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

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

> >   Oops. The above patch is broken. Don't use it.
> >   Please wait a little.
>
> New one:
>
> 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 09:20:00 -0000
> @@ -812,6 +812,7 @@ vioif_start(struct ifnet *ifp)
>
>       for (;;) {
>           int slot, r;
> +        struct mbuf *newm;
>
>           IFQ_DEQUEUE(&ifp->if_snd, m);
>
> @@ -833,7 +834,23 @@ 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);
> +            newm = m_defrag(m, M_NOWAIT);
> +            if ((newm != NULL) &&
> +                (bus_dmamap_load_mbuf(virtio_dmat(vsc),
> +                sc->sc_tx_dmamaps[slot],
> +                newm, BUS_DMA_WRITE|BUS_DMA_NOWAIT) == 0)) {
> +                m = newm;
> +                break;
> +            }
> +            /* FALLTHROUGH */
> +        default:
>               virtio_enqueue_abort(vsc, vq, slot);
>               aprint_error_dev(sc->sc_dev,
>                   "tx dmamap load failed, error code %d\n", r);
>
>
>
> BTW, what hypervisor are you using?

Once again... (not tested)

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 09:51:02 -0000
@@ -833,7 +833,20 @@ 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 = m_defrag(m, M_NOWAIT)) != NULL) &&
+			    (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)