xref: /openbmc/qemu/migration/migration.h (revision 0c4a94b8)
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 "qemu-common.h"
18 #include "qemu/thread.h"
19 #include "exec/cpu-common.h"
20 #include "qemu/coroutine_int.h"
21 #include "hw/qdev.h"
22 #include "io/channel.h"
23 
24 /* State for the incoming migration */
25 struct MigrationIncomingState {
26     QEMUFile *from_src_file;
27 
28     /*
29      * Free at the start of the main state load, set as the main thread finishes
30      * loading state.
31      */
32     QemuEvent main_thread_load_event;
33 
34     size_t         largest_page_size;
35     bool           have_fault_thread;
36     QemuThread     fault_thread;
37     QemuSemaphore  fault_thread_sem;
38     /* Set this when we want the fault thread to quit */
39     bool           fault_thread_quit;
40 
41     bool           have_listen_thread;
42     QemuThread     listen_thread;
43     QemuSemaphore  listen_thread_sem;
44 
45     /* For the kernel to send us notifications */
46     int       userfault_fd;
47     /* To notify the fault_thread to wake, e.g., when need to quit */
48     int       userfault_event_fd;
49     QEMUFile *to_src_file;
50     QemuMutex rp_mutex;    /* We send replies from multiple threads */
51     void     *postcopy_tmp_page;
52     void     *postcopy_tmp_zero_page;
53 
54     QEMUBH *bh;
55 
56     int state;
57 
58     bool have_colo_incoming_thread;
59     QemuThread colo_incoming_thread;
60     /* The coroutine we should enter (back) after failover */
61     Coroutine *migration_incoming_co;
62     QemuSemaphore colo_incoming_sem;
63 };
64 
65 MigrationIncomingState *migration_incoming_get_current(void);
66 void migration_incoming_state_destroy(void);
67 
68 #define TYPE_MIGRATION "migration"
69 
70 #define MIGRATION_CLASS(klass) \
71     OBJECT_CLASS_CHECK(MigrationClass, (klass), TYPE_MIGRATION)
72 #define MIGRATION_OBJ(obj) \
73     OBJECT_CHECK(MigrationState, (obj), TYPE_MIGRATION)
74 #define MIGRATION_GET_CLASS(obj) \
75     OBJECT_GET_CLASS(MigrationClass, (obj), TYPE_MIGRATION)
76 
77 typedef struct MigrationClass {
78     /*< private >*/
79     DeviceClass parent_class;
80 } MigrationClass;
81 
82 struct MigrationState
83 {
84     /*< private >*/
85     DeviceState parent_obj;
86 
87     /*< public >*/
88     size_t bytes_xfer;
89     size_t xfer_limit;
90     QemuThread thread;
91     QEMUBH *cleanup_bh;
92     QEMUFile *to_dst_file;
93 
94     /* bytes already send at the beggining of current interation */
95     uint64_t iteration_initial_bytes;
96     /* time at the start of current iteration */
97     int64_t iteration_start_time;
98     /*
99      * The final stage happens when the remaining data is smaller than
100      * this threshold; it's calculated from the requested downtime and
101      * measured bandwidth
102      */
103     int64_t threshold_size;
104 
105     /* params from 'migrate-set-parameters' */
106     MigrationParameters parameters;
107 
108     int state;
109 
110     /* State related to return path */
111     struct {
112         QEMUFile     *from_dst_file;
113         QemuThread    rp_thread;
114         bool          error;
115     } rp_state;
116 
117     double mbps;
118     /* Timestamp when recent migration starts (ms) */
119     int64_t start_time;
120     /* Total time used by latest migration (ms) */
121     int64_t total_time;
122     /* Timestamp when VM is down (ms) to migrate the last stuff */
123     int64_t downtime_start;
124     int64_t downtime;
125     int64_t expected_downtime;
126     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
127     int64_t setup_time;
128     /*
129      * Whether guest was running when we enter the completion stage.
