Re: [PATCH v2] RDMA/vmw_pvrdma: Use resource ids from physical device if available

[Adit Ranadive <aditr@vmware.com>]

On 10/28/19 9:58 AM, Jason Gunthorpe wrote:
> On Mon, Oct 28, 2019 at 04:46:09PM +0000, Adit Ranadive wrote:
>> On 10/28/19 9:27 AM, Jason Gunthorpe wrote:
>>> On Tue, Oct 22, 2019 at 08:06:50PM +0000, Adit Ranadive wrote:
>>>> @@ -195,7 +198,9 @@ struct ib_qp *pvrdma_create_qp(struct ib_pd *pd,
>>>>  	union pvrdma_cmd_resp rsp;
>>>>  	struct pvrdma_cmd_create_qp *cmd = &req.create_qp;
>>>>  	struct pvrdma_cmd_create_qp_resp *resp = &rsp.create_qp_resp;
>>>> +	struct pvrdma_cmd_create_qp_resp_v2 *resp_v2 = &rsp.create_qp_resp_v2;
>>>>  	struct pvrdma_create_qp ucmd;
>>>> +	struct pvrdma_create_qp_resp qp_resp = {};
>>>>  	unsigned long flags;
>>>>  	int ret;
>>>>  	bool is_srq = !!init_attr->srq;
>>>> @@ -260,6 +265,15 @@ struct ib_qp *pvrdma_create_qp(struct ib_pd *pd,
>>>>  				goto err_qp;
>>>>  			}
>>>>  
>>>> +			/* Userspace supports qpn and qp handles? */
>>>> +			if (dev->dsr_version >= PVRDMA_QPHANDLE_VERSION &&
>>>> +			    udata->outlen != sizeof(qp_resp)) {
>>>
>>> Is != really what you want? Or is <= better? != means you can't ever
>>> make qp_resp bigger.
>>
>> I thought about using != or < before sending the patch. Since we removed
>> the flag anyways using != here made sense to be more strict about what's
>> acceptable. I'm not sure if we'll ever make it bigger.
> 
> It is a big gamble you will never need to add new entries to this
> struct forever more. Better to be safe, IMHO.
> 

Okay. Will send a v3 for this.