xref: /openbmc/qemu/migration/multifd.h (revision b2580720)
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 #include "ram.h"
17 
18 typedef struct MultiFDRecvData MultiFDRecvData;
19 
20 bool multifd_send_setup(void);
21 void multifd_send_shutdown(void);
22 void multifd_send_channel_created(void);
23 int multifd_recv_setup(Error **errp);
24 void multifd_recv_cleanup(void);
25 void multifd_recv_shutdown(void);
26 bool multifd_recv_all_channels_created(void);
27 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
28 void multifd_recv_sync_main(void);
29 int multifd_send_sync_main(void);
30 bool multifd_queue_page(RAMBlock *block, ram_addr_t offset);
31 bool multifd_recv(void);
32 MultiFDRecvData *multifd_get_recv_data(void);
33 
34 /* Multifd Compression flags */
35 #define MULTIFD_FLAG_SYNC (1 << 0)
36 
37 /* We reserve 4 bits for compression methods */
38 #define MULTIFD_FLAG_COMPRESSION_MASK (0xf << 1)
39 /* we need to be compatible. Before compression value was 0 */
40 #define MULTIFD_FLAG_NOCOMP (0 << 1)
41 #define MULTIFD_FLAG_ZLIB (1 << 1)
42 #define MULTIFD_FLAG_ZSTD (2 << 1)
43 #define MULTIFD_FLAG_QPL (4 << 1)
44 #define MULTIFD_FLAG_UADK (8 << 1)
45 
46 /* This value needs to be a multiple of qemu_target_page_size() */
47 #define MULTIFD_PACKET_SIZE (512 * 1024)
48 
49 typedef struct {
50     uint32_t magic;
51     uint32_t version;
52     uint32_t flags;
53     /* maximum number of allocated pages */
54     uint32_t pages_alloc;
55     /* non zero pages */
56     uint32_t normal_pages;
57     /* size of the next packet that contains pages */
58     uint32_t next_packet_size;
59     uint64_t packet_num;
60     /* zero pages */
61     uint32_t zero_pages;
62     uint32_t unused32[1];    /* Reserved for future use */
63     uint64_t unused64[3];    /* Reserved for future use */
64     char ramblock[256];
65     /*
66      * This array contains the pointers to:
67      *  - normal pages (initial normal_pages entries)
68      *  - zero pages (following zero_pages entries)
69      */
70     uint64_t offset[];
71 } __attribute__((packed)) MultiFDPacket_t;
72 
73 typedef struct {
74     /* number of used pages */
75     uint32_t num;
76     /* number of normal pages */
77     uint32_t normal_num;
78     /* number of allocated pages */
79     uint32_t allocated;
80     /* offset of each page */
81     ram_addr_t *offset;
82     RAMBlock *block;
83 } MultiFDPages_t;
84 
85 struct MultiFDRecvData {
86     void *opaque;
87     size_t size;
88     /* for preadv */
89     off_t file_offset;
90 };
91 
92 typedef struct {
93     /* Fields are only written at creating/deletion time */
94     /* No lock required for them, they are read only */
95 
96     /* channel number */
97     uint8_t id;
98     /* channel thread name */
99     char *name;
100     /* channel thread id */
101     QemuThread thread;
102     bool thread_created;
103     QemuThread tls_thread;
104     bool tls_thread_created;
105     /* communication channel */
106     QIOChannel *c;
107     /* packet allocated len */
108     uint32_t packet_len;
109     /* guest page size */
110     uint32_t page_size;
111     /* number of pages in a full packet */
112     uint32_t page_count;
113     /* multifd flags for sending ram */
114     int write_flags;
115 
116     /* sem where to wait for more work */
117     QemuSemaphore sem;
118     /* syncs main thread and channels */
119     QemuSemaphore sem_sync;
120 
121     /* multifd flags for each packet */
122     uint32_t flags;
123     /*
124      * The sender thread has work to do if either of below boolean is set.
125      *
126      * @pending_job:  a job is pending
127      * @pending_sync: a sync request is pending
128      *
129      * For both of these fields, they're only set by the requesters, and
130      * cleared by the multifd sender threads.
