regression: xen domU no longer supports "type=cdrom" vbd disk
I use xl.cfg "disk" entries like the following to mount a virtual CDROM in a Xen domU: 'format=raw, vdev=0x5, access=ro, devtype=cdrom, target=/images/NetBSD-9.0-amd64.iso' However since upgrading my -current source tree I've been seeing: xenbus0: ignoring device/vbd/4 type cdrom As shown in this patch I had to comment out the core of the mentioned change to be able to use an ISO image again as a virtual CDROM again: --- xenbus_probe.c.~1.55.~ 2020-05-30 17:32:39.672816814 -0700 +++ xenbus_probe.c 2020-06-08 14:13:45.025527521 -0700 @@ -443,6 +443,14 @@ kmem_free(xbusd, xbusd->xbusd_sz); break; } +//revision 1.51 +//date: 2020-04-28 06:21:01 -0700; author: bouyer; state: Exp; lines: +30 -9; commitid: 5XOy6F9zbgN8C96C; +//Skip block device with device-type "cdrom", as their emulation can't be +//disabled; and the backend driver doesn't handle them either. +//Fix hang when booting with 'ioemu:hdc:cdrom' type disks. +//While there convert some printf to aprint_error() +// +#if 0 /* XXX breaks use of ISO files! */ if (strcmp(xa.xa_type, "vbd") == 0) { char dtype[10]; if (xenbus_read(NULL, xbusd->xbusd_path, @@ -461,6 +469,7 @@ continue; } } +#endif err = read_backend_details(xbusd); if (err != 0) { aprint_error_dev(xenbus_dev, Now it works again: xbd4 at xenbus0 id 4: Xen Virtual Block Device Interface xbd4: using event channel 12 ... boot device: xbd4 root on xbd4a dumps on xbd4b root file system type: cd9660 -- Greg A. Woods Kelowna, BC +1 250 762-7675 RoboHack Planix, Inc. Avoncote Farms pgpyhCAjH0HNg.pgp Description: OpenPGP Digital Signature
Re: regression: xen domU no longer supports "type=cdrom" vbd disk
On Mon, 8 Jun 2020 at 22:26, Greg A. Woods wrote: > > I use xl.cfg "disk" entries like the following to mount a virtual CDROM > in a Xen domU: > > 'format=raw, vdev=0x5, access=ro, devtype=cdrom, > target=/images/NetBSD-9.0-amd64.iso' > > However since upgrading my -current source tree I've been seeing: > > xenbus0: ignoring device/vbd/4 type cdrom > > As shown in this patch I had to comment out the core of the mentioned > change to be able to use an ISO image again as a virtual CDROM again: > > > --- xenbus_probe.c.~1.55.~ 2020-05-30 17:32:39.672816814 -0700 > +++ xenbus_probe.c 2020-06-08 14:13:45.025527521 -0700 > @@ -443,6 +443,14 @@ > kmem_free(xbusd, xbusd->xbusd_sz); > break; > } > +//revision 1.51 > +//date: 2020-04-28 06:21:01 -0700; author: bouyer; state: Exp; lines: +30 > -9; commitid: 5XOy6F9zbgN8C96C; > +//Skip block device with device-type "cdrom", as their emulation can't be > +//disabled; and the backend driver doesn't handle them either. > +//Fix hang when booting with 'ioemu:hdc:cdrom' type disks. > +//While there convert some printf to aprint_error() > +// > +#if 0 /* XXX breaks use of ISO files! */ > if (strcmp(xa.xa_type, "vbd") == 0) { > char dtype[10]; > if (xenbus_read(NULL, xbusd->xbusd_path, > @@ -461,6 +469,7 @@ > continue; > } > } > +#endif > err = read_backend_details(xbusd); > if (err != 0) { > aprint_error_dev(xenbus_dev, > > > Now it works again: > > xbd4 at xenbus0 id 4: Xen Virtual Block Device Interface > xbd4: using event channel 12 > ... > boot device: xbd4 > root on xbd4a dumps on xbd4b > root file system type: cd9660 I believe this was necessary at least under XCP-NG in PVHVM mode with platform:viridian set to false - before the change the CD-ROM had to be unconfigured as the system was hanging. After the change this was no longer necessary and the CD-ROM was available. > > -- > Greg A. Woods > > Kelowna, BC +1 250 762-7675 RoboHack > Planix, Inc. Avoncote Farms --
Re: regression: xen domU no longer supports "type=cdrom" vbd disk
On Mon, Jun 08, 2020 at 02:26:39PM -0700, Greg A. Woods wrote: > I use xl.cfg "disk" entries like the following to mount a virtual CDROM > in a Xen domU: > > 'format=raw, vdev=0x5, access=ro, devtype=cdrom, > target=/images/NetBSD-9.0-amd64.iso' > > However since upgrading my -current source tree I've been seeing: > > xenbus0: ignoring device/vbd/4 type cdrom > > As shown in this patch I had to comment out the core of the mentioned > change to be able to use an ISO image again as a virtual CDROM again: Actually this change matches what other OSes do with 'devtype=cdrom', we were an outsider here. For PV or PVH domUs you can omit the devtype keyword, it's only needed for HVM guests (if you want to boot from the cdrom image). -- Manuel Bouyer NetBSD: 26 ans d'experience feront toujours la difference --
Re: regression: xen domU no longer supports "type=cdrom" vbd disk
At Tue, 9 Jun 2020 00:00:17 +0200, Manuel Bouyer wrote: Subject: Re: regression: xen domU no longer supports "type=cdrom" vbd disk > > On Mon, Jun 08, 2020 at 02:26:39PM -0700, Greg A. Woods wrote: > > I use xl.cfg "disk" entries like the following to mount a virtual CDROM > > in a Xen domU: > > > > 'format=raw, vdev=0x5, access=ro, devtype=cdrom, > > target=/images/NetBSD-9.0-amd64.iso' > > > > However since upgrading my -current source tree I've been seeing: > > > > xenbus0: ignoring device/vbd/4 type cdrom > > > > As shown in this patch I had to comment out the core of the mentioned > > change to be able to use an ISO image again as a virtual CDROM again: > > Actually this change matches what other OSes do with 'devtype=cdrom', > we were an outsider here. > > For PV or PVH domUs you can omit the devtype keyword, it's only > needed for HVM guests (if you want to boot from the cdrom image). Ah OK, I think I understand, thanks! Perhaps this could be mentioned quite explicitly in in the CHANGES file (though that's not the first place I though to look, unfortunately) Maybe the xen/howto on the wiki could be more explicit about mapping a "image.iso" file to a disk vdev (perhaps instead of the currently less helpful suggestions about mapping an existing actual /dev/cd0a device). (Of course the xen/howto could use a lot of help.) (Not to mention but also some upstream Xen docs seem to need updating too, e.g. the xl-disk-configuration(5) manual page (that we unfortunately do not seem to install in the xentools package). Lots of guides mention using "devtype=cdrom" any time an "image.iso" is used.) -- Greg A. Woods Kelowna, BC +1 250 762-7675 RoboHack Planix, Inc. Avoncote Farms pgpa_VTJPzkrr.pgp Description: OpenPGP Digital Signature