migration/migration.h - third_party/qemu - Git at Google

 /*
  * 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 "qemu/thread.h"
 #include "qemu/coroutine_int.h"
 #include "io/channel.h"
 #include "net/announce.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

 /* State for the incoming migration */
 struct MigrationIncomingState {
     QEMUFile *from_src_file;

     /*
      * 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;
     QemuSemaphore  fault_thread_sem;
     /* Set this when we want the fault thread to quit */
     bool           fault_thread_quit;

     bool           have_listen_thread;
     QemuThread     listen_thread;
     QemuSemaphore  listen_thread_sem;

     /* 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;
     void     *postcopy_tmp_page;
     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 */
     bool postcopy_recover_triggered;
     QemuSemaphore postcopy_pause_sem_dst;
     QemuSemaphore postcopy_pause_sem_fault;

     /* List of listening socket addresses  */
     SocketAddressList *socket_address_list;
 };

 MigrationIncomingState *migration_incoming_get_current(void);
 void migration_incoming_state_destroy(void);
 /*
  * Functions to work with blocktime context
  */
 void fill_destination_postcopy_migration_info(MigrationInfo *info);

 #define TYPE_MIGRATION "migration"

 #define MIGRATION_CLASS(klass) \
     OBJECT_CLASS_CHECK(MigrationClass, (klass), TYPE_MIGRATION)
 #define MIGRATION_OBJ(obj) \
     OBJECT_CHECK(MigrationState, (obj), TYPE_MIGRATION)
 #define MIGRATION_GET_CLASS(obj) \
     OBJECT_GET_CLASS(MigrationClass, (obj), TYPE_MIGRATION)

 typedef struct MigrationClass {
     /*< private >*/
     DeviceClass parent_class;
 } MigrationClass;

 struct MigrationState
 {
     /*< private >*/
     DeviceState parent_obj;

     /*< public >*/
     QemuThread thread;
     QEMUBH *cleanup_bh;
     QEMUFile *to_dst_file;
     /*
      * Protects to_dst_file pointer.  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 {
         QEMUFile     *from_dst_file;
         QemuThread    rp_thread;
         bool          error;
         QemuSemaphore rp_sem;
     } 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 enabled_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 semaphore is used to notify COLO thread to do checkpoint */
     QemuSemaphore colo_checkpoint_sem;
     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 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;
 };

 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);

 bool migrate_postcopy(void);

 bool migrate_release_ram(void);
 bool migrate_postcopy_ram(void);
 bool migrate_zero_blocks(void);
 bool migrate_dirty_bitmaps(void);
 bool migrate_ignore_shared(void);
 bool migrate_validate_uuid(void);

 bool migrate_auto_converge(void);
 bool migrate_use_multifd(void);
 bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
 MultiFDCompression migrate_multifd_compression(void);
 int migrate_multifd_zlib_level(void);
 int migrate_multifd_zstd_level(void);

 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);
 bool migrate_colo_enabled(void);

 bool migrate_use_block(void);
 bool migrate_use_block_incremental(void);
 int migrate_max_cpu_throttle(void);
 bool migrate_use_return_path(void);

 uint64_t ram_get_total_transferred_pages(void);

 bool migrate_use_compression(void);
 int migrate_compress_level(void);
 int migrate_compress_threads(void);
 int migrate_compress_wait_thread(void);
 int migrate_decompress_threads(void);
 bool migrate_use_events(void);
 bool migrate_postcopy_blocktime(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, const char* rbname,
                               ram_addr_t start, size_t len);
 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 init_dirty_bitmap_incoming_migration(void);
 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);

 #endif
	/*
	* 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 "qemu/thread.h"
	#include "qemu/coroutine_int.h"
	#include "io/channel.h"
	#include "net/announce.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

	/* State for the incoming migration */
	struct MigrationIncomingState {
	QEMUFile *from_src_file;

	/*
	* 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;
	QemuSemaphore fault_thread_sem;
	/* Set this when we want the fault thread to quit */
	bool fault_thread_quit;

	bool have_listen_thread;
	QemuThread listen_thread;
	QemuSemaphore listen_thread_sem;

	/* 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;
	void *postcopy_tmp_page;
	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 */
	bool postcopy_recover_triggered;
	QemuSemaphore postcopy_pause_sem_dst;
	QemuSemaphore postcopy_pause_sem_fault;

	/* List of listening socket addresses */
	SocketAddressList *socket_address_list;
	};

	MigrationIncomingState *migration_incoming_get_current(void);
	void migration_incoming_state_destroy(void);
	/*
	* Functions to work with blocktime context
	*/
	void fill_destination_postcopy_migration_info(MigrationInfo *info);

	#define TYPE_MIGRATION "migration"

	#define MIGRATION_CLASS(klass) \
	OBJECT_CLASS_CHECK(MigrationClass, (klass), TYPE_MIGRATION)
	#define MIGRATION_OBJ(obj) \
	OBJECT_CHECK(MigrationState, (obj), TYPE_MIGRATION)
	#define MIGRATION_GET_CLASS(obj) \
	OBJECT_GET_CLASS(MigrationClass, (obj), TYPE_MIGRATION)

	typedef struct MigrationClass {
	/< private >/
	DeviceClass parent_class;
	} MigrationClass;

	struct MigrationState
	{
	/< private >/
	DeviceState parent_obj;

	/< public >/
	QemuThread thread;
	QEMUBH *cleanup_bh;
	QEMUFile *to_dst_file;
	/*
	* Protects to_dst_file pointer. 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 {
	QEMUFile *from_dst_file;
	QemuThread rp_thread;
	bool error;
	QemuSemaphore rp_sem;
	} 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 enabled_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 semaphore is used to notify COLO thread to do checkpoint */
	QemuSemaphore colo_checkpoint_sem;
	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 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;
	};

	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);

	bool migrate_postcopy(void);

	bool migrate_release_ram(void);
	bool migrate_postcopy_ram(void);
	bool migrate_zero_blocks(void);
	bool migrate_dirty_bitmaps(void);
	bool migrate_ignore_shared(void);
	bool migrate_validate_uuid(void);

	bool migrate_auto_converge(void);
	bool migrate_use_multifd(void);
	bool migrate_pause_before_switchover(void);
	int migrate_multifd_channels(void);
	MultiFDCompression migrate_multifd_compression(void);
	int migrate_multifd_zlib_level(void);
	int migrate_multifd_zstd_level(void);

	int migrate_use_xbzrle(void);
	int64_t migrate_xbzrle_cache_size(void);
	bool migrate_colo_enabled(void);

	bool migrate_use_block(void);
	bool migrate_use_block_incremental(void);
	int migrate_max_cpu_throttle(void);
	bool migrate_use_return_path(void);

	uint64_t ram_get_total_transferred_pages(void);

	bool migrate_use_compression(void);
	int migrate_compress_level(void);
	int migrate_compress_threads(void);
	int migrate_compress_wait_thread(void);
	int migrate_decompress_threads(void);
	bool migrate_use_events(void);
	bool migrate_postcopy_blocktime(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, const char rbname,
	ram_addr_t start, size_t len);
	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 init_dirty_bitmap_incoming_migration(void);
	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);

	#endif