[Qemu-devel] [PATCH] augment info migrate with page status

[Glauber Costa <glommer@redhat.com>]

This patch augments info migrate output with status about:
* ram bytes remaining
* ram bytes transferred
* ram bytes total

This should be enough for management tools to realize
whether or not there is progress in migration. We can
add more information later on, if the need arrives

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 migration.c |    3 +++
 sysemu.h    |    4 ++++
 vl.c        |   21 ++++++++++++++++++++-
 3 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/migration.c b/migration.c
index b9e3368..a771f37 100644
--- a/migration.c
+++ b/migration.c
@@ -116,6 +116,9 @@ void do_info_migrate(Monitor *mon)
         switch (s->get_status(s)) {
         case MIG_STATE_ACTIVE:
             monitor_printf(mon, "active\n");
+            monitor_printf(mon, "transferred ram: %lu kbytes\n", ram_bytes_transferred() >> 10);
+            monitor_printf(mon, "remaining ram: %lu kbytes\n", ram_bytes_remaining() >> 10);
+            monitor_printf(mon, "total ram: %lu kbytes\n", ram_bytes_total() >> 10);
             break;
         case MIG_STATE_COMPLETED:
             monitor_printf(mon, "completed\n");
diff --git a/sysemu.h b/sysemu.h
index 7d65804..73f63df 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -28,6 +28,10 @@ void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
 void vm_start(void);
 void vm_stop(int reason);
 
+unsigned long ram_bytes_remaining(void);
+unsigned long ram_bytes_transferred(void);
+unsigned long ram_bytes_total(void);
+
 int64_t cpu_get_ticks(void);
 void cpu_enable_ticks(void);
 void cpu_disable_ticks(void);
diff --git a/vl.c b/vl.c
index d84ecef..74ad688 100644
--- a/vl.c
+++ b/vl.c
@@ -3236,6 +3236,7 @@ static int ram_save_block(QEMUFile *f)
 }
 
 static ram_addr_t ram_save_threshold = 10;
+static ram_addr_t bytes_transferred = 0;
 
 static ram_addr_t ram_save_remaining(void)
 {
@@ -3250,6 +3251,21 @@ static ram_addr_t ram_save_remaining(void)
     return count;
 }
 
+unsigned long ram_bytes_remaining(void)
+{
+    return ram_save_remaining() * TARGET_PAGE_SIZE;
+}
+
+unsigned long ram_bytes_transferred(void)
+{
+    return bytes_transferred;
+}
+
+unsigned long ram_bytes_total(void)
+{
+    return last_ram_offset;
+}
+
 static int ram_save_live(QEMUFile *f, int stage, void *opaque)
 {
     ram_addr_t addr;
@@ -3271,6 +3287,7 @@ static int ram_save_live(QEMUFile *f, int stage, void *opaque)
         int ret;
 
         ret = ram_save_block(f);
+        bytes_transferred += ret * TARGET_PAGE_SIZE;
         if (ret == 0) /* no more blocks */
             break;
     }
@@ -3280,7 +3297,9 @@ static int ram_save_live(QEMUFile *f, int stage, void *opaque)
     if (stage == 3) {
 
         /* flush all remaining blocks regardless of rate limiting */
-        while (ram_save_block(f) != 0);
+        while (ram_save_block(f) != 0) {
+            bytes_transferred += TARGET_PAGE_SIZE;
+        }
         cpu_physical_memory_set_dirty_tracking(0);
     }
 
-- 
1.5.6.6