Re: [Qemu-devel] [PATCH 10/12] netbuffer: add a public api filter_buffer_release_all

[Jason Wang <jasowang@redhat.com>]

On 07/30/2015 01:50 PM, Yang Hongyang wrote:
> On 07/30/2015 01:25 PM, Jason Wang wrote:
>>
>>
>> On 07/29/2015 06:51 PM, Yang Hongyang wrote:
>>> add a public api filter_buffer_release_all to release all
>>> buffered packets.
>>> also introduce qemu_find_netfilters_by_model to find all buffer
>>> filters.
>>>
>>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>>> ---
>>>   include/net/filter.h |  5 +++++
>>>   net/filter-buffer.c  | 41 +++++++++++++++++++++++++++++++++++++++++
>>>   net/filter.c         | 18 ++++++++++++++++++
>>>   3 files changed, 64 insertions(+)
>>>
>>> diff --git a/include/net/filter.h b/include/net/filter.h
>>> index 5292563..798b5b2 100644
>>> --- a/include/net/filter.h
>>> +++ b/include/net/filter.h
>>> @@ -50,5 +50,10 @@ NetFilterState *qemu_new_net_filter(NetFilterInfo
>>> *info,
>>>                                       const char *name);
>>>   void netfilter_add(QemuOpts *opts, Error **errp);
>>>   void qmp_netfilter_add(QDict *qdict, QObject **ret, Error **errp);
>>> +int qemu_find_netfilters_by_model(const char *model, NetFilterState
>>> **nfs,
>>> +                                  int max);
>>> +
>>> +/* netbuffer filter */
>>> +void filter_buffer_release_all(void);
>>>
>>>   #endif /* QEMU_NET_FILTER_H */
>>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>>> index 628e66f..8bac73b 100644
>>> --- a/net/filter-buffer.c
>>> +++ b/net/filter-buffer.c
>>> @@ -11,12 +11,14 @@
>>>   #include "filters.h"
>>>   #include "qemu-common.h"
>>>   #include "qemu/error-report.h"
>>> +#include "qemu/main-loop.h"
>>>
>>>   typedef struct FILTERBUFFERState {
>>>       NetFilterState nf;
>>>       NetClientState dummy; /* used to send buffered packets */
>>>       NetQueue *incoming_queue;
>>>       NetQueue *inflight_queue;
>>> +    QEMUBH *flush_bh;
>>
>> bh should be stopped and restarted during vm stop and continue.
>
> Sorry, could you explain more about this? do you mean to check
> the vm state before bh_schedule?

Rethink about this. Looks safe since qemu_can_send_packet() check vmstate.

> how to stop&restart a bh? bh_delete bh_new bh_schedule?

qemu_bh_cancel() and qemu_bh_schedule().