Re: [PATCH rdma-next 10/11] RDMA/erdma: Add the ABI definitions

[Leon Romanovsky <leon@kernel.org>]

On Fri, Dec 24, 2021 at 06:55:41AM +0800, Yanjun Zhu wrote:
> 在 2021/12/24 2:45, Leon Romanovsky 写道:
> > On Thu, Dec 23, 2021 at 11:46:03PM +0800, Yanjun Zhu wrote:
> > > 在 2021/12/21 10:48, Cheng Xu 写道:
> > > > Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
> > > > ---
> > > >    include/uapi/rdma/erdma-abi.h | 49 +++++++++++++++++++++++++++++++++++
> > > >    1 file changed, 49 insertions(+)
> > > >    create mode 100644 include/uapi/rdma/erdma-abi.h
> > > > 
> > > > diff --git a/include/uapi/rdma/erdma-abi.h b/include/uapi/rdma/erdma-abi.h
> > > > new file mode 100644
> > > > index 000000000000..6bcba10c1e41
> > > > --- /dev/null
> > > > +++ b/include/uapi/rdma/erdma-abi.h
> > > > @@ -0,0 +1,49 @@
> > > > +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR Linux-OpenIB) */
> > > > +/*
> > > > + * Copyright (c) 2020-2021, Alibaba Group.
> > > > + */
> > > > +
> > > > +#ifndef __ERDMA_USER_H__
> > > > +#define __ERDMA_USER_H__
> > > > +
> > > > +#include <linux/types.h>
> > > > +
> > > > +#define ERDMA_ABI_VERSION       1
> > > 
> > > ERDMA_ABI_VERSION should be 2？
> > 
> > Why?
> > 
> > This field is for rdma-core and we don't have erdma provider in that
> > library yet. It always starts from 1 for new drivers.
> Please check this link:
> http://mail.spinics.net/lists/linux-rdma/msg63012.html

OK, I still don't understand why.

RXE case is different, because rdma-core already had broken RXE
implementation, so this is why the version was incremented.

> 
> Jason mentioned in this link:
> 
> "
> /*
>  * For 64 bit machines ABI version 1 and 2 are the same. Otherwise 32
>  * bit machines require ABI version 2 which guarentees the user and
>  * kernel use the same ABI.
>  */
> "
> 
> Zhu Yanjun
> > 
> > Thanks
>