Re: [PATCH v6 14/15] qmp: Include "reserve" property of memory backends

[Markus Armbruster]

David Hildenbrand <david@redhat.com> writes:

> On 23.04.21 13:00, Markus Armbruster wrote:
>> David Hildenbrand <david@redhat.com> writes:
>> 
>>> Let's include the new property.
>>>
>>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> Cc: Eric Blake <eblake@redhat.com>
>>> Cc: Markus Armbruster <armbru@redhat.com>
>>> Cc: Igor Mammedov <imammedo@redhat.com>
>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>> ---
>>>   hw/core/machine-qmp-cmds.c | 1 +
>>>   qapi/machine.json          | 4 ++++
>>>   2 files changed, 5 insertions(+)
>>>
>>> diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c
>>> index d41db5b93b..2d135ecdd0 100644
>>> --- a/hw/core/machine-qmp-cmds.c
>>> +++ b/hw/core/machine-qmp-cmds.c
>>> @@ -175,6 +175,7 @@ static int query_memdev(Object *obj, void *opaque)
>>>           m->dump = object_property_get_bool(obj, "dump", &error_abort);
>>>           m->prealloc = object_property_get_bool(obj, "prealloc", 
>>> &error_abort);
>>>           m->share = object_property_get_bool(obj, "share", &error_abort);
>>> +        m->reserve = object_property_get_bool(obj, "reserve", 
>>> &error_abort);
>>>           m->policy = object_property_get_enum(obj, "policy", 
>>> "HostMemPolicy",
>>>                                                &error_abort);
>>>           host_nodes = object_property_get_qobject(obj,
>>> diff --git a/qapi/machine.json b/qapi/machine.json
>>> index 32650bfe9e..5932139d20 100644
>>> --- a/qapi/machine.json
>>> +++ b/qapi/machine.json
>>> @@ -798,6 +798,9 @@
>>>   #
>>>   # @share: whether memory is private to QEMU or shared (since 6.1)
>>>   #
>>> +# @reserve: whether swap space (or huge pages) was reserved if applicable
>>> +#           (since 6.1)
>>> +#
>>>   # @host-nodes: host nodes for its memory policy
>>>   #
>>>   # @policy: memory policy of memory backend
>>> @@ -812,6 +815,7 @@
>>>       'dump':       'bool',
>>>       'prealloc':   'bool',
>>>       'share':      'bool',
>>> +    'reserve':    'bool',
>>>       'host-nodes': ['uint16'],
>>>       'policy':     'HostMemPolicy' }}
>> 
>> Double-checking: true means definitely reserved, and false means
>> definitely not reserved.  Correct?
>
> True means "reserved if applicable" which means "not reserved if not 
> applicable". False means "definitely not reserved".
>
> (any recommendation how to rephrase are appreciated; I tried my best -- 
> this interface here makes it especially hard -- it's easier for the 
> property itself)

When is it "applicable"?