Messages in this thread | | | Date | Sat, 8 Dec 2018 21:47:29 +0800 | From | Tiwei Bie <> | Subject | Re: [RFC 3/3] virtio_ring: use new vring flags |
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On Fri, Dec 07, 2018 at 01:10:48PM -0500, Michael S. Tsirkin wrote: > On Fri, Dec 07, 2018 at 04:48:42PM +0800, Tiwei Bie wrote: > > Switch to using the _SPLIT_ and _PACKED_ variants of vring flags > > in split ring and packed ring respectively. > > > > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> > > --- > > @@ -502,7 +505,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > > } > > } > > /* Last one doesn't continue. */ > > - desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); > > + desc[prev].flags &= cpu_to_virtio16(_vq->vdev, > > + (u16)~BIT(VRING_SPLIT_DESC_F_NEXT)); > > > > if (indirect) { > > /* Now that the indirect table is filled in, map it. */ > > I kind of dislike it that this forces use of a cast here. > Kind of makes it more fragile. Let's use a temporary instead?
I tried something like this:
u16 mask = ~BIT(VRING_SPLIT_DESC_F_NEXT);
And it will still cause the warning:
warning: large integer implicitly truncated to unsigned type [-Woverflow] u16 mask = ~BIT(VRING_SPLIT_DESC_F_NEXT);
If the cast isn't wanted, maybe use ~(1 << VRING_SPLIT_DESC_F_NEXT) directly?
> > > -- > > 2.17.1
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