| /* |
| * QEMU live migration |
| * |
| * Copyright IBM, Corp. 2008 |
| * |
| * Authors: |
| * Anthony Liguori <aliguori@us.ibm.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * |
| */ |
| |
| #ifndef QEMU_MIGRATION_H |
| #define QEMU_MIGRATION_H |
| |
| #include "exec/cpu-common.h" |
| #include "hw/qdev-core.h" |
| #include "qapi/qapi-types-migration.h" |
| #include "qapi/qmp/json-writer.h" |
| #include "qemu/thread.h" |
| #include "qemu/coroutine_int.h" |
| #include "io/channel.h" |
| #include "io/channel-buffer.h" |
| #include "net/announce.h" |
| #include "qom/object.h" |
| #include "postcopy-ram.h" |
| |
| struct PostcopyBlocktimeContext; |
| |
| #define MIGRATION_RESUME_ACK_VALUE (1) |
| |
| /* |
| * 1<<6=64 pages -> 256K chunk when page size is 4K. This gives us |
| * the benefit that all the chunks are 64 pages aligned then the |
| * bitmaps are always aligned to LONG. |
| */ |
| #define CLEAR_BITMAP_SHIFT_MIN 6 |
| /* |
| * 1<<18=256K pages -> 1G chunk when page size is 4K. This is the |
| * default value to use if no one specified. |
| */ |
| #define CLEAR_BITMAP_SHIFT_DEFAULT 18 |
| /* |
| * 1<<31=2G pages -> 8T chunk when page size is 4K. This should be |
| * big enough and make sure we won't overflow easily. |
| */ |
| #define CLEAR_BITMAP_SHIFT_MAX 31 |
| |
| /* This is an abstraction of a "temp huge page" for postcopy's purpose */ |
| typedef struct { |
| /* |
| * This points to a temporary huge page as a buffer for UFFDIO_COPY. It's |
| * mmap()ed and needs to be freed when cleanup. |
| */ |
| void *tmp_huge_page; |
| /* |
| * This points to the host page we're going to install for this temp page. |
| * It tells us after we've received the whole page, where we should put it. |
| */ |
| void *host_addr; |
| /* Number of small pages copied (in size of TARGET_PAGE_SIZE) */ |
| unsigned int target_pages; |
| /* Whether this page contains all zeros */ |
| bool all_zero; |
| } PostcopyTmpPage; |
| |
| typedef enum { |
| PREEMPT_THREAD_NONE = 0, |
| PREEMPT_THREAD_CREATED, |
| PREEMPT_THREAD_QUIT, |
| } PreemptThreadStatus; |
| |
| /* State for the incoming migration */ |
| struct MigrationIncomingState { |
| QEMUFile *from_src_file; |
| /* Previously received RAM's RAMBlock pointer */ |
| RAMBlock *last_recv_block[RAM_CHANNEL_MAX]; |
| /* A hook to allow cleanup at the end of incoming migration */ |
| void *transport_data; |
| void (*transport_cleanup)(void *data); |
| /* |
| * Used to sync thread creations. Note that we can't create threads in |
| * parallel with this sem. |
| */ |
| QemuSemaphore thread_sync_sem; |
| /* |
| * Free at the start of the main state load, set as the main thread finishes |
| * loading state. |
| */ |
| QemuEvent main_thread_load_event; |
| |
| /* For network announces */ |
| AnnounceTimer announce_timer; |
| |
| size_t largest_page_size; |
| bool have_fault_thread; |
| QemuThread fault_thread; |
| /* Set this when we want the fault thread to quit */ |
| bool fault_thread_quit; |
| |
| bool have_listen_thread; |
| QemuThread listen_thread; |
| |
| /* For the kernel to send us notifications */ |
| int userfault_fd; |
| /* To notify the fault_thread to wake, e.g., when need to quit */ |
| int userfault_event_fd; |
| QEMUFile *to_src_file; |
| QemuMutex rp_mutex; /* We send replies from multiple threads */ |
| /* RAMBlock of last request sent to source */ |
| RAMBlock *last_rb; |
| /* |
| * Number of postcopy channels including the default precopy channel, so |
| * vanilla postcopy will only contain one channel which contain both |
| * precopy and postcopy streams. |
| * |
| * This is calculated when the src requests to enable postcopy but before |
| * it starts. Its value can depend on e.g. whether postcopy preemption is |
| * enabled. |
| */ |
| unsigned int postcopy_channels; |
| /* QEMUFile for postcopy only; it'll be handled by a separate thread */ |
| QEMUFile *postcopy_qemufile_dst; |
| /* |
| * When postcopy_qemufile_dst is properly setup, this sem is posted. |
| * One can wait on this semaphore to wait until the preempt channel is |
| * properly setup. |
| */ |
| QemuSemaphore postcopy_qemufile_dst_done; |
| /* Postcopy priority thread is used to receive postcopy requested pages */ |
