https://bugzilla.redhat.com/show_bug.cgi?id=1142631
This patch resolves a situation where the same "<target dev='$name'...>"
can be used for multiple disks in the domain.
While the $name is "mostly" advisory regarding the expected order that
the disk is added to the domain and not guaranteed to map to the device
name in the guest OS, it still should be unique enough such that other
domblk* type operations can be performed.
Without the patch, the domblklist will list the same Target twice:
$ virsh domblklist $dom
Target Source
------------------------------------------------
sda /var/lib/libvirt/images/file.qcow2
sda /var/lib/libvirt/images/file.img
Additionally, getting domblkstat, domblkerror, domblkinfo, and other block*
type calls will not be able to reference the second target.
Fortunately, hotplug disallows adding a "third" sda value:
$ qemu-img create -f raw /var/lib/libvirt/images/file2.img 10M
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sda
error: Failed to attach disk
error: operation failed: target sda already exists
$
BUT, it since 'sdb' doesn't exist one would get the following on the same
hotplug attempt, but changing to use 'sdb' instead of 'sda'
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sdb
error: Failed to attach disk
error: internal error: unable to execute QEMU command 'device_add': Duplicate ID 'scsi0-0-1' for device
$
Since we cannot fix this issue at parsing time, the best that can be done so
as to not "lose" a domain is to make the check prior to starting the guest
with the results as follows:
$ virsh start $dom
error: Failed to start domain $dom
error: XML error: target 'sda' duplicated for disk sources '/var/lib/libvirt/images/file.qcow2' and '/var/lib/libvirt/images/file.img'
$
Running 'make check' found a few more instances in the tests where this
duplicated target dev value was being used. These also exhibited some
duplicated 'id=' values (negating the uniqueness argument of aliases) in
the corresponding .args file and of course the *xmlout version of a few
input XML files.
In general, we try to make virt-xml-validate tolerant of input
elements in any order when possible. However, as written, the
RNG grammar did not permit <source> unless there was an explicit
type= attribute (even though the C code manages just fine by
defaulting to type='file'). After making the attribute optional
on the 'file' branch, I noticed that the use of diskspec was now
redundant with the branch when no <source> was supplied.
View this patch with 'git diff -b' for a better picture of the
schema change.
* docs/schemas/domaincommon.rng (disk): Hoist 'diskspec' out of
choice, make type='file' default, and still preserve interleave.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-source-pool.xml:
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-drive-discard.xml:
New files.
* tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml:
* tests/qemuxml2argvdata/qemuxml2argv-disk-drive-discard.xml:
Reorder XML.
* tests/qemuxml2xmltest.c (mymain): Cover new files.
Signed-off-by: Eric Blake <eblake@redhat.com>
Libvirtd would crash if a domain contained an empty cdrom drive of
type='volume' as the disk def->srcpool member would be dereferenced. Fix
it by checking if the source pool is present before dereferencing it.
Also alter tests to catch this issue in the future.
Reported by: Kevin Shanahan
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1056328
<controller type='pci' index='0' model='pci-root'/>
is auto-added to pc* machine types.
Without this controller PCI bus 0 is not available and
no PCI addresses are assigned by default.
Since older libvirt supported PCI bus 0 even without
this controller, it is removed from the XML when migrating.
With this patch, one can specify the disk source using libvirt
storage like:
<disk type='volume' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source pool='default' volume='fc18.img'/>
<target dev='vdb' bus='virtio'/>
</disk>
"seclabels" and "startupPolicy" are not supported for this new
disk type ("volume"). They will be supported in later patches.
docs/formatdomain.html.in:
* Add documents for new XMLs
docs/schemas/domaincommon.rng:
* Add rng for new XMLs;
src/conf/domain_conf.h:
* New struct for 'volume' type disk source (virDomainDiskSourcePoolDef)
* Add VIR_DOMAIN_DISK_TYPE_VOLUME for enum virDomainDiskType
src/conf/domain_conf.c:
* New helper virDomainDiskSourcePoolDefParse to parse the 'volume'
type disk source.
* New helper virDomainDiskSourcePoolDefFree to free the source def
if 'volume' type disk.
tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml:
tests/qemuxml2xmltest.c:
* New test
