Date: Mon, 15 Jun 2020 21:32:08 +0200 From: Vincenzo Maffione <vmaffione@freebsd.org> To: Jessica Clarke <jrtc27@freebsd.org> Cc: Tom Jones <thj@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r361944 - in head/sys/dev/virtio: . network Message-ID: <CA%2B_eA9jeR8va5fGLPggL9wnPic_gcfBZk_3fmtowapTUTYp6MA@mail.gmail.com> In-Reply-To: <0FD9E443-1B40-4495-B2C0-4803121EF911@freebsd.org> References: <202006082151.058LpabU003001@repo.freebsd.org> <20200614195126.GB68578@tom-desk.erg.abdn.ac.uk> <97EEF019-16A4-4626-A484-A00979B52A74@freebsd.org> <20200614212230.GC68578@tom-desk.erg.abdn.ac.uk> <0FD9E443-1B40-4495-B2C0-4803121EF911@freebsd.org>
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Il giorno lun 15 giu 2020 alle ore 00:05 Jessica Clarke <jrtc27@freebsd.org> ha scritto: > On 14 Jun 2020, at 22:22, Tom Jones <thj@freebsd.org> wrote: > > On Sun, Jun 14, 2020 at 09:56:03PM +0100, Jessica Clarke wrote: > >> On 14 Jun 2020, at 20:51, Tom Jones <thj@freebsd.org> wrote: > >>> On Mon, Jun 08, 2020 at 09:51:36PM +0000, Jessica Clarke wrote: > >>>> Author: jrtc27 > >>>> Date: Mon Jun 8 21:51:36 2020 > >>>> New Revision: 361944 > >>>> URL: https://svnweb.freebsd.org/changeset/base/361944 > >>>> > >>>> Log: > >>>> virtio: Support non-legacy network device and queue > >>>> > >>>> The non-legacy interface always defines num_buffers in the header, > >>>> regardless of whether VIRTIO_NET_F_MRG_RXBUF, just leaving it unused. > We > >>>> also need to ensure our virtqueue doesn't filter out > VIRTIO_F_VERSION_1 > >>>> during negotiation, as it supports non-legacy transports just fine. > This > >>>> fixes network packet transmission on TinyEMU. > >>>> > >>>> Reviewed by: br, brooks (mentor), jhb (mentor) > >>>> Approved by: br, brooks (mentor), jhb (mentor) > >>>> Differential Revision: https://reviews.freebsd.org/D25132 > >>>> > >>>> Modified: > >>>> head/sys/dev/virtio/network/if_vtnet.c > >>>> head/sys/dev/virtio/network/if_vtnetvar.h > >>>> head/sys/dev/virtio/virtio.c > >>>> head/sys/dev/virtio/virtqueue.c > >>>> > >>> > >>> Hi Jessica, > >>> > >>> After updating my current bhyve vm today (on a 12.1 host), networking > no longer > >>> works. Reverting this commit seems to resolve the issue. I think vtnet > is not > >>> passing enough data up to the ip layer. > >>> > >>> If I capture on the tap interface for the vm I see arp requests and arp > >>> replies, however kern.msgbuf is full of: > >>> > >>> <5>arp: short packet received on vtnet0 > >>> > >>> and netstat does not see any replies to arp requests: > >>> > >>> root@freebsd-current:~ # netstat -s -p arp > >>> arp: > >>> 11 ARP requests sent > >>> 0 ARP requests failed to sent > >>> 0 ARP replies sent > >>> 0 ARP requests received > >>> 0 ARP replies received > >>> 0 ARP packets received > >>> 24 total packets dropped due to no ARP entry > >>> 2 ARP entrys timed out > >>> 0 Duplicate IPs seen > >>> > >>> If I set up an arp entry manually I can see ICMP echo requests and > responses on > >>> the tap interface, but the vm does not see the responses. > >>> > >>> root@freebsd-current:~ # netstat -s -p ip > >>> ip: > >>> 7 total packets received > >>> 0 bad header checksums > >>> 0 with size smaller than minimum > >>> 7 with data size < data length > >>> 0 with ip length > max ip packet size > >>> 0 with header length < data size > >>> 0 with data length < header length > >>> > >>> The line > >>> > >>> 7 with data size < data length > >>> > >>> makes me think that vtnet is truncating packets. > >>> > >>> markj pointed me at this bug in irc which might also be related: > >>> > >>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=247242 > >> > >> Hi Tom, > >> Sorry about that; it seems bhyve hits the "legacy and no MrgRxBuf" > >> case. Could you please try the patch below? > >> > >> Jess > >> > > > > This changed fixed the issue for me. Please feel free to add > > > > Tested By: thj > > > > when you commit. > > Great, thanks for the report. > > > In testing I this lor went by, I wonder if this is something you care > about: > > > > acquiring duplicate lock of same type: "vtnet0-rx0" > > 1st vtnet0-rx0 @ > /usr/home/tj/code/freebsd/projects/review-D25220/sys/dev/virtio/network/if_vtnet.c:1780 > > 2nd vtnet0-rx0 @ > /usr/home/tj/code/freebsd/projects/review-D25220/sys/kern/subr_taskqueue.c:281 > > stack backtrace: > > #0 0xffffffff80c32881 at witness_debugger+0x71 > > #1 0xffffffff80ba3e54 at __mtx_lock_flags+0x94 > > #2 0xffffffff80c24bd2 at taskqueue_enqueue+0x42 > > #3 0xffffffff80a1af99 at vtnet_rxq_tq_intr+0xb9 > > #4 0xffffffff80c2520a at taskqueue_run_locked+0xaa > > #5 0xffffffff80c26284 at taskqueue_thread_loop+0x94 > > #6 0xffffffff80b830e0 at fork_exit+0x80 > > #7 0xffffffff81040eae at fork_trampoline+0xe > > Hm, I think that's just a false-positive, because if_vtnet constructs > the taskqueue using the same name as its own internal mutexes. Though > the locking around vtnet_rx_vq_intr and vtnet_rxq_tq_intr is a bit > fishy given they're rather similar yet inconsistent. I would imagine > rxq->vtnrx_stats.vrxs_rescheduled is supposed to be protected by that > mutex, but wouldn't like to say whether taskqueue_enqueue needs to be. > Vincenzo, you recently touched code around there, perhaps you could be > persuaded to have a quick look?.. > Yes, you are right on both. There is also code duplication that can be easily removed. I will fix that. Cheers, Vincenzo > > Jess > >
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