130      * If migration is interrupted by any reason, we need to continue
131      * running the guest on source.
132      */
133     bool vm_was_running;
134 
135     /* Flag set once the migration has been asked to enter postcopy */
136     bool start_postcopy;
137     /* Flag set after postcopy has sent the device state */
138     bool postcopy_after_devices;
139 
140     /* Flag set once the migration thread is running (and needs joining) */
141     bool migration_thread_running;
142 
143     /* Flag set once the migration thread called bdrv_inactivate_all */
144     bool block_inactive;
145 
146     /* Migration is paused due to pause-before-switchover */
147     QemuSemaphore pause_sem;
148 
149     /* The semaphore is used to notify COLO thread that failover is finished */
150     QemuSemaphore colo_exit_sem;
151 
152     /* The semaphore is used to notify COLO thread to do checkpoint */
153     QemuSemaphore colo_checkpoint_sem;
154     int64_t colo_checkpoint_time;
155     QEMUTimer *colo_delay_timer;
156 
157     /* The first error that has occurred.
158        We used the mutex to be able to return the 1st error message */
159     Error *error;
160     /* mutex to protect errp */
161     QemuMutex error_mutex;
162 
163     /* Do we have to clean up -b/-i from old migrate parameters */
164     /* This feature is deprecated and will be removed */
165     bool must_remove_block_options;
166 
167     /*
168      * Global switch on whether we need to store the global state
169      * during migration.
170      */
171     bool store_global_state;
172 
173     /* Whether the VM is only allowing for migratable devices */
174     bool only_migratable;
175 
176     /* Whether we send QEMU_VM_CONFIGURATION during migration */
177     bool send_configuration;
178     /* Whether we send section footer during migration */
179     bool send_section_footer;
180 };
181 
182 void migrate_set_state(int *state, int old_state, int new_state);
183 
184 void migration_fd_process_incoming(QEMUFile *f);
185 void migration_ioc_process_incoming(QIOChannel *ioc);
186 
187 bool  migration_has_all_channels(void);
188 
189 uint64_t migrate_max_downtime(void);
190 
191 void migrate_set_error(MigrationState *s, const Error *error);
192 void migrate_fd_error(MigrationState *s, const Error *error);
193 
194 void migrate_fd_connect(MigrationState *s, Error *error_in);
195 
196 void migrate_init(MigrationState *s);
197 bool migration_is_blocked(Error **errp);
198 /* True if outgoing migration has entered postcopy phase */
199 bool migration_in_postcopy(void);
200 MigrationState *migrate_get_current(void);
201 
202 bool migrate_postcopy(void);
203 
204 bool migrate_release_ram(void);
205 bool migrate_postcopy_ram(void);
206 bool migrate_zero_blocks(void);
207 
208 bool migrate_auto_converge(void);
209 bool migrate_use_multifd(void);
210 bool migrate_pause_before_switchover(void);
211 int migrate_multifd_channels(void);
212 int migrate_multifd_page_count(void);
213 
214 int migrate_use_xbzrle(void);
215 int64_t migrate_xbzrle_cache_size(void);
216 bool migrate_colo_enabled(void);
217 
218 bool migrate_use_block(void);
219 bool migrate_use_block_incremental(void);
220 bool migrate_use_return_path(void);
221 
222 bool migrate_use_compression(void);
223 int migrate_compress_level(void);
224 int migrate_compress_threads(void);
225 int migrate_decompress_threads(void);
226 bool migrate_use_events(void);
227 
228 /* Sending on the return path - generic and then for each message type */
229 void migrate_send_rp_shut(MigrationIncomingState *mis,
230                           uint32_t value);
231 void migrate_send_rp_pong(MigrationIncomingState *mis,
232                           uint32_t value);
233 int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
234                               ram_addr_t start, size_t len);
235 
236 #endif
237