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 bool multifd_send_setup(void);
  17 void multifd_send_shutdown(void);
  18 int multifd_recv_setup(Error **errp);
  19 void multifd_recv_cleanup(void);
  20 void multifd_recv_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 bool 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     bool thread_created;
  77     QemuThread tls_thread;
  78     bool tls_thread_created;
  79     /* communication channel */
  80     QIOChannel *c;
  81     /* is the yank function registered */
  82     bool registered_yank;
  83     /* packet allocated len */
  84     uint32_t packet_len;
  85     /* guest page size */
  86     uint32_t page_size;
  87     /* number of pages in a full packet */
  88     uint32_t page_count;
  89     /* multifd flags for sending ram */
  90     int write_flags;
  91
  92     /* sem where to wait for more work */
  93     QemuSemaphore sem;
  94     /* syncs main thread and channels */
  95     QemuSemaphore sem_sync;
  96
  97     /* multifd flags for each packet */
  98     uint32_t flags;
  99     /*
 100      * The sender thread has work to do if either of below boolean is set.
 101      *
 102      * @pending_job:  a job is pending
 103      * @pending_sync: a sync request is pending
 104      *
 105      * For both of these fields, they're only set by the requesters, and
 106      * cleared by the multifd sender threads.
 107      */
 108     bool pending_job;
 109     bool pending_sync;
 110     /* array of pages to sent.
 111      * The owner of 'pages' depends of 'pending_job' value:
 112      * pending_job == 0 -> migration_thread can use it.
 113      * pending_job != 0 -> multifd_channel can use it.
 114      */
 115     MultiFDPages_t *pages;
 116
 117     /* thread local variables. No locking required */
 118
 119     /* pointer to the packet */
 120     MultiFDPacket_t *packet;
 121     /* size of the next packet that contains pages */
 122     uint32_t next_packet_size;
 123     /* packets sent through this channel */
 124     uint64_t packets_sent;
 125     /* non zero pages sent through this channel */
 126     uint64_t total_normal_pages;
 127     /* buffers to send */
 128     struct iovec *iov;
 129     /* number of iovs used */
 130     uint32_t iovs_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     bool thread_created;
 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     /* should this thread finish */
 161     bool quit;
 162     /* multifd flags for each packet */
 163     uint32_t flags;
 164     /* global number of generated multifd packets */
 165     uint64_t packet_num;
 166
 167     /* thread local variables. No locking required */
 168
 169     /* pointer to the packet */
 170     MultiFDPacket_t *packet;
 171     /* size of the next packet that contains pages */
 172     uint32_t next_packet_size;
 173     /* packets received through this channel */
 174     uint64_t packets_recved;
 175     /* ramblock */
 176     RAMBlock *block;
 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 void multifd_send_fill_packet(MultiFDSendParams *p);
 208
 209 static inline void multifd_send_prepare_header(MultiFDSendParams *p)
 210 {
 211     p->iov[0].iov_len = p->packet_len;
 212     p->iov[0].iov_base = p->packet;
 213     p->iovs_num++;
 214 }
 215
 216
 217 #endif