xref: /openbmc/qemu/migration/migration.h (revision 988717b46b6424907618cb845ace9d69062703af)
1  /*
2   * QEMU live migration
3   *
4   * Copyright IBM, Corp. 2008
5   *
6   * Authors:
7   *  Anthony Liguori   <aliguori@us.ibm.com>
8   *
9   * This work is licensed under the terms of the GNU GPL, version 2.  See
10   * the COPYING file in the top-level directory.
11   *
12   */
13  
14  #ifndef QEMU_MIGRATION_H
15  #define QEMU_MIGRATION_H
16  
17  #include "exec/cpu-common.h"
18  #include "hw/qdev-core.h"
19  #include "qapi/qapi-types-migration.h"
20  #include "qemu/thread.h"
21  #include "qemu/coroutine_int.h"
22  #include "io/channel.h"
23  #include "net/announce.h"
24  
25  struct PostcopyBlocktimeContext;
26  
27  #define  MIGRATION_RESUME_ACK_VALUE  (1)
28  
29  /*
30   * 1<<6=64 pages -> 256K chunk when page size is 4K.  This gives us
31   * the benefit that all the chunks are 64 pages aligned then the
32   * bitmaps are always aligned to LONG.
33   */
34  #define CLEAR_BITMAP_SHIFT_MIN             6
35  /*
36   * 1<<18=256K pages -> 1G chunk when page size is 4K.  This is the
37   * default value to use if no one specified.
38   */
39  #define CLEAR_BITMAP_SHIFT_DEFAULT        18
40  /*
41   * 1<<31=2G pages -> 8T chunk when page size is 4K.  This should be
42   * big enough and make sure we won't overflow easily.
43   */
44  #define CLEAR_BITMAP_SHIFT_MAX            31
45  
46  /* State for the incoming migration */
47  struct MigrationIncomingState {
48      QEMUFile *from_src_file;
49  
50      /*
51       * Free at the start of the main state load, set as the main thread finishes
52       * loading state.
53       */
54      QemuEvent main_thread_load_event;
55  
56      /* For network announces */
57      AnnounceTimer  announce_timer;
58  
59      size_t         largest_page_size;
60      bool           have_fault_thread;
61      QemuThread     fault_thread;
62      QemuSemaphore  fault_thread_sem;
63      /* Set this when we want the fault thread to quit */
64      bool           fault_thread_quit;
65  
66      bool           have_listen_thread;
67      QemuThread     listen_thread;
68      QemuSemaphore  listen_thread_sem;
69  
70      /* For the kernel to send us notifications */
71      int       userfault_fd;
72      /* To notify the fault_thread to wake, e.g., when need to quit */
73      int       userfault_event_fd;
74      QEMUFile *to_src_file;
75      QemuMutex rp_mutex;    /* We send replies from multiple threads */
76      /* RAMBlock of last request sent to source */
77      RAMBlock *last_rb;
78      void     *postcopy_tmp_page;
79      void     *postcopy_tmp_zero_page;
80      /* PostCopyFD's for external userfaultfds & handlers of shared memory */
81      GArray   *postcopy_remote_fds;
82  
83      QEMUBH *bh;
84  
85      int state;
86  
87      bool have_colo_incoming_thread;
88      QemuThread colo_incoming_thread;
89      /* The coroutine we should enter (back) after failover */
90      Coroutine *migration_incoming_co;
91      QemuSemaphore colo_incoming_sem;
92  
93      /*
94       * PostcopyBlocktimeContext to keep information for postcopy
95       * live migration, to calculate vCPU block time
96       * */
97      struct PostcopyBlocktimeContext *blocktime_ctx;
98  
99      /* notify PAUSED postcopy incoming migrations to try to continue */
100      bool postcopy_recover_triggered;
101      QemuSemaphore postcopy_pause_sem_dst;
102      QemuSemaphore postcopy_pause_sem_fault;
103  
104      /* List of listening socket addresses  */
105      SocketAddressList *socket_address_list;
106  };
107  
108  MigrationIncomingState *migration_incoming_get_current(void);
109  void migration_incoming_state_destroy(void);
110  /*
111   * Functions to work with blocktime context
112   */
113  void fill_destination_postcopy_migration_info(MigrationInfo *info);
114  
115  #define TYPE_MIGRATION "migration"
116  
117  #define MIGRATION_CLASS(klass) \
118      OBJECT_CLASS_CHECK(MigrationClass, (klass), TYPE_MIGRATION)
119  #define MIGRATION_OBJ(obj) \
120      OBJECT_CHECK(MigrationState, (obj), TYPE_MIGRATION)
121  #define MIGRATION_GET_CLASS(obj) \
122      OBJECT_GET_CLASS(MigrationClass, (obj), TYPE_MIGRATION)
123  
124  typedef struct MigrationClass {
125      /*< private >*/
126      DeviceClass parent_class;
127  } MigrationClass;
128  
129  struct MigrationState
130  {
131      /*< private >*/
132      DeviceState parent_obj;
133  
134      /*< public >*/
135      QemuThread thread;
136      QEMUBH *cleanup_bh;
137      QEMUFile *to_dst_file;
138      /*
139       * Protects to_dst_file pointer.  We need to make sure we won't
140       * yield or hang during the critical section, since this lock will
141       * be used in OOB command handler.
