Re: [PATCH rdma-core 1/2] mlx5: Use non-cached mapping when Blueflame is not used

Yishai Hadas
2017-10-30T16:31:12Z

On 10/30/2017 4:57 PM, Jason Gunthorpe wrote:
> On Sun, Oct 29, 2017 at 11:26:04PM +0200, Yishai Hadas wrote:
>>>> @@ -632,6 +632,11 @@ enum mlx5dv_set_ctx_attr_type {
>>>> MLX5DV_CTX_ATTR_BUF_ALLOCATORS = 1,
>>>> };
>>>> +enum {
>>>> + MLX5_MMAP_GET_REGULAR_PAGES_CMD = 0,
>>>> + MLX5_MMAP_GET_NC_PAGES_CMD = 3,
>>>> +};
>>>> +
>>>
>>> These are added to a public header, but I couldn't see where they
>>> would get used by a DV user??
>>
>> A DV user already had access to the mlx5 mmap command before this series by
>> using the mlx5dv_get_qp() API:
>> qp_out->uar_mmap_offset = mqp->bf->uar_mmap_offset;
>
> Okay.
>
> As long as existing users can reasonably be expected to handle this
> new value in the uar_mmap_offset output field...
>

Yes, we expect existing users to work properly.

This output field was exposed by the DV API to enable re-mmap of the UAR
address by a secondary process by using the same 'uar_mmap_offset'
regardless its internal command value.