[PULL 35/38] migration: Enable UFFD_FEATURE_THREAD_ID even without blocktime feat

Juan Quintela posted 38 patches 4 years ago
Maintainers: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Fam Zheng <fam@euphon.net>, Alistair Francis <alistair@alistair23.me>, Andrew Baumann <Andrew.Baumann@microsoft.com>, "Michael S. Tsirkin" <mst@redhat.com>, Vikram Garhwal <fnu.vikram@xilinx.com>, Aurelien Jarno <aurelien@aurel32.net>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Paolo Bonzini <pbonzini@redhat.com>, Stafford Horne <shorne@gmail.com>, Juan Quintela <quintela@redhat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Pavel Pisa <pisa@cmp.felk.cvut.cz>, Laurent Vivier <laurent@vivier.eu>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Artyom Tarasenko <atar4qemu@gmail.com>, Gerd Hoffmann <kraxel@redhat.com>, Ani Sinha <ani@anisinha.ca>, Greg Kurz <groug@kaod.org>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Hannes Reinecke <hare@suse.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Jason Wang <jasowang@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Daniel Henrique Barboza <danielhb413@gmail.com>, Igor Mammedov <imammedo@redhat.com>
[PULL 35/38] migration: Enable UFFD_FEATURE_THREAD_ID even without blocktime feat
Posted by Juan Quintela 4 years ago
From: Peter Xu <peterx@redhat.com>

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>
---
 migration/postcopy-ram.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index d18b5d05b2..2176ed68a5 100644
--- 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
 
-- 
2.34.1