142       */
143      QemuMutex qemu_file_lock;
144  
145      /*
146       * Used to allow urgent requests to override rate limiting.
147       */
148      QemuSemaphore rate_limit_sem;
149  
150      /* pages already send at the beginning of current iteration */
151      uint64_t iteration_initial_pages;
152  
153      /* pages transferred per second */
154      double pages_per_second;
155  
156      /* bytes already send at the beginning of current iteration */
157      uint64_t iteration_initial_bytes;
158      /* time at the start of current iteration */
159      int64_t iteration_start_time;
160      /*
161       * The final stage happens when the remaining data is smaller than
162       * this threshold; it's calculated from the requested downtime and
163       * measured bandwidth
164       */
165      int64_t threshold_size;
166  
167      /* params from 'migrate-set-parameters' */
168      MigrationParameters parameters;
169  
170      int state;
171  
172      /* State related to return path */
173      struct {
174          QEMUFile     *from_dst_file;
175          QemuThread    rp_thread;
176          bool          error;
177          QemuSemaphore rp_sem;
178      } rp_state;
179  
180      double mbps;
181      /* Timestamp when recent migration starts (ms) */
182      int64_t start_time;
183      /* Total time used by latest migration (ms) */
184      int64_t total_time;
185      /* Timestamp when VM is down (ms) to migrate the last stuff */
186      int64_t downtime_start;
187      int64_t downtime;
188      int64_t expected_downtime;
189      bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
190      int64_t setup_time;
191      /*
192       * Whether guest was running when we enter the completion stage.
193       * If migration is interrupted by any reason, we need to continue
194       * running the guest on source.
195       */
196      bool vm_was_running;
197  
198      /* Flag set once the migration has been asked to enter postcopy */
199      bool start_postcopy;
200      /* Flag set after postcopy has sent the device state */
201      bool postcopy_after_devices;
202  
203      /* Flag set once the migration thread is running (and needs joining) */
204      bool migration_thread_running;
205  
206      /* Flag set once the migration thread called bdrv_inactivate_all */
207      bool block_inactive;
208  
209      /* Migration is waiting for guest to unplug device */
210      QemuSemaphore wait_unplug_sem;
211  
212      /* Migration is paused due to pause-before-switchover */
213      QemuSemaphore pause_sem;
214  
215      /* The semaphore is used to notify COLO thread that failover is finished */
216      QemuSemaphore colo_exit_sem;
217  
218      /* The semaphore is used to notify COLO thread to do checkpoint */
219      QemuSemaphore colo_checkpoint_sem;
220      int64_t colo_checkpoint_time;
221      QEMUTimer *colo_delay_timer;
222  
223      /* The first error that has occurred.
224         We used the mutex to be able to return the 1st error message */
225      Error *error;
226      /* mutex to protect errp */
227      QemuMutex error_mutex;
228  
229      /* Do we have to clean up -b/-i from old migrate parameters */
230      /* This feature is deprecated and will be removed */
231      bool must_remove_block_options;
232  
233      /*
234       * Global switch on whether we need to store the global state
235       * during migration.
