Re: [virtio-comment] Re: [PATCH v4 1/2] virtio-net: update description for VIRTIO_NET_F_GUEST_CSUM.

[Jason Wang <jasowang@redhat.com>]

On Fri, Dec 1, 2023 at 2:30âPM Heng Qi <hengqi@linux.alibaba.com> wrote:
>
>
>
> å 2023/12/1 äå2:24, Heng Qi åé:
> >
> >
> > å 2023/12/1 äå1:18, Jason Wang åé:
> >> On Wed, Nov 29, 2023 at 4:23âPM Heng Qi <hengqi@linux.alibaba.com>
> >> wrote:
> >>>
> >>>
> >>> å 2023/11/29 äå4:00, Jason Wang åé:
> >>>> On Tue, Nov 28, 2023 at 4:08âPM Heng Qi <hengqi@linux.alibaba.com>
> >>>> wrote:
> >>>>> To prevent readers from misunderstanding that the driver can
> >>>>> only handles packets with partial checksum when
> >>>>> VIRTIO_NET_F_GUEST_CSUM is negotiated, we update the description.
> >>>>>
> >>>>> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
> >>>>> ---
> >>>>>    device-types/net/description.tex | 2 +-
> >>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/device-types/net/description.tex
> >>>>> b/device-types/net/description.tex
> >>>>> index aff5e08..529f470 100644
> >>>>> --- a/device-types/net/description.tex
> >>>>> +++ b/device-types/net/description.tex
> >>>>> @@ -38,7 +38,7 @@ \subsection{Feature bits}\label{sec:Device Types
> >>>>> / Network Device / Feature bits
> >>>>>    \begin{description}
> >>>>>    \item[VIRTIO_NET_F_CSUM (0)] Device handles packets with
> >>>>> partial checksum offload.
> >>>>>
> >>>>> -\item[VIRTIO_NET_F_GUEST_CSUM (1)] Driver handles packets with
> >>>>> partial checksum.
> >>>>> +\item[VIRTIO_NET_F_GUEST_CSUM (1)] Driver handles packets with
> >>>>> partial checksum or full checksum.
> >>>> So patch 2 said
> >>>>
> >>>> "
> >>>> +\item[VIRTIO_NET_F_GUEST_FULL_CSUM (64)] Driver handles packets with
> >>>> full checksum.
> >>>>    \end{description}
> >>>> "
> >>>>
> >>>> Is there any difference between the two "full checksum" here?
> >>> There's no difference.
> >>>
> >>> The core is that VIRTIO_NET_F_GUEST_FULL_CSUM means that the driver
> >>> "can
> >>> only" handle packets with full checksum.
> >> This seems to be odd.
> >>
> >> Driver can always handle packet with full checksum, no?
> >
> > Yes.
> >
> >> I meant it
> >> will be then to be functional equivalent to !
> >> VIRTIO_NET_F_GUEST_FULL_CSUM?
> >
> > Are you referring to
> > "functional equivalent to !VIRTIO_NET_F_GUEST_CSUM" ?
>
> Sorry, this is a typo. I meant
>
> Are you referring to
> "functional equivalent to !VIRTIO_NET_F_GUEST_FULL_CSUM" ?
>
> > If so, I think it's no.
> >
> > Maybe a description similar to the following would be more clearer:
> >
> > +\item[VIRTIO_NET_F_GUEST_FULL_CSUM (64)] Driver does not handle
> > packets with partial checksum.

I may miss something here, but what's the difference between

VIRTIO_NET_F_GUEST_FULL_CSUM

and

!VIRTIO_NET_F_GUEST_CSUM?

Thanks

> >
> > Thanks!
> >
> >>
> >> Thanks
> >>
> >>> Thanks!
> >>>
> >>>> Thanks
> >>>>
> >>>>> \item[VIRTIO_NET_F_CTRL_GUEST_OFFLOADS (2)] Control channel offloads
> >>>>>            reconfiguration support.
> >>>>> --
> >>>>> 2.19.1.6.gb485710b
> >>>>>
> >
> >
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