Re: [Qemu-devel] [PATCH v3 2/2] net: introduce command to query rx-filter information

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> On 05/23/2013 03:08 AM, Amos Kong wrote:
>> We want to implement mac programming over macvtap through Libvirt,
>> related rx-filter configuration contains main mac, some of rx-mode
>> and mac-table.
>> 
>> The previous patch adds QMP event to notify management of rx-filter
>> change. This patch adds a monitor command to query rx-filter
>> information.
>> 
>> A flag is used to avoid events flooding, if user don't query
>
> s/don't/doesn't/
>
>> rx-filter after receives one event, new events won't be sent
>
> s/after/after it/
>
>> to qmp monitor.
>> 
>> +++ b/net/net.c
>> @@ -961,6 +961,53 @@ void print_net_client(Monitor *mon, NetClientState *nc)
>>                     nc->info_str);
>>  }
>>  
>> +RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
>> +                                      Error **errp)
>> +{
>> +    NetClientState *nc;
>> +    RxFilterInfoList *filter_list = NULL, *last_entry = NULL;
>> +
>> +    QTAILQ_FOREACH(nc, &net_clients, next) {
>> +        RxFilterInfoList *entry;
>> +        RxFilterInfo *info;
>> +
>> +        if (nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC) {
>> +            continue;
>> +        }
>> +        if (has_name && strcmp(nc->name, name) != 0) {
>
> Do you need the has_name argument here, or can you ensure that the
> caller passes NULL when the caller's has_name was false, for one less
> parameter and the same amount of information?

QAPI always generates a has_FOO parameter for an optional FOO parameter,
even when FOO is a pointer, which has the perfectly obvious special "not
given" value NULL.  I hate that.

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