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 18:11:00 +0900

 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);
 
 
 -- 
 -----------------------------------------------
                  SAITOH Masanobu (msaitoh%execsw.org@localhost
                                   msaitoh%netbsd.org@localhost)