LXR qemu/migration-exec.c

   1/*
   2 * QEMU live migration
   3 *
   4 * Copyright IBM, Corp. 2008
   5 * Copyright Dell MessageOne 2008
   6 *
   7 * Authors:
   8 *  Anthony Liguori   <aliguori@us.ibm.com>
   9 *  Charles Duffy     <charles_duffy@messageone.com>
  10 *
  11 * This work is licensed under the terms of the GNU GPL, version 2.  See
  12 * the COPYING file in the top-level directory.
  13 *
  14 */
  15
  16#include "qemu-common.h"
  17#include "qemu_socket.h"
  18#include "migration.h"
  19#include "qemu-char.h"
  20#include "buffered_file.h"
  21#include "block.h"
  22#include <sys/types.h>
  23#include <sys/wait.h>
  24
  25//#define DEBUG_MIGRATION_EXEC
  26
  27#ifdef DEBUG_MIGRATION_EXEC
  28#define DPRINTF(fmt, ...) \
  29    do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  30#else
  31#define DPRINTF(fmt, ...) \
  32    do { } while (0)
  33#endif
  34
  35static int file_errno(MigrationState *s)
  36{
  37    return errno;
  38}
  39
  40static int file_write(MigrationState *s, const void * buf, size_t size)
  41{
  42    return write(s->fd, buf, size);
  43}
  44
  45static int exec_close(MigrationState *s)
  46{
  47    int ret = 0;
  48    DPRINTF("exec_close\n");
  49    if (s->opaque) {
  50        ret = qemu_fclose(s->opaque);
  51        s->opaque = NULL;
  52        s->fd = -1;
  53        if (ret != -1 &&
  54            WIFEXITED(ret)
  55            && WEXITSTATUS(ret) == 0) {
  56            ret = 0;
  57        } else {
  58            ret = -1;
  59        }
  60    }
  61    return ret;
  62}
  63
  64int exec_start_outgoing_migration(MigrationState *s, const char *command)
  65{
  66    FILE *f;
  67
  68    f = popen(command, "w");
  69    if (f == NULL) {
  70        DPRINTF("Unable to popen exec target\n");
  71        goto err_after_popen;
  72    }
  73
  74    s->fd = fileno(f);
  75    if (s->fd == -1) {
  76        DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  77        goto err_after_open;
  78    }
  79
  80    socket_set_nonblock(s->fd);
  81
  82    s->opaque = qemu_popen(f, "w");
  83
  84    s->close = exec_close;
  85    s->get_error = file_errno;
  86    s->write = file_write;
  87
  88    migrate_fd_connect(s);
  89    return 0;
  90
  91err_after_open:
  92    pclose(f);
  93err_after_popen:
  94    return -1;
  95}
  96
  97static void exec_accept_incoming_migration(void *opaque)
  98{
  99    QEMUFile *f = opaque;
 100
 101    process_incoming_migration(f);
 102    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 103    qemu_fclose(f);
 104}
 105
 106int exec_start_incoming_migration(const char *command)
 107{
 108    QEMUFile *f;
 109
 110    DPRINTF("Attempting to start an incoming migration\n");
 111    f = qemu_popen_cmd(command, "r");
 112    if(f == NULL) {
 113        DPRINTF("Unable to apply qemu wrapper to popen file\n");
 114        return -errno;
 115    }
 116
 117    qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 118                         exec_accept_incoming_migration, NULL, f);
 119
 120    return 0;
 121}
 122