xref: /openbmc/qemu/migration/multifd.h (revision d525f73f)
1 /*
2  * Multifd common functions
3  *
4  * Copyright (c) 2019-2020 Red Hat Inc
5  *
6  * Authors:
7  *  Juan Quintela <quintela@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 
13 #ifndef QEMU_MIGRATION_MULTIFD_H
14 #define QEMU_MIGRATION_MULTIFD_H
15 
16 int multifd_save_setup(Error **errp);
17 void multifd_save_cleanup(void);
18 int multifd_load_setup(Error **errp);
19 int multifd_load_cleanup(Error **errp);
20 bool multifd_recv_all_channels_created(void);
21 bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
22 void multifd_recv_sync_main(void);
23 int multifd_send_sync_main(QEMUFile *f);
24 int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset);
25 
26 /* Multifd Compression flags */
27 #define MULTIFD_FLAG_SYNC (1 << 0)
28 
29 /* We reserve 3 bits for compression methods */
30 #define MULTIFD_FLAG_COMPRESSION_MASK (7 << 1)
31 /* we need to be compatible. Before compression value was 0 */
32 #define MULTIFD_FLAG_NOCOMP (0 << 1)
33 #define MULTIFD_FLAG_ZLIB (1 << 1)
34 #define MULTIFD_FLAG_ZSTD (2 << 1)
35 
36 /* This value needs to be a multiple of qemu_target_page_size() */
37 #define MULTIFD_PACKET_SIZE (512 * 1024)
38 
39 typedef struct {
40     uint32_t magic;
41     uint32_t version;
42     uint32_t flags;
43     /* maximum number of allocated pages */
44     uint32_t pages_alloc;
45     /* non zero pages */
46     uint32_t normal_pages;
47     /* size of the next packet that contains pages */
48     uint32_t next_packet_size;
49     uint64_t packet_num;
50     uint64_t unused[4];    /* Reserved for future use */
51     char ramblock[256];
52     uint64_t offset[];
53 } __attribute__((packed)) MultiFDPacket_t;
54 
55 typedef struct {
56     /* number of used pages */
57     uint32_t num;
58     /* number of allocated pages */
59     uint32_t allocated;
60     /* global number of generated multifd packets */
61     uint64_t packet_num;
62     /* offset of each page */
63     ram_addr_t *offset;
64     RAMBlock *block;
65 } MultiFDPages_t;
66 
67 typedef struct {
68     /* Fields are only written at creating/deletion time */
69     /* No lock required for them, they are read only */
70 
71     /* channel number */
72     uint8_t id;
73     /* channel thread name */
74     char *name;
75     /* channel thread id */
76     QemuThread thread;
77     /* communication channel */
78     QIOChannel *c;
79     /* is the yank function registered */
80     bool registered_yank;
81     /* packet allocated len */
82     uint32_t packet_len;
83     /* multifd flags for sending ram */
84     int write_flags;
85 
86     /* sem where to wait for more work */
87     QemuSemaphore sem;
88     /* syncs main thread and channels */
89     QemuSemaphore sem_sync;
90 
91     /* this mutex protects the following parameters */
92     QemuMutex mutex;
93     /* is this channel thread running */
94     bool running;
95     /* should this thread finish */
96     bool quit;
97     /* multifd flags for each packet */
98     uint32_t flags;
99     /* global number of generated multifd packets */
100     uint64_t packet_num;
101     /* thread has work to do */
102     int pending_job;
103     /* array of pages to sent.
104      * The owner of 'pages' depends of 'pending_job' value:
105      * pending_job == 0 -> migration_thread can use it.
106      * pending_job != 0 -> multifd_channel can use it.
107      */
108     MultiFDPages_t *pages;
109 
110     /* thread local variables. No locking required */
111 
112     /* pointer to the packet */
113     MultiFDPacket_t *packet;
114     /* size of the next packet that contains pages */
115     uint32_t next_packet_size;
116     /* packets sent through this channel */
117     uint64_t num_packets;
118     /* non zero pages sent through this channel */
119     uint64_t total_normal_pages;
120     /* buffers to send */
121     struct iovec *iov;
122     /* number of iovs used */
123     uint32_t iovs_num;
124     /* Pages that are not zero */
125     ram_addr_t *normal;
126     /* num of non zero pages */
127     uint32_t normal_num;
128     /* used for compression methods */
129     void *data;
130 }  MultiFDSendParams;
131 
132 typedef struct {
133     /* Fields are only written at creating/deletion time */
134     /* No lock required for them, they are read only */
135 
136     /* channel number */
137     uint8_t id;
138     /* channel thread name */
139     char *name;
140     /* channel thread id */
141     QemuThread thread;
142     /* communication channel */
143     QIOChannel *c;
144     /* packet allocated len */
145     uint32_t packet_len;
146 
147     /* syncs main thread and channels */
148     QemuSemaphore sem_sync;
149 
150     /* this mutex protects the following parameters */
151     QemuMutex mutex;
152     /* is this channel thread running */
153     bool running;
154     /* should this thread finish */
155     bool quit;
156     /* multifd flags for each packet */
157     uint32_t flags;
158     /* global number of generated multifd packets */
159     uint64_t packet_num;
160 
161     /* thread local variables. No locking required */
162 
163     /* pointer to the packet */
164     MultiFDPacket_t *packet;
165     /* size of the next packet that contains pages */
166     uint32_t next_packet_size;
167     /* packets sent through this channel */
168     uint64_t num_packets;
169     /* ramblock host address */
170     uint8_t *host;
171     /* non zero pages recv through this channel */
172     uint64_t total_normal_pages;
173     /* buffers to recv */
174     struct iovec *iov;
175     /* Pages that are not zero */
176     ram_addr_t *normal;
177     /* num of non zero pages */
178     uint32_t normal_num;
179     /* used for de-compression methods */
180     void *data;
181 } MultiFDRecvParams;
182 
183 typedef struct {
184     /* Setup for sending side */
185     int (*send_setup)(MultiFDSendParams *p, Error **errp);
186     /* Cleanup for sending side */
187     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
188     /* Prepare the send packet */
189     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
190     /* Setup for receiving side */
191     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
192     /* Cleanup for receiving side */
193     void (*recv_cleanup)(MultiFDRecvParams *p);
194     /* Read all pages */
195     int (*recv_pages)(MultiFDRecvParams *p, Error **errp);
196 } MultiFDMethods;
197 
198 void multifd_register_ops(int method, MultiFDMethods *ops);
199 
200 #endif
201 
202