Archipelago » qemu

/*

 * QEMU live migration

 *

 * Copyright IBM, Corp. 2008

 * Copyright Dell MessageOne 2008

 *

 * Authors:

 *  Anthony Liguori   <aliguori@us.ibm.com>

 *  Charles Duffy     <charles_duffy@messageone.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 "qemu-char.h"

#include "sysemu.h"

#include "buffered_file.h"

#include "block.h"

//#define DEBUG_MIGRATION_EXEC

#ifdef DEBUG_MIGRATION_EXEC

#define dprintf(fmt, ...) \

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

#else

#define dprintf(fmt, ...) \

    do { } while (0)

#endif

static int file_errno(FdMigrationState *s)

{

    return errno;

}

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

{

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

}

static int exec_close(FdMigrationState *s)

{

    dprintf("exec_close\n");

    if (s->opaque) {

        qemu_fclose(s->opaque);

        s->opaque = NULL;

        s->fd = -1;

    }

    return 0;

}

MigrationState *exec_start_outgoing_migration(const char *command,

                                             int64_t bandwidth_limit,

                                             int detach)

{

    FdMigrationState *s;

    FILE *f;

    s = qemu_mallocz(sizeof(*s));

    f = popen(command, "w");

    if (f == NULL) {

        dprintf("Unable to popen exec target\n");

        goto err_after_alloc;

    }

    s->fd = fileno(f);

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

        dprintf("Unable to retrieve file descriptor for popen'd handle\n");

        goto err_after_open;

    }

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

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

        goto err_after_open;

    }

    s->opaque = qemu_popen(f, "w");

    s->close = exec_close;

    s->get_error = file_errno;

    s->write = file_write;

    s->mig_state.cancel = migrate_fd_cancel;

    s->mig_state.get_status = migrate_fd_get_status;

    s->mig_state.release = migrate_fd_release;

    s->state = MIG_STATE_ACTIVE;

    s->mon_resume = NULL;

    s->bandwidth_limit = bandwidth_limit;

    if (!detach)

        migrate_fd_monitor_suspend(s);

    migrate_fd_connect(s);

    return &s->mig_state;

err_after_open:

    pclose(f);

err_after_alloc:

    qemu_free(s);

    return NULL;

}

int exec_start_incoming_migration(const char *command)

{

    int ret;

    QEMUFile *f;

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

    f = qemu_popen_cmd(command, "r");

    if(f == NULL) {

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

        return -errno;

    }

    vm_stop(0); /* just in case */

    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");

    vm_start();

    qemu_fclose(f);

    return 0;

err:

    qemu_fclose(f);

    return -errno;

}