LXR qemu/migration-unix.c

   1/*
   2 * QEMU live migration via Unix Domain Sockets
   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 * Contributions after 2012-01-13 are licensed under the terms of the
  13 * GNU GPL, version 2 or (at your option) any later version.
  14 */
  15
  16#include "qemu-common.h"
  17#include "qemu/sockets.h"
  18#include "migration/migration.h"
  19#include "migration/qemu-file.h"
  20#include "block/block.h"
  21
  22//#define DEBUG_MIGRATION_UNIX
  23
  24#ifdef DEBUG_MIGRATION_UNIX
  25#define DPRINTF(fmt, ...) \
  26    do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
  27#else
  28#define DPRINTF(fmt, ...) \
  29    do { } while (0)
  30#endif
  31
  32static void unix_wait_for_connect(int fd, void *opaque)
  33{
  34    MigrationState *s = opaque;
  35
  36    if (fd < 0) {
  37        DPRINTF("migrate connect error\n");
  38        s->file = NULL;
  39        migrate_fd_error(s);
  40    } else {
  41        DPRINTF("migrate connect success\n");
  42        s->file = qemu_fopen_socket(fd, "wb");
  43        migrate_fd_connect(s);
  44    }
  45}
  46
  47void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp)
  48{
  49    unix_nonblocking_connect(path, unix_wait_for_connect, s, errp);
  50}
  51
  52static void unix_accept_incoming_migration(void *opaque)
  53{
  54    struct sockaddr_un addr;
  55    socklen_t addrlen = sizeof(addr);
  56    int s = (intptr_t)opaque;
  57    QEMUFile *f;
  58    int c;
  59
  60    do {
  61        c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
  62    } while (c == -1 && errno == EINTR);
  63    qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
  64    close(s);
  65
  66    DPRINTF("accepted migration\n");
  67
  68    if (c == -1) {
  69        fprintf(stderr, "could not accept migration connection\n");
  70        goto out;
  71    }
  72
  73    f = qemu_fopen_socket(c, "rb");
  74    if (f == NULL) {
  75        fprintf(stderr, "could not qemu_fopen socket\n");
  76        goto out;
  77    }
  78
  79    process_incoming_migration(f);
  80    return;
  81
  82out:
  83    close(c);
  84}
  85
  86void unix_start_incoming_migration(const char *path, Error **errp)
  87{
  88    int s;
  89
  90    s = unix_listen(path, NULL, 0, errp);
  91    if (s < 0) {
  92        return;
  93    }
  94
  95    qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL,
  96                         (void *)(intptr_t)s);
  97}
  98