Re: [PATCH for-next 4/8] RDMA/hns: Add check for the validity of sl configuration in UD SQ WQE

[liweihang <liweihang@huawei.com>]

On 2020/11/17 0:09, Jason Gunthorpe wrote:
> On Sat, Nov 14, 2020 at 03:46:58AM +0000, liweihang wrote:
>> On 2020/11/13 2:33, Jason Gunthorpe wrote:
>>> On Fri, Oct 30, 2020 at 07:39:31PM +0800, Weihang Li wrote:
>>>> From: Jiaran Zhang <zhangjiaran@huawei.com>
>>>>
>>>> According to the RoCE v1 specification, the sl (service level) 0-7 are
>>>> mapped directly to priorities 0-7 respectively, sl 8-15 are reserved. The
>>>> driver should verify whether the value of sl is larger than 7, if so, an
>>>> exception should be returned.
>>>>
>>>> Fixes: d6a3627e311c ("RDMA/hns: Optimize wqe buffer set flow for post send")
>>>> Signed-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
>>>> Signed-off-by: Weihang Li <liweihang@huawei.com>
>>>>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 10 +++++++++-
>>>>  1 file changed, 9 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
>>>> index 7a1d30f..69386a5 100644
>>>> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
>>>> @@ -427,9 +427,10 @@ static inline int set_ud_wqe(struct hns_roce_qp *qp,
>>>>  			     void *wqe, unsigned int *sge_idx,
>>>>  			     unsigned int owner_bit)
>>>>  {
>>>> -	struct hns_roce_dev *hr_dev = to_hr_dev(qp->ibqp.device);
>>>>  	struct hns_roce_ah *ah = to_hr_ah(ud_wr(wr)->ah);
>>>>  	struct hns_roce_v2_ud_send_wqe *ud_sq_wqe = wqe;
>>>> +	struct ib_device *ib_dev = qp->ibqp.device;
>>>> +	struct hns_roce_dev *hr_dev = to_hr_dev(ib_dev);
>>>>  	unsigned int curr_idx = *sge_idx;
>>>>  	int valid_num_sge;
>>>>  	u32 msg_len = 0;
>>>> @@ -489,6 +490,13 @@ static inline int set_ud_wqe(struct hns_roce_qp *qp,
>>>>  		       V2_UD_SEND_WQE_BYTE_36_TCLASS_S, ah->av.tclass);
>>>>  	roce_set_field(ud_sq_wqe->byte_40, V2_UD_SEND_WQE_BYTE_40_FLOW_LABEL_M,
>>>>  		       V2_UD_SEND_WQE_BYTE_40_FLOW_LABEL_S, ah->av.flowlabel);
>>>> +
>>>> +	if (unlikely(ah->av.sl > MAX_SERVICE_LEVEL)) {
>>>> +		ibdev_err(ib_dev,
>>>> +			  "failed to fill ud av, ud sl (%d) shouldn't be larger than %d.\n",
>>>> +			  ah->av.sl, MAX_SERVICE_LEVEL);
>>>> +		return -EINVAL;
>>>> +	}
>>>
>>> We should not print for things like this, IIRC userspace can cause the
>>> ah's sl to become set out of bounds
> 
>  
>> In "Annex A 16: RoCE", I found the following description:
>>
>> 	SL 0-7 are mapped directly to Priorities 0-7, respectively
>>
>> 	SL 8-15 are reserved.
>>
>> 	CA16-18: An attempt to use an Address Vector for a RoCE port containing
>> 	a reserved SL value shall result in the Invalid Address Vector verb result.
>>
>> So what should we do if the user wants to use the reserved sl? Should I just let it
>> do mask with 0x7 when creating AH?
> 
> Fail and don't print anything
> 
> Jason
> 

OK, thank you.

Weihang