Re: [PATCH 1/2] vdpa/mlx5: Support creating resources with uid == 0

[Jason Wang]

在 2021/5/31 上午11:02, Jason Wang 写道:
> 在 2021/5/30 下午3:54, Eli Cohen 写道:
> > Currently all resources must be created with uid != 0 which is essential
> > userspace processes allocating virtquueue resources. Since this is a
> > kernel implementation, it is perfectly legal to open resources with
> > uid == 0.
> >
> > In case frimware supports, avoid allocating user context.
>
>
> Typo "frimware".
>
> Otherwise.
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
>
> (I don't see any code to check the firmware capability, is this 
> intended?)


Speak too fast. I see the MLX5_CAP_GEN(), so it's fine.

Thanks


> Thanks
>
>
> > Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
> > ---
> >   drivers/vdpa/mlx5/core/resources.c | 6 ++++++
> >   include/linux/mlx5/mlx5_ifc.h      | 4 +++-
> >   2 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/mlx5/core/resources.c 
> > b/drivers/vdpa/mlx5/core/resources.c
> > index 6521cbd0f5c2..836ab9ef0fa6 100644
> > --- a/drivers/vdpa/mlx5/core/resources.c
> > +++ b/drivers/vdpa/mlx5/core/resources.c
> > @@ -54,6 +54,9 @@ static int create_uctx(struct mlx5_vdpa_dev *mvdev, 
> > u16 *uid)
> >       void *in;
> >       int err;
> >   +    if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0))
> > +        return 0;
> > +
> >       /* 0 means not supported */
> >       if (!MLX5_CAP_GEN(mvdev->mdev, log_max_uctx))
> >           return -EOPNOTSUPP;
> > @@ -79,6 +82,9 @@ static void destroy_uctx(struct mlx5_vdpa_dev 
> > *mvdev, u32 uid)
> >       u32 out[MLX5_ST_SZ_DW(destroy_uctx_out)] = {};
> >       u32 in[MLX5_ST_SZ_DW(destroy_uctx_in)] = {};
> >   +    if (!uid)
> > +        return;
> > +
> >       MLX5_SET(destroy_uctx_in, in, opcode, MLX5_CMD_OP_DESTROY_UCTX);
> >       MLX5_SET(destroy_uctx_in, in, uid, uid);
> >   diff --git a/include/linux/mlx5/mlx5_ifc.h 
> > b/include/linux/mlx5/mlx5_ifc.h
> > index 9c68b2da14c6..606d2aeacad4 100644
> > --- a/include/linux/mlx5/mlx5_ifc.h
> > +++ b/include/linux/mlx5/mlx5_ifc.h
> > @@ -1487,7 +1487,9 @@ struct mlx5_ifc_cmd_hca_cap_bits {
> >       u8         uar_4k[0x1];
> >       u8         reserved_at_241[0x9];
> >       u8         uar_sz[0x6];
> > -    u8         reserved_at_250[0x8];
> > +    u8         reserved_at_248[0x2];
> > +    u8         umem_uid_0[0x1];
> > +    u8         reserved_at_250[0x5];
> >       u8         log_pg_sz[0x8];
> >         u8         bf[0x1];