Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups

[Paolo Bonzini <pbonzini@redhat.com>]

On 20/11/18 18:31, Igor Druzhinin wrote:
> On 14/11/2018 17:42, Igor Druzhinin wrote:
>> On 06/11/2018 12:16, Igor Druzhinin wrote:
>>> When blk_flush called in NVMe reset path S/C queues are already freed
>>> which means that re-entering AIO handling loop having some IO requests
>>> unfinished will lockup or crash as their SG structures being potentially
>>> reused. Call blk_drain before freeing the queues to avoid this nasty
>>> scenario.
>>>
>>> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
>>> ---
>>>  hw/block/nvme.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
>>> index fc7dacb..cdf836e 100644
>>> --- a/hw/block/nvme.c
>>> +++ b/hw/block/nvme.c
>>> @@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
>>>  {
>>>      int i;
>>>  
>>> +    blk_drain(n->conf.blk);
>>> +
>>>      for (i = 0; i < n->num_queues; i++) {
>>>          if (n->sq[i] != NULL) {
>>>              nvme_free_sq(n->sq[i], n);
>>>
>>
>> ping?
>>
> 
> CC: Paolo Bonzini <pbonzini@redhat.com>
> 

Looks good to me.  Kevin, Max?

Paolo