Re: [PATCH v1 2/8] migration: should_skip() implemented

[Vladimir Sementsov-Ogievskiy]

23.03.2022 13:53, Nikita Lapshin wrote:

From: Nikita Lapshin <nikita.laps...@virtuozzo.com>

For next changes it is convenient to make all decisions about
sections skipping in one function.

Signed-off-by: Nikita Lapshin <nikita.laps...@openvz.org>
---
  migration/savevm.c | 54 ++++++++++++++++++++++++----------------------
  1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 02ed94c180..c68f187ef7 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -943,6 +943,15 @@ static int vmstate_save(QEMUFile *f, SaveStateEntry *se,
      return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
  }

+static bool should_skip(SaveStateEntry *se)

+{
+    if (se->ops && se->ops->is_active && !se->ops->is_active(se->opaque)) {
+        return true;
+    }
+
+    return false;

that may be simply

   return se->ops && se->ops->is_active && !se->ops->is_active(se->opaque);

But may be in future commits the code will be more complicated and we prepare 
for it now, will see.

+}
+
  /*
   * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
   */

[..]

          trace_savevm_section_start(se->idstr, se->section_id);

@@ -1417,6 +1417,9 @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,

              trace_savevm_section_skip(se->idstr, se->section_id);
              continue;
          }
+        if (should_skip(se)) {
+            continue;
+        }

Except for this and ...

trace_savevm_section_start(se->idstr, se->section_id); @@ -1522,10 +1525,8 @@ void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size,

          if (!se->ops || !se->ops->save_live_pending) {
              continue;
          }
-        if (se->ops->is_active) {
-            if (!se->ops->is_active(se->opaque)) {
-                continue;
-            }
+        if (should_skip(se)) {
+            continue;
          }
          se->ops->save_live_pending(f, se->opaque, threshold_size,
                                     res_precopy_only, res_compatible,
@@ -1635,6 +1636,9 @@ int qemu_save_device_state(QEMUFile *f)
          if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
              continue;
          }
+        if (should_skip(se)) {
+            continue;
+        }

this all other chunks are simple refactoring.

Let's do no-logic-change refactoring in a separate commit, and these two 
changes in another one, with description what and why.

save_section_header(f, se, QEMU_VM_SECTION_FULL); @@ -2542,10 +2546,8 @@ static int qemu_loadvm_state_setup(QEMUFile *f)

          if (!se->ops || !se->ops->load_setup) {
              continue;
          }
-        if (se->ops->is_active) {
-            if (!se->ops->is_active(se->opaque)) {
-                continue;
-            }
+        if (should_skip(se)) {
+            continue;
          }

ret = se->ops->load_setup(f, se->opaque);

--
Best regards,
Vladimir