[PATCH] multifd: Updated QAPI format for 'migrate' qemu monitor command

[Het Gala]

To prevent double data encoding of uris, instead of passing transport
mechanisms, host address and port all together in form of a single string
and writing different parsing functions, we intend the user to explicitly
mention most of the parameters through the medium of qmp command itself.

The current patch is continuation of patchset series
https://www.mail-archive.com/qemu-devel@nongnu.org/msg901274.html
and reply to the ongoing discussion for better QAPI design here
https://www.mail-archive.com/qemu-devel@nongnu.org/msg903753.html.

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
Suggested-by: Manish Mishra <manish.mishra@nutanix.com>
Signed-off-by: Het Gala <het.gala@nutanix.com>
---
 qapi/migration.json | 127 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 125 insertions(+), 2 deletions(-)

diff --git a/qapi/migration.json b/qapi/migration.json
index 88ecf86ac8..fd9286ea0f 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1449,12 +1449,101 @@
 ##
 { 'command': 'migrate-continue', 'data': {'state': 'MigrationStatus'} }
 
+##
+# @MigrateTransport:
+#
+# The supported communication transport mechanisms for migration
+#
+# @socket: Supported communication type between two devices for migration.
+#          Socket is able to cover all of 'tcp', 'unix', 'vsock' and
+#          'fd' already
+#
+# @exec: Supported communication type to redirect migration stream into file.
+#
+# Since 7.1
+##
+{ 'enum': 'MigrateTransport',
+  'data': ['socket', 'exec'] }
+
+##
+# @MigrateSocketAddrType:
+#
+# To support different type of socket.
+#
+# @socket-type: Different type of socket connections.
+#
+# Since (7.1)
+##
+{ 'struct': 'MigrateSocketAddrType',
+  'data': {'socket-type': 'SocketAddress' } }
+
+##
+# @MigrateAddress:
+#
+# The options available for communication transport mechanisms for migration
+#
+# Since 7.1
+##
+{ 'union' : 'MigrateAddress',
+  'base' : { 'transport' : 'MigrateTransport'},
+  'discriminator' : 'transport',
+  'data' : {
+           'socket' : 'MigrateSocketAddrType',
+           'exec' : 'String' } }
+
+##
+# @MigrateChannelType:
+#
+# The supported options for migration channel type requests
+#
+# @control: Support request for main outbound migration control channel
+#
+# @data: Supported Channel type for multifd data channels
+#
+# @async: Supported Channel type for post-copy async requests
+#
+# Since 7.1
+##
+{ 'enum': 'MigrateChannelType',
+  'data': ['control', 'data', 'async'] }
+
+##
+# @MigrateChannel:
+#
+# Information regarding migration Channel-type for transferring packets,
+# source and corresponding destination interface for socket connection
+# and number of multifd channels over the interface.
+#
+# @channeltype: Name of Channel type for transfering packet information
+#
+# @src-addr: SocketAddress of source interface
+#
+# @dest-addr: SocketAddress of destination interface
+#
+# @multifd-count: number of multifd channels used to migrate
+#                    data between a specific source and destination
+#                    interface. Default value in this case is 2.
+#
+# Since 7.1
+##
+{ 'struct': 'MigrateChannel',
+  'data' : {
+    'channeltype' : 'MigrateChannelType',
+    '*src-addr' : 'MigrateAddress',
+    'dest-addr' : 'MigrateAddress',
+    '*multifd-count' : 'int' } }
+
 ##
 # @migrate:
 #
 # Migrates the current running guest to another Virtual Machine.
 #
 # @uri: the Uniform Resource Identifier of the destination VM
+#       for migration thread
+#
+# @channels: list of migration channel type, pair of source and
+#            destination interface with number of multifd-channels
+#            for each pair
 #
 # @blk: do block migration (full disk copy)
 #
@@ -1479,15 +1568,49 @@
 # 3. The user Monitor's "detach" argument is invalid in QMP and should not
 #    be used
 #
+# 4. The uri argument should have the Uniform Resource Identifier of default
+#    destination VM. This connection will be bound to default network
+#
+# 5. Both 'uri' and 'channels' arguments, are mututally exclusive.
+#
+# 6. The 'channels' argument should contain atleast one control channel for
+#    main outbound migration.
+#
 # Example:
 #
 # -> { "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } }
 # <- { "return": {} }
 #
+# -> { "execute": "migrate",
+#      "arguments": {
+#          "channels": [ { 'channeltype': 'control',
+#                          'dest-addr': {'transport': 'socket',
+#                                        'type': 'inet',
+#                                        'host': '10.12.34.9', 'port': 
'1050'}},
+#                        { 'channeltype': 'data',
+#                          'src-addr': {'transport': 'socket',
+#                                        'type': 'inet',
+#                                        'host': '10.12.34.9',
+#                                        'port': '4000', 'ipv4': 'true'},
+#                          'dest-addr': { 'transport': 'socket',
+#                                          'type': 'inet',
+#                                          'host': '10.12.34.92',
+#                                          'port': '1234', 'ipv4': 'true'},
+#                          'multifd-count': 5 },
+#                        { 'channeltype': 'data',
+#                          'src-addr': {'transport': 'socket',
+#                                        'type': 'inet',
+#                                        'host': '10.2.3.4', 'port': '1000'},
+#                          'dest-addr': {'transport': 'socket',
+#                                         'type': 'inet',
+#                                         'host': '0.0.0.4', 'port': '3000'},
+#                          'multifd-count': 3 } ] } }
+# <- { "return": {} }
+#
 ##
 { 'command': 'migrate',
-  'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool',
-           '*detach': 'bool', '*resume': 'bool' } }
+  'data': {'*uri': 'str', '*channels': ['MigrateChannel'], '*blk': 'bool',
+           '*inc': 'bool', '*detach': 'bool', '*resume': 'bool' } }
 
 ##
 # @migrate-incoming:
-- 
2.31.1