qga: conditionalize schema for commands requiring fstrim

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 filesystem trimming commands
on POSIX platforms lacking required APIs.

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>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Message-ID: <20240712132459.3974109-15-berrange@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 9207cb7a8ff01b4d137b0d20329583e2f320eda8..d92fa0ec8727ec06773c26a4f4c1480b1268485c 100644 (file)
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1144,22 +1144,9 @@ error:
 
 #endif /* HAVE_GETIFADDRS */
 
-#if !defined(CONFIG_FSTRIM)
-GuestFilesystemTrimResponse *
-qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}
-#endif
-
 /* add unsupported commands to the list of blocked RPCs */
 GList *ga_command_init_blockedrpcs(GList *blockedrpcs)
 {
-#if !defined(CONFIG_FSTRIM)
-    blockedrpcs = g_list_append(blockedrpcs, g_strdup("guest-fstrim"));
-#endif
-
     return blockedrpcs;
 }
 

diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 62462f092c13bb31d78802857eaf4e7f46ab3f30..21c65d180630f04beb5985d67d718cbabe2da7cc 100644 (file)
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -510,7 +510,8 @@
 ##
 { 'struct': 'GuestFilesystemTrimResult',
   'data': {'path': 'str',
-           '*trimmed': 'int', '*minimum': 'int', '*error': 'str'} }
+           '*trimmed': 'int', '*minimum': 'int', '*error': 'str'},
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSTRIM'] } }
 
 ##
 # @GuestFilesystemTrimResponse:
@@ -520,7 +521,8 @@
 # Since: 2.4
 ##
 { 'struct': 'GuestFilesystemTrimResponse',
-  'data': {'paths': ['GuestFilesystemTrimResult']} }
+  'data': {'paths': ['GuestFilesystemTrimResult']},
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSTRIM'] } }
 
 ##
 # @guest-fstrim:
@@ -542,7 +544,8 @@
 ##
 { 'command': 'guest-fstrim',
   'data': { '*minimum': 'int' },
-  'returns': 'GuestFilesystemTrimResponse' }
+  'returns': 'GuestFilesystemTrimResponse',
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSTRIM'] } }
 
 ##
 # @guest-suspend-disk: