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(void);
  25 int 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     /* communication channel */
  77     QIOChannel *c;
  78     /* is the yank function registered */
  79     bool registered_yank;
  80     /* packet allocated len */
  81     uint32_t packet_len;
  82     /* guest page size */
  83     uint32_t page_size;
  84     /* number of pages in a full packet */
  85     uint32_t page_count;
  86     /* multifd flags for sending ram */
  87     int write_flags;
  88
  89     /* sem where to wait for more work */
  90     QemuSemaphore sem;
  91     /* syncs main thread and channels */
  92     QemuSemaphore sem_sync;
  93
  94     /* this mutex protects the following parameters */
  95     QemuMutex mutex;
  96     /* is this channel thread running */
  97     bool running;
  98     /* should this thread finish */
  99     bool quit;
 100     /* multifd flags for each packet */
 101     uint32_t flags;
 102     /* global number of generated multifd packets */
 103     uint64_t packet_num;
 104     /* thread has work to do */
 105     int pending_job;
 106     /* array of pages to sent.
 107      * The owner of 'pages' depends of 'pending_job' value:
 108      * pending_job == 0 -> migration_thread can use it.
 109      * pending_job != 0 -> multifd_channel can use it.
 110      */
 111     MultiFDPages_t *pages;
 112
 113     /* thread local variables. No locking required */
 114
 115     /* pointer to the packet */
 116     MultiFDPacket_t *packet;
 117     /* size of the next packet that contains pages */
 118     uint32_t next_packet_size;
 119     /* packets sent through this channel */
 120     uint64_t num_packets;
 121     /* non zero pages sent through this channel */
 122     uint64_t total_normal_pages;
 123     /* buffers to send */
 124     struct iovec *iov;
 125     /* number of iovs used */
 126     uint32_t iovs_num;
 127     /* Pages that are not zero */
 128     ram_addr_t *normal;
 129     /* num of non zero pages */
 130     uint32_t normal_num;
 131     /* used for compression methods */
 132     void *data;
 133 }  MultiFDSendParams;
 134
 135 typedef struct {
 136     /* Fields are only written at creating/deletion time */
 137     /* No lock required for them, they are read only */
 138
 139     /* channel number */
 140     uint8_t id;
 141     /* channel thread name */
 142     char *name;
 143     /* channel thread id */
 144     QemuThread thread;
 145     /* communication channel */
 146     QIOChannel *c;
 147     /* packet allocated len */
 148     uint32_t packet_len;
 149     /* guest page size */
 150     uint32_t page_size;
 151     /* number of pages in a full packet */
 152     uint32_t page_count;
 153
 154     /* syncs main thread and channels */
 155     QemuSemaphore sem_sync;
 156
 157     /* this mutex protects the following parameters */
 158     QemuMutex mutex;
 159     /* is this channel thread running */
 160     bool running;
 161     /* should this thread finish */
 162     bool quit;
 163     /* multifd flags for each packet */
 164     uint32_t flags;
 165     /* global number of generated multifd packets */
 166     uint64_t packet_num;
 167
 168     /* thread local variables. No locking required */
 169
 170     /* pointer to the packet */
 171     MultiFDPacket_t *packet;
 172     /* size of the next packet that contains pages */
 173     uint32_t next_packet_size;
 174     /* packets sent through this channel */
 175     uint64_t num_packets;
 176     /* ramblock */
 177     RAMBlock *block;
 178     /* ramblock host address */
 179     uint8_t *host;
 180     /* non zero pages recv through this channel */
 181     uint64_t total_normal_pages;
 182     /* buffers to recv */
 183     struct iovec *iov;
 184     /* Pages that are not zero */
 185     ram_addr_t *normal;
 186     /* num of non zero pages */
 187     uint32_t normal_num;
 188     /* used for de-compression methods */
 189     void *data;
 190 } MultiFDRecvParams;
 191
 192 typedef struct {
 193     /* Setup for sending side */
 194     int (*send_setup)(MultiFDSendParams *p, Error **errp);
 195     /* Cleanup for sending side */
 196     void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
 197     /* Prepare the send packet */
 198     int (*send_prepare)(MultiFDSendParams *p, Error **errp);
 199     /* Setup for receiving side */
 200     int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
 201     /* Cleanup for receiving side */
 202     void (*recv_cleanup)(MultiFDRecvParams *p);
 203     /* Read all pages */
 204     int (*recv_pages)(MultiFDRecvParams *p, Error **errp);
 205 } MultiFDMethods;
 206
 207 void multifd_register_ops(int method, MultiFDMethods *ops);
 208
 209 #endif
 210