Define and export vcpu_dirty_limit_period to eliminate a dependency
on MigrationState.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 include/migration/client-options.h | 1 +
 migration/options.c                | 7 +++++++
 system/dirtylimit.c                | 3 +--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/migration/client-options.h b/include/migration/client-options.h
index 887fea1..59f4b55 100644
--- a/include/migration/client-options.h
+++ b/include/migration/client-options.h
@@ -20,5 +20,6 @@ bool migrate_switchover_ack(void);
 /* parameters */
 
 MigMode migrate_mode(void);
+uint64_t migrate_vcpu_dirty_limit_period(void);
 
 #endif
diff --git a/migration/options.c b/migration/options.c
index 642cfb0..09178c6 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -924,6 +924,13 @@ const char *migrate_tls_hostname(void)
     return s->parameters.tls_hostname;
 }
 
+uint64_t migrate_vcpu_dirty_limit_period(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return s->parameters.x_vcpu_dirty_limit_period;
+}
+
 uint64_t migrate_xbzrle_cache_size(void)
 {
     MigrationState *s = migrate_get_current();
diff --git a/system/dirtylimit.c b/system/dirtylimit.c
index 1622bb7..b0afaa0 100644
--- a/system/dirtylimit.c
+++ b/system/dirtylimit.c
@@ -77,14 +77,13 @@ static bool dirtylimit_quit;
 
 static void vcpu_dirty_rate_stat_collect(void)
 {
-    MigrationState *s = migrate_get_current();
     VcpuStat stat;
     int i = 0;
     int64_t period = DIRTYLIMIT_CALC_TIME_MS;
 
     if (migrate_dirty_limit() &&
         migration_is_active()) {
-        period = s->parameters.x_vcpu_dirty_limit_period;
+        period = migrate_vcpu_dirty_limit_period();
     }
 
     /* calculate vcpu dirtyrate */
-- 
1.8.3.1