Date: Sun, 19 Jul 2015 11:58:20 -0400 From: "George Neville-Neil" <gnn@freebsd.org> To: "Colin Percival" <cperciva@freebsd.org> Cc: "Kristof Provost" <kp@FreeBSD.org>, "Mark Felder" <feld@FreeBSD.org>, freebsd-xen@freebsd.org Subject: Re: Networking under Xen Message-ID: <55D3D012-140C-4230-8F23-5975D1A5CACD@freebsd.org> In-Reply-To: <55A611B1.6000000@freebsd.org> References: <4E7B7075-4E0D-4EA7-9F5D-6D252CFBD487@gmail.com> <1436890526.3162974.323521249.6B73E6E2@webmail.messagingengine.com> <55A55AE8.4090101@freebsd.org> <1436901780.3211878.323698017.360F8D73@webmail.messagingengine.com> <20F2398D-ECDF-4CF4-966D-18C894779C4C@FreeBSD.org> <55A611B1.6000000@freebsd.org>
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On 15 Jul 2015, at 3:54, Colin Percival wrote:
> On 07/15/15 00:44, Kristof Provost wrote:
>>> On 14 Jul 2015, at 21:23, Mark Felder <feld@FreeBSD.org> wrote:
>>> On Tue, Jul 14, 2015, at 13:54, Colin Percival wrote:
>>>> More precisely *pf* is a known issue. It's inserting TCP checksums
>>>> into TSO packets. I reported this a long time ago and I don't know
>>>> why pf still hasn't been fixed.
>>>
>>> I think Kristof may have solved this in HEAD with all of the care
>>> and
>>> feeding he has been doing to pf, but I haven't verified.
>>
>> I wouldn’t expect so. As far as I know I’ve not fixed anything
>> TSO or
>> checksum related.
>
> In my tests, deleting these lines from pf_ioctl.c
>
> 3570 /* We need a proper CSUM befor we start (s. OpenBSD ip_output) */
> 3571 if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
> 3572 in_delayed_cksum(*m);
> 3573 (*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
> 3574 }
>
> unbreaks pf+TSO on EC2 instances. I'm not entirely sure why these
> lines
> are there in the first place, which is why I didn't want to simply go
> in
> and remove them -- but it may be that wrapping those lines in
> something
> like "if ((csum_flags & CSUM_TSO) == 0)" would solve the problem
> without
> breaking anything else.
>
Since Kristof is already working on this, I'll let him address it. If
necessary
open a PR on this specifically please.
Best,
George
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