tpm: Return QMP error when TPM is disabled in build

When the management layer queries a binary built using --disable-tpm
for TPM devices, it gets confused by getting empty responses:

  { "execute": "query-tpm" }
  {
      "return": [
      ]
  }
  { "execute": "query-tpm-types" }
  {
      "return": [
      ]
  }
  { "execute": "query-tpm-models" }
  {
      "return": [
      ]
  }

To make it clearer by returning an error:
- Make the TPM QAPI schema conditional
  All of tpm.json is now 'if': 'defined(CONFIG_TPM)'.
- Adapt the HMP command
- Remove stubs which became unnecessary

The management layer now gets a 'CommandNotFound' error:

  { "execute": "query-tpm" }
  {
      "error": {
          "class": "CommandNotFound",
          "desc": "The command query-tpm has not been found"
      }
  }

Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/qapi/tpm.json b/qapi/tpm.json
index 6a10c9ed8d..75590979fd 100644
--- a/qapi/tpm.json
+++ b/qapi/tpm.json
@@ -17,7 +17,9 @@
 #
 # Since: 1.5
 ##
-{ 'enum': 'TpmModel', 'data': [ 'tpm-tis', 'tpm-crb', 'tpm-spapr' ] }
+{ 'enum': 'TpmModel', 'data': [ 'tpm-tis', 'tpm-crb', 'tpm-spapr' ],
+  'if': 'defined(CONFIG_TPM)' }
+
 ##
 # @query-tpm-models:
 #
@@ -33,7 +35,8 @@
 # <- { "return": [ "tpm-tis", "tpm-crb", "tpm-spapr" ] }
 #
 ##
-{ 'command': 'query-tpm-models', 'returns': ['TpmModel'] }
+{ 'command': 'query-tpm-models', 'returns': ['TpmModel'],
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @TpmType:
@@ -46,7 +49,8 @@
 #
 # Since: 1.5
 ##
-{ 'enum': 'TpmType', 'data': [ 'passthrough', 'emulator' ] }
+{ 'enum': 'TpmType', 'data': [ 'passthrough', 'emulator' ],
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @query-tpm-types:
@@ -63,7 +67,8 @@
 # <- { "return": [ "passthrough", "emulator" ] }
 #
 ##
-{ 'command': 'query-tpm-types', 'returns': ['TpmType'] }
+{ 'command': 'query-tpm-types', 'returns': ['TpmType'],
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @TPMPassthroughOptions:
@@ -79,7 +84,8 @@
 ##
 { 'struct': 'TPMPassthroughOptions',
   'data': { '*path': 'str',
-            '*cancel-path': 'str' } }
+            '*cancel-path': 'str' },
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @TPMEmulatorOptions:
@@ -90,7 +96,8 @@
 #
 # Since: 2.11
 ##
-{ 'struct': 'TPMEmulatorOptions', 'data': { 'chardev' : 'str' } }
+{ 'struct': 'TPMEmulatorOptions', 'data': { 'chardev' : 'str' },
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @TpmTypeOptions:
@@ -104,7 +111,8 @@
 ##
 { 'union': 'TpmTypeOptions',
    'data': { 'passthrough' : 'TPMPassthroughOptions',
-             'emulator': 'TPMEmulatorOptions' } }
+             'emulator': 'TPMEmulatorOptions' },
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @TPMInfo:
@@ -122,7 +130,8 @@
 { 'struct': 'TPMInfo',
   'data': {'id': 'str',
            'model': 'TpmModel',
-           'options': 'TpmTypeOptions' } }
+           'options': 'TpmTypeOptions' },
+  'if': 'defined(CONFIG_TPM)' }
 
 ##
 # @query-tpm:
@@ -152,4 +161,5 @@
 #    }
 #
 ##
-{ 'command': 'query-tpm', 'returns': ['TPMInfo'] }
+{ 'command': 'query-tpm', 'returns': ['TPMInfo'],
+  'if': 'defined(CONFIG_TPM)' }