migration: Optimization about wait-unplug migration state

qemu_savevm_nr_failover_devices() is originally designed to
get the number of failover devices, but it actually returns
the number of "unplug-pending" failover devices now. Moreover,
what drives migration state to wait-unplug should be the number
of "unplug-pending" failover devices, not all failover devices.

We can also notice that qemu_savevm_state_guest_unplug_pending()
and qemu_savevm_nr_failover_devices() is equivalent almost (from
the code view). So the latter is incorrect semantically and
useless, just delete it.

In the qemu_savevm_state_guest_unplug_pending(), once hit a
unplug-pending failover device, then it can return true right
now to save cpu time.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/migration/savevm.h b/migration/savevm.h
index c42b9c80ee..ba64a7e271 100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -31,7 +31,6 @@
 
 bool qemu_savevm_state_blocked(Error **errp);
 void qemu_savevm_state_setup(QEMUFile *f);
-int qemu_savevm_nr_failover_devices(void);
 bool qemu_savevm_state_guest_unplug_pending(void);
 int qemu_savevm_state_resume_prepare(MigrationState *s);
 void qemu_savevm_state_header(QEMUFile *f);