Re: [PATCH v2 11/18] hw/block/nvme: add remaining mandatory controller parameters

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 7/3/20 4:37 PM, Klaus Jensen wrote:
> On Jul  3 13:02, Philippe Mathieu-Daudé wrote:
>> On 7/3/20 12:10 PM, Klaus Jensen wrote:
>>> On Jul  3 11:21, Philippe Mathieu-Daudé wrote:
>>>> On 7/3/20 10:46 AM, Klaus Jensen wrote:
>>>>> On Jul  3 10:31, Philippe Mathieu-Daudé wrote:
>>>>>> On 7/3/20 8:34 AM, Klaus Jensen wrote:
>>>>>>> From: Klaus Jensen <k.jensen@samsung.com>
>>>>>>>
>>>>>>> Add support for any remaining mandatory controller operating parameters
>>>>>>> (features).
>>>>>>>
>>>>>>> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
>>>>>>> Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
>>>>>>> ---
>>>>>>>  hw/block/nvme.c       | 39 +++++++++++++++++++++++++++++++++------
>>>>>>>  hw/block/nvme.h       | 18 ++++++++++++++++++
>>>>>>>  hw/block/trace-events |  2 ++
>>>>>>>  include/block/nvme.h  |  7 +++++++
>>>>>>>  4 files changed, 60 insertions(+), 6 deletions(-)
>>>>>>>
>>>>>>> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
>>>>>>> index ba523f6768bf..affb9a967534 100644
>>>>>>> --- a/hw/block/nvme.c
>>>>>>> +++ b/hw/block/nvme.c
>>>>>>> @@ -1056,8 +1056,16 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>>>>>>>      uint32_t dw10 = le32_to_cpu(cmd->cdw10);
>>>>>>>      uint32_t dw11 = le32_to_cpu(cmd->cdw11);
>>>>>>>      uint32_t result;
>>>>>>> +    uint8_t fid = NVME_GETSETFEAT_FID(dw10);
>>>>>>> +    uint16_t iv;
>>>>>>>  
>>>>>>> -    switch (dw10) {
>>>>>>> +    trace_pci_nvme_getfeat(nvme_cid(req), fid, dw11);
>>>>>>> +
>>>>>>> +    if (!nvme_feature_support[fid]) {
>>>>>>> +        return NVME_INVALID_FIELD | NVME_DNR;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    switch (fid) {
>>>>>>>      case NVME_TEMPERATURE_THRESHOLD:
>>>>>>>          result = 0;
>>>>>>>  
>>>>>>> @@ -1088,14 +1096,27 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>>>>>>>                               ((n->params.max_ioqpairs - 1) << 16));
>>>>>>>          trace_pci_nvme_getfeat_numq(result);
>>>>>>>          break;
>>>>>>> +    case NVME_INTERRUPT_VECTOR_CONF:
>>>>>>> +        iv = dw11 & 0xffff;
>>>>>>> +        if (iv >= n->params.max_ioqpairs + 1) {
>>>>>>> +            return NVME_INVALID_FIELD | NVME_DNR;
>>>>>>> +        }
>>>>>>> +
>>>>>>> +        result = iv;
>>>>>>> +        if (iv == n->admin_cq.vector) {
>>>>>>> +            result |= NVME_INTVC_NOCOALESCING;
>>>>>>> +        }
>>>>>>> +
>>>>>>> +        result = cpu_to_le32(result);
>>>>>>> +        break;
>>>>>>>      case NVME_ASYNCHRONOUS_EVENT_CONF:
>>>>>>>          result = cpu_to_le32(n->features.async_config);
>>>>>>>          break;
>>>>>>>      case NVME_TIMESTAMP:
>>>>>>>          return nvme_get_feature_timestamp(n, cmd);
>>>>>>>      default:
>>>>>>> -        trace_pci_nvme_err_invalid_getfeat(dw10);
>>>>>>> -        return NVME_INVALID_FIELD | NVME_DNR;
>>>>>>> +        result = cpu_to_le32(nvme_feature_default[fid]);
>>>>>>
>>>>>> So here we expect uninitialized fid entries to return 0, right?
