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 "sysemu.h"
  20#include "buffered_file.h"
  21#include "block.h"
  22#include "qemu_socket.h"
  23
  24//#define DEBUG_MIGRATION_FD
  25
  26#ifdef DEBUG_MIGRATION_FD
  27#define DPRINTF(fmt, ...) \
  28    do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
  29#else
  30#define DPRINTF(fmt, ...) \
  31    do { } while (0)
  32#endif
  33
  34static int fd_errno(FdMigrationState *s)
  35{
  36    return errno;
  37}
  38
  39static int fd_write(FdMigrationState *s, const void * buf, size_t size)
  40{
  41    return write(s->fd, buf, size);
  42}
  43
  44static int fd_close(FdMigrationState *s)
  45{
  46    DPRINTF("fd_close\n");
  47    if (s->fd != -1) {
  48        close(s->fd);
  49        s->fd = -1;
  50    }
  51    return 0;
  52}
  53
  54MigrationState *fd_start_outgoing_migration(Monitor *mon,
  55                                            const char *fdname,
  56                                            int64_t bandwidth_limit,
  57                                            int detach,
  58                                            int blk,
  59                                            int inc)
  60{
  61    FdMigrationState *s;
  62
  63    s = qemu_mallocz(sizeof(*s));
  64
  65    s->fd = monitor_get_fd(mon, fdname);
  66    if (s->fd == -1) {
  67        DPRINTF("fd_migration: invalid file descriptor identifier\n");
  68        goto err_after_alloc;
  69    }
  70
  71    if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {
  72        DPRINTF("Unable to set nonblocking mode on file descriptor\n");
  73        goto err_after_open;
  74    }
  75
  76    s->get_error = fd_errno;
  77    s->write = fd_write;
  78    s->close = fd_close;
  79    s->mig_state.cancel = migrate_fd_cancel;
  80    s->mig_state.get_status = migrate_fd_get_status;
  81    s->mig_state.release = migrate_fd_release;
  82
  83    s->mig_state.blk = blk;
  84    s->mig_state.shared = inc;
  85
  86    s->state = MIG_STATE_ACTIVE;
  87    s->mon = NULL;
  88    s->bandwidth_limit = bandwidth_limit;
  89
  90    if (!detach) {
  91        migrate_fd_monitor_suspend(s, mon);
  92    }
  93
  94    migrate_fd_connect(s);
  95    return &s->mig_state;
  96
  97err_after_open:
  98    close(s->fd);
  99err_after_alloc:
 100    qemu_free(s);
 101    return NULL;
 102}
 103
 104static void fd_accept_incoming_migration(void *opaque)
 105{
 106    QEMUFile *f = opaque;
 107
 108    process_incoming_migration(f);
 109    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 110    qemu_fclose(f);
 111}
 112
 113int fd_start_incoming_migration(const char *infd)
 114{
 115    int fd;
 116    QEMUFile *f;
 117
 118    DPRINTF("Attempting to start an incoming migration via fd\n");
 119
 120    fd = strtol(infd, NULL, 0);
 121    f = qemu_fdopen(fd, "rb");
 122    if(f == NULL) {
 123        DPRINTF("Unable to apply qemu wrapper to file descriptor\n");
 124        return -errno;
 125    }
 126
 127    qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
 128
 129    return 0;
 130}
 131