Re: kern/52211: vioif stops on dmamap load error

[Masanobu SAITOH <msaitoh%execsw.org@localhost>]

The following reply was made to PR kern/52211; it has been noted by GNATS.

From: Masanobu SAITOH <msaitoh%execsw.org@localhost>
To: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, hannken%eis.cs.tu-bs.de@localhost
Cc: msaitoh%execsw.org@localhost
Subject: Re: kern/52211: vioif stops on dmamap load error
Date: Thu, 11 May 2017 18:17:51 +0900

 On 2017/05/11 18:11, Masanobu SAITOH wrote:
 > On 2017/05/11 17:33, Masanobu SAITOH wrote:
 >> On 2017/05/11 17:20, J. Hannken-Illjes wrote:
 >>> The following reply was made to PR kern/52211; it has been noted by GNATS.
 >>>
 >>> From: "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>
 >>> To: gnats-bugs%NetBSD.org@localhost
 >>> Cc:
 >>> Subject: Re: kern/52211: vioif stops on dmamap load error
 >>> Date: Thu, 11 May 2017 10:18:09 +0200
 >>>
 >>>   > On 11. May 2017, at 10:10, Masanobu SAITOH <msaitoh%execsw.org@localhost> wrote:
 >>>   >
 >>>   >   Coudl you show me the output of ifconfig vioif0?
 >>>   vioif0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
 >>>       address: XX:XX:XX:XX:XX:XX
 >>>       inet XXX.XXX.XXX.XXX netmask 0xffffff00 broadcast XXX.XXX.XXX.255
 >>>       inet6 fe80::XXXX:XXXX:XXXX:XXXX%vioif0 prefixlen 64 scopeid 0x1
 >>>       inet6 XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX prefixlen 64
 >>
 >> Yes, it has neither TSO nor JUMBO_MTU.
 >>
 >> If a lof of mbuf chain is a normal case for vioif(4) it would
 >> worth to try m_defrag(), but I suspect it's not a normal case
 >> and it's caused by a bug in vioif or the upper layer.
 >>
 >>>   --
 >>>   J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig (Germany)
 >>>
 > 
 > Could you test with the following diff?
 > 
 > 
 > Index: if_vioif.c
 > ===================================================================
 > RCS file: /cvsroot/src/sys/dev/pci/if_vioif.c,v
 > retrieving revision 1.34
 > diff -u -p -r1.34 if_vioif.c
 > --- if_vioif.c    28 Mar 2017 04:10:33 -0000    1.34
 > +++ if_vioif.c    11 May 2017 09:10:36 -0000
 > @@ -833,7 +833,21 @@ retry:
 >           r = bus_dmamap_load_mbuf(virtio_dmat(vsc),
 >                        sc->sc_tx_dmamaps[slot],
 >                        m, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
 > -        if (r != 0) {
 > +        switch (r) {
 > +        case 0:
 > +            break;
 > +        case EFBIG:
 > +            printf("%s: loadup_mbuf() returned EFBIG (%d segs)\n",
 > +                device_xname(sc->sc_dev),
 > +                sc->sc_tx_dmamaps[slot]->dm_nsegs);
 > +            if ((m_defrag(m, M_NOWAIT) == 0) &&
 > +                (bus_dmamap_load_mbuf(virtio_dmat(vsc),
 > +                sc->sc_tx_dmamaps[slot],
 > +                m, BUS_DMA_WRITE|BUS_DMA_NOWAIT) == 0))
 > +                break;
 > +
 > +            /* FALLTHROUGH */
 > +        default:
 >               virtio_enqueue_abort(vsc, vq, slot);
 >               aprint_error_dev(sc->sc_dev,
 >                   "tx dmamap load failed, error code %d\n", r);
 > 
 > 
 Oops. The above patch is broken. Don't use it.
 Please wait a little.
 
 -- 
 -----------------------------------------------
                  SAITOH Masanobu (msaitoh%execsw.org@localhost
                                   msaitoh%netbsd.org@localhost)