From 6dd4f44c4f6b1046e5ceb593b9ab4f8fbb92f028 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 19 Sep 2024 12:30:42 -0400 Subject: [PATCH 01/18] migration: Cleanup migrate_fd_cleanup() on accessing to_dst_file The cleanup function can in many cases needs cleanup on its own. The major thing we want to do here is not referencing to_dst_file when without the file mutex. When at it, touch things elsewhere too to make it look slightly better in general. One thing to mention is, migration_thread has its own "running" boolean, so it doesn't need to rely on to_dst_file being non-NULL. Multifd has a dependency so it needs to be skipped if to_dst_file is not yet set; add a richer comment for such reason. Resolves: Coverity CID 1527402 Reported-by: Peter Maydell Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240919163042.116767-1-peterx@redhat.com Signed-off-by: Peter Xu --- migration/migration.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 021faee2f3..f5f428e764 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1405,6 +1405,9 @@ void migrate_set_state(MigrationStatus *state, MigrationStatus old_state, static void migrate_fd_cleanup(MigrationState *s) { MigrationEventType type; + QEMUFile *tmp = NULL; + + trace_migrate_fd_cleanup(); g_free(s->hostname); s->hostname = NULL; @@ -1415,26 +1418,29 @@ static void migrate_fd_cleanup(MigrationState *s) close_return_path_on_source(s); - if (s->to_dst_file) { - QEMUFile *tmp; - - trace_migrate_fd_cleanup(); + if (s->migration_thread_running) { bql_unlock(); - if (s->migration_thread_running) { - qemu_thread_join(&s->thread); - s->migration_thread_running = false; - } + qemu_thread_join(&s->thread); + s->migration_thread_running = false; bql_lock(); + } - multifd_send_shutdown(); - qemu_mutex_lock(&s->qemu_file_lock); + WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) { + /* + * Close the file handle without the lock to make sure the critical + * section won't block for long. + */ tmp = s->to_dst_file; s->to_dst_file = NULL; - qemu_mutex_unlock(&s->qemu_file_lock); + } + + if (tmp) { /* - * Close the file handle without the lock to make sure the - * critical section won't block for long. + * We only need to shutdown multifd if tmp!=NULL, because if + * tmp==NULL, it means the main channel isn't established, while + * multifd is only setup after that (in migration_thread()). */ + multifd_send_shutdown(); migration_ioc_unregister_yank_from_file(tmp); qemu_fclose(tmp); } From e620b1e4770bc779a6a9467ff753e0acdd4c57f5 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Fri, 11 Oct 2024 11:36:52 -0400 Subject: [PATCH 02/18] migration: Put thread names together with macros Keep migration thread names together, so it's easier to see a list of all possible migration threads. Still two functional changes below besides the macro defintions: - There's one dirty rate thread that we overlooked before, now we add that too and name it as "mig/dirtyrate" following the old rules. - The old name "mig/src/rp-thr" has "-thr" but it may not be useful if it's a thread name anyway, while "rp" can be slightly hard to read. Taking this chance to rename it to "mig/src/return", hopefully a better name. Reviewed-by: Fabiano Rosas Acked-by: Hyman Huang Reviewed-by: Zhang Chen Link: https://lore.kernel.org/r/20241011153652.517440-1-peterx@redhat.com Signed-off-by: Peter Xu --- migration/colo.c | 3 ++- migration/dirtyrate.c | 6 ++++-- migration/migration.c | 9 +++++---- migration/migration.h | 14 ++++++++++++++ migration/multifd.c | 6 +++--- migration/postcopy-ram.c | 6 ++++-- migration/savevm.c | 3 ++- 7 files changed, 34 insertions(+), 13 deletions(-) diff --git a/migration/colo.c b/migration/colo.c index 6449490221..9590f281d0 100644 --- a/migration/colo.c +++ b/migration/colo.c @@ -935,7 +935,8 @@ void coroutine_fn colo_incoming_co(void) assert(bql_locked()); assert(migration_incoming_colo_enabled()); - qemu_thread_create(&th, "mig/dst/colo", colo_process_incoming_thread, + qemu_thread_create(&th, MIGRATION_THREAD_DST_COLO, + colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE); mis->colo_incoming_co = qemu_coroutine_self(); diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c index 233acb0855..a74a6aeb56 100644 --- a/migration/dirtyrate.c +++ b/migration/dirtyrate.c @@ -29,6 +29,7 @@ #include "sysemu/runstate.h" #include "exec/memory.h" #include "qemu/xxhash.h" +#include "migration.h" /* * total_dirty_pages is procted by BQL and is used @@ -839,8 +840,9 @@ void qmp_calc_dirty_rate(int64_t calc_time, init_dirtyrate_stat(config); - qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread, - (void *)&config, QEMU_THREAD_DETACHED); + qemu_thread_create(&thread, MIGRATION_THREAD_DIRTY_RATE, + get_dirtyrate_thread, (void *)&config, + QEMU_THREAD_DETACHED); } diff --git a/migration/migration.c b/migration/migration.c index f5f428e764..7609e0feed 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2484,7 +2484,7 @@ static int open_return_path_on_source(MigrationState *ms) trace_open_return_path_on_source(); - qemu_thread_create(&ms->rp_state.rp_thread, "mig/src/rp-thr", + qemu_thread_create(&ms->rp_state.rp_thread, MIGRATION_THREAD_SRC_RETURN, source_return_path_thread, ms, QEMU_THREAD_JOINABLE); ms->rp_state.rp_thread_created = true; @@ -3473,7 +3473,8 @@ static void *migration_thread(void *opaque) Error *local_err = NULL; int ret; - thread = migration_threads_add("live_migration", qemu_get_thread_id()); + thread = migration_threads_add(MIGRATION_THREAD_SRC_MAIN, + qemu_get_thread_id()); rcu_register_thread(); @@ -3823,10 +3824,10 @@ void migrate_fd_connect(MigrationState *s, Error *error_in) } if (migrate_background_snapshot()) { - qemu_thread_create(&s->thread, "mig/snapshot", + qemu_thread_create(&s->thread, MIGRATION_THREAD_SNAPSHOT, bg_migration_thread, s, QEMU_THREAD_JOINABLE); } else { - qemu_thread_create(&s->thread, "mig/src/main", + qemu_thread_create(&s->thread, MIGRATION_THREAD_SRC_MAIN, migration_thread, s, QEMU_THREAD_JOINABLE); } s->migration_thread_running = true; diff --git a/migration/migration.h b/migration/migration.h index 38aa1402d5..b9ce5aa4ff 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -28,6 +28,20 @@ #include "sysemu/runstate.h" #include "migration/misc.h" +#define MIGRATION_THREAD_SNAPSHOT "mig/snapshot" +#define MIGRATION_THREAD_DIRTY_RATE "mig/dirtyrate" + +#define MIGRATION_THREAD_SRC_MAIN "mig/src/main" +#define MIGRATION_THREAD_SRC_MULTIFD "mig/src/send_%d" +#define MIGRATION_THREAD_SRC_RETURN "mig/src/return" +#define MIGRATION_THREAD_SRC_TLS "mig/src/tls" + +#define MIGRATION_THREAD_DST_COLO "mig/dst/colo" +#define MIGRATION_THREAD_DST_MULTIFD "mig/src/recv_%d" +#define MIGRATION_THREAD_DST_FAULT "mig/dst/fault" +#define MIGRATION_THREAD_DST_LISTEN "mig/dst/listen" +#define MIGRATION_THREAD_DST_PREEMPT "mig/dst/preempt" + struct PostcopyBlocktimeContext; #define MIGRATION_RESUME_ACK_VALUE (1) diff --git a/migration/multifd.c b/migration/multifd.c index 9b200f4ad9..697fe86fdf 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -723,7 +723,7 @@ static bool multifd_tls_channel_connect(MultiFDSendParams *p, args->p = p; p->tls_thread_created = true; - qemu_thread_create(&p->tls_thread, "mig/src/tls", + qemu_thread_create(&p->tls_thread, MIGRATION_THREAD_SRC_TLS, multifd_tls_handshake_thread, args, QEMU_THREAD_JOINABLE); return true; @@ -841,7 +841,7 @@ bool multifd_send_setup(void) + sizeof(uint64_t) * page_count; p->packet = g_malloc0(p->packet_len); } - p->name = g_strdup_printf("mig/src/send_%d", i); + p->name = g_strdup_printf(MIGRATION_THREAD_SRC_MULTIFD, i); p->write_flags = 0; if (!multifd_new_send_channel_create(p, &local_err)) { @@ -1259,7 +1259,7 @@ int multifd_recv_setup(Error **errp) + sizeof(uint64_t) * page_count; p->packet = g_malloc0(p->packet_len); } - p->name = g_strdup_printf("mig/dst/recv_%d", i); + p->name = g_strdup_printf(MIGRATION_THREAD_DST_MULTIFD, i); p->normal = g_new0(ram_addr_t, page_count); p->zero = g_new0(ram_addr_t, page_count); } diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 83f6160a36..a535fd2e30 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -1230,7 +1230,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) return -1; } - postcopy_thread_create(mis, &mis->fault_thread, "mig/dst/fault", + postcopy_thread_create(mis, &mis->fault_thread, + MIGRATION_THREAD_DST_FAULT, postcopy_ram_fault_thread, QEMU_THREAD_JOINABLE); mis->have_fault_thread = true; @@ -1250,7 +1251,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) * This thread needs to be created after the temp pages because * it'll fetch RAM_CHANNEL_POSTCOPY PostcopyTmpPage immediately. */ - postcopy_thread_create(mis, &mis->postcopy_prio_thread, "mig/dst/preempt", + postcopy_thread_create(mis, &mis->postcopy_prio_thread, + MIGRATION_THREAD_DST_PREEMPT, postcopy_preempt_thread, QEMU_THREAD_JOINABLE); mis->preempt_thread_status = PREEMPT_THREAD_CREATED; } diff --git a/migration/savevm.c b/migration/savevm.c index 7e1e27182a..e796436979 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2131,7 +2131,8 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) } mis->have_listen_thread = true; - postcopy_thread_create(mis, &mis->listen_thread, "mig/dst/listen", + postcopy_thread_create(mis, &mis->listen_thread, + MIGRATION_THREAD_DST_LISTEN, postcopy_ram_listen_thread, QEMU_THREAD_DETACHED); trace_loadvm_postcopy_handle_listen("return"); From 37dfcba1a04989830c706f9cbc00450e5d3a7447 Mon Sep 17 00:00:00 2001 From: Hanna Czenczek Date: Tue, 15 Oct 2024 19:04:37 +0200 Subject: [PATCH 03/18] migration: Ensure vmstate_save() sets errp migration/savevm.c contains some calls to vmstate_save() that are followed by migrate_set_error() if the integer return value indicates an error. migrate_set_error() requires that the `Error *` object passed to it is set. Therefore, vmstate_save() is assumed to always set *errp on error. Right now, that assumption is not met: vmstate_save_state_v() (called internally by vmstate_save()) will not set *errp if vmstate_subsection_save() or vmsd->post_save() fail. Fix that by adding an *errp parameter to vmstate_subsection_save(), and by generating a generic error in case post_save() fails (as is already done for pre_save()). Without this patch, qemu will crash after vmstate_subsection_save() or post_save() have failed inside of a vmstate_save() call (unless migrate_set_error() then happen to discard the new error because s->error is already set). This happens e.g. when receiving the state from a virtio-fs back-end (virtiofsd) fails. Signed-off-by: Hanna Czenczek Link: https://lore.kernel.org/r/20241015170437.310358-1-hreitz@redhat.com Signed-off-by: Peter Xu --- migration/vmstate.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/migration/vmstate.c b/migration/vmstate.c index ff5d589a6d..fa002b24e8 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -22,7 +22,8 @@ #include "trace.h" static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, - void *opaque, JSONWriter *vmdesc); + void *opaque, JSONWriter *vmdesc, + Error **errp); static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, void *opaque); @@ -441,12 +442,13 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, json_writer_end_array(vmdesc); } - ret = vmstate_subsection_save(f, vmsd, opaque, vmdesc); + ret = vmstate_subsection_save(f, vmsd, opaque, vmdesc, errp); if (vmsd->post_save) { int ps_ret = vmsd->post_save(opaque); - if (!ret) { + if (!ret && ps_ret) { ret = ps_ret; + error_setg(errp, "post-save failed: %s", vmsd->name); } } return ret; @@ -518,7 +520,8 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, } static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, - void *opaque, JSONWriter *vmdesc) + void *opaque, JSONWriter *vmdesc, + Error **errp) { const VMStateDescription * const *sub = vmsd->subsections; bool vmdesc_has_subsections = false; @@ -546,7 +549,7 @@ static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, qemu_put_byte(f, len); qemu_put_buffer(f, (uint8_t *)vmsdsub->name, len); qemu_put_be32(f, vmsdsub->version_id); - ret = vmstate_save_state(f, vmsdsub, opaque, vmdesc); + ret = vmstate_save_state_with_err(f, vmsdsub, opaque, vmdesc, errp); if (ret) { return ret; } From 8c58e2d5ba405dc23865d989647a2fe10eec4402 Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:50 +0800 Subject: [PATCH 04/18] accel/tcg/icount-common: Remove the reference to the unused header file Signed-off-by: Hyman Huang Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/5e33b423d0b8506e5cb33fff42b50aa301b7731b.1729146786.git.yong.huang@smartx.com Signed-off-by: Peter Xu --- accel/tcg/icount-common.c | 1 - 1 file changed, 1 deletion(-) diff --git a/accel/tcg/icount-common.c b/accel/tcg/icount-common.c index 8d3d3a7e9d..30bf8500dc 100644 --- a/accel/tcg/icount-common.c +++ b/accel/tcg/icount-common.c @@ -36,7 +36,6 @@ #include "sysemu/runstate.h" #include "hw/core/cpu.h" #include "sysemu/cpu-timers.h" -#include "sysemu/cpu-throttle.h" #include "sysemu/cpu-timers-internal.h" /* From 054e5d66e53e48f842c1cce61dc1b714fe9bf0ee Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:51 +0800 Subject: [PATCH 05/18] migration: Stop CPU throttling conditionally Since CPU throttling only occurs when auto-converge is on, stop it conditionally. Signed-off-by: Hyman Huang Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/f0c787080bb9ab0c37952f0ca5bfaa525d5ddd14.1729146786.git.yong.huang@smartx.com Signed-off-by: Peter Xu --- migration/migration.