Archipelago » qemu

/*

 * QEMU live migration via generic fd

 *

 * Copyright Red Hat, Inc. 2009

 *

 * Authors:

 *  Chris Lalancette <clalance@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 *

 */

#include "qemu-common.h"

#include "qemu_socket.h"

#include "migration.h"

#include "monitor.h"

#include "qemu-char.h"

#include "sysemu.h"

#include "buffered_file.h"

#include "block.h"

#include "qemu_socket.h"

//#define DEBUG_MIGRATION_FD

#ifdef DEBUG_MIGRATION_FD

#define dprintf(fmt, ...) \

    do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)

#else

#define dprintf(fmt, ...) \

    do { } while (0)

#endif

static int fd_errno(FdMigrationState *s)

{

    return errno;

}

static int fd_write(FdMigrationState *s, const void * buf, size_t size)

{

    return write(s->fd, buf, size);

}

static int fd_close(FdMigrationState *s)

{

    dprintf("fd_close\n");

    if (s->fd != -1) {

        close(s->fd);

        s->fd = -1;

    }

    return 0;

}

MigrationState *fd_start_outgoing_migration(Monitor *mon,

                                            const char *fdname,

                                            int64_t bandwidth_limit,

                                            int detach,

                                            int blk,

                                            int inc)

{

    FdMigrationState *s;

    s = qemu_mallocz(sizeof(*s));

    s->fd = monitor_get_fd(mon, fdname);

    if (s->fd == -1) {

        dprintf("fd_migration: invalid file descriptor identifier\n");

        goto err_after_alloc;

    }

    if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {

        dprintf("Unable to set nonblocking mode on file descriptor\n");

        goto err_after_open;

    }

    s->get_error = fd_errno;

    s->write = fd_write;

    s->close = fd_close;

    s->mig_state.cancel = migrate_fd_cancel;

    s->mig_state.get_status = migrate_fd_get_status;

    s->mig_state.release = migrate_fd_release;

    s->mig_state.blk = blk;

    s->mig_state.shared = inc;

    s->state = MIG_STATE_ACTIVE;

    s->mon = NULL;

    s->bandwidth_limit = bandwidth_limit;

    if (!detach) {

        migrate_fd_monitor_suspend(s, mon);

    }

    migrate_fd_connect(s);

    return &s->mig_state;

err_after_open:

    close(s->fd);

err_after_alloc:

    qemu_free(s);

    return NULL;

}

static void fd_accept_incoming_migration(void *opaque)

{

    QEMUFile *f = opaque;

    int ret;

    ret = qemu_loadvm_state(f);

    if (ret < 0) {

        fprintf(stderr, "load of migration failed\n");

        goto err;

    }

    qemu_announce_self();

    dprintf("successfully loaded vm state\n");

    /* we've successfully migrated, close the fd */

    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);

    if (autostart)

        vm_start();

err:

    qemu_fclose(f);

}

int fd_start_incoming_migration(const char *infd)

{

    int fd;

    QEMUFile *f;

    dprintf("Attempting to start an incoming migration via fd\n");

    fd = strtol(infd, NULL, 0);

    f = qemu_fdopen(fd, "rb");

    if(f == NULL) {

        dprintf("Unable to apply qemu wrapper to file descriptor\n");

        return -errno;

    }

    qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL,

                         (void *)(unsigned long)f);

    return 0;

}