Merge branch 'qemu'

diff --cc vl.c
index ae9170d8305768b8ef56d2b00e4c2cbba8a6f6ef,be6d9a285700724e64496b055c8bd756c883eb0c..c16ee995b4cf689aade51faca19145c571e9d483
--- 1/vl.c
--- 2/vl.c
+++ b/vl.c
@@@ -4369,15 -4292,25 +4372,27 @@@ void do_info_slirp(void
  typedef struct TAPState {
      VLANClientState *vc;
      int fd;
 +    struct TAPState *next;
      char down_script[1024];
 +    char script_arg[1024];
  } TAPState;
  
+ static void qemu_tap_announce_self(void);
+ 
  static void tap_receive(void *opaque, const uint8_t *buf, int size)
  {
+     static int arp_state = 0;
      TAPState *s = opaque;
      int ret;
+ 
+     if (!arp_state ) {
+         arp_state = 1;
+         /* send arp like package to vlan when enter is the first.
+            for xen migration.
+         */
+         qemu_tap_announce_self();
+     }
+ 
      for(;;) {
          ret = write(s->fd, buf, size); /* No error handling ?! */
          if (ret < 0 && (errno == EINTR || errno == EAGAIN)) {
@@@ -4685,9 -4576,58 +4700,59 @@@ static int launch_script(const char *se
      return 0;
  }
  
+ #if defined(__linux__)
+ #define SELF_ANNOUNCE_ROUNDS 5
+ #define ETH_P_EXPERIMENTAL 0x01F1 /* just a number in experimental range */
+ #define EXPERIMENTAL_MAGIC 0xf1f23f4f
+ static int announce_self_create(unsigned char *buf, 
+                          unsigned char mac_addr[ETH_ALEN])
+ {
+     struct ethhdr *eh = (struct ethhdr*)buf;
+     uint32_t *magic   = (uint32_t*)(eh+1);
+     unsigned char *p  = (unsigned char*)(magic + 1);
+ 
+     /* ethernet header */
+     memset(eh->h_dest,   0xff,     ETH_ALEN);
+     memcpy(eh->h_source, mac_addr, ETH_ALEN);
+     eh->h_proto = htons(ETH_P_EXPERIMENTAL);
+ 
+     /* magic data */
+     *magic = EXPERIMENTAL_MAGIC;
+ 
+     return p - buf; /* sizeof(*eh) + sizeof(*magic) */
+ }
+ 
+ static void qemu_tap_announce_self(void)
+ {
+     int i, j, len;
+     VLANState *vlan;
+     VLANClientState *vc;
+     uint8_t buf[256];
+ 
+     for (i=0; i<nb_nics; i++) {     /* for all nics */
+         fprintf(logfile, "Send fake arp for domain %d, MAC: [%02X:%02X:%02X:%02X:%02X:%02X]\n",
+                           domid, nd_table[i].macaddr[0], 
+                           nd_table[i].macaddr[1], nd_table[i].macaddr[2], 
+                           nd_table[i].macaddr[3], nd_table[i].macaddr[4], 
+                           nd_table[i].macaddr[5]);
+         len = announce_self_create(buf, nd_table[i].macaddr);
+         vlan = nd_table[i].vlan;
+         for(vc = vlan->first_client; vc != NULL; vc = vc->next) {
+             if (vc->fd_read == tap_receive) { /* send only if tap */
+                 for (j=0; j<SELF_ANNOUNCE_ROUNDS ; j++) {
+                     vc->fd_read(vc->opaque, buf, len);
+                 }
+             }
+         } /* for vc -- look for tap_receive */
+     } /* for i -- all nics */
+ }
+ #else
+ static void qemu_tap_announce_self(void) {}
+ #endif
+ 
  static int net_tap_init(VLANState *vlan, const char *ifname1,
 -                        const char *setup_script, const char *down_script)
 +                        const char *setup_script, const char *down_script,
 +                        const char *script_arg)
  {
      TAPState *s;
      int fd;