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/migration/migration.c b/migration/migration.c index 7609e0feed..e81c70b9d2 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3295,7 +3295,9 @@ static MigIterateState migration_iteration_run(MigrationState *s) static void migration_iteration_finish(MigrationState *s) { /* If we enabled cpu throttling for auto-converge, turn it off. */ - cpu_throttle_stop(); + if (migrate_auto_converge()) { + cpu_throttle_stop(); + } bql_lock(); switch (s->state) { From d481cec75658b313be3ae8fea3f800780e5c937b Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:52 +0800 Subject: [PATCH 06/18] migration: Move cpu-throttle.c from system to migration Move cpu-throttle.c from system to migration since it's only used for migration; this makes us avoid exporting the util functions and variables in misc.h but export them in migration.h when implementing the periodic ramblock dirty sync feature in the upcoming commits. Since CPU throttle timers are only used in migration, move their registry to migration_object_init. Signed-off-by: Hyman Huang Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/c1b3efaa0cb49e03d422e9da97bdb65cc3d234d1.1729146786.git.yong.huang@smartx.com [peterx: Fix build on MacOS on cocoa.m, not move cpu-throttle.h yet] [peterx: Fix subject spelling, per pm215] Signed-off-by: Peter Xu --- {system => migration}/cpu-throttle.c | 0 migration/meson.build | 1 + migration/migration.c | 3 +++ migration/trace-events | 3 +++ system/cpu-timers.c | 3 --- system/meson.build | 1 - system/trace-events | 3 --- 7 files changed, 7 insertions(+), 7 deletions(-) rename {system => migration}/cpu-throttle.c (100%) diff --git a/system/cpu-throttle.c b/migration/cpu-throttle.c similarity index 100% rename from system/cpu-throttle.c rename to migration/cpu-throttle.c diff --git a/migration/meson.build b/migration/meson.build index 66d3de86f0..d53cf3417a 100644 --- a/migration/meson.build +++ b/migration/meson.build @@ -13,6 +13,7 @@ system_ss.add(files( 'block-dirty-bitmap.c', 'channel.c', 'channel-block.c', + 'cpu-throttle.c', 'dirtyrate.c', 'exec.c', 'fd.c', diff --git a/migration/migration.c b/migration/migration.c index e81c70b9d2..64c1d0c1db 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -263,6 +263,9 @@ void migration_object_init(void) ram_mig_init(); dirty_bitmap_mig_init(); + + /* Initialize cpu throttle timers */ + cpu_throttle_init(); } typedef struct { diff --git a/migration/trace-events b/migration/trace-events index c65902f042..9a19599804 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -378,3 +378,6 @@ migration_block_progression(unsigned percent) "Completed %u%%" # page_cache.c migration_pagecache_init(int64_t max_num_items) "Setting cache buckets to %" PRId64 migration_pagecache_insert(void) "Error allocating page" + +# cpu-throttle.c +cpu_throttle_set(int new_throttle_pct) "set guest CPU throttled by %d%%" diff --git a/system/cpu-timers.c b/system/cpu-timers.c index 0b31c9a1b6..856e502e34 100644 --- a/system/cpu-timers.c +++ b/system/cpu-timers.c @@ -35,7 +35,6 @@ #include "sysemu/runstate.h" #include "hw/core/cpu.h" #include "sysemu/cpu-timers.h" -#include "sysemu/cpu-throttle.h" #include "sysemu/cpu-timers-internal.h" /* clock and ticks */ @@ -272,6 +271,4 @@ void cpu_timers_init(void) seqlock_init(&timers_state.vm_clock_seqlock); qemu_spin_init(&timers_state.vm_clock_lock); vmstate_register(NULL, 0, &vmstate_timers, &timers_state); - - cpu_throttle_init(); } diff --git a/system/meson.build b/system/meson.build index a296270cb0..4952f4b2c7 100644 --- a/system/meson.build +++ b/system/meson.build @@ -10,7 +10,6 @@ system_ss.add(files( 'balloon.c', 'bootdevice.c', 'cpus.c', - 'cpu-throttle.c', 'cpu-timers.c', 'datadir.c', 'dirtylimit.c', diff --git a/system/trace-events b/system/trace-events index 074d001e90..2ed1d59b1f 100644 --- a/system/trace-events +++ b/system/trace-events @@ -44,6 +44,3 @@ dirtylimit_state_finalize(void) dirtylimit_throttle_pct(int cpu_index, uint64_t pct, int64_t time_us) "CPU[%d] throttle percent: %" PRIu64 ", throttle adjust time %"PRIi64 " us" dirtylimit_set_vcpu(int cpu_index, uint64_t quota) "CPU[%d] set dirty page rate limit %"PRIu64 dirtylimit_vcpu_execute(int cpu_index, int64_t sleep_time_us) "CPU[%d] sleep %"PRIi64 " us" - -# cpu-throttle.c -cpu_throttle_set(int new_throttle_pct) "set guest CPU throttled by %d%%" From 6a39ba7cab67da05b91e215142ce5781e77e5d9f Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:53 +0800 Subject: [PATCH 07/18] migration: Remove "rs" parameter in migration_bitmap_sync_precopy The global static variable ram_state in fact is referred to by the "rs" parameter in migration_bitmap_sync_precopy. For ease of calling by the callees, use the global variable directly in migration_bitmap_sync_precopy and remove "rs" parameter. The migration_bitmap_sync_precopy will be exported in the next commit. Signed-off-by: Hyman Huang Reviewed-by: Peter Xu Link: https://lore.kernel.org/r/283c335d61463bf477160da91b24da45cdaf3e43.1729146786.git.yong.huang@smartx.com Signed-off-by: Peter Xu --- migration/ram.