so it needs to be
161236f62f11SPeter Xu * blocked too. It's by default true, just be explicit.
161336f62f11SPeter Xu */
161436f62f11SPeter Xu qemu_file_set_blocking(file, true);
161536f62f11SPeter Xu mis->postcopy_qemufile_dst = file;
16165655aab0SPeter Xu qemu_sem_post(&mis->postcopy_qemufile_dst_done);
161736f62f11SPeter Xu trace_postcopy_preempt_new_channel();
161836f62f11SPeter Xu }
161936f62f11SPeter Xu
1620f0afaf6cSPeter Xu /*
1621f0afaf6cSPeter Xu * Setup the postcopy preempt channel with the IOC. If ERROR is specified,
1622f0afaf6cSPeter Xu * setup the error instead. This helper will free the ERROR if specified.
1623f0afaf6cSPeter Xu */
1624d0edb8a1SPeter Xu static void
postcopy_preempt_send_channel_done(MigrationState * s,QIOChannel * ioc,Error * local_err)1625f0afaf6cSPeter Xu postcopy_preempt_send_channel_done(MigrationState *s,
1626f0afaf6cSPeter Xu QIOChannel *ioc, Error *local_err)
1627d0edb8a1SPeter Xu {
1628f0afaf6cSPeter Xu if (local_err) {
1629d0edb8a1SPeter Xu migrate_set_error(s, local_err);
1630d0edb8a1SPeter Xu error_free(local_err);
1631d0edb8a1SPeter Xu } else {
1632d0edb8a1SPeter Xu migration_ioc_register_yank(ioc);
1633d0edb8a1SPeter Xu s->postcopy_qemufile_src = qemu_file_new_output(ioc);
1634d0edb8a1SPeter Xu trace_postcopy_preempt_new_channel();
1635d0edb8a1SPeter Xu }
1636d0edb8a1SPeter Xu
1637d0edb8a1SPeter Xu /*
1638d0edb8a1SPeter Xu * Kick the waiter in all cases. The waiter should check upon
1639d0edb8a1SPeter Xu * postcopy_qemufile_src to know whether it failed or not.
1640d0edb8a1SPeter Xu */
1641d0edb8a1SPeter Xu qemu_sem_post(&s->postcopy_qemufile_src_sem);
1642f0afaf6cSPeter Xu }
1643f0afaf6cSPeter Xu
1644f0afaf6cSPeter Xu static void
postcopy_preempt_tls_handshake(QIOTask * task,gpointer opaque)1645f0afaf6cSPeter Xu postcopy_preempt_tls_handshake(QIOTask *task, gpointer opaque)
1646f0afaf6cSPeter Xu {
1647f0afaf6cSPeter Xu g_autoptr(QIOChannel) ioc = QIO_CHANNEL(qio_task_get_source(task));
1648f0afaf6cSPeter Xu MigrationState *s = opaque;
1649f0afaf6cSPeter Xu Error *local_err = NULL;
1650f0afaf6cSPeter Xu
1651f0afaf6cSPeter Xu qio_task_propagate_error(task, &local_err);
1652f0afaf6cSPeter Xu postcopy_preempt_send_channel_done(s, ioc, local_err);
1653f0afaf6cSPeter Xu }
1654f0afaf6cSPeter Xu
1655f0afaf6cSPeter Xu static void
postcopy_preempt_send_channel_new(QIOTask * task,gpointer opaque)1656f0afaf6cSPeter Xu postcopy_preempt_send_channel_new(QIOTask *task, gpointer opaque)
1657f0afaf6cSPeter Xu {
1658f0afaf6cSPeter Xu g_autoptr(QIOChannel) ioc = QIO_CHANNEL(qio_task_get_source(task));
