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   <aliguori@us.ibm.com>
   9  *  Charles Duffy     <charles_duffy@messageone.com>
  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 "console.h"
  22 #include "buffered_file.h"
  23 #include "block.h"
  24
  25 //#define DEBUG_MIGRATION_EXEC
  26
  27 #ifdef DEBUG_MIGRATION_EXEC
  28 #define dprintf(fmt, ...) \
  29     do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  30 #else
  31 #define dprintf(fmt, ...) \
  32     do { } while (0)
  33 #endif
  34
  35 static int file_errno(FdMigrationState *s)
  36 {
  37     return errno;
  38 }
  39
  40 static int file_write(FdMigrationState *s, const void * buf, size_t size)
  41 {
  42     return write(s->fd, buf, size);
  43 }
  44
  45 static int exec_close(FdMigrationState *s)
  46 {
  47     dprintf("exec_close\n");
  48     if (s->opaque) {
  49         qemu_fclose(s->opaque);
  50         s->opaque = NULL;
  51         s->fd = -1;
  52     }
  53     return 0;
  54 }
  55
  56 MigrationState *exec_start_outgoing_migration(const char *command,
  57                                              int64_t bandwidth_limit,
  58                                              int async)
  59 {
  60     FdMigrationState *s;
  61     FILE *f;
  62
  63     s = qemu_mallocz(sizeof(*s));
  64
  65     f = popen(command, "w");
  66     if (f == NULL) {
  67         dprintf("Unable to popen exec target\n");
  68         goto err_after_alloc;
  69     }
  70
  71     s->fd = fileno(f);
  72     if (s->fd == -1) {
  73         dprintf("Unable to retrieve file descriptor for popen'd handle\n");
  74         goto err_after_open;
  75     }
  76
  77     if (fcntl(s->fd, F_SETFD, O_NONBLOCK) == -1) {
  78         dprintf("Unable to set nonblocking mode on file descriptor\n");
  79         goto err_after_open;
  80     }
  81
  82     s->opaque = qemu_popen(f, "w");
  83
  84     s->close = exec_close;
  85     s->get_error = file_errno;
  86     s->write = file_write;
  87     s->mig_state.cancel = migrate_fd_cancel;
  88     s->mig_state.get_status = migrate_fd_get_status;
  89     s->mig_state.release = migrate_fd_release;
  90
  91     s->state = MIG_STATE_ACTIVE;
  92     s->detach = !async;
  93     s->bandwidth_limit = bandwidth_limit;
  94
  95     if (s->detach == 1) {
  96         dprintf("detaching from monitor\n");
  97         monitor_suspend();
  98         s->detach = 2;
  99     }
 100
 101     migrate_fd_connect(s);
 102     return &s->mig_state;
 103
 104 err_after_open:
 105     pclose(f);
 106 err_after_alloc:
 107     qemu_free(s);
 108     return NULL;
 109 }
 110
 111 static void exec_accept_incoming_migration(void *opaque)
 112 {
 113     QEMUFile *f = opaque;
 114     int ret;
 115
 116     ret = qemu_loadvm_state(f);
 117     if (ret < 0) {
 118         fprintf(stderr, "load of migration failed\n");
 119         goto err;
 120     }
 121     qemu_announce_self();
 122     dprintf("successfully loaded vm state\n");
 123     /* we've successfully migrated, close the fd */
 124     qemu_set_fd_handler2(qemu_popen_fd(f), NULL, NULL, NULL, NULL);
 125
 126 err:
 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_popen_fd(f), NULL,
 142                          exec_accept_incoming_migration, NULL,
 143                          (void *)(unsigned long)f);
 144
 145     return 0;
 146 }