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 326ce7eb79..04fd805901 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1088,9 +1088,10 @@ static void migration_bitmap_sync(RAMState *rs, bool last_stage) } } -static void migration_bitmap_sync_precopy(RAMState *rs, bool last_stage) +static void migration_bitmap_sync_precopy(bool last_stage) { Error *local_err = NULL; + assert(ram_state); /* * The current notifier usage is just an optimization to migration, so we @@ -1101,7 +1102,7 @@ static void migration_bitmap_sync_precopy(RAMState *rs, bool last_stage) local_err = NULL; } - migration_bitmap_sync(rs, last_stage); + migration_bitmap_sync(ram_state, last_stage); if (precopy_notify(PRECOPY_NOTIFY_AFTER_BITMAP_SYNC, &local_err)) { error_report_err(local_err); @@ -2782,7 +2783,7 @@ static bool ram_init_bitmaps(RAMState *rs, Error **errp) if (!ret) { goto out_unlock; } - migration_bitmap_sync_precopy(rs, false); + migration_bitmap_sync_precopy(false); } } out_unlock: @@ -3248,7 +3249,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque) WITH_RCU_READ_LOCK_GUARD() { if (!migration_in_postcopy()) { - migration_bitmap_sync_precopy(rs, true); + migration_bitmap_sync_precopy(true); } ret = rdma_registration_start(f, RAM_CONTROL_FINISH); @@ -3330,7 +3331,7 @@ static void ram_state_pending_exact(void *opaque, uint64_t *must_precopy, if (!migration_in_postcopy()) { bql_lock(); WITH_RCU_READ_LOCK_GUARD() { - migration_bitmap_sync_precopy(rs, false); + migration_bitmap_sync_precopy(false); } bql_unlock(); } From 52ac968ab28b2e1eee2e083f19f2a70fdece5a2e Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:54 +0800 Subject: [PATCH 08/18] migration: Support periodic RAMBlock dirty bitmap sync When VM is configured with huge memory, the current throttle logic doesn't look like to scale, because migration_trigger_throttle() is only called for each iteration, so it won't be invoked for a long time if one iteration can take a long time. The periodic dirty sync aims to fix the above issue by synchronizing the ramblock from remote dirty bitmap and, when necessary, triggering the CPU throttle multiple times during a long iteration. This is a trade-off between synchronization overhead and CPU throttle impact. Signed-off-by: Hyman Huang Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/f61f1b3653f2acf026901103e1c73d157d38b08f.1729146786.git.yong.huang@smartx.com [peterx: make prev_cnt global, and reset for each migration] Signed-off-by: Peter Xu --- include/sysemu/cpu-throttle.h | 14 +++++++ migration/cpu-throttle.c | 70 ++++++++++++++++++++++++++++++++++- migration/migration.c | 14 ++++++- migration/migration.h | 1 + migration/ram.c | 2 +- migration/trace-events | 1 + 6 files changed, 98 insertions(+), 4 deletions(-) diff --git a/include/sysemu/cpu-throttle.h b/include/sysemu/cpu-throttle.h index d65bdef6d0..420702b8d3 100644 --- a/include/sysemu/cpu-throttle.h +++ b/include/sysemu/cpu-throttle.h @@ -65,4 +65,18 @@ bool cpu_throttle_active(void); */ int cpu_throttle_get_percentage(void); +/** + * cpu_throttle_dirty_sync_timer_tick: + * + * Dirty sync timer hook. + */ +void cpu_throttle_dirty_sync_timer_tick(void *opaque); + +/** + * cpu_throttle_dirty_sync_timer: + * + * Start or stop the dirty sync timer. + */ +void cpu_throttle_dirty_sync_timer(bool enable); + #endif /* SYSEMU_CPU_THROTTLE_H */ diff --git a/migration/cpu-throttle.c b/migration/cpu-throttle.c index 7632dc6143..5179019e33 100644 --- a/migration/cpu-throttle.c +++ b/migration/cpu-throttle.c @@ -28,16 +28,23 @@ #include "qemu/main-loop.h" #include "sysemu/cpus.h" #include "sysemu/cpu-throttle.h" +#include "migration.h" +#include "migration-stats.h" #include "trace.h" /* vcpu throttling controls */ -static QEMUTimer *throttle_timer; +static QEMUTimer *throttle_timer, *throttle_dirty_sync_timer; static unsigned int throttle_percentage; +static bool throttle_dirty_sync_timer_active; +static uint64_t throttle_dirty_sync_count_prev; #define CPU_THROTTLE_PCT_MIN 1 #define CPU_THROTTLE_PCT_MAX 99 #define CPU_THROTTLE_TIMESLICE_NS 10000000 +/* Making sure RAMBlock dirty bitmap is synchronized every five seconds */ +#define CPU_THROTTLE_DIRTY_SYNC_TIMESLICE_MS 5000 + static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque) { double pct; @@ -112,6 +119,7 @@ void cpu_throttle_set(int new_throttle_pct) void cpu_throttle_stop(void) { qatomic_set(&throttle_percentage, 0); + cpu_throttle_dirty_sync_timer(false); } bool cpu_throttle_active(void) @@ -124,8 +132,68 @@ int cpu_throttle_get_percentage(void) return qatomic_read(&throttle_percentage); } +void cpu_throttle_dirty_sync_timer_tick(void *opaque) +{ + uint64_t sync_cnt = stat64_get(&mig_stats.dirty_sync_count); + + /* + * The first iteration copies all memory anyhow and has no + * effect on guest performance, therefore omit it to avoid + * paying extra for the sync penalty. + */ + if (sync_cnt <= 1) { + goto end; + } + + if (sync_cnt == throttle_dirty_sync_count_prev) { + trace_cpu_throttle_dirty_sync(); + WITH_RCU_READ_LOCK_GUARD() { + migration_bitmap_sync_precopy(false); + } + } + +end: + throttle_dirty_sync_count_prev = stat64_get(&mig_stats.dirty_sync_count); + + timer_mod(throttle_dirty_sync_timer, + qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + + CPU_THROTTLE_DIRTY_SYNC_TIMESLICE_MS); +} + +static bool cpu_throttle_dirty_sync_active(void) +{ + return qatomic_read(&throttle_dirty_sync_timer_active); +} + +void cpu_throttle_dirty_sync_timer(bool enable) +{ + assert(throttle_dirty_sync_timer); + + if (enable) { + if (!cpu_throttle_dirty_sync_active()) { + /* + * Always reset the dirty sync count cache, in case migration + * was cancelled once. + */ + throttle_dirty_sync_count_prev = 0; + timer_mod(throttle_dirty_sync_timer, + qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + + CPU_THROTTLE_DIRTY_SYNC_TIMESLICE_MS); + qatomic_set(&throttle_dirty_sync_timer_active, 1); + } + } else { + if (cpu_throttle_dirty_sync_active()) { + timer_del(throttle_dirty_sync_timer); + qatomic_set(&throttle_dirty_sync_timer_active, 0); + } + } +} + void cpu_throttle_init(void) { throttle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT, cpu_throttle_timer_tick, NULL); + throttle_dirty_sync_timer = + timer_new_ms(QEMU_CLOCK_VIRTUAL_RT, + cpu_throttle_dirty_sync_timer_tick, NULL); } diff --git a/migration/migration.c b/migration/migration.c index 64c1d0c1db..9bcc9db4fb 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3297,12 +3297,17 @@ static MigIterateState migration_iteration_run(MigrationState *s) static void