[Qemu-devel] [PATCH 17/19] migration-tcp: modify tcp_accept_incoming_migration() to handle ft_mode, and add a hack not to close fd when ft_mode is enabled.

[Yoshiaki Tamura]

When ft_mode is set in the header, tcp_accept_incoming_migration()
sets ft_trans_incoming() as a callback, and call
qemu_file_get_notify() to receive FT transaction iteratively.  We also
need a hack no to close fd before moving to ft_transaction mode, so
that we can reuse the fd for it.  vm_change_state_handler is added to
turn off ft_mode when cont is pressed.

Signed-off-by: Yoshiaki Tamura <tamura.yoshi...@lab.ntt.co.jp>
---
 migration-tcp.c |   67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 66 insertions(+), 1 deletions(-)

diff --git a/migration-tcp.c b/migration-tcp.c
index 55777c8..84076d6 100644
--- a/migration-tcp.c
+++ b/migration-tcp.c
@@ -18,6 +18,8 @@
 #include "sysemu.h"
 #include "buffered_file.h"
 #include "block.h"
+#include "ft_trans_file.h"
+#include "event-tap.h"
 
 //#define DEBUG_MIGRATION_TCP
 
@@ -29,6 +31,8 @@
     do { } while (0)
 #endif
 
+static VMChangeStateEntry *vmstate;
+
 static int socket_errno(FdMigrationState *s)
 {
     return socket_error();
@@ -56,7 +60,8 @@ static int socket_read(FdMigrationState *s, const void * buf, 
size_t size)
 static int tcp_close(FdMigrationState *s)
 {
     DPRINTF("tcp_close\n");
-    if (s->fd != -1) {
+    /* FIX ME: accessing ft_mode here isn't clean */
+    if (s->fd != -1 && ft_mode != FT_INIT) {
         close(s->fd);
         s->fd = -1;
     }
@@ -150,6 +155,36 @@ MigrationState *tcp_start_outgoing_migration(Monitor *mon,
     return &s->mig_state;
 }
 
+static void ft_trans_incoming(void *opaque)
+{
+    QEMUFile *f = opaque;
+
+    qemu_file_get_notify(f);
+    if (qemu_file_has_error(f)) {
+        ft_mode = FT_ERROR;
+        qemu_fclose(f);
+    }
+}
+
+static void ft_trans_reset(void *opaque, int running, int reason)
+{
+    QEMUFile *f = opaque;
+
+    if (running) {
+        if (ft_mode != FT_ERROR) {
+            qemu_fclose(f);
+        }
+        ft_mode = FT_OFF;
+        qemu_del_vm_change_state_handler(vmstate);
+    }
+}
+
+static void ft_trans_schedule_replay(QEMUFile *f)
+{
+    event_tap_schedule_replay();
+    vmstate = qemu_add_vm_change_state_handler(ft_trans_reset, f);
+}
+
 static void tcp_accept_incoming_migration(void *opaque)
 {
     struct sockaddr_in addr;
@@ -175,8 +210,38 @@ static void tcp_accept_incoming_migration(void *opaque)
         goto out;
     }
 
+    if (ft_mode == FT_INIT) {
+        autostart = 0;
+    }
+
     process_incoming_migration(f);
+
+    if (ft_mode == FT_INIT) {
+        int ret;
+
+        socket_set_nodelay(c);
+
+        f = qemu_fopen_ft_trans(s, c);
+        if (f == NULL) {
+            fprintf(stderr, "could not qemu_fopen_ft_trans\n");
+            goto out;
+        }
+
+        /* need to wait sender to setup */
+        ret = qemu_ft_trans_begin(f);
+        if (ret < 0) {
+            goto out;
+        }
+
+        qemu_set_fd_handler2(c, NULL, ft_trans_incoming, NULL, f);
+        ft_trans_schedule_replay(f);
+        ft_mode = FT_TRANSACTION_RECV;
+
+        return;
+    }
+
     qemu_fclose(f);
+
 out:
     close(c);
 out2:
-- 
1.7.1.2