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 int multifd_save_setup(Error **errp);
  17 void multifd_save_cleanup(void);
  18 int multifd_load_setup(Error **errp);
  19 void multifd_load_cleanup(void);
  20 void multifd_load_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(QEMUFile *f);
  25 int multifd_queue_page(QEMUFile *f, 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     /* global number of generated multifd packets */
  62     uint64_t packet_num;
  63     /* offset of each page */
  64     ram_addr_t *offset;
  65     RAMBlock *block;
  66 } MultiFDPages_t;
  67
  68 typedef struct {
  69     /* Fields are only written at creating/deletion time */
  70     /* No lock required for them, they are read only */
  71
  72     /* channel number */
  73     uint8_t id;
  74     /* channel thread name */
  75     char *name;
  76     /* channel thread id */
  77     QemuThread thread;
  78     /* communication channel */
  79     QIOChannel *c;
  80     /* is the yank function registered */
  81     bool registered_yank;
  82     /* packet allocated len */
  83     uint32_t packet_len;
  84     /* guest page size */
  85     uint32_t page_size;
  86     /* number of pages in a full packet */
  87     uint32_t page_count;
  88     /* multifd flags for sending ram */
  89     int write_flags;
  90
  91     /* sem where to wait for more work */
  92     QemuSemaphore sem;
  93     /* syncs main thread and channels */
  94     QemuSemaphore sem_sync;
  95
  96     /* this mutex protects the following parameters */
  97     QemuMutex mutex;
  98     /* is this channel thread running */
  99     bool running;
 100     /* should this thread finish */
 101     bool quit;
 102     /* multifd flags for each packet */
 103     uint32_t flags;
 104     /* global number of generated multifd packets */
 105     uint64_t packet_num;
 106     /* thread has work to do */
 107     int pending_job;
 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 num_packets;
 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     /* Pages that are not zero */
 130     ram_addr_t *normal;
 131     /* num of non zero pages */
 132     uint32_t normal_num;
 133     /* used for compression methods */
 134     void *data;
 135 }  MultiFDSendParams;
 136
 137 typedef struct {
 138     /* Fields are only written at creating/deletion time */
 139     /* No lock required for them, they are read only */
 140
 141     /* channel number */
 142     uint8_t id;
 143     /* channel thread name */
 144     char *name;
 145     /* channel thread id */
 146     QemuThread thread;
 147     /* communication channel */
 148     QIOChannel *c;
 149     /* packet allocated len */
 150     uint32_t packet_len;
 151     /* guest page size */
 152     uint32_t page_size;
 153     /* number of pages in a full packet */
 154     uint32_t page_count;
 155
 156     /* syncs main thread and channels */
 157     QemuSemaphore sem_sync;
 158
 159     /* this mutex protects the following parameters */
 160     QemuMutex mutex;
 161     /* is this channel thread running */
 162     bool running;
 163     /* should this thread finish */
 164     bool quit;
 165     /* multifd flags for each packet */
 166     uint32_t flags;
 167     /* global number of generated multifd packets */
 168     uint64_t packet_num;
 169
 170     /* thread local variables. No locking required */
 171
 172     /* pointer to the packet */
 173     MultiFDPacket_t *packet;
 174     /* size of the next packet that contains pages */
 175     uint32_t next_packet_size;
 176     /* packets sent through this channel */
 177     uint64_t num_packets;
 178     /* ramblock */
 179     RAMBlock *block;
 180     /* ramblock host address */
 181     uint8_t *host;
 182     /* non zero pages recv through this channel */
 183     uint64_t total_normal_pages;
 184     /* buffers to recv */
 185     struct iovec *iov;
 186     /* Pages that are not zero */
 187     ram_addr_t *normal;
 188     /* num of non zero pages */
 189     uint32_t normal_num;
 190     /* used for de-compression methods */
 191     void *data;
 192 } MultiFDRecvParams;
 193
 194 typedef struct {
 195     /* Setup for sending side */
 196     int (*send_setup)(MultiFDSendParams *p, Error **errp);
 197     /* Cleanup for sending side */
 198     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
 199     /* Prepare the send packet */
 200     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
 201     /* Setup for receiving side */
 202     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
 203     /* Cleanup for receiving side */
 204     void (*recv_cleanup)(MultiFDRecvParams *p);
 205     /* Read all pages */
 206     int (*recv_pages)(MultiFDRecvParams *p, Error **errp);
 207 } MultiFDMethods;
 208
 209 void multifd_register_ops(int method, MultiFDMethods *ops);
 210
 211 #endif
 212