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