Re: [PATCH 2/3] tap: implement vhost_call_cb

[David Gibson <david@gibson.dropbear.id.au>]

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On Wed, Apr 02, 2025 at 09:16:22AM +0200, Stefano Brivio wrote:
[snip]
> >  static int tap_ns_tun(void *arg)
> >  {
> > +	/* TODO we need to check if vhost support VIRTIO_NET_F_MRG_RXBUF and VHOST_NET_F_VIRTIO_NET_HDR actually */
> > +	static const uint64_t features =
> > +		(1ULL << VIRTIO_F_VERSION_1) | (1ULL << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
> >  	struct ifreq ifr = { .ifr_flags = IFF_TAP | IFF_NO_PI };
> 
> I kind of wonder, by the way, if IFF_TUN simplifies things here. It's
> something we should already add, as an option, see also:
> https://bugs.passt.top/show_bug.cgi?id=49, but if it makes your life
> easier for any reason you might consider adding it right away.

I agree that supporting IFF_TUN would be a good idea in general.  I
think trying to do it in the middle of this will be unnecessary
difficulty though.  There are a bunch of places throughout the code
that assume we have Ethernet headers, and changing that will require a
pretty wide ranging rework.

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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