1659f0afaf6cSPeter Xu MigrationState *s = opaque;
1660f0afaf6cSPeter Xu QIOChannelTLS *tioc;
1661f0afaf6cSPeter Xu Error *local_err = NULL;
1662f0afaf6cSPeter Xu
1663f0afaf6cSPeter Xu if (qio_task_propagate_error(task, &local_err)) {
1664f0afaf6cSPeter Xu goto out;
1665f0afaf6cSPeter Xu }
1666f0afaf6cSPeter Xu
1667f0afaf6cSPeter Xu if (migrate_channel_requires_tls_upgrade(ioc)) {
16680deb7e9bSJuan Quintela tioc = migration_tls_client_create(ioc, s->hostname, &local_err);
1669f0afaf6cSPeter Xu if (!tioc) {
1670f0afaf6cSPeter Xu goto out;
1671f0afaf6cSPeter Xu }
1672f0afaf6cSPeter Xu trace_postcopy_preempt_tls_handshake();
1673f0afaf6cSPeter Xu qio_channel_set_name(QIO_CHANNEL(tioc), "migration-tls-preempt");
1674f0afaf6cSPeter Xu qio_channel_tls_handshake(tioc, postcopy_preempt_tls_handshake,
1675f0afaf6cSPeter Xu s, NULL, NULL);
1676f0afaf6cSPeter Xu /* Setup the channel until TLS handshake finished */
1677f0afaf6cSPeter Xu return;
1678f0afaf6cSPeter Xu }
1679f0afaf6cSPeter Xu
1680f0afaf6cSPeter Xu out:
1681f0afaf6cSPeter Xu /* This handles both good and error cases */
1682f0afaf6cSPeter Xu postcopy_preempt_send_channel_done(s, ioc, local_err);
1683d0edb8a1SPeter Xu }
1684d0edb8a1SPeter Xu
16855655aab0SPeter Xu /*
16865655aab0SPeter Xu * This function will kick off an async task to establish the preempt
16875655aab0SPeter Xu * channel, and wait until the connection setup completed. Returns 0 if
16885655aab0SPeter Xu * channel established, -1 for error.
16895655aab0SPeter Xu */
postcopy_preempt_establish_channel(MigrationState * s)16905655aab0SPeter Xu int postcopy_preempt_establish_channel(MigrationState *s)
1691d0edb8a1SPeter Xu {
1692d0edb8a1SPeter Xu /* If preempt not enabled, no need to wait */
1693d0edb8a1SPeter Xu if (!migrate_postcopy_preempt()) {
1694d0edb8a1SPeter Xu return 0;
1695d0edb8a1SPeter Xu }
1696d0edb8a1SPeter Xu
169706064a67SPeter Xu /*
169806064a67SPeter Xu * Kick off async task to establish preempt channel. Only do so with
169906064a67SPeter Xu * 8.0+ machines, because 7.1/7.2 require the channel to be created in
170006064a67SPeter Xu * setup phase of migration (even if racy in an unreliable network).
170106064a67SPeter Xu */
170206064a67SPeter Xu if (!s->preempt_pre_7_2) {
17035655aab0SPeter Xu postcopy_preempt_setup(s);
170406064a67SPeter Xu }
17055655aab0SPeter Xu
1706d0edb8a1SPeter Xu /*
1707d0edb8a1SPeter Xu * We need the postcopy preempt channel to be established before
1708d0edb8a1SPeter Xu * starting doing anything.
