qga: conditionalize schema for commands unsupported on non-Linux POSIX

Rather than creating stubs for every command that just return
QERR_UNSUPPORTED, use 'if' conditions in the QAPI schema to
fully exclude generation of the commands on non-Linux POSIX
platforms

The command will be rejected at QMP dispatch time instead,
avoiding reimplementing rejection by blocking the stub commands.
This changes the error message for affected commands from

    {"class": "CommandNotFound", "desc": "Command FOO has been disabled"}

to

    {"class": "CommandNotFound", "desc": "The command FOO has not been found"}

This has the additional benefit that the QGA protocol reference
now documents what conditions enable use of the command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20240712132459.3974109-10-berrange@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>

qga/commands-posix.c

@@ -887,56 +887,6 @@ void qmp_guest_set_user_password(const char *username,
 }
 #endif /* __linux__ || __FreeBSD__ */
 
-#ifndef __linux__
-
-void qmp_guest_suspend_disk(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-}
-
-void qmp_guest_suspend_ram(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-}
-
-void qmp_guest_suspend_hybrid(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-}
-
-GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}
-
-int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return -1;
-}
-
-GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}
-
-GuestMemoryBlockResponseList *
-qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}
-
-GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}
-
-#endif
-
 #ifdef HAVE_GETIFADDRS
 static GuestNetworkInterface *
 guest_find_interface(GuestNetworkInterfaceList *head,
@@ -1272,22 +1222,6 @@ qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
 /* add unsupported commands to the list of blocked RPCs */
 GList *ga_command_init_blockedrpcs(GList *blockedrpcs)
 {
-#if !defined(__linux__)
-    {
-        const char *list[] = {
-            "guest-suspend-disk", "guest-suspend-ram",
-            "guest-suspend-hybrid", "guest-get-vcpus", "guest-set-vcpus",
-            "guest-get-memory-blocks", "guest-set-memory-blocks",
-            "guest-get-memory-block-info",
-            NULL};
-        const char **p = list;
-
-        while (*p) {
-            blockedrpcs = g_list_append(blockedrpcs, g_strdup(*p++));
-        }
-    }
-#endif
-
 #if !defined(HAVE_GETIFADDRS)
     blockedrpcs = g_list_append(blockedrpcs,
                               g_strdup("guest-network-get-interfaces"));

qga/qapi-schema.json

@@ -566,7 +566,8 @@
 #
 # Since: 1.1
 ##
-{ 'command': 'guest-suspend-disk', 'success-response': false }
+{ 'command': 'guest-suspend-disk', 'success-response': false,
+  'if': { 'any': ['CONFIG_LINUX', 'CONFIG_WIN32'] } }
 
 ##
 # @guest-suspend-ram:
@@ -602,7 +603,8 @@
 #
 # Since: 1.1
 ##
-{ 'command': 'guest-suspend-ram', 'success-response': false }
+{ 'command': 'guest-suspend-ram', 'success-response': false,
+  'if': { 'any': ['CONFIG_LINUX', 'CONFIG_WIN32'] } }
 
 ##
 # @guest-suspend-hybrid:
@@ -638,7 +640,7 @@
 # Since: 1.1
 ##
 { 'command': 'guest-suspend-hybrid', 'success-response': false,
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestIpAddressType:
@@ -751,7 +753,8 @@
 { 'struct': 'GuestLogicalProcessor',
   'data': {'logical-id': 'int',
            'online': 'bool',
-           '*can-offline': 'bool'} }
+           '*can-offline': 'bool'},
+  'if': { 'any': ['CONFIG_LINUX', 'CONFIG_WIN32'] } }
 
 ##
 # @guest-get-vcpus:
@@ -766,7 +769,8 @@
 # Since: 1.5
 ##
 { 'command': 'guest-get-vcpus',
-  'returns': ['GuestLogicalProcessor'] }
+  'returns': ['GuestLogicalProcessor'],
+  'if': { 'any': ['CONFIG_LINUX', 'CONFIG_WIN32'] } }
 
 ##
 # @guest-set-vcpus:
@@ -809,7 +813,7 @@
 { 'command': 'guest-set-vcpus',
   'data':    {'vcpus': ['GuestLogicalProcessor'] },
   'returns': 'int',
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestDiskBusType:
@@ -1103,7 +1107,7 @@
   'data': {'phys-index': 'uint64',
            'online': 'bool',
            '*can-offline': 'bool'},
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @guest-get-memory-blocks:
@@ -1120,7 +1124,7 @@
 ##
 { 'command': 'guest-get-memory-blocks',
   'returns': ['GuestMemoryBlock'],
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestMemoryBlockResponseType:
@@ -1144,7 +1148,7 @@
 { 'enum': 'GuestMemoryBlockResponseType',
   'data': ['success', 'not-found', 'operation-not-supported',
            'operation-failed'],
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestMemoryBlockResponse:
@@ -1163,7 +1167,7 @@
   'data': { 'phys-index': 'uint64',
             'response': 'GuestMemoryBlockResponseType',
             '*error-code': 'int' },
-  'if': 'CONFIG_POSIX'}
+  'if': 'CONFIG_LINUX'}
 
 ##
 # @guest-set-memory-blocks:
@@ -1195,7 +1199,7 @@
 { 'command': 'guest-set-memory-blocks',
   'data':    {'mem-blks': ['GuestMemoryBlock'] },
   'returns': ['GuestMemoryBlockResponse'],
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestMemoryBlockInfo:
@@ -1208,7 +1212,7 @@
 ##
 { 'struct': 'GuestMemoryBlockInfo',
   'data': {'size': 'uint64'},
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @guest-get-memory-block-info:
@@ -1221,7 +1225,7 @@
 ##
 { 'command': 'guest-get-memory-block-info',
   'returns': 'GuestMemoryBlockInfo',
-  'if': 'CONFIG_POSIX' }
+  'if': 'CONFIG_LINUX' }
 
 ##
 # @GuestExecStatus: