qmp_device_list_properties() skips properties whose name starts with
"legacy-".  This is a flawed test for "is a legacy property".

The test is flawed because non-legacy properties can and do start with
"legacy-".  Back when it was added, no such properties existed.  Right
now, three such properties do: property "legacy-cmb" of device "nvme",
and properties "legacy-cache" and "legacy-multi-node" of devices
"x86_64-cpu", "i386-cpu", and its children.

This affects QMP command "device-list-properties", HMP command
"device_add T,help", and command line option "-device T,help".

Legacy properties are gone since commit a61383f7ab (qdev: Legacy
properties are now unused internally, drop, 2025-10-22).  This makes
the fix easy: delete the code that skips them.

Reproducer: -device nvme,help doesn't show legacy-cmb before the
patch, and does after.

Fixes: f4eb32b590 (qmp: show QOM properties in device-list-properties, 2014-05-20)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 qom/qom-qmp-cmds.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/qom/qom-qmp-cmds.c b/qom/qom-qmp-cmds.c
index 48b38d2b7f..330895361d 100644
--- a/qom/qom-qmp-cmds.c
+++ b/qom/qom-qmp-cmds.c
@@ -218,13 +218,6 @@ ObjectPropertyInfoList *qmp_device_list_properties(const char *typename,
             continue;
         }
 
-        /* Skip legacy properties since they are just string versions of
-         * properties that we already list.
-         */
-        if (strstart(prop->name, "legacy-", NULL)) {
-            continue;
-        }
-
         info = g_new0(ObjectPropertyInfo, 1);
         info->name = g_strdup(prop->name);
         info->type = g_strdup(prop->type);
-- 
2.54.0

On Wed, Jul 08, 2026 at 04:09:48PM +0200, Markus Armbruster wrote:
> qmp_device_list_properties() skips properties whose name starts with
> "legacy-".  This is a flawed test for "is a legacy property".
> 
> The test is flawed because non-legacy properties can and do start with
> "legacy-".  Back when it was added, no such properties existed.  Right
> now, three such properties do: property "legacy-cmb" of device "nvme",
> and properties "legacy-cache" and "legacy-multi-node" of devices
> "x86_64-cpu", "i386-cpu", and its children.
> 
> This affects QMP command "device-list-properties", HMP command
> "device_add T,help", and command line option "-device T,help".
> 
> Legacy properties are gone since commit a61383f7ab (qdev: Legacy
> properties are now unused internally, drop, 2025-10-22).  This makes
> the fix easy: delete the code that skips them.
> 
> Reproducer: -device nvme,help doesn't show legacy-cmb before the
> patch, and does after.
> 
> Fixes: f4eb32b590 (qmp: show QOM properties in device-list-properties, 2014-05-20)
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  qom/qom-qmp-cmds.c | 7 -------
>  1 file changed, 7 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
-- 
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