| QemuThread postcopy_prio_thread; |
| /* |
| * Always set by the main vm load thread only, but can be read by the |
| * postcopy preempt thread. "volatile" makes sure all reads will be |
| * uptodate across cores. |
| */ |
| volatile PreemptThreadStatus preempt_thread_status; |
| /* |
| * Used to sync between the ram load main thread and the fast ram load |
| * thread. It protects postcopy_qemufile_dst, which is the postcopy |
| * fast channel. |
| * |
| * The ram fast load thread will take it mostly for the whole lifecycle |
| * because it needs to continuously read data from the channel, and |
| * it'll only release this mutex if postcopy is interrupted, so that |
| * the ram load main thread will take this mutex over and properly |
| * release the broken channel. |
| */ |
| QemuMutex postcopy_prio_thread_mutex; |
| /* |
| * An array of temp host huge pages to be used, one for each postcopy |
| * channel. |
| */ |
| PostcopyTmpPage *postcopy_tmp_pages; |
| /* This is shared for all postcopy channels */ |
| void *postcopy_tmp_zero_page; |
| /* PostCopyFD's for external userfaultfds & handlers of shared memory */ |
| GArray *postcopy_remote_fds; |
| |
| QEMUBH *bh; |
| |
| int state; |
| |
| bool have_colo_incoming_thread; |
| QemuThread colo_incoming_thread; |
| /* The coroutine we should enter (back) after failover */ |
| Coroutine *migration_incoming_co; |
| QemuSemaphore colo_incoming_sem; |
| |
| /* |
| * PostcopyBlocktimeContext to keep information for postcopy |
| * live migration, to calculate vCPU block time |
| * */ |
| struct PostcopyBlocktimeContext *blocktime_ctx; |
| |
| /* notify PAUSED postcopy incoming migrations to try to continue */ |
| QemuSemaphore postcopy_pause_sem_dst; |
| QemuSemaphore postcopy_pause_sem_fault; |
| /* |
| * This semaphore is used to allow the ram fast load thread (only when |
| * postcopy preempt is enabled) fall into sleep when there's network |
| * interruption detected. When the recovery is done, the main load |
| * thread will kick the fast ram load thread using this semaphore. |
| */ |
| QemuSemaphore postcopy_pause_sem_fast_load; |
| |
| /* List of listening socket addresses */ |
| SocketAddressList *socket_address_list; |
| |
| /* A tree of pages that we requested to the source VM */ |
| GTree *page_requested; |
| /* For debugging purpose only, but would be nice to keep */ |
| int page_requested_count; |
| /* |
| * The mutex helps to maintain the requested pages that we sent to the |
| * source, IOW, to guarantee coherent between the page_requests tree and |
| * the per-ramblock receivedmap. Note! This does not guarantee consistency |
| * of the real page copy procedures (using UFFDIO_[ZERO]COPY). E.g., even |
| * if one bit in receivedmap is cleared, UFFDIO_COPY could have happened |
| * for that page already. This is intended so that the mutex won't |
| * serialize and blocked by slow operations like UFFDIO_* ioctls. However |
| * this should be enough to make sure the page_requested tree always |
| * contains valid information. |
| */ |
| QemuMutex page_request_mutex; |
| }; |
| |
| MigrationIncomingState *migration_incoming_get_current(void); |
| void migration_incoming_state_destroy(void); |
| void migration_incoming_transport_cleanup(MigrationIncomingState *mis); |
| /* |
| * Functions to work with blocktime context |
| */ |
| void fill_destination_postcopy_migration_info(MigrationInfo *info); |
| |
| #define TYPE_MIGRATION "migration" |
| |
| typedef struct MigrationClass MigrationClass; |
| DECLARE_OBJ_CHECKERS(MigrationState, MigrationClass, |
| MIGRATION_OBJ, TYPE_MIGRATION) |
| |
| struct MigrationClass { |
| /*< private >*/ |
| DeviceClass parent_class; |
| }; |
| |
| struct MigrationState { |
| /*< private >*/ |
| DeviceState parent_obj; |
| |
| /*< public >*/ |
| QemuThread thread; |
| QEMUBH *vm_start_bh; |
| QEMUBH *cleanup_bh; |
| /* Protected by qemu_file_lock */ |
| QEMUFile *to_dst_file; |
| /* Postcopy specific transfer channel */ |
| QEMUFile *postcopy_qemufile_src; |
| /* |
| * It is posted when the preempt channel is established. Note: this is |
| * used for both the start or recover of a postcopy migration. We'll |
| * post to this sem every time a new preempt channel is created in the |
