[Qemu-devel] [PATCH COLO-Frame v14 27/40] migration/savevm: Add new helpers to process the different stages of loadvm

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

There are several stages during loadvm process. In different stage,
migration incoming processes different section.
We want to control these stages more accuracy, to optimize the COLO
capability.

Here we add two new helper functions: qemu_loadvm_state_begin()
and qemu_load_device_state().
Besides, we make qemu_loadvm_state_main() API public.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
v14:
- Split from patch 'COLO: Separate the process of saving/loading ram and device state'
---
 include/sysemu/sysemu.h |  3 +++
 migration/savevm.c      | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 91eeda3..c0694a1 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -134,6 +134,9 @@ void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
                                            uint64_t *length_list);
 
 int qemu_loadvm_state(QEMUFile *f);
+int qemu_loadvm_state_begin(QEMUFile *f);
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+int qemu_load_device_state(QEMUFile *f);
 
 typedef enum DisplayType
 {
diff --git a/migration/savevm.c b/migration/savevm.c
index 48e1615..c32b2fe 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1249,8 +1249,6 @@ enum LoadVMExitCodes {
     LOADVM_QUIT     =  1,
 };
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
-
 /* ------ incoming postcopy messages ------ */
 /* 'advise' arrives before any transfers just to tell us that a postcopy
  * *might* happen - it might be skipped if precopy transferred everything
@@ -1832,7 +1830,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
     return 0;
 }
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
 {
     uint8_t section_type;
     int ret;
@@ -1965,6 +1963,40 @@ int qemu_loadvm_state(QEMUFile *f)
     return ret;
 }
 
+int qemu_loadvm_state_begin(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    Error *local_err = NULL;
+    int ret;
+
+    if (qemu_savevm_state_blocked(&local_err)) {
+        error_report_err(local_err);
+        return -EINVAL;
+    }
+    /* Load QEMU_VM_SECTION_START section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to loadvm begin work: %d", ret);
+    }
+    return ret;
+}
+
+int qemu_load_device_state(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    int ret;
+
+    /* Load QEMU_VM_SECTION_FULL section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to load device state: %d", ret);
+        return ret;
+    }
+
+    cpu_synchronize_all_post_init();
+    return 0;
+}
+
 void hmp_savevm(Monitor *mon, const QDict *qdict)
 {
     BlockDriverState *bs, *bs1;
-- 
1.8.3.1