migration_iteration_finish(MigrationState *s) { - /* If we enabled cpu throttling for auto-converge, turn it off. */ + bql_lock(); + + /* + * If we enabled cpu throttling for auto-converge, turn it off. + * Stopping CPU throttle should be serialized by BQL to avoid + * racing for the throttle_dirty_sync_timer. + */ if (migrate_auto_converge()) { cpu_throttle_stop(); } - bql_lock(); switch (s->state) { case MIGRATION_STATUS_COMPLETED: runstate_set(RUN_STATE_POSTMIGRATE); @@ -3520,6 +3525,11 @@ static void *migration_thread(void *opaque) qemu_savevm_send_colo_enable(s->to_dst_file); } + if (migrate_auto_converge()) { + /* Start RAMBlock dirty bitmap sync timer */ + cpu_throttle_dirty_sync_timer(true); + } + bql_lock(); ret = qemu_savevm_state_setup(s->to_dst_file, &local_err); bql_unlock(); diff --git a/migration/migration.h b/migration/migration.h index b9ce5aa4ff..7dc59c5e8d 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -551,4 +551,5 @@ int migration_rp_wait(MigrationState *s); */ void migration_rp_kick(MigrationState *s); +void migration_bitmap_sync_precopy(bool last_stage); #endif diff --git a/migration/ram.c b/migration/ram.c index 04fd805901..b24e45442c 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1088,7 +1088,7 @@ static void migration_bitmap_sync(RAMState *rs, bool last_stage) } } -static void migration_bitmap_sync_precopy(bool last_stage) +void migration_bitmap_sync_precopy(bool last_stage) { Error *local_err = NULL; assert(ram_state); diff --git a/migration/trace-events b/migration/trace-events index 9a19599804..0638183056 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -381,3 +381,4 @@ migration_pagecache_insert(void) "Error allocating page" # cpu-throttle.c cpu_throttle_set(int new_throttle_pct) "set guest CPU throttled by %d%%" +cpu_throttle_dirty_sync(void) "" From bfd66ccb8d5e34023ba841f6c751d06f482d91ae Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Thu, 17 Oct 2024 14:42:55 +0800 Subject: [PATCH 09/18] tests/migration: Add case for periodic ramblock dirty sync Signed-off-by: Hyman Huang Reviewed-by: Peter Xu Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/cb61504f1a1e9d5f2ca4dac12e518deb076ce9f3.1729146786.git.yong.huang@smartx.com Signed-off-by: Peter Xu --- tests/qtest/migration-test.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c index 95e45b5029..e6a2803e71 100644 --- a/tests/qtest/migration-test.c +++ b/tests/qtest/migration-test.c @@ -2791,6 +2791,8 @@ static void test_migrate_auto_converge(void) * so we need to decrease a bandwidth. */ const int64_t init_pct = 5, inc_pct = 25, max_pct = 95; + uint64_t prev_dirty_sync_cnt, dirty_sync_cnt; + int max_try_count, hit = 0; if (test_migrate_start(&from, &to, uri, &args)) { return; @@ -2827,6 +2829,36 @@ static void test_migrate_auto_converge(void) } while (true); /* The first percentage of throttling should be at least init_pct */ g_assert_cmpint(percentage, >=, init_pct); + + /* + * End the loop when the dirty sync count greater than 1. + */ + while ((dirty_sync_cnt = get_migration_pass(from)) < 2) { + usleep(1000 * 1000); + } + + prev_dirty_sync_cnt = dirty_sync_cnt; + + /* + * The RAMBlock dirty sync count must changes in 5 seconds, here we set + * the timeout to 10 seconds to ensure it changes. + * + * Note that migrate_ensure_non_converge set the max-bandwidth to 3MB/s, + * while the qtest mem is >= 100MB, one iteration takes at least 33s (100/3) + * to complete; this ensures that the RAMBlock dirty sync occurs. + */ + max_try_count = 10; + while (--max_try_count) { + dirty_sync_cnt = get_migration_pass(from); + if (dirty_sync_cnt != prev_dirty_sync_cnt) { + hit = 1; + break; + } + prev_dirty_sync_cnt = dirty_sync_cnt; + sleep(1); + } + g_assert_cmpint(hit, ==, 1); + /* Now, when we tested that throttling works, let it converge */ migrate_ensure_converge(from); From 88c3b57f48db781c9fd0b117622f331d0f6fec92 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Tue, 22 Oct 2024 08:34:02 +0200 Subject: [PATCH 10/18] migration/dirtyrate: Silence warning about strcpy() on OpenBSD The linker on OpenBSD complains: ld: warning: dirtyrate.c:447 (../src/migration/dirtyrate.c:447)(...): warning: strcpy() is almost always misused, please use strlcpy() It's currently not a real problem in this case since both arrays have the same size (256 bytes). But just in case somebody changes the size of the source array in the future, let's better play safe and use g_strlcpy() here instead, with an additional check that the string has been copied as a whole. Signed-off-by: Thomas Huth Reviewed-by: Hyman Huang Link: https://lore.kernel.org/r/20241022063402.184213-1-thuth@redhat.com [peterx: Fix over-80 chars] Signed-off-by: Peter Xu --- migration/dirtyrate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c index a74a6aeb56..f7e86686fc 100644 --- a/migration/dirtyrate.c +++ b/migration/dirtyrate.c @@ -437,6 +437,7 @@ static void get_ramblock_dirty_info(RAMBlock *block, struct DirtyRateConfig *config) { uint64_t sample_pages_per_gigabytes = config->sample_pages_per_gigabytes; + gsize len; /* Right shift 30 bits to calc ramblock size in GB */ info->sample_pages_count = (qemu_ram_get_used_length(block) * @@ -445,7 +446,9 @@ static void get_ramblock_dirty_info(RAMBlock *block, info->ramblock_pages = qemu_ram_get_used_length(block) >> qemu_target_page_bits(); info->ramblock_addr = qemu_ram_get_host_addr(block); - strcpy(info->idstr, qemu_ram_get_idstr(block)); + len = g_strlcpy(info->idstr, qemu_ram_get_idstr(block), + sizeof(info->idstr)); + g_assert(len < sizeof(info->idstr)); } static void free_ramblock_dirty_info(struct RamblockDirtyInfo *infos, int count) From 228529d1fec305c05a7c7e173258b1c939ef3b1b Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 22 Oct 2024 15:45:01 -0400 Subject: [PATCH 11/18] migration: Deprecate query-migrationthreads command Per previous discussion [1,2], this patch deprecates query-migrationthreads command. To summarize, the major reason of the deprecation is due to no sensible way to consume the API properly: (1) The reported list of threads are incomplete (ignoring destination threads and non-multifd threads). (2) For CPU pinning, there's no way to properly pin the threads with the API if the threads will start running right away after migration threads can