Re: [PATCH v2 1/3] virtio: add ability to delete vq through a pointer

[Pan Nengyuan]

On 2019/12/6 0:45, Amit Shah wrote:
> On Wed, 2019-12-04 at 15:31 +0800, address@hidden wrote:
>> From: Pan Nengyuan <address@hidden>
> 
> Shouldn't this be From: mst?
> 
> I didn't find a ref to the original patch to confirm if you had to
> adapt it in any way, though.
> 

Here is the original
patch:　https://lists.nongnu.org/archive/html/qemu-devel/2019-12/msg00402.html

I just change one line(set used_elems to NULL). In next version, I will
change function name from virtio_delete_queue to virtio_queue_cleanup
(It's too similar between "virtio_del_queue" and "virtio_delete_queue"):
https://lists.nongnu.org/archive/html/qemu-devel/2019-12/msg00877.html.

According to these, should I change it in next version?

Thanks.

>> Devices tend to maintain vq pointers, allow deleting them trough a vq
>> pointer.
>>
>> Signed-off-by: Michael S. Tsirkin <address@hidden>
>> Signed-off-by: Pan Nengyuan <address@hidden>
>> ---
>> Changes v2 to v1:
>> - add a new function virtio_delete_queue to cleanup vq through a vq
>> pointer
>> ---
>>  hw/virtio/virtio.c         | 16 +++++++++++-----
>>  include/hw/virtio/virtio.h |  2 ++
>>  2 files changed, 13 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> index 04716b5..6de3cfd 100644
>> --- a/hw/virtio/virtio.c
>> +++ b/hw/virtio/virtio.c
>> @@ -2330,17 +2330,23 @@ VirtQueue *virtio_add_queue(VirtIODevice
>> *vdev, int queue_size,
>>      return &vdev->vq[i];
>>  }
>>  
>> +void virtio_delete_queue(VirtQueue *vq)
>> +{
>> +    vq->vring.num = 0;
>> +    vq->vring.num_default = 0;
>> +    vq->handle_output = NULL;
>> +    vq->handle_aio_output = NULL;
>> +    g_free(vq->used_elems);
>> +    vq->used_elems = NULL;
>> +}
>> +
>>  void virtio_del_queue(VirtIODevice *vdev, int n)
>>  {
>>      if (n < 0 || n >= VIRTIO_QUEUE_MAX) {
>>          abort();
>>      }
>>  
>> -    vdev->vq[n].vring.num = 0;
>> -    vdev->vq[n].vring.num_default = 0;
>> -    vdev->vq[n].handle_output = NULL;
>> -    vdev->vq[n].handle_aio_output = NULL;
>> -    g_free(vdev->vq[n].used_elems);
>> +    virtio_delete_queue(&vdev->vq[n]);
>>  }
>>  
>>  static void virtio_set_isr(VirtIODevice *vdev, int value)
>> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
>> index c32a815..e18756d 100644
>> --- a/include/hw/virtio/virtio.h
>> +++ b/include/hw/virtio/virtio.h
>> @@ -183,6 +183,8 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev,
>> int queue_size,
>>  
>>  void virtio_del_queue(VirtIODevice *vdev, int n);
>>  
>> +void virtio_delete_queue(VirtQueue *vq);
>> +
>>  void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
>>                      unsigned int len);
>>  void virtqueue_flush(VirtQueue *vq, unsigned int count);
> 
> 
> .
>