236       */
237      bool store_global_state;
238  
239      /* Whether we send QEMU_VM_CONFIGURATION during migration */
240      bool send_configuration;
241      /* Whether we send section footer during migration */
242      bool send_section_footer;
243  
244      /* Needed by postcopy-pause state */
245      QemuSemaphore postcopy_pause_sem;
246      QemuSemaphore postcopy_pause_rp_sem;
247      /*
248       * Whether we abort the migration if decompression errors are
249       * detected at the destination. It is left at false for qemu
250       * older than 3.0, since only newer qemu sends streams that
251       * do not trigger spurious decompression errors.
252       */
253      bool decompress_error_check;
254  
255      /*
256       * This decides the size of guest memory chunk that will be used
257       * to track dirty bitmap clearing.  The size of memory chunk will
258       * be GUEST_PAGE_SIZE << N.  Say, N=0 means we will clear dirty
259       * bitmap for each page to send (1<<0=1); N=10 means we will clear
260       * dirty bitmap only once for 1<<10=1K continuous guest pages
261       * (which is in 4M chunk).
262       */
263      uint8_t clear_bitmap_shift;
264  };
265  
266  void migrate_set_state(int *state, int old_state, int new_state);
267  
268  void migration_fd_process_incoming(QEMUFile *f, Error **errp);
269  void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp);
270  void migration_incoming_process(void);
271  
272  bool  migration_has_all_channels(void);
273  
274  uint64_t migrate_max_downtime(void);
275  
276  void migrate_set_error(MigrationState *s, const Error *error);
277  void migrate_fd_error(MigrationState *s, const Error *error);
278  
279  void migrate_fd_connect(MigrationState *s, Error *error_in);
280  
281  bool migration_is_setup_or_active(int state);
282  bool migration_is_running(int state);
283  
284  void migrate_init(MigrationState *s);
285  bool migration_is_blocked(Error **errp);
286  /* True if outgoing migration has entered postcopy phase */
287  bool migration_in_postcopy(void);
288  MigrationState *migrate_get_current(void);
289  
290  bool migrate_postcopy(void);
291  
292  bool migrate_release_ram(void);
293  bool migrate_postcopy_ram(void);
294  bool migrate_zero_blocks(void);
295  bool migrate_dirty_bitmaps(void);
296  bool migrate_ignore_shared(void);
297  bool migrate_validate_uuid(void);
298  
299  bool migrate_auto_converge(void);
300  bool migrate_use_multifd(void);
301  bool migrate_pause_before_switchover(void);
302  int migrate_multifd_channels(void);
303  
304  int migrate_use_xbzrle(void);
305  int64_t migrate_xbzrle_cache_size(void);
306  bool migrate_colo_enabled(void);
307  
308  bool migrate_use_block(void);
309  bool migrate_use_block_incremental(void);
310  int migrate_max_cpu_throttle(void);
311  bool migrate_use_return_path(void);
312  
313  uint64_t ram_get_total_transferred_pages(void);
314  
315  bool migrate_use_compression(void);
316  int migrate_compress_level(void);
317  int migrate_compress_threads(void);
318  int migrate_compress_wait_thread(void);
319  int migrate_decompress_threads(void);
320  bool migrate_use_events(void);
321  bool migrate_postcopy_blocktime(void);
322  
323  /* Sending on the return path - generic and then for each message type */
324  void migrate_send_rp_shut(MigrationIncomingState *mis,
325                            uint32_t value);
326  void migrate_send_rp_pong(MigrationIncomingState *mis,
327                            uint32_t value);
328  int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
329                                ram_addr_t start, size_t len);
330  void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
331                                   char *block_name);
332  void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value);
333  
334  void dirty_bitmap_mig_before_vm_start(void);
335  void init_dirty_bitmap_incoming_migration(void);
336  void migrate_add_address(SocketAddress *address);
337  
338  int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque);
339  
340  #define qemu_ram_foreach_block \
341    #warning "Use foreach_not_ignored_block in migration code"
342  
343  void migration_make_urgent_request(void);
344  void migration_consume_urgent_request(void);
345  bool migration_rate_limit(void);
346  
347  #endif
348