be queried, so the threads will always run on the default cores for a short window. (3) For VM debugging, one can use "-name $VM,debug-threads=on" instead, which will provide proper names for all migration threads. [1] https://lore.kernel.org/r/20240930195837.825728-1-peterx@redhat.com [2] https://lore.kernel.org/r/20241011153417.516715-1-peterx@redhat.com Reviewed-by: Fabiano Rosas Acked-by: Markus Armbruster Link: https://lore.kernel.org/r/20241022194501.1022443-1-peterx@redhat.com Signed-off-by: Peter Xu --- docs/about/deprecated.rst | 8 ++++++++ qapi/migration.json | 7 ++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 1e1e9f5f18..8e85607bdd 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -147,6 +147,14 @@ options are removed in favor of using explicit ``blockdev-create`` and ``blockdev-add`` calls. See :doc:`/interop/live-block-operations` for details. +``query-migrationthreads`` (since 9.2) +'''''''''''''''''''''''''''''''''''''' + +To be removed with no replacement, as it reports only a limited set of +threads (for example, it only reports source side of multifd threads, +without reporting any destination threads, or non-multifd source threads). +For debugging purpose, please use ``-name $VM,debug-threads=on`` instead. + Incorrectly typed ``device_add`` arguments (since 6.2) '''''''''''''''''''''''''''''''''''''''''''''''''''''' diff --git a/qapi/migration.json b/qapi/migration.json index 3af6aa1740..a605dc26db 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -2284,12 +2284,17 @@ # # Returns information of migration threads # +# Features: +# +# @deprecated: This command is deprecated with no replacement yet. +# # Returns: @MigrationThreadInfo # # Since: 7.2 ## { 'command': 'query-migrationthreads', - 'returns': ['MigrationThreadInfo'] } + 'returns': ['MigrationThreadInfo'], + 'features': ['deprecated'] } ## # @snapshot-save: From 7fc8beb16ee05399837efb41d0924fa1897da864 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 24 Oct 2024 17:30:49 -0400 Subject: [PATCH 12/18] migration: Take migration object refcount earlier for threads MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Both migration thread or background snapshot thread will take a refcount of the migration object at the entrace of the thread function. That makes sense, because it protects the object from being freed by the main thread in migration_shutdown() later, but it might still race with it if the thread is scheduled too late. Consider the case right after pthread_create() happened, VM shuts down with the object released, but right after that the migration thread finally got created, referencing MigrationState* in the opaque pointer which is already freed. The only 100% safe way to make sure it won't get freed is taking the refcount right before the thread is created, meanwhile when BQL is held. Reviewed-by: Cédric Le Goater Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20241024213056.1395400-2-peterx@redhat.com Signed-off-by: Peter Xu --- migration/migration.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 9bcc9db4fb..a3bf494d91 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3488,7 +3488,6 @@ static void *migration_thread(void *opaque) rcu_register_thread(); - object_ref(OBJECT(s)); update_iteration_initial_status(s); if (!multifd_send_setup()) { @@ -3626,7 +3625,6 @@ static void *bg_migration_thread(void *opaque) int ret; rcu_register_thread(); - object_ref(OBJECT(s)); migration_rate_set(RATE_LIMIT_DISABLED); @@ -3838,6 +3836,14 @@ void migrate_fd_connect(MigrationState *s, Error *error_in) } } + /* + * Take a refcount to make sure the migration object won't get freed by + * the main thread already in migration_shutdown(). + * + * The refcount will be released at the end of the thread function. + */ + object_ref(OBJECT(s)); + if (migrate_background_snapshot()) { qemu_thread_create(&s->thread, MIGRATION_THREAD_SNAPSHOT, bg_migration_thread, s, QEMU_THREAD_JOINABLE); From a4ddab35819556aeb88b8c2f3e6f7823175481eb Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 24 Oct 2024 17:30:50 -0400 Subject: [PATCH 13/18] migration: Unexport dirty_bitmap_mig_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It's only used within migration/, so it shouldn't be exported. Reviewed-by: Cédric Le Goater Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20241024213056.1395400-3-peterx@redhat.com Signed-off-by: Peter Xu --- include/migration/misc.h | 3 --- migration/migration.h | 4 ++++ 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/include/migration/misc.h b/include/migration/misc.h index bfadc5613b..df57be6b5e 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -108,7 +108,4 @@ bool migration_incoming_postcopy_advised(void); /* True if background snapshot is active */ bool migration_in_bg_snapshot(void); -/* migration/block-dirty-bitmap.c */ -void dirty_bitmap_mig_init(void); - #endif diff --git a/migration/migration.h b/migration/migration.h index 7dc59c5e8d..0956e9274b 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -552,4 +552,8 @@ int migration_rp_wait(MigrationState *s); void migration_rp_kick(MigrationState *s); void migration_bitmap_sync_precopy(bool last_stage); + +/* migration/block-dirty-bitmap.c */ +void dirty_bitmap_mig_init(void); + #endif From 64dcd2c9c627b88ec7d071e1b49f0180b467fc71 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 24 Oct 2024 17:30:51 -0400 Subject: [PATCH 14/18] migration: Unexport ram_mig_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It's only used within migration/. Reviewed-by: Cédric Le Goater Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20241024213056.1395400-4-peterx@redhat.com Signed-off-by: Peter Xu --- include/migration/misc.h | 1 - migration/ram.h | 1 + 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/include/migration/misc.h b/include/migration/misc.h index df57be6b5e..e8490e3af5 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -39,7 +39,6 @@ void precopy_add_notifier(NotifierWithReturn *n); void precopy_remove_notifier(NotifierWithReturn *n); int precopy_notify(PrecopyNotifyReason reason, Error **errp); -void ram_mig_init(void); void qemu_guest_free_page_hint(void *addr, size_t len); bool migrate_ram_is_ignored(RAMBlock *block); diff --git a/migration/ram.h b/migration/ram.h