[RFC Patch 11/12] IXGBEVF: Migrate VF statistic data

[Lan Tianyu <tianyu.lan@intel.com>]

VF statistic regs are read-only and can't be migrated via writing back
directly.

Currently, statistic data returned to user space by the driver is not equal
to value of statistic regs. VF driver records value of statistic regs as base data
when net interface is up or open, calculate increased count of regs during
last period of online service and added it to saved_reset data. When user
space collects statistic data, VF driver returns result of
"current - base + saved_reset". "Current" is reg value at that point.

Restoring net function after migration just likes net interface is up or open.
Call existed function to update base and saved_reset data to keep statistic
data continual during migration.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 04b6ce7..d22160f 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -3005,6 +3005,7 @@ int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
 			return 0;
 
 		del_timer_sync(&adapter->service_timer);
+		ixgbevf_update_stats(adapter);
 		pr_info("migration start\n");
 		migration_status = MIGRATION_IN_PROGRESS; 
 
@@ -3017,6 +3018,8 @@ int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
 			return 1;
 
 		ixgbevf_restore_state(adapter);
+		ixgbevf_save_reset_stats(adapter);
+		ixgbevf_init_last_counter_stats(adapter);
 		migration_status = MIGRATION_COMPLETED;
 		pr_info("migration end\n");
 		return 0;
-- 
1.8.4.rc0.1.g8f6a3e5.dirty