[PULL,16/28] migration: convert exec socket protocol to use QIOChannel

diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index 2e5040c..c73fb8a 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,4 +1,4 @@ 
-common-obj-y += migration.o socket.o fd.o
+common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += vmstate.o
 common-obj-y += qemu-file.o qemu-file-buf.o qemu-file-unix.o qemu-file-stdio.o
 common-obj-y += qemu-file-channel.o
@@ -6,7 +6,6 @@  common-obj-y += xbzrle.o postcopy-ram.o
 common-obj-y += qjson.o
 
 common-obj-$(CONFIG_RDMA) += rdma.o
-common-obj-$(CONFIG_POSIX) += exec.o
 
 common-obj-y += block.o
 
diff --git a/migration/exec.c b/migration/exec.c
index 5594209..c825e27 100644
--- a/migration/exec.c
+++ b/migration/exec.c
@@ -3,10 +3,12 @@ 
  *
  * Copyright IBM, Corp. 2008
  * Copyright Dell MessageOne 2008
+ * Copyright Red Hat, Inc. 2015-2016
  *
  * Authors:
  *  Anthony Liguori   <aliguori@us.ibm.com>
  *  Charles Duffy     <charles_duffy@messageone.com>
+ *  Daniel P. Berrange <berrange@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
@@ -18,53 +20,53 @@ 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu-common.h"
-#include "qemu/sockets.h"
-#include "qemu/main-loop.h"
 #include "migration/migration.h"
-#include "migration/qemu-file.h"
-#include "block/block.h"
-#include <sys/wait.h>
+#include "io/channel-command.h"
+#include "trace.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
 
 void exec_start_outgoing_migration(MigrationState *s, const char *command, Error **errp)
 {
-    s->to_dst_file = qemu_popen_cmd(command, "w");
-    if (s->to_dst_file == NULL) {
-        error_setg_errno(errp, errno, "failed to popen the migration target");
+    QIOChannel *ioc;
+    const char *argv[] = { "/bin/sh", "-c", command, NULL };
+
+    trace_migration_exec_outgoing(command);
+    ioc = QIO_CHANNEL(qio_channel_command_new_spawn(argv,
+                                                    O_WRONLY,
+                                                    errp));
+    if (!ioc) {
         return;
     }
 
-    migrate_fd_connect(s);
+    migration_set_outgoing_channel(s, ioc);
+    object_unref(OBJECT(ioc));
 }
 
-static void exec_accept_incoming_migration(void *opaque)
+static gboolean exec_accept_incoming_migration(QIOChannel *ioc,
+                                               GIOCondition condition,
+                                               gpointer opaque)
 {
-    QEMUFile *f = opaque;
-
-    qemu_set_fd_handler(qemu_get_fd(f), NULL, NULL, NULL);
-    process_incoming_migration(f);
+    migration_set_incoming_channel(migrate_get_current(), ioc);
+    object_unref(OBJECT(ioc));
+    return FALSE; /* unregister */
 }
 
 void exec_start_incoming_migration(const char *command, Error **errp)
 {
-    QEMUFile *f;
+    QIOChannel *ioc;
+    const char *argv[] = { "/bin/sh", "-c", command, NULL };
 
-    DPRINTF("Attempting to start an incoming migration\n");
-    f = qemu_popen_cmd(command, "r");
-    if(f == NULL) {
-        error_setg_errno(errp, errno, "failed to popen the migration source");
+    trace_migration_exec_incoming(command);
+    ioc = QIO_CHANNEL(qio_channel_command_new_spawn(argv,
+                                                    O_RDONLY,
+                                                    errp));
+    if (!ioc) {
         return;
     }
 
-    qemu_set_fd_handler(qemu_get_fd(f), exec_accept_incoming_migration, NULL,
-                        f);
+    qio_channel_add_watch(ioc,
+                          G_IO_IN,
+                          exec_accept_incoming_migration,
+                          NULL,
+                          NULL);
 }
diff --git a/migration/migration.c b/migration/migration.c
index 8decc7d..695384b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -311,10 +311,8 @@  void qemu_start_incoming_migration(const char *uri, Error **errp)
     } else if (strstart(uri, "rdma:", &p)) {
         rdma_start_incoming_migration(p, errp);
 #endif
-#if !defined(WIN32)
     } else if (strstart(uri, "exec:", &p)) {
         exec_start_incoming_migration(p, errp);
-#endif
     } else if (strstart(uri, "unix:", &p)) {
         unix_start_incoming_migration(p, errp);
     } else if (strstart(uri, "fd:", &p)) {
@@ -1069,10 +1067,8 @@  void qmp_migrate(const char *uri, bool has_blk, bool blk,
     } else if (strstart(uri, "rdma:", &p)) {
         rdma_start_outgoing_migration(s, p, &local_err);
 #endif
-#if !defined(WIN32)
     } else if (strstart(uri, "exec:", &p)) {
         exec_start_outgoing_migration(s, p, &local_err);
-#endif
     } else if (strstart(uri, "unix:", &p)) {
         unix_start_outgoing_migration(s, p, &local_err);
     } else if (strstart(uri, "fd:", &p)) {
diff --git a/trace-events b/trace-events
index e9945e7..1584b0a 100644
--- a/trace-events
+++ b/trace-events
@@ -1595,6 +1595,10 @@  postcopy_ram_incoming_cleanup_entry(void) ""
 postcopy_ram_incoming_cleanup_exit(void) ""
 postcopy_ram_incoming_cleanup_join(void) ""
 
+# migration/exec.c
+migration_exec_outgoing(const char *cmd) "cmd=%s"
+migration_exec_incoming(const char *cmd) "cmd=%s"
+
 # migration/fd.c
 migration_fd_outgoing(int fd) "fd=%d"
 migration_fd_incoming(int fd) "fd=%d"