index bc0318b834..0d1981f888 100644 --- a/migration/ram.h +++ b/migration/ram.h @@ -44,6 +44,7 @@ extern XBZRLECacheStats xbzrle_counters; INTERNAL_RAMBLOCK_FOREACH(block) \ if (!qemu_ram_is_migratable(block)) {} else +void ram_mig_init(void); int xbzrle_cache_resize(uint64_t new_size, Error **errp); uint64_t ram_bytes_remaining(void); uint64_t ram_bytes_total(void); From f018eb62b2bb7618b0cb8a796ac4b76fd786ecaf Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 24 Oct 2024 17:30:52 -0400 Subject: [PATCH 15/18] migration: Drop migration_is_setup_or_active() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This helper is mostly the same as migration_is_running(), except that one has COLO reported as true, the other has CANCELLING reported as true. Per my past years experience on the state changes, none of them should matter. To make it slightly safer, report both COLO || CANCELLING to be true in migration_is_running(), then drop the other one. We kept the 1st only because the name is simpler, and clear enough. Reviewed-by: Cédric Le Goater Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20241024213056.1395400-5-peterx@redhat.com Signed-off-by: Peter Xu --- hw/vfio/common.c | 2 +- include/migration/misc.h | 4 ++-- migration/migration.c | 35 +++-------------------------------- migration/ram.c | 5 ++--- net/vhost-vdpa.c | 3 +-- 5 files changed, 9 insertions(+), 40 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 36d0cf6585..dcef44fe55 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -149,7 +149,7 @@ bool vfio_viommu_preset(VFIODevice *vbasedev) static void vfio_set_migration_error(int ret) { - if (migration_is_setup_or_active()) { + if (migration_is_running()) { migration_file_set_error(ret, NULL); } } diff --git a/include/migration/misc.h b/include/migration/misc.h index e8490e3af5..86ef160f19 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -52,11 +52,12 @@ void dump_vmstate_json_to_file(FILE *out_fp); /* migration/migration.c */ void migration_object_init(void); void migration_shutdown(void); + bool migration_is_idle(void); bool migration_is_active(void); bool migration_is_device(void); +bool migration_is_running(void); bool migration_thread_is_self(void); -bool migration_is_setup_or_active(void); typedef enum MigrationEventType { MIG_EVENT_PRECOPY_SETUP, @@ -95,7 +96,6 @@ void migration_add_notifier_mode(NotifierWithReturn *notify, MigrationNotifyFunc func, MigMode mode); void migration_remove_notifier(NotifierWithReturn *notify); -bool migration_is_running(void); void migration_file_set_error(int ret, Error *err); /* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */ diff --git a/migration/migration.c b/migration/migration.c index a3bf494d91..65f77e3aa9 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1113,33 +1113,6 @@ void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value) migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf); } -/* - * Return true if we're already in the middle of a migration - * (i.e. any of the active or setup states) - */ -bool migration_is_setup_or_active(void) -{ - MigrationState *s = current_migration; - - switch (s->state) { - case MIGRATION_STATUS_ACTIVE: - case MIGRATION_STATUS_POSTCOPY_ACTIVE: - case MIGRATION_STATUS_POSTCOPY_PAUSED: - case MIGRATION_STATUS_POSTCOPY_RECOVER_SETUP: - case MIGRATION_STATUS_POSTCOPY_RECOVER: - case MIGRATION_STATUS_SETUP: - case MIGRATION_STATUS_PRE_SWITCHOVER: - case MIGRATION_STATUS_DEVICE: - case MIGRATION_STATUS_WAIT_UNPLUG: - case MIGRATION_STATUS_COLO: - return true; - - default: - return false; - - } -} - bool migration_is_running(void) { MigrationState *s = current_migration; @@ -1155,11 +1128,10 @@ bool migration_is_running(void) case MIGRATION_STATUS_DEVICE: case MIGRATION_STATUS_WAIT_UNPLUG: case MIGRATION_STATUS_CANCELLING: + case MIGRATION_STATUS_COLO: return true; - default: return false; - } } @@ -1658,8 +1630,7 @@ bool migration_incoming_postcopy_advised(void) bool migration_in_bg_snapshot(void) { - return migrate_background_snapshot() && - migration_is_setup_or_active(); + return migrate_background_snapshot() && migration_is_running(); } bool migration_is_idle(void) @@ -2332,7 +2303,7 @@ static void *source_return_path_thread(void *opaque) trace_source_return_path_thread_entry(); rcu_register_thread(); - while (migration_is_setup_or_active()) { + while (migration_is_running()) { trace_source_return_path_thread_loop_top(); header_type = qemu_get_be16(rp); diff --git a/migration/ram.c b/migration/ram.c index b24e45442c..9d9daccedc 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2860,7 +2860,7 @@ void qemu_guest_free_page_hint(void *addr, size_t len) size_t used_len, start, npages; /* This function is currently expected to be used during live migration */ - if (!migration_is_setup_or_active()) { + if (!migration_is_running()) { return; } @@ -3208,8 +3208,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) } out: - if (ret >= 0 - && migration_is_setup_or_active()) { + if (ret >= 0 && migration_is_running()) { if (migrate_multifd() && migrate_multifd_flush_after_each_section() && !migrate_mapped_ram()) { ret = multifd_ram_flush_and_sync(); diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index 46b02c50be..231b45246c 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -375,8 +375,7 @@ static int vhost_vdpa_net_data_start(NetClientState *nc) assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); - if (s->always_svq || - migration_is_setup_or_active()) { + if (s->always_svq || migration_is_running()) { v->shadow_vqs_enabled = true; } else { v->shadow_vqs_enabled = false; From 34a8892decdcec13d641f57bcb2a9c35fbc4c07b Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 24 Oct 2024 17:30:53 -0400 Subject: [PATCH 16/18] migration: Drop migration_is_idle() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now with the current migration_is_running(), it will report exactly the opposite of what will be reported by migration_is_idle(). Drop migration_is_idle(), instead use "!migration_is_running()" which should be identical on functionality. In reality, most of the idle check is inverted, so it's even easier to write with "migrate_is_running()" check. Reviewed-by: Cédric Le Goater Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20241024213056.1395400-6-peterx@redhat.com