1709d0edb8a1SPeter Xu */
1710d0edb8a1SPeter Xu qemu_sem_wait(&s->postcopy_qemufile_src_sem);
1711d0edb8a1SPeter Xu
1712d0edb8a1SPeter Xu return s->postcopy_qemufile_src ? 0 : -1;
1713d0edb8a1SPeter Xu }
1714d0edb8a1SPeter Xu
postcopy_preempt_setup(MigrationState * s)1715fc063a7bSPeter Xu void postcopy_preempt_setup(MigrationState *s)
171636f62f11SPeter Xu {
1717d0edb8a1SPeter Xu /* Kick an async task to connect */
1718d0edb8a1SPeter Xu socket_send_channel_create(postcopy_preempt_send_channel_new, s);
171936f62f11SPeter Xu }
172036f62f11SPeter Xu
postcopy_pause_ram_fast_load(MigrationIncomingState * mis)172160bb3c58SPeter Xu static void postcopy_pause_ram_fast_load(MigrationIncomingState *mis)
172260bb3c58SPeter Xu {
172360bb3c58SPeter Xu trace_postcopy_pause_fast_load();
172460bb3c58SPeter Xu qemu_mutex_unlock(&mis->postcopy_prio_thread_mutex);
172560bb3c58SPeter Xu qemu_sem_wait(&mis->postcopy_pause_sem_fast_load);
172660bb3c58SPeter Xu qemu_mutex_lock(&mis->postcopy_prio_thread_mutex);
172760bb3c58SPeter Xu trace_postcopy_pause_fast_load_continued();
172860bb3c58SPeter Xu }
172960bb3c58SPeter Xu
preempt_thread_should_run(MigrationIncomingState * mis)17306621883fSPeter Xu static bool preempt_thread_should_run(MigrationIncomingState *mis)
17316621883fSPeter Xu {
17326621883fSPeter Xu return mis->preempt_thread_status != PREEMPT_THREAD_QUIT;
17336621883fSPeter Xu }
17346621883fSPeter Xu
postcopy_preempt_thread(void * opaque)173536f62f11SPeter Xu void *postcopy_preempt_thread(void *opaque)
173636f62f11SPeter Xu {
173736f62f11SPeter Xu MigrationIncomingState *mis = opaque;
173836f62f11SPeter Xu int ret;
173936f62f11SPeter Xu
174036f62f11SPeter Xu trace_postcopy_preempt_thread_entry();
174136f62f11SPeter Xu
174236f62f11SPeter Xu rcu_register_thread();
174336f62f11SPeter Xu
174436f62f11SPeter Xu qemu_sem_post(&mis->thread_sync_sem);
174536f62f11SPeter Xu
1746a5d35dc7SPeter Xu /*
1747a5d35dc7SPeter Xu * The preempt channel is established in asynchronous way. Wait
1748a5d35dc7SPeter Xu * for its completion.
1749a5d35dc7SPeter Xu */
1750a5d35dc7SPeter Xu qemu_sem_wait(&mis->postcopy_qemufile_dst_done);
1751a5d35dc7SPeter Xu
175236f62f11SPeter Xu /* Sending RAM_SAVE_FLAG_EOS to terminate this thread */
175360bb3c58SPeter Xu qemu_mutex_lock(&mis->postcopy_prio_thread_mutex);
17546621883fSPeter Xu while (preempt_thread_should_run(mis)) {
175560bb3c58SPeter Xu ret = ram_load_postcopy(mis->postcopy_qemufile_dst,
175660bb3c58SPeter Xu RAM_CHANNEL_POSTCOPY);
175760bb3c58SPeter Xu /* If error happened, go into recovery routine */
17586621883fSPeter Xu if (ret && preempt_thread_should_run(mis)) {
175960bb3c58SPeter Xu postcopy_pause_ram_fast_load(mis);
176060bb3c58SPeter Xu } else {
176160bb3c58SPeter Xu /* We're done */
176260bb3c58SPeter Xu break;
176360bb3c58SPeter Xu }
176460bb3c58SPeter Xu }
176560bb3c58SPeter Xu qemu_mutex_unlock(&mis->postcopy_prio_thread_mutex);
176636f62f11SPeter Xu
176736f62f11SPeter Xu rcu_unregister_thread();
176836f62f11SPeter Xu
176936f62f11SPeter Xu trace_postcopy_preempt_thread_exit();
177036f62f11SPeter Xu
177160bb3c58SPeter Xu return NULL;
177236f62f11SPeter Xu }
1773