[Qemu-trivial] [PATCH v2] qapi-schema: clarify 'colo' state for MigrationStatus

[zhanghailiang]

VM can not get into colo state unless users enable 'x-colo'
capability for migration, Here it is necessary to clarify
this.

Suggested-by: Eric Blake <address@hidden>
Signed-off-by: zhanghailiang <address@hidden>
---
v2:
- Clarify colo state for RunState too as Eric suggested.
---
 qapi-schema.json | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index 5dc96af..04f5aab 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -176,8 +176,9 @@
 #
 # @guest-panicked: guest has been panicked as a result of guest OS panic
 #
-# @colo: guest is paused to save/restore VM state under colo checkpoint (since
-# 2.8)
+# @colo: guest is paused to save/restore VM state under colo checkpoint,
+#        VM can not get into this state unless colo capability is enabled
+#        for migration. (since 2.8)
 ##
 { 'enum': 'RunState',
   'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
@@ -462,7 +463,8 @@
 #
 # @failed: some error occurred during migration process.
 #
-# @colo: VM is in the process of fault tolerance. (since 2.8)
+# @colo: VM is in the process of fault tolerance, VM can not get into this
+#        state unless colo capability is enabled for migration. (since 2.8)
 #
 # Since: 2.3
 #
-- 
1.8.3.1