Defining a domain with a SCSI disk attached via a hostdev
tag and a source address unit value longer than two digits
causes an error when editing the domain with virsh edit,
even if no changes are made to the domain definition.
The error suggests invalid XML, somewhere:
# virsh edit lmb_guest
error: XML document failed to validate against schema:
Unable to validate doc against /usr/local/share/libvirt/schemas/domain.rng
Extra element devices in interleave
Element domain failed to validate content
The virt-xml-validate tool fails with a similar error:
# virt-xml-validate lmb_guest.xml
Relax-NG validity error : Extra element devices in interleave
lmb_guest.xml:17: element devices: Relax-NG validity error :
Element domain failed to validate content
lmb_guest.xml fails to validate
The hostdev tag requires a source address to be specified,
which includes bus, target, and unit address attributes.
According to the SCSI Architecture Model spec (section
4.9 of SAM-2), a LUN address is 64 bits and thus could be
up to 20 decimal digits long. Unfortunately, the XML
schema limits this string to just two digits. Similarly,
the target field can be up to 32 bits in length, which
would be 10 decimal digits.
# lsscsi -xx
[0:0:19:0x4022401100000000] disk IBM 2107900 3.44 /dev/sda
# lsscsi
[0:0:19:1074872354]disk IBM 2107900 3.44 /dev/sda
# cat lmb_guest.xml
<domain type='kvm'>
<name>lmb_guest</name>
<memory unit='MiB'>1024</memory>
...trimmed...
<devices>
<controller type='scsi' model='virtio-scsi' index='0'/>
<hostdev mode='subsystem' type='scsi'>
<source>
<adapter name='scsi_host0'/>
<address bus='0' target='19' unit='1074872354'/>
</source>
</hostdev>
...trimmed...
Since the reference unit and target fields are used in
several places in the XML schema, create a separate one
specific for SCSI Logical Units that will permit the
greater length. This permits both the validation utility
and the virsh edit command to succeed when a hostdev
tag is included.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
