[Qemu-devel] [PATCH 04/14] migration: let incoming side use thread context

[Peter Xu <peterx@redhat.com>]

The old incoming migration is running in main thread and default
gcontext.  With the new qio_channel_add_watch_full() we can now let it
run in the thread's own gcontext (if there is one).

Currently this patch does nothing alone.  But when any of the incoming
migration is run in another iothread (e.g., the upcoming migrate-recover
command), this patch will bind the incoming logic to the iothread
instead of the main thread (which may already get page faulted and
hanged).

RDMA is not considered for now since it's not even using the QIO APIs at
all.

CC: Juan Quintela <quintela@redhat.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
CC: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/exec.c   | 11 ++++++-----
 migration/fd.c     | 11 ++++++-----
 migration/socket.c | 12 +++++++-----
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/migration/exec.c b/migration/exec.c
index 0bc5a427dd..f401fc005e 100644
--- a/migration/exec.c
+++ b/migration/exec.c
@@ -55,6 +55,7 @@ void exec_start_incoming_migration(const char *command, Error **errp)
 {
     QIOChannel *ioc;
     const char *argv[] = { "/bin/sh", "-c", command, NULL };
+    GSource *source;
 
     trace_migration_exec_incoming(command);
     ioc = QIO_CHANNEL(qio_channel_command_new_spawn(argv,
@@ -65,9 +66,9 @@ void exec_start_incoming_migration(const char *command, Error **errp)
     }
 
     qio_channel_set_name(ioc, "migration-exec-incoming");
-    qio_channel_add_watch(ioc,
-                          G_IO_IN,
-                          exec_accept_incoming_migration,
-                          NULL,
-                          NULL);
+    source = qio_channel_add_watch_full(ioc, G_IO_IN,
+                                        exec_accept_incoming_migration,
+                                        NULL, NULL,
+                                        g_main_context_get_thread_default());
+    g_source_unref(source);
 }
diff --git a/migration/fd.c b/migration/fd.c
index cd06182d1e..9c593eb3ff 100644
--- a/migration/fd.c
+++ b/migration/fd.c
@@ -55,6 +55,7 @@ void fd_start_incoming_migration(const char *infd, Error **errp)
 {
     QIOChannel *ioc;
     int fd;
+    GSource *source;
 
     fd = strtol(infd, NULL, 0);
     trace_migration_fd_incoming(fd);
@@ -66,9 +67,9 @@ void fd_start_incoming_migration(const char *infd, Error **errp)
     }
 
     qio_channel_set_name(QIO_CHANNEL(ioc), "migration-fd-incoming");
-    qio_channel_add_watch(ioc,
-                          G_IO_IN,
-                          fd_accept_incoming_migration,
-                          NULL,
-                          NULL);
+    source = qio_channel_add_watch_full(ioc, G_IO_IN,
+                                        fd_accept_incoming_migration,
+                                        NULL, NULL,
+                                        g_main_context_get_thread_default());
+    g_source_unref(source);
 }
diff --git a/migration/socket.c b/migration/socket.c
index e090097077..82c330083c 100644
--- a/migration/socket.c
+++ b/migration/socket.c
@@ -164,6 +164,7 @@ static void socket_start_incoming_migration(SocketAddress *saddr,
                                             Error **errp)
 {
     QIOChannelSocket *listen_ioc = qio_channel_socket_new();
+    GSource *source;
 
     qio_channel_set_name(QIO_CHANNEL(listen_ioc),
                          "migration-socket-listener");
@@ -173,11 +174,12 @@ static void socket_start_incoming_migration(SocketAddress *saddr,
         return;
     }
 
-    qio_channel_add_watch(QIO_CHANNEL(listen_ioc),
-                          G_IO_IN,
-                          socket_accept_incoming_migration,
-                          listen_ioc,
-                          (GDestroyNotify)object_unref);
+    source = qio_channel_add_watch_full(QIO_CHANNEL(listen_ioc), G_IO_IN,
+                                        socket_accept_incoming_migration,
+                                        listen_ioc,
+                                        (GDestroyNotify)object_unref,
+                                        g_main_context_get_thread_default());
+    g_source_unref(source);
 }
 
 void tcp_start_incoming_migration(const char *host_port, Error **errp)
-- 
2.14.3