Re: [RFC PATCH rdma-next 03/10] RDMA/rxe: Allow registering FLUSH flags for supported device only

[lizhijian@xxxxxxxxxxx]

Hey Tom, Tomas, all

I recall that the SPEC says:
> A19.4.3.1 HCA RESOURCES
> This Annex introduces the following new HCA attributes:
> • Ability to support Memory Placement Extensions
> a) Ability to support FLUSH
> i) Ability to support FLUSH with PLT Global Visibility
> ii) Ability to support FLUSH with PLT Persistence

Do you have any idea that can the HCA support just part of the FLUSH capabilities.
For example,  HCA_foo only supports PLT Global Visibility, no PLT Persistence support.

Thanks
Zhijian



On 28/12/2021 16:07, Li Zhijian wrote:
> Device should enable IB_DEVICE_RDMA_FLUSH capability if it want to
> support RDMA FLUSH.
>
> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxxxxx>
> ---
>   include/rdma/ib_verbs.h | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index f04d66539879..51d58b641201 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -291,6 +291,7 @@ enum ib_device_cap_flags {
>   	/* The device supports padding incoming writes to cacheline. */
>   	IB_DEVICE_PCI_WRITE_END_PADDING		= (1ULL << 36),
>   	IB_DEVICE_ALLOW_USER_UNREG		= (1ULL << 37),
> +	IB_DEVICE_RDMA_FLUSH			= (1ULL << 38),
>   };
>   
>   enum ib_atomic_cap {
> @@ -4319,6 +4320,10 @@ static inline int ib_check_mr_access(struct ib_device *ib_dev,
>   	if (flags & IB_ACCESS_ON_DEMAND &&
>   	    !(ib_dev->attrs.device_cap_flags & IB_DEVICE_ON_DEMAND_PAGING))
>   		return -EINVAL;
> +
> +	if (flags & IB_ACCESS_FLUSH &&
> +	    !(ib_dev->attrs.device_cap_flags & IB_DEVICE_RDMA_FLUSH))
> +		return -EINVAL;
>   	return 0;
>   }
>