[Qemu-devel] [RFC PATCH v2 11/12] mc: introduce new capabilities to control micro-checkpointing

[mrhines@linux.vnet.ibm.com]

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

New capabilities include the use of RDMA acceleration,
use of network buffering, and keepalive support, as documented
in patch #1.

Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
---
 qapi-schema.json | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index 98abdac..1fdf208 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -720,10 +720,44 @@
 # @auto-converge: If enabled, QEMU will automatically throttle down the guest
 #          to speed up convergence of RAM migration. (since 1.6)
 #
+# @mc: The migration will never end, and the VM will instead be continuously
+#          micro-checkpointed (MC). Use the command migrate-set-mc-delay to 
+#          control the frequency at which the checkpoints occur. 
+#          Disabled by default. (Since 2.x)
+#
+# @mc-net-disable: Deactivate network buffering against outbound network 
+#          traffic while Micro-Checkpointing (@mc) is active.
+#          Enabled by default. Disabling will make the MC protocol inconsistent
+#          and potentially break network connections upon an actual failure.
+#          Only for performance testing. (Since 2.x)
+#
+# @mc-rdma-copy: MC requires creating a local-memory checkpoint before
+#          transmission to the destination. This requires heavy use of 
+#          memcpy() which dominates the processor pipeline. This option 
+#          makes use of *local* RDMA to perform the copy instead of the CPU.
+#          Enabled by default only if the migration transport is RDMA.
+#          Disabled by default otherwise. (Since 2.x)
+#
+# @rdma-keepalive: RDMA connections do not timeout by themselves if a peer
+#         has disconnected prematurely or failed. User-level keepalives
+#         allow the migration to abort cleanly if there is a problem with the
+#         destination host. For debugging, this can be problematic as
+#         the keepalive may cause the peer to abort prematurely if we are
+#         at a GDB breakpoint, for example.
+#         Enabled by default. (Since 2.x)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
-  'data': ['xbzrle', 'x-rdma-pin-all', 'auto-converge', 'zero-blocks'] }
+  'data': ['xbzrle', 
+           'rdma-pin-all', 
+           'auto-converge', 
+           'zero-blocks',
+           'mc', 
+           'mc-net-disable',
+           'mc-rdma-copy',
+           'rdma-keepalive'
+          ] }
 
 ##
 # @MigrationCapabilityStatus
-- 
1.8.1.2