migration/multifd.h

   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 3 bits for compression methods */
  38 #define MULTIFD_FLAG_COMPRESSION_MASK (7 << 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
  44 /* This value needs to be a multiple of qemu_target_page_size() */
  45 #define MULTIFD_PACKET_SIZE (512 * 1024)
  46
  47 typedef struct {
  48     uint32_t magic;
  49     uint32_t version;
  50     uint32_t flags;
  51     /* maximum number of allocated pages */
  52     uint32_t pages_alloc;
  53     /* non zero pages */
  54     uint32_t normal_pages;
  55     /* size of the next packet that contains pages */
  56     uint32_t next_packet_size;
  57     uint64_t packet_num;
  58     /* zero pages */
  59     uint32_t zero_pages;
  60     uint32_t unused32[1];    /* Reserved for future use */
  61     uint64_t unused64[3];    /* Reserved for future use */
  62     char ramblock[256];
  63     /*
  64      * This array contains the pointers to:
  65      *  - normal pages (initial normal_pages entries)
  66      *  - zero pages (following zero_pages entries)
  67      */
  68     uint64_t offset[];
  69 } __attribute__((packed)) MultiFDPacket_t;
  70
  71 typedef struct {
  72     /* number of used pages */
  73     uint32_t num;
  74     /* number of normal pages */
  75     uint32_t normal_num;
  76     /* number of allocated pages */
  77     uint32_t allocated;
  78     /* offset of each page */
  79     ram_addr_t *offset;
  80     RAMBlock *block;
  81 } MultiFDPages_t;
  82
  83 struct MultiFDRecvData {
  84     void *opaque;
  85     size_t size;
  86     /* for preadv */
  87     off_t file_offset;
  88 };
  89
  90 typedef struct {
  91     /* Fields are only written at creating/deletion time */
  92     /* No lock required for them, they are read only */
  93
  94     /* channel number */
  95     uint8_t id;
  96     /* channel thread name */
  97     char *name;
  98     /* channel thread id */
  99     QemuThread thread;
 100     bool thread_created;
 101     QemuThread tls_thread;
 102     bool tls_thread_created;
 103     /* communication channel */
 104     QIOChannel *c;
 105     /* packet allocated len */
 106     uint32_t packet_len;
 107     /* guest page size */
 108     uint32_t page_size;
 109     /* number of pages in a full packet */
 110     uint32_t page_count;
 111     /* multifd flags for sending ram */
 112     int write_flags;
 113
 114     /* sem where to wait for more work */
 115     QemuSemaphore sem;
 116     /* syncs main thread and channels */
 117     QemuSemaphore sem_sync;
 118
 119     /* multifd flags for each packet */
 120     uint32_t flags;
 121     /*
 122      * The sender thread has work to do if either of below boolean is set.
 123      *
 124      * @pending_job:  a job is pending
 125      * @pending_sync: a sync request is pending
 126      *
 127      * For both of these fields, they're only set by the requesters, and
 128      * cleared by the multifd sender threads.
 129      */
 130     bool pending_job;
 131     bool pending_sync;
 132     /* array of pages to sent.
 133      * The owner of 'pages' depends of 'pending_job' value:
 134      * pending_job == 0 -> migration_thread can use it.
 135      * pending_job != 0 -> multifd_channel can use it.
 136      */
 137     MultiFDPages_t *pages;
 138
 139     /* thread local variables. No locking required */
 140
 141     /* pointer to the packet */
 142     MultiFDPacket_t *packet;
 143     /* size of the next packet that contains pages */
 144     uint32_t next_packet_size;
 145     /* packets sent through this channel */
 146     uint64_t packets_sent;
 147     /* non zero pages sent through this channel */
 148     uint64_t total_normal_pages;
 149     /* zero pages sent through this channel */
 150     uint64_t total_zero_pages;
 151     /* buffers to send */
 152     struct iovec *iov;
 153     /* number of iovs used */
 154     uint32_t iovs_num;
 155     /* used for compression methods */
 156     void *compress_data;
 157 }  MultiFDSendParams;
 158
 159 typedef struct {
 160     /* Fields are only written at creating/deletion time */
 161     /* No lock required for them, they are read only */
 162
 163     /* channel number */
 164     uint8_t id;
 165     /* channel thread name */
 166     char *name;
 167     /* channel thread id */
 168     QemuThread thread;
 169     bool thread_created;
 170     /* communication channel */
 171     QIOChannel *c;
 172     /* packet allocated len */
 173     uint32_t packet_len;
 174     /* guest page size */
 175     uint32_t page_size;
 176     /* number of pages in a full packet */
 177     uint32_t page_count;
 178
 179     /* syncs main thread and channels */
 180     QemuSemaphore sem_sync;
 181     /* sem where to wait for more work */
 182     QemuSemaphore sem;
 183
 184     /* this mutex protects the following parameters */
 185     QemuMutex mutex;
 186     /* should this thread finish */
 187     bool quit;
 188     /* multifd flags for each packet */
 189     uint32_t flags;
 190     /* global number of generated multifd packets */
 191     uint64_t packet_num;
 192     int pending_job;
 193     MultiFDRecvData *data;
 194
 195     /* thread local variables. No locking required */
 196
 197     /* pointer to the packet */
 198     MultiFDPacket_t *packet;
 199     /* size of the next packet that contains pages */
 200     uint32_t next_packet_size;
 201     /* packets received through this channel */
 202     uint64_t packets_recved;
 203     /* ramblock */
 204     RAMBlock *block;
 205     /* ramblock host address */
 206     uint8_t *host;
 207     /* non zero pages recv through this channel */
 208     uint64_t total_normal_pages;
 209     /* zero pages recv through this channel */
 210     uint64_t total_zero_pages;
 211     /* buffers to recv */
 212     struct iovec *iov;
 213     /* Pages that are not zero */
 214     ram_addr_t *normal;
 215     /* num of non zero pages */
 216     uint32_t normal_num;
 217     /* Pages that are zero */
 218     ram_addr_t *zero;
 219     /* num of zero pages */
 220     uint32_t zero_num;
 221     /* used for de-compression methods */
 222     void *compress_data;
 223 } MultiFDRecvParams;
 224
 225 typedef struct {
 226     /* Setup for sending side */
 227     int (*send_setup)(MultiFDSendParams *p, Error **errp);
 228     /* Cleanup for sending side */
 229     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
 230     /* Prepare the send packet */
 231     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
 232     /* Setup for receiving side */
 233     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
 234     /* Cleanup for receiving side */
 235     void (*recv_cleanup)(MultiFDRecvParams *p);
 236     /* Read all data */
 237     int (*recv)(MultiFDRecvParams *p, Error **errp);
 238 } MultiFDMethods;
 239
 240 void multifd_register_ops(int method, MultiFDMethods *ops);
 241 void multifd_send_fill_packet(MultiFDSendParams *p);
 242 bool multifd_send_prepare_common(MultiFDSendParams *p);
 243 void multifd_send_zero_page_detect(MultiFDSendParams *p);
 244 void multifd_recv_zero_page_process(MultiFDRecvParams *p);
 245
 246 static inline void multifd_send_prepare_header(MultiFDSendParams *p)
 247 {
 248     p->iov[0].iov_len = p->packet_len;
 249     p->iov[0].iov_base = p->packet;
 250     p->iovs_num++;
 251 }
 252
 253 void multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc);
 254
 255 #endif