[PATCH 5/5] migration/rdma: Check for postcopy sooner

Juan Quintela posted 5 patches 2 years, 9 months ago
[PATCH 5/5] migration/rdma: Check for postcopy sooner
Posted by Juan Quintela 2 years, 9 months ago
It makes no sense first try to see if there is an rdma error and then
do nothing on postcopy stage.  Change it so we check we are in
postcopy before doing anything.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/rdma.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/migration/rdma.c b/migration/rdma.c
index 17c4b9206f..2cd8f1cc66 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -3234,19 +3234,19 @@ static size_t qemu_rdma_save_page(QEMUFile *f,
     RDMAContext *rdma;
     int ret;
 
-    RCU_READ_LOCK_GUARD();
-    rdma = qatomic_rcu_read(&rioc->rdmaout);
-
-    if (!rdma) {
-        return -EIO;
-    }
-
-    CHECK_ERROR_STATE();
-
     if (migration_in_postcopy()) {
         return RAM_SAVE_CONTROL_NOT_SUPP;
     }
 
+    RCU_READ_LOCK_GUARD();
+    rdma = qatomic_rcu_read(&rioc->rdmaout);
+
+    if (!rdma) {
+        return -EIO;
+    }
+
+    CHECK_ERROR_STATE();
+
     qemu_fflush(f);
 
     /*
@@ -3866,6 +3866,10 @@ static int qemu_rdma_registration_start(QEMUFile *f,
     QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(qemu_file_get_ioc(f));
     RDMAContext *rdma;
 
+    if (migration_in_postcopy()) {
+        return 0;
+    }
+
     RCU_READ_LOCK_GUARD();
     rdma = qatomic_rcu_read(&rioc->rdmaout);
     if (!rdma) {
@@ -3874,10 +3878,6 @@ static int qemu_rdma_registration_start(QEMUFile *f,
 
     CHECK_ERROR_STATE();
 
-    if (migration_in_postcopy()) {
-        return 0;
-    }
-
     trace_qemu_rdma_registration_start(flags);
     qemu_put_be64(f, RAM_SAVE_FLAG_HOOK);
     qemu_fflush(f);
@@ -3897,6 +3897,10 @@ static int qemu_rdma_registration_stop(QEMUFile *f,
     RDMAControlHeader head = { .len = 0, .repeat = 1 };
     int ret = 0;
 
+    if (migration_in_postcopy()) {
+        return 0;
+    }
+
     RCU_READ_LOCK_GUARD();
     rdma = qatomic_rcu_read(&rioc->rdmaout);
     if (!rdma) {
@@ -3905,10 +3909,6 @@ static int qemu_rdma_registration_stop(QEMUFile *f,
 
     CHECK_ERROR_STATE();
 
-    if (migration_in_postcopy()) {
-        return 0;
-    }
-
     qemu_fflush(f);
     ret = qemu_rdma_drain_cq(f, rdma);
 
-- 
2.40.0
Re: [PATCH 5/5] migration/rdma: Check for postcopy sooner
Posted by Daniel P. Berrangé 2 years, 9 months ago
On Thu, May 04, 2023 at 01:44:43PM +0200, Juan Quintela wrote:
> It makes no sense first try to see if there is an rdma error and then
> do nothing on postcopy stage.  Change it so we check we are in
> postcopy before doing anything.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/rdma.c | 34 +++++++++++++++++-----------------
>  1 file changed, 17 insertions(+), 17 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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