[Qemu-devel] [PULL 4/8] rdma: introduce capability for chunk registration

[mrhines@linux.vnet.ibm.com]

From: "Michael R. Hines" <mrhines@us.ibm.com>

This capability allows you to disable dynamic chunk registration
for better throughput on high-performance links.

It is enabled by default.

Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
---
 include/migration/migration.h |    2 ++
 migration.c                   |   11 ++++++++++-
 qapi-schema.json              |    2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 0f4510f..e71ac12 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -144,4 +144,6 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
                              ram_addr_t offset, size_t size);
 
 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
+
+bool migrate_chunk_register_destination(void);
 #endif
diff --git a/migration.c b/migration.c
index 3b4b467..b46e103 100644
--- a/migration.c
+++ b/migration.c
@@ -66,6 +66,7 @@ MigrationState *migrate_get_current(void)
         .state = MIG_STATE_SETUP,
         .bandwidth_limit = MAX_THROTTLE,
         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
+        .enabled_capabilities[MIGRATION_CAPABILITY_CHUNK_REGISTER_DESTINATION] = true,
     };
 
     return &current_migration;
@@ -120,7 +121,6 @@ void process_incoming_migration(QEMUFile *f)
     Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
     int fd = qemu_get_fd(f);
 
-    assert(fd != -1);
     qemu_set_nonblock(fd);
     qemu_coroutine_enter(co, f);
 }
@@ -474,6 +474,15 @@ void qmp_migrate_set_downtime(double value, Error **errp)
     max_downtime = (uint64_t)value;
 }
 
+bool migrate_chunk_register_destination(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_CHUNK_REGISTER_DESTINATION];
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;
diff --git a/qapi-schema.json b/qapi-schema.json
index 751d3c2..691bae6 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -602,7 +602,7 @@
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
-  'data': ['xbzrle'] }
+  'data': ['xbzrle', 'chunk_register_destination'] }
 
 ##
 # @MigrationCapabilityStatus
-- 
1.7.10.4