net/qapi: add x-query-usernet command

Add a QMP command to query user-mode network stack (slirp) connection
states, providing a structured alternative to "info usernet" HMP.

The new command returns a list of UsernetInfo, with hub-id, hub-name,
and connection info for each slirp stack. It is marked unstable as it
is meant for debugging.

Rewrite hmp_info_usernet() as a thin wrapper over qmp_x_query_usernet()
so the HMP and QMP paths share the same implementation.

This is part of the effort to decouple HMP from QEMU core.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Marc-Andre Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260828-qemu-no-hmp-v5-10-9227de146347@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/qapi/net.json b/qapi/net.json
index 1a6382825c..5d3342fba2 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -1261,3 +1261,47 @@
 ##
 { 'event': 'NETDEV_VHOST_USER_DISCONNECTED',
   'data': { 'netdev-id': 'str' } }
+
+##
+# @UsernetInfo:
+#
+# Information about a user-mode network stack (slirp).
+#
+# @hub-id: The hub id, if available.
+#
+# @hub-name: The name of the hub.
+#
+# @info: Network information from slirp.
+#
+# Since: 11.2
+##
+{ 'struct': 'UsernetInfo',
+  'data': {
+    '*hub-id': 'int',
+    'hub-name': 'str',
+    'info': 'str' },
+  'if': 'CONFIG_SLIRP' }
+
+##
+# @x-query-usernet:
+#
+# Query user-mode network stack connection states.
+#
+# Features:
+#
+# @unstable: This command is meant for debugging.
+#
+# Returns: list of user-mode network stack information.
+#
+# Since: 11.2
+#
+# .. qmp-example::
+#
+#     -> { "execute": "x-query-usernet" }
+#     <- { "return": [ { "hub-id": 0, "hub-name": "vnet",
+#                        "info": "..." } ] }
+##
+{ 'command': 'x-query-usernet',
+  'returns': ['UsernetInfo'],
+  'if': 'CONFIG_SLIRP',
+  'features': [ 'unstable' ] }