From ed076b2838fb9c9b7e137352e72408d9267fd702 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Wed, 22 Nov 2017 15:41:32 +0100
Subject: migration: Reenable incoming live-block-migration

RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20171122154132.15363-1-dgilbert@redhat.com>
Patchwork-id: 77779
O-Subject: [RHEL-7.5 qemu-kvm-rhev PATCH 1/1] migration: Reenable incoming live-block-migration
Bugzilla: 1515173
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

rhel7 has always disabled outgoing old-style live block migration
(but in -rhev enabled nbd block migration); however it allows
incoming old-style live block migration to allow reception of a stream
from rhel6.

I added --disable-live-block-migration to upstream in ed1701c6a5a,
however that really did disable it completely.

In the 7.5 world we've inherited the upstream version and lost the
incoming support.

Reenable incoming support even when outgoing is disabled.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
(cherry picked from commit e6f62c7eb81f164ad5aef99a4f7ff48200928938)
(cherry picked from commit d5fb1ed0bc8fe06f7f9ffa50df033f1be6a19335)
(cherry picked from commit d4f3d9c5f333b1b97e0eea3eff665988d92f7a24)
(cherry picked from commit 011f4eb1ad9f4a3b358a904348340b010cf54512)
---
 include/migration/misc.h | 7 +++----
 migration/Makefile.objs  | 2 +-
 migration/block.h        | 6 +++++-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/include/migration/misc.h b/include/migration/misc.h
index 4ebf24c..10084e0 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -22,11 +22,10 @@ void ram_mig_init(void);
 
 /* migration/block.c */
 
-#ifdef CONFIG_LIVE_BLOCK_MIGRATION
+/* RHEL7 allows incoming block migration even with
+ * --disable-live-block-migration to allow RHEL6->7 migration.
+ */
 void blk_mig_init(void);
-#else
-static inline void blk_mig_init(void) {}
-#endif
 
 #define SELF_ANNOUNCE_ROUNDS 5
 
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index c83ec47..5cb9fc0 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -10,6 +10,6 @@ common-obj-y += block-dirty-bitmap.o
 
 common-obj-$(CONFIG_RDMA) += rdma.o
 
-common-obj-$(CONFIG_LIVE_BLOCK_MIGRATION) += block.o
+common-obj-y += block.o
 
 rdma.o-libs := $(RDMA_LIBS)
diff --git a/migration/block.h b/migration/block.h
index 3178609..1cc81b0 100644
--- a/migration/block.h
+++ b/migration/block.h
@@ -14,7 +14,11 @@
 #ifndef MIGRATION_BLOCK_H
 #define MIGRATION_BLOCK_H
 
-#ifdef CONFIG_LIVE_BLOCK_MIGRATION
+/* RHEL7: live block migration is still compiled in even
+ * with --disable-live-block-migration since we must
+ * allow inbound migration from RHEL6.
+ */
+#if 1 /* CONFIG_LIVE_BLOCK_MIGRATION */
 int blk_mig_active(void);
 int blk_mig_bulk_active(void);
 uint64_t blk_mig_bytes_transferred(void);
-- 
1.8.3.1