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

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

On 2017/05/03 17:40, hannken%eis.cs.tu-bs.de@localhost wrote:
> > Number:         52211
> > Category:       kern
> > Synopsis:       vioif stops on dmamap load error
> > Confidential:   no
> > Severity:       serious
> > Priority:       medium
> > Responsible:    kern-bug-people
> > State:          open
> > Class:          sw-bug
> > Submitter-Id:   net
> > Arrival-Date:   Wed May 03 08:40:00 +0000 2017
> > Originator:     Juergen Hannken-Illjes
> > Release:        NetBSD 7.1
> > Organization:
> 	
> > Environment:
> 	
> 	
> System: NetBSD vpnserv.isf.cs.tu-bs.de 7.1 NetBSD 7.1 (gateway.i386) #0: Mon Mar 13 16:40:12 MET 2017  build%builder.isf.cs.tu-bs.de@localhost:/build/nbsd7/obj/obj.i386/sys/arch/i386/compile/gateway.i386 i386
> Architecture: i386
> Machine: i386
> > Description:
> 	
>  From time to time the machine prints
>
> 	vioif0: tx dmamap load failed, error code 27

27 is EFBIG.

In vioif.c::vioif_start():
>                 r = bus_dmamap_load_mbuf(virtio_dmat(vsc),
>                                          sc->sc_tx_dmamaps[slot],
>                                          m, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
>                 if (r != 0) {
>                         virtio_enqueue_abort(vsc, vq, slot);
>                         aprint_error_dev(sc->sc_dev,
>                             "tx dmamap load failed, error code %d\n", r);
>                         break;
>                 }

 ixg(4), rtwn(4) and vge(4) have a code which calls m_defrag() when
bus_dmamap_load_mbuf() returned EFBIG. On ixg(4) it really occurs
and the recovery works fine if a interface's TSO flag is set.

 Coudl you show me the output of ifconfig vioif0?

 For vioif, it has no TSO function. It also doesn't have JUMBO_MTU,
so I'm afraid it has another bug in somewhere else.


> and most times the interface seems to stop as the machine is no longer
> accessible from the network.
>
>       $NetBSD: if_vioif.c,v 1.7.2.3 2016/12/23 05:57:40 snj Exp $
> > How-To-Repeat:
> 	
> > Fix:
> 	
>
> > Unformatted:



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