LXR qemu/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 "buffered_file.h"
  21#include "block.h"
  22#include <sys/types.h>
  23#include <sys/wait.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
  35static int file_errno(FdMigrationState *s)
  36{
  37    return errno;
  38}
  39
  40static int file_write(FdMigrationState *s, const void * buf, size_t size)
  41{
  42    return write(s->fd, buf, size);
  43}
  44
  45static int exec_close(FdMigrationState *s)
  46{
  47    int ret = 0;
  48    DPRINTF("exec_close\n");
  49    if (s->opaque) {
  50        ret = qemu_fclose(s->opaque);
  51        s->opaque = NULL;
  52        s->fd = -1;
  53        if (ret != -1 &&
  54            WIFEXITED(ret)
  55            && WEXITSTATUS(ret) == 0) {
  56            ret = 0;
  57        } else {
  58            ret = -1;
  59        }
  60    }
  61    return ret;
  62}
  63
  64MigrationState *exec_start_outgoing_migration(Monitor *mon,
  65                                              const char *command,
  66                                              int64_t bandwidth_limit,
  67                                              int detach,
  68                                              int blk,
  69                                              int inc)
  70{
  71    FdMigrationState *s;
  72    FILE *f;
  73
  74    s = qemu_mallocz(sizeof(*s));
  75
  76    f = popen(command, "w");
  77    if (f == NULL) {
  78        DPRINTF("Unable to popen exec target\n");
  79        goto err_after_alloc;
  80    }
  81
  82    s->fd = fileno(f);
  83    if (s->fd == -1) {
  84        DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  85        goto err_after_open;
  86    }
  87
  88    socket_set_nonblock(s->fd);
  89
  90    s->opaque = qemu_popen(f, "w");
  91
  92    s->close = exec_close;
  93    s->get_error = file_errno;
  94    s->write = file_write;
  95    s->mig_state.cancel = migrate_fd_cancel;
  96    s->mig_state.get_status = migrate_fd_get_status;
  97    s->mig_state.release = migrate_fd_release;
  98
  99    s->mig_state.blk = blk;
 100    s->mig_state.shared = inc;
 101
 102    s->state = MIG_STATE_ACTIVE;
 103    s->mon = NULL;
 104    s->bandwidth_limit = bandwidth_limit;
 105
 106    if (!detach) {
 107        migrate_fd_monitor_suspend(s, mon);
 108    }
 109
 110    migrate_fd_connect(s);
 111    return &s->mig_state;
 112
 113err_after_open:
 114    pclose(f);
 115err_after_alloc:
 116    qemu_free(s);
 117    return NULL;
 118}
 119
 120static void exec_accept_incoming_migration(void *opaque)
 121{
 122    QEMUFile *f = opaque;
 123
 124    process_incoming_migration(f);
 125    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 126    qemu_fclose(f);
 127}
 128
 129int exec_start_incoming_migration(const char *command)
 130{
 131    QEMUFile *f;
 132
 133    DPRINTF("Attempting to start an incoming migration\n");
 134    f = qemu_popen_cmd(command, "r");
 135    if(f == NULL) {
 136        DPRINTF("Unable to apply qemu wrapper to popen file\n");
 137        return -errno;
 138    }
 139
 140    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 141                         exec_accept_incoming_migration, NULL, f);
 142
 143    return 0;
 144}
 145