LXR qemu/migration-fd.c

   1/*
   2 * QEMU live migration via generic fd
   3 *
   4 * Copyright Red Hat, Inc. 2009
   5 *
   6 * Authors:
   7 *  Chris Lalancette <clalance@redhat.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 *
  12 */
  13
  14#include "qemu-common.h"
  15#include "qemu_socket.h"
  16#include "migration.h"
  17#include "monitor.h"
  18#include "qemu-char.h"
  19#include "buffered_file.h"
  20#include "block.h"
  21#include "qemu_socket.h"
  22
  23//#define DEBUG_MIGRATION_FD
  24
  25#ifdef DEBUG_MIGRATION_FD
  26#define DPRINTF(fmt, ...) \
  27    do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
  28#else
  29#define DPRINTF(fmt, ...) \
  30    do { } while (0)
  31#endif
  32
  33static int fd_errno(FdMigrationState *s)
  34{
  35    return errno;
  36}
  37
  38static int fd_write(FdMigrationState *s, const void * buf, size_t size)
  39{
  40    return write(s->fd, buf, size);
  41}
  42
  43static int fd_close(FdMigrationState *s)
  44{
  45    DPRINTF("fd_close\n");
  46    if (s->fd != -1) {
  47        close(s->fd);
  48        s->fd = -1;
  49    }
  50    return 0;
  51}
  52
  53MigrationState *fd_start_outgoing_migration(Monitor *mon,
  54                                            const char *fdname,
  55                                            int64_t bandwidth_limit,
  56                                            int detach,
  57                                            int blk,
  58                                            int inc)
  59{
  60    FdMigrationState *s;
  61
  62    s = qemu_mallocz(sizeof(*s));
  63
  64    s->fd = monitor_get_fd(mon, fdname);
  65    if (s->fd == -1) {
  66        DPRINTF("fd_migration: invalid file descriptor identifier\n");
  67        goto err_after_alloc;
  68    }
  69
  70    if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {
  71        DPRINTF("Unable to set nonblocking mode on file descriptor\n");
  72        goto err_after_open;
  73    }
  74
  75    s->get_error = fd_errno;
  76    s->write = fd_write;
  77    s->close = fd_close;
  78    s->mig_state.cancel = migrate_fd_cancel;
  79    s->mig_state.get_status = migrate_fd_get_status;
  80    s->mig_state.release = migrate_fd_release;
  81
  82    s->mig_state.blk = blk;
  83    s->mig_state.shared = inc;
  84
  85    s->state = MIG_STATE_ACTIVE;
  86    s->mon = NULL;
  87    s->bandwidth_limit = bandwidth_limit;
  88
  89    if (!detach) {
  90        migrate_fd_monitor_suspend(s, mon);
  91    }
  92
  93    migrate_fd_connect(s);
  94    return &s->mig_state;
  95
  96err_after_open:
  97    close(s->fd);
  98err_after_alloc:
  99    qemu_free(s);
 100    return NULL;
 101}
 102
 103static void fd_accept_incoming_migration(void *opaque)
 104{
 105    QEMUFile *f = opaque;
 106
 107    process_incoming_migration(f);
 108    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 109    qemu_fclose(f);
 110}
 111
 112int fd_start_incoming_migration(const char *infd)
 113{
 114    int fd;
 115    QEMUFile *f;
 116
 117    DPRINTF("Attempting to start an incoming migration via fd\n");
 118
 119    fd = strtol(infd, NULL, 0);
 120    f = qemu_fdopen(fd, "rb");
 121    if(f == NULL) {
 122        DPRINTF("Unable to apply qemu wrapper to file descriptor\n");
 123        return -errno;
 124    }
 125
 126    qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
 127
 128    return 0;
 129}
 130