migration: Enable UFFD_FEATURE_THREAD_ID even without blocktime feat

This patch allows us to read the tid even without blocktime feature enabled.
It's useful when tracing postcopy fault thread on faulted pages to show thread
id too with the address.

Remove the comments - they're merely not helpful at all.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index d18b5d05b2fb742b4fc3fe79575270d432fcaca8..2176ed68a502ee4d092fe60c93a043c2d02bfe6f 100644 (file)
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -283,15 +283,13 @@ static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
     }
 
 #ifdef UFFD_FEATURE_THREAD_ID
-    if (migrate_postcopy_blocktime() && mis &&
-        UFFD_FEATURE_THREAD_ID & supported_features) {
-        /* kernel supports that feature */
-        /* don't create blocktime_context if it exists */
-        if (!mis->blocktime_ctx) {
-            mis->blocktime_ctx = blocktime_context_new();
-        }
-
+    if (UFFD_FEATURE_THREAD_ID & supported_features) {
         asked_features |= UFFD_FEATURE_THREAD_ID;
+        if (migrate_postcopy_blocktime()) {
+            if (!mis->blocktime_ctx) {
+                mis->blocktime_ctx = blocktime_context_new();
+            }
+        }
     }
 #endif