[Qemu-devel] [PATCH 2/2] set migration max downtime

[Glauber Costa <glommer@redhat.com>]

provide a monitor command to allow one to set the maximum
downtime he is willing to suffer during migration, in miliseconds.

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>
---
 migration.c |    5 +++++
 migration.h |    2 ++
 monitor.c   |    2 ++
 3 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/migration.c b/migration.c
index 4036e64..b303a2f 100644
--- a/migration.c
+++ b/migration.c
@@ -114,6 +114,11 @@ int64_t migrate_max_downtime(void)
     return max_downtime;
 }
 
+void do_migrate_set_downtime(Monitor *mon, uint32_t value)
+{
+    max_downtime = (int64_t)value * 1000000LL;
+}
+
 void do_info_migrate(Monitor *mon)
 {
     MigrationState *s = current_migration;
diff --git a/migration.h b/migration.h
index b0637ba..505668f 100644
--- a/migration.h
+++ b/migration.h
@@ -57,6 +57,8 @@ void do_migrate_set_speed(Monitor *mon, const char *value);
 
 int64_t migrate_max_downtime(void);
 
+void do_migrate_set_downtime(Monitor *mon, uint32_t value);
+
 void do_info_migrate(Monitor *mon);
 
 int exec_start_incoming_migration(const char *host_port);
diff --git a/monitor.c b/monitor.c
index 0f38c71..291281d 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1744,6 +1744,8 @@ static const mon_cmd_t mon_cmds[] = {
       "", "cancel the current VM migration" },
     { "migrate_set_speed", "s", do_migrate_set_speed,
       "value", "set maximum speed (in bytes) for migrations" },
+    { "migrate_set_downtime", "i", do_migrate_set_downtime,
+      "value", "set maximum tolerated downtime (in miliseconds) for migrations" },
 #if defined(TARGET_I386)
     { "drive_add", "ss", drive_hot_add, "pci_addr=[[<domain>:]<bus>:]<slot>\n"
                                          "[file=file][,if=type][,bus=n]\n"
-- 
1.5.6.6