Re: [RFC PATCH 01/12] vdpa: correct the VIRTIO_DEVICE_F_MASK example value

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Aug 09, 2026 at 06:19:59PM +0000, Alexander Graf wrote:
> The comment above VIRTIO_DEVICE_F_MASK spells the mask out by hand as
> 0xfffffc000fffffff, which was correct while VIRTIO_TRANSPORT_F_END was
> 41. The bound is 42 now, so the macro expands to 0xfffff8000fffffff.
> The comment is the only place we write the expansion out, so someone
> checking a provisioned feature mask against it reads the wrong boundary
> between transport and per-device bits.
> 
> The macro derives its value from the bound and needs no change, so
> correct the comment.


Or better just drop it, we will forget to update when we chaange it
again.

> 
> Fixes: 838bebb4c926 ("virtio: Define feature bit for administration virtqueue")
> Assisted-by: Kiro:claude-opus-5 checkpatch sparse
> Signed-off-by: Alexander Graf <graf@amazon.com>
> ---
>  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 47c6c3d23f5c..1757a33f298f 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -548,7 +548,7 @@ vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
>  
>  /*
>   * Bitmask for all per-device features: feature bits VIRTIO_TRANSPORT_F_START
> - * through VIRTIO_TRANSPORT_F_END are unset, i.e. 0xfffffc000fffffff for
> + * through VIRTIO_TRANSPORT_F_END are unset, i.e. 0xfffff8000fffffff for
>   * all 64bit features. If the features are extended beyond 64 bits, or new
>   * "holes" are reserved for other type of features than per-device, this
>   * macro would have to be updated.