Signed-off-by: Peter Xu --- hw/virtio/virtio-mem.c | 2 +- include/migration/misc.h | 1 - migration/migration.c | 21 +-------------------- migration/ram.c | 2 +- system/qdev-monitor.c | 4 ++-- 5 files changed, 5 insertions(+), 25 deletions(-) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index ae1e81d7ba..80ada89551 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -188,7 +188,7 @@ static bool virtio_mem_is_busy(void) * after plugging them) until we're running on the destination (as we didn't * migrate these blocks when they were unplugged). */ - return migration_in_incoming_postcopy() || !migration_is_idle(); + return migration_in_incoming_postcopy() || migration_is_running(); } typedef int (*virtio_mem_range_cb)(VirtIOMEM *vmem, void *arg, diff --git a/include/migration/misc.h b/include/migration/misc.h index 86ef160f19..804eb23c06 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -53,7 +53,6 @@ void dump_vmstate_json_to_file(FILE *out_fp); void migration_object_init(void); void migration_shutdown(void); -bool migration_is_idle(void); bool migration_is_active(void); bool migration_is_device(void); bool migration_is_running(void); diff --git a/migration/migration.c b/migration/migration.c index 65f77e3aa9..aedf7f0751 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1633,25 +1633,6 @@ bool migration_in_bg_snapshot(void) return migrate_background_snapshot() && migration_is_running(); } -bool migration_is_idle(void) -{ - MigrationState *s = current_migration; - - if (!s) { - return true; - } - - switch (s->state) { - case MIGRATION_STATUS_NONE: - case MIGRATION_STATUS_CANCELLED: - case MIGRATION_STATUS_COMPLETED: - case MIGRATION_STATUS_FAILED: - return true; - default: - return false; - } -} - bool migration_is_active(void) { MigrationState *s = current_migration; @@ -1730,7 +1711,7 @@ static bool is_busy(Error **reasonp, Error **errp) ERRP_GUARD(); /* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */ - if (runstate_check(RUN_STATE_SAVE_VM) || !migration_is_idle()) { + if (runstate_check(RUN_STATE_SAVE_VM) || migration_is_running()) { error_propagate_prepend(errp, *reasonp, "disallowing migration blocker " "(migration/snapshot in progress) for: "); diff --git a/migration/ram.c b/migration/ram.c index 9d9daccedc..f164dc611f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4498,7 +4498,7 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host, return; } - if (!migration_is_idle()) { + if (migration_is_running()) { /* * Precopy code on the source cannot deal with the size of RAM blocks * changing at random points in time - especially after sending the diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c index 44994ea0e1..320c47b72d 100644 --- a/system/qdev-monitor.c +++ b/system/qdev-monitor.c @@ -679,7 +679,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, return NULL; } - if (!migration_is_idle()) { + if (migration_is_running()) { error_setg(errp, "device_add not allowed while migrating"); return NULL; } @@ -928,7 +928,7 @@ void qdev_unplug(DeviceState *dev, Error **errp) return; } - if (!migration_is_idle() && !dev->allow_unplug_during_migration) { + if (migration_is_running() && !dev->allow_unplug_during_migration) { error_setg(errp, "device_del not allowed while migrating"); return; } From b0350c51955f8581873593385672b40b9ec7eb74 Mon Sep 17 00:00:00 2001 From: "Maciej S. Szmigiero" Date: Tue, 29 Oct 2024 15:58:14 +0100 Subject: [PATCH 17/18] migration/ram: Add load start trace event There's a RAM load complete trace event but there wasn't its start equivalent. Signed-off-by: Maciej S. Szmigiero Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/94ddfa7ecb83a78f73b82867dd30c8767592d257.1730203967.git.maciej.szmigiero@oracle.com Signed-off-by: Peter Xu --- migration/ram.c | 1 + migration/trace-events | 1 + 2 files changed, 2 insertions(+) diff --git a/migration/ram.c b/migration/ram.c index f164dc611f..05ff9eb328 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4294,6 +4294,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) * it will be necessary to reduce the granularity of this * critical section. */ + trace_ram_load_start(); WITH_RCU_READ_LOCK_GUARD() { if (postcopy_running) { /* diff --git a/migration/trace-events b/migration/trace-events index 0638183056..bb0e0cc6dc 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -115,6 +115,7 @@ colo_flush_ram_cache_end(void) "" save_xbzrle_page_skipping(void) "" save_xbzrle_page_overflow(void) "" ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: %" PRIu64 " milliseconds, %d iterations" +ram_load_start(void) "" ram_load_complete(int ret, uint64_t seq_iter) "exit_code %d seq iteration %" PRIu64 ram_write_tracking_ramblock_start(const char *block_id, size_t page_size, void *addr, size_t length) "%s: page_size: %zu addr: %p length: %zu" ram_write_tracking_ramblock_stop(const char *block_id, size_t page_size, void *addr, size_t length) "%s: page_size: %zu addr: %p length: %zu" From 00b4b216534d84ace7b0583cec70a3aaf256cb25 Mon Sep 17 00:00:00 2001 From: "Maciej S. Szmigiero" Date: Tue, 29 Oct 2024 15:58:15 +0100 Subject: [PATCH 18/18] migration/multifd: Zero p->flags before starting filling a packet This way there aren't stale flags there. p->flags can't contain SYNC to be sent at the next RAM packet since syncs are now handled separately in multifd_send_thread. Reviewed-by: Fabiano Rosas Reviewed-by: Peter Xu Signed-off-by: Maciej S. Szmigiero Link: https://lore.kernel.org/r/1c96b6cdb797e6f035eb1a4ad9bfc24f4c7f5df8.1730203967.git.maciej.szmigiero@oracle.com Signed-off-by: Peter Xu --- migration/multifd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/multifd.c b/migration/multifd.c index 697fe86fdf..4374e14a96 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -600,6 +600,7 @@ static void *multifd_send_thread(void *opaque) * qatomic_store_release() in multifd_send(). */ if (qatomic_load_acquire(&p->pending_job)) { + p->flags = 0; p->iovs_num = 0; assert(!multifd_payload_empty(p->data)); @@ -651,7 +652,6 @@ static void *multifd_send_thread(void *opaque) } /* p->next_packet_size will always be zero for a SYNC packet */ stat64_add(&mig_stats.multifd_bytes, p->packet_len); - p->flags = 0; } qatomic_set(&p->pending_sync, false);