Re: [PATCH 03/25] block/nvme: Report warning with warn_report()

[Philippe Mathieu-Daudé]

On 10/27/20 3:45 PM, Keith Busch wrote:
> On Tue, Oct 27, 2020 at 02:55:25PM +0100, Philippe Mathieu-Daudé wrote:
>> Instead of displaying warning on stderr, use warn_report()
>> which also displays it on the monitor.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  block/nvme.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/nvme.c b/block/nvme.c
>> index 739a0a700cb..6f1d7f9b2a1 100644
>> --- a/block/nvme.c
>> +++ b/block/nvme.c
>> @@ -399,8 +399,8 @@ static bool nvme_process_completion(NVMeQueuePair *q)
>>          }
>>          cid = le16_to_cpu(c->cid);
> 
> Not related to your patch, but it stands out as odd that this is treated
> as an endian type. The field is just an opaque cookie, so there shouldn't
> be a need for byte swapping. It in fact looks like this is broken on a
> big-endian host, as the swaping on submission uses a 32-bit value. Won't
> that truncate the relavant bits?

You are right, thanks for having a look and catching this bug :)

I suppose we never tested on big-endian host yet.

> 
>>          if (cid == 0 || cid > NVME_QUEUE_SIZE) {
>> -            fprintf(stderr, "Unexpected CID in completion queue: %" PRIu32 
>> "\n",
>> -                    cid);
>> +            warn_report("NVMe: Unexpected CID in completion queue: 
>> %"PRIu32", "
>> +                        "queue size: %u", cid, NVME_QUEUE_SIZE);
>>              continue;
>>          }
>>          trace_nvme_complete_command(s, q->index, cid);
>