xref: /openbmc/qemu/migration/multifd.h (revision 707ded20)
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 bool multifd_send_setup(void);
17 void multifd_send_shutdown(void);
18 int multifd_recv_setup(Error **errp);
19 void multifd_recv_cleanup(void);
20 void multifd_recv_shutdown(void);
21 bool multifd_recv_all_channels_created(void);
22 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
23 void multifd_recv_sync_main(void);
24 int multifd_send_sync_main(void);
25 bool multifd_queue_page(RAMBlock *block, ram_addr_t offset);
26 
27 /* Multifd Compression flags */
28 #define MULTIFD_FLAG_SYNC (1 << 0)
29 
30 /* We reserve 3 bits for compression methods */
31 #define MULTIFD_FLAG_COMPRESSION_MASK (7 << 1)
32 /* we need to be compatible. Before compression value was 0 */
33 #define MULTIFD_FLAG_NOCOMP (0 << 1)
34 #define MULTIFD_FLAG_ZLIB (1 << 1)
35 #define MULTIFD_FLAG_ZSTD (2 << 1)
36 
37 /* This value needs to be a multiple of qemu_target_page_size() */
38 #define MULTIFD_PACKET_SIZE (512 * 1024)
39 
40 typedef struct {
41     uint32_t magic;
42     uint32_t version;
43     uint32_t flags;
44     /* maximum number of allocated pages */
45     uint32_t pages_alloc;
46     /* non zero pages */
47     uint32_t normal_pages;
48     /* size of the next packet that contains pages */
49     uint32_t next_packet_size;
50     uint64_t packet_num;
51     uint64_t unused[4];    /* Reserved for future use */
52     char ramblock[256];
53     uint64_t offset[];
54 } __attribute__((packed)) MultiFDPacket_t;
55 
56 typedef struct {
57     /* number of used pages */
58     uint32_t num;
59     /* number of allocated pages */
60     uint32_t allocated;
61     /* offset of each page */
62     ram_addr_t *offset;
63     RAMBlock *block;
64 } MultiFDPages_t;
65 
66 typedef struct {
67     /* Fields are only written at creating/deletion time */
68     /* No lock required for them, they are read only */
69 
70     /* channel number */
71     uint8_t id;
72     /* channel thread name */
73     char *name;
74     /* channel thread id */
75     QemuThread thread;
76     bool thread_created;
77     QemuThread tls_thread;
78     bool tls_thread_created;
79     /* communication channel */
80     QIOChannel *c;
81     /* packet allocated len */
82     uint32_t packet_len;
83     /* guest page size */
84     uint32_t page_size;
85     /* number of pages in a full packet */
86     uint32_t page_count;
87     /* multifd flags for sending ram */
88     int write_flags;
89 
90     /* sem where to wait for more work */
91     QemuSemaphore sem;
92     /* syncs main thread and channels */
93     QemuSemaphore sem_sync;
94 
95     /* multifd flags for each packet */
96     uint32_t flags;
97     /*
98      * The sender thread has work to do if either of below boolean is set.
99      *
100      * @pending_job:  a job is pending
101      * @pending_sync: a sync request is pending
102      *
103      * For both of these fields, they're only set by the requesters, and
104      * cleared by the multifd sender threads.
105      */
106     bool pending_job;
107     bool pending_sync;
108     /* array of pages to sent.
109      * The owner of 'pages' depends of 'pending_job' value:
110      * pending_job == 0 -> migration_thread can use it.
111      * pending_job != 0 -> multifd_channel can use it.
112      */
113     MultiFDPages_t *pages;
114 
115     /* thread local variables. No locking required */
116 
117     /* pointer to the packet */
118     MultiFDPacket_t *packet;
119     /* size of the next packet that contains pages */
120     uint32_t next_packet_size;
121     /* packets sent through this channel */
122     uint64_t packets_sent;
123     /* non zero pages sent through this channel */
124     uint64_t total_normal_pages;
125     /* buffers to send */
126     struct iovec *iov;
127     /* number of iovs used */
128     uint32_t iovs_num;
129     /* used for compression methods */
130     void *data;
131 }  MultiFDSendParams;
132 
133 typedef struct {
134     /* Fields are only written at creating/deletion time */
135     /* No lock required for them, they are read only */
136 
137     /* channel number */
138     uint8_t id;
139     /* channel thread name */
140     char *name;
141     /* channel thread id */
142     QemuThread thread;
143     bool thread_created;
144     /* communication channel */
145     QIOChannel *c;
146     /* packet allocated len */
147     uint32_t packet_len;
148     /* guest page size */
149     uint32_t page_size;
150     /* number of pages in a full packet */
151     uint32_t page_count;
152 
153     /* syncs main thread and channels */
154     QemuSemaphore sem_sync;
155 
156     /* this mutex protects the following parameters */
157     QemuMutex mutex;
158     /* should this thread finish */
159     bool quit;
160     /* multifd flags for each packet */
161     uint32_t flags;
162     /* global number of generated multifd packets */
163     uint64_t packet_num;
164 
165     /* thread local variables. No locking required */
166 
167     /* pointer to the packet */
168     MultiFDPacket_t *packet;
169     /* size of the next packet that contains pages */
170     uint32_t next_packet_size;
171     /* packets received through this channel */
172     uint64_t packets_recved;
173     /* ramblock */
174     RAMBlock *block;
175     /* ramblock host address */
176     uint8_t *host;
177     /* non zero pages recv through this channel */
178     uint64_t total_normal_pages;
179     /* buffers to recv */
180     struct iovec *iov;
181     /* Pages that are not zero */
182     ram_addr_t *normal;
183     /* num of non zero pages */
184     uint32_t normal_num;
185     /* used for de-compression methods */
186     void *data;
187 } MultiFDRecvParams;
188 
189 typedef struct {
190     /* Setup for sending side */
191     int (*send_setup)(MultiFDSendParams *p, Error **errp);
192     /* Cleanup for sending side */
193     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
194     /* Prepare the send packet */
195     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
196     /* Setup for receiving side */
197     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
198     /* Cleanup for receiving side */
199     void (*recv_cleanup)(MultiFDRecvParams *p);
200     /* Read all pages */
201     int (*recv_pages)(MultiFDRecvParams *p, Error **errp);
202 } MultiFDMethods;
203 
204 void multifd_register_ops(int method, MultiFDMethods *ops);
205 void multifd_send_fill_packet(MultiFDSendParams *p);
206 
207 static inline void multifd_send_prepare_header(MultiFDSendParams *p)
208 {
209     p->iov[0].iov_len = p->packet_len;
210     p->iov[0].iov_base = p->packet;
211     p->iovs_num++;
212 }
213 
214 
215 #endif
216