From: Joel Knight Subject: Probe xnf(4) and xbf(4) on Xen 4.17 To: tech Date: Wed, 13 Nov 2024 17:14:00 -0700 Hi. As reported here[1], something changed between Xen 4.13 and 4.17 which causes xnf and xbf to no longer probe on boot. The culprit appears to be XenStore advertising a "9pfs" device, which OpenBSD doesn't support, so xen_probe_devices() aborts early. The 9pfs device is first in the list of devices returned by XS. The diff below results in xnf and xbf attaching again on 7.6. .joel 1 - https://xcp-ng.org/forum/topic/9897/openbsd-xcp-ng-8-3-virtio-net-guesttools-no-longer-works dmesg on -release: OpenBSD 7.6 (GENERIC.MP) #338: Mon Sep 30 08:55:35 MDT 2024 deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP bios0: vendor Xen version "4.17" date 10/02/2024 bios0: Xen HVM domU pvbus0 at mainbus0: Xen 4.17 xen0 at pvbus0: features 0x112705, 64 grant table frames, event channel 3 xen0: failed to attach "device/9pfs/" xspd0 at pci0 dev 3 function 0 "XenSource Platform Device" rev 0x02 dmesg with diff below: OpenBSD 7.6-stable (GENERIC.MP) #6: Tue Nov 12 12:55:03 MST 2024 bios0: vendor Xen version "4.17" date 10/02/2024 bios0: Xen HVM domU pvbus0 at mainbus0: Xen 4.17 xen0 at pvbus0: features 112705, idtvec 112, 64 grant table frames, event channel 3 xbf0 at xen0 backend 0 channel 8: cdrom xbf1 at xen0 backend 0 channel 8: disk sd0 at scsibus1 targ 0 lun 0: xbf2 at xen0 backend 0 channel 9: disk sd1 at scsibus2 targ 0 lun 0: xnf0 at xen0 backend 0 channel 10: address 45:44:b4:f4:f4:94 xspd0 at pci0 dev 3 function 0 "XenSource Platform Device" rev 0x02 Index: sys/dev/pv/xen.c =================================================================== RCS file: /cvs/src/sys/dev/pv/xen.c,v diff -p -u -r1.98 xen.c --- sys/dev/pv/xen.c 24 May 2024 10:05:55 -0000 1.98 +++ sys/dev/pv/xen.c 13 Nov 2024 04:07:20 -0000 @@ -1405,6 +1405,8 @@ xen_probe_devices(struct xen_softc *sc) for (i = 0; i < iov1_cnt; i++) { if (strcmp("suspend", (char *)iovp1[i].iov_base) == 0) continue; + if (strcmp("9pfs", (char *)iovp1[i].iov_base) == 0) + continue; snprintf(path, sizeof(path), "device/%s", (char *)iovp1[i].iov_base); if ((error = xs_cmd(&xst, XS_LIST, path, &iovp2,