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From:   Shunsuke Mie <mie@igel.co.jp>
Date:   Thu, 30 Sep 2021 15:58:00 +0900
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Subject: Re: [RFC PATCH v2 1/1] Providers/rxe: Add dma-buf support
To:     Zhu Yanjun <zyjzyj2000@gmail.com>
Cc:     =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
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        Jianxin Xiong <jianxin.xiong@intel.com>,
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2021=E5=B9=B49=E6=9C=8830=E6=97=A5(=E6=9C=A8) 15:37 Zhu Yanjun <zyjzyj2000@=
gmail.com>:
>
> On Thu, Sep 30, 2021 at 2:20 PM Shunsuke Mie <mie@igel.co.jp> wrote:
> >
> > Implement a new provider method for dma-buf base memory registration.
> >
> > Signed-off-by: Shunsuke Mie <mie@igel.co.jp>
> > ---
> >  providers/rxe/rxe.c | 21 +++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> >
> > diff --git a/providers/rxe/rxe.c b/providers/rxe/rxe.c
> > index 3c3ea8bb..84e00e60 100644
> > --- a/providers/rxe/rxe.c
> > +++ b/providers/rxe/rxe.c
> > @@ -239,6 +239,26 @@ static struct ibv_mr *rxe_reg_mr(struct ibv_pd *pd=
, void *addr, size_t length,
> >         return &vmr->ibv_mr;
> >  }
> >
> > +static struct ibv_mr *rxe_reg_dmabuf_mr(struct ibv_pd *pd, uint64_t of=
fset,
> > +                                       size_t length, uint64_t iova, i=
nt fd,
> > +                                       int access)
> > +{
> > +       struct verbs_mr *vmr;
> > +       int ret;
> > +
> > +       vmr =3D malloc(sizeof(*vmr));
> > +       if (!vmr)
> > +               return NULL;
> > +
>
> Do we need to set vmr to zero like the following?
>
> memset(vmr, 0, sizeof(*vmr));
>
> Zhu Yanjun
Thank you for your quick response.

I think it is better to clear the vmr. Actually the mlx5 driver allocates
the vmr using calloc().

In addition, rxe_reg_mr() (not rxe_reg_dmabuf_mr()) is used the malloc
and not clear the vmr. I think It has to be fixed too. Should I make
another patch to fix this problem?

Thanks a lot.
Shunsuke

~