| * main thread, and we keep post() and wait() in pair. |
| */ |
| QemuSemaphore postcopy_qemufile_src_sem; |
| QIOChannelBuffer *bioc; |
| /* |
| * Protects to_dst_file/from_dst_file pointers. We need to make sure we |
| * won't yield or hang during the critical section, since this lock will be |
| * used in OOB command handler. |
| */ |
| QemuMutex qemu_file_lock; |
| |
| /* |
| * Used to allow urgent requests to override rate limiting. |
| */ |
| QemuSemaphore rate_limit_sem; |
| |
| /* pages already send at the beginning of current iteration */ |
| uint64_t iteration_initial_pages; |
| |
| /* pages transferred per second */ |
| double pages_per_second; |
| |
| /* bytes already send at the beginning of current iteration */ |
| uint64_t iteration_initial_bytes; |
| /* time at the start of current iteration */ |
| int64_t iteration_start_time; |
| /* |
| * The final stage happens when the remaining data is smaller than |
| * this threshold; it's calculated from the requested downtime and |
| * measured bandwidth |
| */ |
| int64_t threshold_size; |
| |
| /* params from 'migrate-set-parameters' */ |
| MigrationParameters parameters; |
| |
| int state; |
| |
| /* State related to return path */ |
| struct { |
| /* Protected by qemu_file_lock */ |
| QEMUFile *from_dst_file; |
| QemuThread rp_thread; |
| bool error; |
| /* |
| * We can also check non-zero of rp_thread, but there's no "official" |
| * way to do this, so this bool makes it slightly more elegant. |
| * Checking from_dst_file for this is racy because from_dst_file will |
| * be cleared in the rp_thread! |
| */ |
| bool rp_thread_created; |
| QemuSemaphore rp_sem; |
| /* |
| * We post to this when we got one PONG from dest. So far it's an |
| * easy way to know the main channel has successfully established |
| * on dest QEMU. |
| */ |
| QemuSemaphore rp_pong_acks; |
| } rp_state; |
| |
| double mbps; |
| /* Timestamp when recent migration starts (ms) */ |
| int64_t start_time; |
| /* Total time used by latest migration (ms) */ |
| int64_t total_time; |
| /* Timestamp when VM is down (ms) to migrate the last stuff */ |
| int64_t downtime_start; |
| int64_t downtime; |
| int64_t expected_downtime; |
| bool capabilities[MIGRATION_CAPABILITY__MAX]; |
| int64_t setup_time; |
| /* |
| * Whether guest was running when we enter the completion stage. |
| * If migration is interrupted by any reason, we need to continue |
| * running the guest on source. |
| */ |
| bool vm_was_running; |
| |
| /* Flag set once the migration has been asked to enter postcopy */ |
| bool start_postcopy; |
| /* Flag set after postcopy has sent the device state */ |
| bool postcopy_after_devices; |
| |
| /* Flag set once the migration thread is running (and needs joining) */ |
| bool migration_thread_running; |
| |
| /* Flag set once the migration thread called bdrv_inactivate_all */ |
| bool block_inactive; |
| |
| /* Migration is waiting for guest to unplug device */ |
| QemuSemaphore wait_unplug_sem; |
| |
| /* Migration is paused due to pause-before-switchover */ |
| QemuSemaphore pause_sem; |
| |
| /* The semaphore is used to notify COLO thread that failover is finished */ |
| QemuSemaphore colo_exit_sem; |
| |
| /* The event is used to notify COLO thread to do checkpoint */ |
| QemuEvent colo_checkpoint_event; |
| int64_t colo_checkpoint_time; |
| QEMUTimer *colo_delay_timer; |
| |
| /* The first error that has occurred. |
| We used the mutex to be able to return the 1st error message */ |
| Error *error; |
| /* mutex to protect errp */ |
| QemuMutex error_mutex; |
| |
| /* Do we have to clean up -b/-i from old migrate parameters */ |
| /* This feature is deprecated and will be removed */ |
| bool must_remove_block_options; |
| |
| /* |
| * Global switch on whether we need to store the global state |
| * during migration. |
| */ |
| bool store_global_state; |
| |
| /* Whether we send QEMU_VM_CONFIGURATION during migration */ |
| bool send_configuration; |
| /* Whether we send section footer during migration */ |
| bool send_section_footer; |
| |
| /* Needed by postcopy-pause state */ |
| QemuSemaphore postcopy_pause_sem; |
| QemuSemaphore postcopy_pause_rp_sem; |
| /* |
