Re: [virtio-comment] [PATCH v2] virtio-net: support distinguishing between partial and full checksum

[Heng Qi <hengqi@linux.alibaba.com>]

å 2023/11/9 äå4:01, Michael S. Tsirkin åé:
> On Thu, Nov 09, 2023 at 11:55:01AM +0800, Jason Wang wrote:
> > > > Most userspace doesn't care about the checksum though.
> > > >
> > > > > Maybe we need a flag
> > > > > to say which offloads are expensive?
> > > > That exposes some device details which seem not good (e.g we may want
> > > > to do migration among hardware and software).
> > > >
> > > > Thanks
> > > If you do then things will be less well tuned on one of the migration
> > > ends but then that is by design, isn't it?
> > Ok, so I'm fine to enable it by default.
> >
> > Thanks
> I was really asking a question. Is it true that full is more expensive
> than partial for the device?

It depends on the device. For performant (e.g. IO queues are hardware 
accelerated)
or well-resourced devices, the overhead of full csum compared to partial 
csum is almost negligible.

> So it should only be enabled if
> strictly required?

I think for software devices, yes.

Thanks.

> > > --
> > > MST
>
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