Re: [PATCH v11 04/12] vhost: move vdpa group bound check to vhost_vdpa

[Eugenio Perez Martin]

On Sun, Jan 11, 2026 at 12:46 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
>
> On Fri, Jan 09, 2026 at 04:24:22PM +0100, Eugenio Pérez wrote:
> > Remove duplication by consolidating these here.  This reduces the
> > posibility of a parent driver missing them.
> >
> > Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
> > ---
> >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 ---
> >  drivers/vdpa/vdpa_sim/vdpa_sim.c  | 6 ------
> >  drivers/vhost/vdpa.c              | 2 +-
> >  3 files changed, 1 insertion(+), 10 deletions(-)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index ddaa1366704b..44062e9d68f0 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -3640,9 +3640,6 @@ static int mlx5_set_group_asid(struct vdpa_device *vdev, u32 group,
> >       struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
> >       int err = 0;
> >
> > -     if (group >= MLX5_VDPA_NUMVQ_GROUPS)
> > -             return -EINVAL;
> > -
> >       mvdev->mres.group2asid[group] = asid;
> >
> >       mutex_lock(&mvdev->mres.lock);
> > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > index c1c6431950e1..df9c7ddc5d78 100644
> > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > @@ -606,12 +606,6 @@ static int vdpasim_set_group_asid(struct vdpa_device *vdpa, unsigned int group,
> >       struct vhost_iotlb *iommu;
> >       int i;
> >
> > -     if (group > vdpasim->dev_attr.ngroups)
> > -             return -EINVAL;
> > -
>
> BTW is the original ">" here an off by one error? Should have been >= ?
> if yes then this is a kind of bugfix and maybe needs a fixes tag.
>

Ouch that's a good catch, thanks! Do you prefer me to mark this patch
as "Fixes:" and send it for backporting to stable to or to create a
new patch just adding the ">=" and then moving the check to the vdpa
core on top?

> > -     if (asid >= vdpasim->dev_attr.nas)
> > -             return -EINVAL;
> > -
> >       iommu = &vdpasim->iommu[asid];
> >
> >       mutex_lock(&vdpasim->mutex);
> > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> > index 05a481e4c385..9d25b735b43d 100644
> > --- a/drivers/vhost/vdpa.c
> > +++ b/drivers/vhost/vdpa.c
> > @@ -680,7 +680,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> >       case VHOST_VDPA_SET_GROUP_ASID:
> >               if (copy_from_user(&s, argp, sizeof(s)))
> >                       return -EFAULT;
> > -             if (s.num >= vdpa->nas)
> > +             if (idx >= vdpa->ngroups || s.num >= vdpa->nas)
> >                       return -EINVAL;
> >               if (!ops->set_group_asid)
> >                       return -EOPNOTSUPP;
> > --
> > 2.52.0
>