>>>>>>
>>>>>
>>>>> Yes, if defaults are not 0 (like NVME_ARBITRATION), it is explicitly set.
>>>>>
>>>>>>> +        break;
>>>>>>>      }
>>>>>>>  
>>>>>>>      req->cqe.result = result;
>>>>>>> @@ -1124,8 +1145,15 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>>>>>>>  {
>>>>>>>      uint32_t dw10 = le32_to_cpu(cmd->cdw10);
>>>>>>>      uint32_t dw11 = le32_to_cpu(cmd->cdw11);
>>>>>>> +    uint8_t fid = NVME_GETSETFEAT_FID(dw10);
>>>>>>>  
>>>>>>> -    switch (dw10) {
>>>>>>> +    trace_pci_nvme_setfeat(nvme_cid(req), fid, dw11);
>>>>>>> +
>>>>>>> +    if (!nvme_feature_support[fid]) {
>>>>>>> +        return NVME_INVALID_FIELD | NVME_DNR;
>>>>>>> +    }
>>>>>>> +
>>>>>>> +    switch (fid) {
>>>>>>>      case NVME_TEMPERATURE_THRESHOLD:
>>>>>>>          if (NVME_TEMP_TMPSEL(dw11) != NVME_TEMP_TMPSEL_COMPOSITE) {
>>>>>>>              break;
>>>>>>> @@ -1172,8 +1200,7 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>>>>>>>      case NVME_TIMESTAMP:
>>>>>>>          return nvme_set_feature_timestamp(n, cmd);
>>>>>>>      default:
>>>>>>> -        trace_pci_nvme_err_invalid_setfeat(dw10);
>>>>>>> -        return NVME_INVALID_FIELD | NVME_DNR;
>>>>>>> +        return NVME_FEAT_NOT_CHANGEABLE | NVME_DNR;
>>>>>>>      }
>>>>>>>      return NVME_SUCCESS;
>>>>>>>  }
>>>>>>> diff --git a/hw/block/nvme.h b/hw/block/nvme.h
>>>>>>> index f8940435f9ef..8ad1e3c89cee 100644
>>>>>>> --- a/hw/block/nvme.h
>>>>>>> +++ b/hw/block/nvme.h
>>>>>>> @@ -87,6 +87,24 @@ typedef struct NvmeFeatureVal {
>>>>>>>      uint32_t    async_config;
>>>>>>>  } NvmeFeatureVal;
>>>>
>>>> What do you think about adding:
>>>>
>>>> --- a/include/block/nvme.h
>>>> +++ b/include/block/nvme.h
>>>> @@ -804,7 +804,8 @@ enum NvmeFeatureIds {
>>>>      NVME_WRITE_ATOMICITY            = 0xa,
>>>>      NVME_ASYNCHRONOUS_EVENT_CONF    = 0xb,
>>>>      NVME_TIMESTAMP                  = 0xe,
>>>> -    NVME_SOFTWARE_PROGRESS_MARKER   = 0x80
>>>> +    NVME_SOFTWARE_PROGRESS_MARKER   = 0x80,
>>>> +    NVME_FEATURE_ID_COUNT           = 0x100
>>>>  };
>>>>
>>>
>>> I can definitely go with that. I added it as NVME_FID_MAX.
>>
>> Good name.
>>
>>>
>>>>>>>  
>>>>>>> +static const uint32_t nvme_feature_default[0x100] = {
>>>>
>>>> Why uint32_t and not uint16_t?
>>>>
>>>
>>> The feature values are by definition 32 bits wide, so even though the
>>> defaults here do not require it, I think uin32_t should be used.
>>
>> Can you prepend a new patch making nvme_get_feature() return uin32_t
>> instead of uint16_t? That would be clearer.
>>
> 
> Ah. Now I see where the confusion comes from ;)
> 
> nvme_get_feature() does not return the value of the feature. It returns
> a uint16_t with a value from the NvmeStatusCodes enum (which really
> should be a typedef used all over the place.

Ah! You are right, I misread it indeed :)