[Qemu-devel] [PATCH 2/2] migration: send and check the devices between source and distination at the begining

[Li Zhijian]

Priviously, if the source and distination have different devices, source could 
goto
the status "paused (postmigrate)", and the distination will exit that means no 
qemu
is alive.

After this patch, at above case, source can dectect the some error early from 
distination
and stop the migration, source keep in status "running".

Signed-off-by: Li Zhijian <address@hidden>
---
 migration/savevm.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 09d8e99..0c07671 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -887,6 +887,7 @@ void qemu_savevm_state_begin(QEMUFile *f,
 
     trace_savevm_state_begin();
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+        save_section_header(f, se, QEMU_VM_SECTION_START);
         if (!se->ops || !se->ops->set_params) {
             continue;
         }
@@ -902,7 +903,7 @@ void qemu_savevm_state_begin(QEMUFile *f,
                 continue;
             }
         }
-        save_section_header(f, se, QEMU_VM_SECTION_START);
+        save_section_header(f, se, QEMU_VM_SECTION_FULL);
 
         ret = se->ops->save_live_setup(f, se->opaque);
         save_section_footer(f, se);
@@ -1775,7 +1776,7 @@ qemu_loadvm_section_start(QEMUFile *f, 
MigrationIncomingState *mis,
 }
 
 static int
-qemu_loadvm_section_full(QEMUFile *f, MigrationIncomingState *mis)
+qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
 {
     uint32_t version_id, section_id;
     SaveStateEntry *se;
@@ -1846,14 +1847,21 @@ static int qemu_loadvm_state_main(QEMUFile *f, 
MigrationIncomingState *mis)
 {
     uint8_t section_type;
     int ret;
+    SaveStateEntry *se;
+    uint32_t instance, version;
 
     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
 
         trace_qemu_loadvm_state_section(section_type);
         switch (section_type) {
         case QEMU_VM_SECTION_START:
+            ret = qemu_loadvm_section_start(f, mis, &se, &instance, &version);
+            if (ret < 0) {
+                return ret;
+            }
+            break;
         case QEMU_VM_SECTION_FULL:
-            ret = qemu_loadvm_section_full(f, mis);
+            ret = qemu_loadvm_section_start_full(f, mis);
             if (ret < 0) {
                 return ret;
             }
-- 
2.7.4