| * Whether we abort the migration if decompression errors are |
| * detected at the destination. It is left at false for qemu |
| * older than 3.0, since only newer qemu sends streams that |
| * do not trigger spurious decompression errors. |
| */ |
| bool decompress_error_check; |
| /* |
| * This variable only affects behavior when postcopy preempt mode is |
| * enabled. |
| * |
| * When set: |
| * |
| * - postcopy preempt src QEMU instance will generate an EOS message at |
| * the end of migration to shut the preempt channel on dest side. |
| * |
| * - postcopy preempt channel will be created at the setup phase on src |
| QEMU. |
| * |
| * When clear: |
| * |
| * - postcopy preempt src QEMU instance will _not_ generate an EOS |
| * message at the end of migration, the dest qemu will shutdown the |
| * channel itself. |
| * |
| * - postcopy preempt channel will be created at the switching phase |
| * from precopy -> postcopy (to avoid race condtion of misordered |
| * creation of channels). |
| * |
| * NOTE: See message-id <ZBoShWArKDPpX/D7@work-vm> on qemu-devel |
| * mailing list for more information on the possible race. Everyone |
| * should probably just keep this value untouched after set by the |
| * machine type (or the default). |
| */ |
| bool preempt_pre_7_2; |
| |
| /* |
| * This decides the size of guest memory chunk that will be used |
| * to track dirty bitmap clearing. The size of memory chunk will |
| * be GUEST_PAGE_SIZE << N. Say, N=0 means we will clear dirty |
| * bitmap for each page to send (1<<0=1); N=10 means we will clear |
| * dirty bitmap only once for 1<<10=1K continuous guest pages |
| * (which is in 4M chunk). |
| */ |
| uint8_t clear_bitmap_shift; |
| |
| /* |
| * This save hostname when out-going migration starts |
| */ |
| char *hostname; |
| |
| /* QEMU_VM_VMDESCRIPTION content filled for all non-iterable devices. */ |
| JSONWriter *vmdesc; |
| }; |
| |
| void migrate_set_state(int *state, int old_state, int new_state); |
| |
| void migration_fd_process_incoming(QEMUFile *f, Error **errp); |
| void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp); |
| void migration_incoming_process(void); |
| |
| bool migration_has_all_channels(void); |
| |
| uint64_t migrate_max_downtime(void); |
| |
| void migrate_set_error(MigrationState *s, const Error *error); |
| void migrate_fd_error(MigrationState *s, const Error *error); |
| |
| void migrate_fd_connect(MigrationState *s, Error *error_in); |
| |
| bool migration_is_setup_or_active(int state); |
| bool migration_is_running(int state); |
| |
| void migrate_init(MigrationState *s); |
| bool migration_is_blocked(Error **errp); |
| /* True if outgoing migration has entered postcopy phase */ |
| bool migration_in_postcopy(void); |
| MigrationState *migrate_get_current(void); |
| |
| uint64_t ram_get_total_transferred_pages(void); |
| |
| /* Sending on the return path - generic and then for each message type */ |
| void migrate_send_rp_shut(MigrationIncomingState *mis, |
| uint32_t value); |
| void migrate_send_rp_pong(MigrationIncomingState *mis, |
| uint32_t value); |
| int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb, |
| ram_addr_t start, uint64_t haddr); |
| int migrate_send_rp_message_req_pages(MigrationIncomingState *mis, |
| RAMBlock *rb, ram_addr_t start); |
| void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, |
| char *block_name); |
| void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value); |
| |
| void dirty_bitmap_mig_before_vm_start(void); |
| void dirty_bitmap_mig_cancel_outgoing(void); |
| void dirty_bitmap_mig_cancel_incoming(void); |
| bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, |
| Error **errp); |
| |
| void migrate_add_address(SocketAddress *address); |
| |
| int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque); |
| |
| #define qemu_ram_foreach_block \ |
| #warning "Use foreach_not_ignored_block in migration code" |
| |
| void migration_make_urgent_request(void); |
| void migration_consume_urgent_request(void); |
| bool migration_rate_limit(void); |
| void migration_cancel(const Error *error); |
| |
| void populate_vfio_info(MigrationInfo *info); |
| void postcopy_temp_page_reset(PostcopyTmpPage *tmp_page); |
| |
| #endif |