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 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     /* 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     /* this mutex protects the following parameters */
  96     QemuMutex mutex;
  97     /* is this channel thread running */
  98     bool running;
  99     /* should this thread finish */
 100     bool quit;
 101     /* multifd flags for each packet */
 102     uint32_t flags;
 103     /* global number of generated multifd packets */
 104     uint64_t packet_num;
 105     /* thread has work to do */
 106     int pending_job;
 107     /* array of pages to sent.
 108      * The owner of 'pages' depends of 'pending_job' value:
 109      * pending_job == 0 -> migration_thread can use it.
 110      * pending_job != 0 -> multifd_channel can use it.
 111      */
 112     MultiFDPages_t *pages;
 113
 114     /* thread local variables. No locking required */
 115
 116     /* pointer to the packet */
 117     MultiFDPacket_t *packet;
 118     /* size of the next packet that contains pages */
 119     uint32_t next_packet_size;
 120     /* packets sent through this channel */
 121     uint64_t num_packets;
 122     /* non zero pages sent through this channel */
 123     uint64_t total_normal_pages;
 124     /* buffers to send */
 125     struct iovec *iov;
 126     /* number of iovs used */
 127     uint32_t iovs_num;
 128     /* Pages that are not zero */
 129     ram_addr_t *normal;
 130     /* num of non zero pages */
 131     uint32_t normal_num;
 132     /* used for compression methods */
 133     void *data;
 134 }  MultiFDSendParams;
 135
 136 typedef struct {
 137     /* Fields are only written at creating/deletion time */
 138     /* No lock required for them, they are read only */
 139
 140     /* channel number */
 141     uint8_t id;
 142     /* channel thread name */
 143     char *name;
 144     /* channel thread id */
 145     QemuThread thread;
 146     /* communication channel */
 147     QIOChannel *c;
 148     /* packet allocated len */
 149     uint32_t packet_len;
 150     /* guest page size */
 151     uint32_t page_size;
 152     /* number of pages in a full packet */
 153     uint32_t page_count;
 154
 155     /* syncs main thread and channels */
 156     QemuSemaphore sem_sync;
 157
 158     /* this mutex protects the following parameters */
 159     QemuMutex mutex;
 160     /* is this channel thread running */
 161     bool running;
 162     /* should this thread finish */
 163     bool quit;
 164     /* multifd flags for each packet */
 165     uint32_t flags;
 166     /* global number of generated multifd packets */
 167     uint64_t packet_num;
 168
 169     /* thread local variables. No locking required */
 170
 171     /* pointer to the packet */
 172     MultiFDPacket_t *packet;
 173     /* size of the next packet that contains pages */
 174     uint32_t next_packet_size;
 175     /* packets sent through this channel */
 176     uint64_t num_packets;
 177     /* ramblock host address */
 178     uint8_t *host;
 179     /* non zero pages recv through this channel */
 180     uint64_t total_normal_pages;
 181     /* buffers to recv */
 182     struct iovec *iov;
 183     /* Pages that are not zero */
 184     ram_addr_t *normal;
 185     /* num of non zero pages */
 186     uint32_t normal_num;
 187     /* used for de-compression methods */
 188     void *data;
 189 } MultiFDRecvParams;
 190
 191 typedef struct {
 192     /* Setup for sending side */
 193     int (*send_setup)(MultiFDSendParams *p, Error **errp);
 194     /* Cleanup for sending side */
 195     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
 196     /* Prepare the send packet */
 197     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
 198     /* Setup for receiving side */
 199     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
 200     /* Cleanup for receiving side */
 201     void (*recv_cleanup)(MultiFDRecvParams *p);
 202     /* Read all pages */
 203     int (*recv_pages)(MultiFDRecvParams *p, Error **errp);
 204 } MultiFDMethods;
 205
 206 void multifd_register_ops(int method, MultiFDMethods *ops);
 207
 208 #endif
 209