[PATCH 3/3] migration/postcopy: replace have_listen_thread check with PostcopyState check

[Wei Yang]

After previous cleanup, postcopy thread is running only when
PostcopyState is LISTENNING or RUNNING. This means it is not necessary
to spare a variable have_listen_thread to represent the state.

Replace the check on have_listen_thread with PostcopyState and remove
the variable.

Signed-off-by: Wei Yang <address@hidden>
---
 migration/migration.h | 1 -
 migration/ram.c       | 2 +-
 migration/ram.h       | 1 +
 migration/savevm.c    | 4 +---
 4 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/migration/migration.h b/migration/migration.h
index 4f2fe193dc..a4d639663d 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -63,7 +63,6 @@ struct MigrationIncomingState {
     /* Set this when we want the fault thread to quit */
     bool           fault_thread_quit;
 
-    bool           have_listen_thread;
     QemuThread     listen_thread;
     QemuSemaphore  listen_thread_sem;
 
diff --git a/migration/ram.c b/migration/ram.c
index 769d3f6454..dfc50d57d5 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4188,7 +4188,7 @@ static bool postcopy_is_advised(void)
     return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END;
 }
 
-static bool postcopy_is_running(void)
+bool postcopy_is_running(void)
 {
     PostcopyState ps = postcopy_state_get();
     return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END;
diff --git a/migration/ram.h b/migration/ram.h
index bd0eee79b6..44fe4753ad 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -59,6 +59,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 /* For incoming postcopy discard */
 int ram_discard_range(const char *block_name, uint64_t start, size_t length);
 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
+bool postcopy_is_running(void);
 
 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 
diff --git a/migration/savevm.c b/migration/savevm.c
index dcad8897a3..2a0e0b94df 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1836,7 +1836,6 @@ static void *postcopy_ram_listen_thread(void *opaque)
     qemu_loadvm_state_cleanup();
 
     rcu_unregister_thread();
-    mis->have_listen_thread = false;
     postcopy_state_set(POSTCOPY_INCOMING_END, NULL);
 
     return NULL;
@@ -1880,7 +1879,6 @@ static int 
loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
         return -1;
     }
 
-    mis->have_listen_thread = true;
     /* Start up the listening thread and wait for it to signal ready */
     qemu_sem_init(&mis->listen_thread_sem, 0);
     qemu_thread_create(&mis->listen_thread, "postcopy/listen",
@@ -2518,7 +2516,7 @@ int qemu_loadvm_state(QEMUFile *f)
 
     trace_qemu_loadvm_state_post_main(ret);
 
-    if (mis->have_listen_thread) {
+    if (postcopy_is_running()) {
         /* Listen thread still going, can't clean up yet */
         return ret;
     }
-- 
2.17.1