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.

 *

 * Contributions after 2012-01-13 are licensed under the terms of the

 * GNU GPL, version 2 or (at your option) any later version.

 */

#include "qemu-common.h"

#include "qemu_socket.h"

#include "migration.h"

#include "qemu-char.h"

#include "buffered_file.h"

#include "block.h"

#include <sys/types.h>

#include <sys/wait.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(MigrationState *s)

{

    return errno;

}

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

{

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

}

static int exec_close(MigrationState *s)

{

    int ret = 0;

    DPRINTF("exec_close\n");

    if (s->opaque) {

        ret = qemu_fclose(s->opaque);

        s->opaque = NULL;

        s->fd = -1;

        if (ret >= 0 && !(WIFEXITED(ret) && WEXITSTATUS(ret) == 0)) {

            /* close succeeded, but non-zero exit code: */

            ret = -EIO; /* fake errno value */

        }

    }

    return ret;

}

int exec_start_outgoing_migration(MigrationState *s, const char *command)

{

    FILE *f;

    f = popen(command, "w");

    if (f == NULL) {

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

        goto err_after_popen;

    }

    s->fd = fileno(f);

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

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

        goto err_after_open;

    }

    socket_set_nonblock(s->fd);

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

    s->close = exec_close;

    s->get_error = file_errno;

    s->write = file_write;

    migrate_fd_connect(s);

    return 0;

err_after_open:

    pclose(f);

err_after_popen:

    return -1;

}

static void exec_accept_incoming_migration(void *opaque)

{

    QEMUFile *f = opaque;

    process_incoming_migration(f);

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

    qemu_fclose(f);

}

int exec_start_incoming_migration(const char *command)

{

    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;

    }

    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,

                         exec_accept_incoming_migration, NULL, f);

    return 0;

}