Re: [PATCH] vdpa/mlx5: Fix wrong use of bit numbers

[Michael S. Tsirkin]

On Mon, Mar 01, 2021 at 03:52:45PM +0800, Jason Wang wrote:
> 
> On 2021/3/1 2:28 下午, Eli Cohen wrote:
> > VIRTIO_F_VERSION_1 is a bit number. Use BIT_ULL() with mask
> > conditionals.
> > 
> > Also, in mlx5_vdpa_is_little_endian() use BIT_ULL for consistency with
> > the rest of the code.
> > 
> > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> > Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
> 
> 
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

And CC stable I guess?

> 
> > ---
> >   drivers/vdpa/mlx5/net/mlx5_vnet.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index dc7031132fff..7d21b857a94a 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -821,7 +821,7 @@ static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
> >   	MLX5_SET(virtio_q, vq_ctx, event_qpn_or_msix, mvq->fwqp.mqp.qpn);
> >   	MLX5_SET(virtio_q, vq_ctx, queue_size, mvq->num_ent);
> >   	MLX5_SET(virtio_q, vq_ctx, virtio_version_1_0,
> > -		 !!(ndev->mvdev.actual_features & VIRTIO_F_VERSION_1));
> > +		 !!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_F_VERSION_1)));
> >   	MLX5_SET64(virtio_q, vq_ctx, desc_addr, mvq->desc_addr);
> >   	MLX5_SET64(virtio_q, vq_ctx, used_addr, mvq->device_addr);
> >   	MLX5_SET64(virtio_q, vq_ctx, available_addr, mvq->driver_addr);
> > @@ -1578,7 +1578,7 @@ static void teardown_virtqueues(struct mlx5_vdpa_net *ndev)
> >   static inline bool mlx5_vdpa_is_little_endian(struct mlx5_vdpa_dev *mvdev)
> >   {
> >   	return virtio_legacy_is_little_endian() ||
> > -		(mvdev->actual_features & (1ULL << VIRTIO_F_VERSION_1));
> > +		(mvdev->actual_features & BIT_ULL(VIRTIO_F_VERSION_1));
> >   }
> >   static __virtio16 cpu_to_mlx5vdpa16(struct mlx5_vdpa_dev *mvdev, u16 val)