set migration max downtime

provide a monitor command to allow one to set the maximum
downtime he is willing to suffer during migration, in seconds.
"ms", "us", "ns" and "s" are accepted as modifiers.

This parameter will be used by ram_save_live() code to determine
a safe moment to enter stage 3

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/migration.c b/migration.c
index 748752e82a..190b37e550 100644
--- a/migration.c
+++ b/migration.c
@@ -118,6 +118,25 @@ uint64_t migrate_max_downtime(void)
     return max_downtime;
 }
 
+void do_migrate_set_downtime(Monitor *mon, const char *value)
+{
+    char *ptr;
+    double d;
+
+    d = strtod(value, &ptr);
+    if (!strcmp(ptr,"ms")) {
+        d *= 1000000;
+    } else if (!strcmp(ptr,"us")) {
+        d *= 1000;
+    } else if (!strcmp(ptr,"ns")) {
+    } else {
+        /* all else considered to be seconds */
+        d *= 1000000000;
+    }
+
+    max_downtime = (uint64_t)d;
+}
+
 void do_info_migrate(Monitor *mon)
 {
     MigrationState *s = current_migration;