Re: [PATCH] vdpa: Consider device id larger than 31

From: Eli Cohen
Date: Sun Nov 28 2021 - 02:34:26 EST


On Fri, Nov 26, 2021 at 10:48:12AM +0800, Jason Wang wrote:
> On Fri, Nov 26, 2021 at 2:09 AM Parav Pandit <parav@xxxxxxxxxx> wrote:
> >
> > virtio device id value can be more than 31. Hence, use BIT_ULL in
> > assignment.
> >
> > Fixes: 33b347503f01 ("vdpa: Define vdpa mgmt device, ops and a netlink interface")
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Signed-off-by: Parav Pandit <parav@xxxxxxxxxx>
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
>
> > ---
> > drivers/vdpa/vdpa.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> > index 7332a74a4b00..e91c71aeeddf 100644
> > --- a/drivers/vdpa/vdpa.c
> > +++ b/drivers/vdpa/vdpa.c
> > @@ -404,7 +404,7 @@ static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *m
> > goto msg_err;
> >
> > while (mdev->id_table[i].device) {
> > - supported_classes |= BIT(mdev->id_table[i].device);
> > + supported_classes |= BIT_ULL(mdev->id_table[i].device);
> > i++;
> > }
> >

type of mdev->id_table[i].device is __u32 so in theory you're limited
to device ID's up to 63.
Maybe add assert here?

> > --
> > 2.26.2
> >
>