131      */
132     bool pending_job;
133     bool pending_sync;
134     /* array of pages to sent.
135      * The owner of 'pages' depends of 'pending_job' value:
136      * pending_job == 0 -> migration_thread can use it.
137      * pending_job != 0 -> multifd_channel can use it.
138      */
139     MultiFDPages_t *pages;
140 
141     /* thread local variables. No locking required */
142 
143     /* pointer to the packet */
144     MultiFDPacket_t *packet;
145     /* size of the next packet that contains pages */
146     uint32_t next_packet_size;
147     /* packets sent through this channel */
148     uint64_t packets_sent;
149     /* non zero pages sent through this channel */
150     uint64_t total_normal_pages;
151     /* zero pages sent through this channel */
152     uint64_t total_zero_pages;
153     /* buffers to send */
154     struct iovec *iov;
155     /* number of iovs used */
156     uint32_t iovs_num;
157     /* used for compression methods */
158     void *compress_data;
159 }  MultiFDSendParams;
160 
161 typedef struct {
162     /* Fields are only written at creating/deletion time */
163     /* No lock required for them, they are read only */
164 
165     /* channel number */
166     uint8_t id;
167     /* channel thread name */
168     char *name;
169     /* channel thread id */
170     QemuThread thread;
171     bool thread_created;
172     /* communication channel */
173     QIOChannel *c;
174     /* packet allocated len */
175     uint32_t packet_len;
176     /* guest page size */
177     uint32_t page_size;
178     /* number of pages in a full packet */
179     uint32_t page_count;
180 
181     /* syncs main thread and channels */
182     QemuSemaphore sem_sync;
183     /* sem where to wait for more work */
184     QemuSemaphore sem;
185 
186     /* this mutex protects the following parameters */
187     QemuMutex mutex;
188     /* should this thread finish */
189     bool quit;
190     /* multifd flags for each packet */
191     uint32_t flags;
192     /* global number of generated multifd packets */
193     uint64_t packet_num;
194     int pending_job;
195     MultiFDRecvData *data;
196 
197     /* thread local variables. No locking required */
198 
199     /* pointer to the packet */
200     MultiFDPacket_t *packet;
201     /* size of the next packet that contains pages */
202     uint32_t next_packet_size;
203     /* packets received through this channel */
204     uint64_t packets_recved;
205     /* ramblock */
206     RAMBlock *block;
207     /* ramblock host address */
208     uint8_t *host;
209     /* non zero pages recv through this channel */
210     uint64_t total_normal_pages;
211     /* zero pages recv through this channel */
212     uint64_t total_zero_pages;
213     /* buffers to recv */
214     struct iovec *iov;
215     /* Pages that are not zero */
216     ram_addr_t *normal;
217     /* num of non zero pages */
218     uint32_t normal_num;
219     /* Pages that are zero */
220     ram_addr_t *zero;
221     /* num of zero pages */
222     uint32_t zero_num;
223     /* used for de-compression methods */
224     void *compress_data;
225 } MultiFDRecvParams;
226 
227 typedef struct {
228     /* Setup for sending side */
229     int (*send_setup)(MultiFDSendParams *p, Error **errp);
230     /* Cleanup for sending side */
231     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
232     /* Prepare the send packet */
233     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
234     /* Setup for receiving side */
235     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
236     /* Cleanup for receiving side */
237     void (*recv_cleanup)(MultiFDRecvParams *p);
238     /* Read all data */
239     int (*recv)(MultiFDRecvParams *p, Error **errp);
240 } MultiFDMethods;
241 
242 void multifd_register_ops(int method, MultiFDMethods *ops);
243 void multifd_send_fill_packet(MultiFDSendParams *p);
244 bool multifd_send_prepare_common(MultiFDSendParams *p);
245 void multifd_send_zero_page_detect(MultiFDSendParams *p);
246 void multifd_recv_zero_page_process(MultiFDRecvParams *p);
247 
248 static inline void multifd_send_prepare_header(MultiFDSendParams *p)
249 {
250     p->iov[0].iov_len = p->packet_len;
251     p->iov[0].iov_base = p->packet;
252     p->iovs_num++;
253 }
254 
255 void multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc);
256 
257 #endif
258