Re: [PATCH v3 1/3] hw/virtio: Comment virtqueue_flush() must be called with RCU read lock

[Philippe Mathieu-Daudé]

On 9/27/21 12:18, Cornelia Huck wrote:
> On Mon, Sep 06 2021, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
> 
>> Reported-by: Stefano Garzarella <sgarzare@redhat.com>
>> Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  include/hw/virtio/virtio.h | 7 +++++++
>>  hw/virtio/virtio.c         | 1 +
>>  2 files changed, 8 insertions(+)
>>
>> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
>> index 8bab9cfb750..c1c5f6e53c8 100644
>> --- a/include/hw/virtio/virtio.h
>> +++ b/include/hw/virtio/virtio.h
>> @@ -186,6 +186,13 @@ void virtio_delete_queue(VirtQueue *vq);
>>  
>>  void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
>>                      unsigned int len);
>> +/**
>> + * virtqueue_flush:
>> + * @vq: The #VirtQueue
>> + * @count: Number of elements to flush
>> + *
>> + * Must be called within RCU critical section.
>> + */
> 
> Hm... do these doc comments belong into .h files, or rather into .c files?

Maybe we should restart this old thread, vote(?) and settle on a style?

https://lore.kernel.org/qemu-devel/349cd87b-0526-30b8-d9cd-0eee537ab5a4@redhat.com/

>>  void virtqueue_flush(VirtQueue *vq, unsigned int count);
>>  void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
>>                                unsigned int len);
>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> index 3a1f6c520cb..97f60017466 100644
>> --- a/hw/virtio/virtio.c
>> +++ b/hw/virtio/virtio.c
>> @@ -896,6 +896,7 @@ static void virtqueue_packed_flush(VirtQueue *vq, 
>> unsigned int count)
>>      }
>>  }
>>  
>> +/* Called within rcu_read_lock().  */
>>  void virtqueue_flush(VirtQueue *vq, unsigned int count)
>>  {
>>      if (virtio_device_disabled(vq->vdev)) {
> 
> The content of the change looks good to me, I'm only wondering about
> the style...
>