migration-exec.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  * Copyright Dell MessageOne 2008
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <[email protected]>
   9  *  Charles Duffy     <[email protected]>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2.  See
  12  * the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu-common.h"
  17 #include "qemu_socket.h"
  18 #include "migration.h"
  19 #include "qemu-char.h"
  20 #include "sysemu.h"
  21 #include "buffered_file.h"
  22 #include "block.h"
  23 #include <sys/types.h>
  24 #include <sys/wait.h>
  25
  26 //#define DEBUG_MIGRATION_EXEC
  27
  28 #ifdef DEBUG_MIGRATION_EXEC
  29 #define DPRINTF(fmt, ...) \
  30     do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  31 #else
  32 #define DPRINTF(fmt, ...) \
  33     do { } while (0)
  34 #endif
  35
  36 static int file_errno(FdMigrationState *s)
  37 {
  38     return errno;
  39 }
  40
  41 static int file_write(FdMigrationState *s, const void * buf, size_t size)
  42 {
  43     return write(s->fd, buf, size);
  44 }
  45
  46 static int exec_close(FdMigrationState *s)
  47 {
  48     int ret = 0;
  49     DPRINTF("exec_close\n");
  50     if (s->opaque) {
  51         ret = qemu_fclose(s->opaque);
  52         s->opaque = NULL;
  53         s->fd = -1;
  54         if (ret != -1 &&
  55             WIFEXITED(ret)
  56             && WEXITSTATUS(ret) == 0) {
  57             ret = 0;
  58         } else {
  59             ret = -1;
  60         }
  61     }
  62     return ret;
  63 }
  64
  65 MigrationState *exec_start_outgoing_migration(Monitor *mon,
  66                                               const char *command,
  67                                               int64_t bandwidth_limit,
  68                                               int detach,
  69                                               int blk,
  70                                               int inc)
  71 {
  72     FdMigrationState *s;
  73     FILE *f;
  74
  75     s = qemu_mallocz(sizeof(*s));
  76
  77     f = popen(command, "w");
  78     if (f == NULL) {
  79         DPRINTF("Unable to popen exec target\n");
  80         goto err_after_alloc;
  81     }
  82
  83     s->fd = fileno(f);
  84     if (s->fd == -1) {
  85         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  86         goto err_after_open;
  87     }
  88
  89     socket_set_nonblock(s->fd);
  90
  91     s->opaque = qemu_popen(f, "w");
  92
  93     s->close = exec_close;
  94     s->get_error = file_errno;
  95     s->write = file_write;
  96     s->mig_state.cancel = migrate_fd_cancel;
  97     s->mig_state.get_status = migrate_fd_get_status;
  98     s->mig_state.release = migrate_fd_release;
  99
 100     s->mig_state.blk = blk;
 101     s->mig_state.shared = inc;
 102
 103     s->state = MIG_STATE_ACTIVE;
 104     s->mon = NULL;
 105     s->bandwidth_limit = bandwidth_limit;
 106
 107     if (!detach) {
 108         migrate_fd_monitor_suspend(s, mon);
 109     }
 110
 111     migrate_fd_connect(s);
 112     return &s->mig_state;
 113
 114 err_after_open:
 115     pclose(f);
 116 err_after_alloc:
 117     qemu_free(s);
 118     return NULL;
 119 }
 120
 121 static void exec_accept_incoming_migration(void *opaque)
 122 {
 123     QEMUFile *f = opaque;
 124
 125     process_incoming_migration(f);
 126     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 127     qemu_fclose(f);
 128 }
 129
 130 int exec_start_incoming_migration(const char *command)
 131 {
 132     QEMUFile *f;
 133
 134     DPRINTF("Attempting to start an incoming migration\n");
 135     f = qemu_popen_cmd(command, "r");
 136     if(f == NULL) {
 137         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 138         return -errno;
 139     }
 140
 141     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 142                          exec_accept_incoming_migration, NULL, f);
 143
 144     return 0;
 145 }