Re: port-xen/59745: guest network hosed, host says: xvif6i0 GNTTABOP_copy[0] Rx -3

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Nov 03, 2025 at 01:25:00AM +0000, campbell+netbsd%mumble.net@localhost wrote:
> >Number:         59745
> >Category:       port-xen
> >Synopsis:       guest network hosed, host says: xvif6i0 GNTTABOP_copy[0] Rx -3
> >Confidential:   no
> >Severity:       serious
> >Priority:       medium
> >Responsible:    port-xen-maintainer
> >State:          open
> >Class:          sw-bug
> >Submitter-Id:   net
> >Arrival-Date:   Mon Nov 03 01:25:00 +0000 2025
> >Originator:     Taylor R Campbell
> >Release:        10.1_STABLE
> >Organization:
> The GrantBSD Foundabop
> >Environment:
> NetBSD cole.netbsd.de 10.1_STABLE NetBSD 10.1_STABLE (TNF_XENSERVER_PVH) #1: Sat Oct  4 22:20:13 UTC 2025  spz%franklin.NetBSD.org@localhost:/home/netbsd/10/amd64/obj/sys/arch/amd64/compile/TNF_XENSERVER_PVH amd64
> >Description:
> 
> 	In two incidents recently, we've had a guest on TNF
> 	infrastructure become unreachable over the network -- no
> 	response to pings or TCP connections, nothing logged in
> 	npflog0, system mainly idle.
> 
> 	The host's dmesg is full of messages like this:
> 
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> [ 2451339.802864] xvif6i0 GNTTABOP_copy[0] Rx -3
> 
> 	That's this message:
> 
>     638 	/*
>     639 	 * Copy the data and ack it. Delaying it until the mbuf is
>     640 	 * freed will stall transmit.
>     641 	 */
>     642 	if (HYPERVISOR_grant_table_op(GNTTABOP_copy, gop, copycnt) != 0) {
>     643 		printf("%s: GNTTABOP_copy %s failed", ifp->if_xname, dir);
>     644 		return EINVAL;
>     645 	}

Are you running a debug hypervisor (xen-debug.gz from the package) ?
If so, does anything shows up in xl dmesg or on serial console ?

Also you don't mention the xen version

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--