Commit Graph

1646 Commits

Author SHA1 Message Date
Hu Tao
f1ac62f7ba doc: add domain to address of hostdev pci
libvirt supports pci domain already, so update the documentation.
Otherwise users who lookup the documentation for how to use hostdev may
miss the domain and encounter error when pass-through a pci device in a
domain other than 0.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
2014-07-18 10:22:40 -06:00
Peter Krempa
2a48303800 doc: domain: Clarify that disk type 'lun' works with iSCSI too
Disk type 'lun' enables SCSI command passthrough for a disk. We stated
that it works only with "block" disks. Qemu supports it also when using
the iSCSI protocol.
2014-07-18 17:20:51 +02:00
Cédric Bosdonnat
3ba0469ce6 lxc network configuration allows setting target container NIC name
LXC network devices can now be assigned a custom NIC device name on the
container side. For example, this is configured with:

    <interface type='network'>
      <source network='default'/>
      <guest dev="eth1"/>
    </interface>

In this example the network card will appear as eth1 in the guest.
2014-07-18 14:25:57 +02:00
Eric Blake
7f1ca3d6fe schema: put interleave at correct level
The previous commit 09d4d26 put the interleave at the wrong point;
it didn't allow interleaving with <memory>.

* docs/schema/domaincommon.rng (numatune): Fix interleave location.
* tests/qemuxml2argvdata/qemuxml2argv-numatune-memnode.xml: Adjust test.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-07-16 17:30:31 -06:00
Martin Kletzander
09d4d261e5 schema: add interleave inside numatune
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-07-16 20:36:20 +02:00
Martin Kletzander
a05c01521c conf, schema: add support for memnode elements
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-07-16 20:15:45 +02:00
Martin Kletzander
992000e6d8 conf, schema: add 'id' field for cells
In XML format, by definition, order of fields should not matter, so
order of parsing the elements doesn't affect the end result.  When
specifying guest NUMA cells, we depend only on the order of the 'cell'
elements.  With this patch all older domain XMLs are parsed as before,
but with the 'id' attribute they are parsed and formatted according to
that field.  This will be useful when we have tuning settings for
particular guest NUMA node.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-07-16 20:15:45 +02:00
Michele Paolino
a14abd463a support for QEMU vhost-user
This patch adds support for the QEMU vhost-user feature to libvirt.
vhost-user enables the communication between a QEMU virtual machine
and other userspace process using the Virtio transport protocol.
It uses a char dev (e.g. Unix socket) for the control plane,
while the data plane based on shared memory.

The XML looks like:

<interface type='vhostuser'>
    <mac address='52:54:00:3b:83:1a'/>
    <source type='unix' path='/tmp/vhost.sock' mode='server'/>
    <model type='virtio'/>
</interface>

Signed-off-by: Michele Paolino <m.paolino@virtualopensystems.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-07-16 18:44:57 +02:00
Chunyan Liu
a9fd30e633 storagevol: add nocow to vol xml
Add 'nocow' to storage volume xml so that user can have an option
to set NOCOW flag to the newly created volume. It's useful on btrfs
file system to enhance performance.

Btrfs has low performance when hosting VM images, even more when the guest
in those VM are also using btrfs as file system. One way to mitigate this
bad performance is to turn off COW attributes on VM files. Generally, there
are two ways to turn off COW on btrfs: a) by mounting fs with nodatacow,
then all newly created files will be NOCOW. b) per file. Add the NOCOW file
attribute. It could only be done to empty or new files.

This patch tries the second way, according to 'nocow' option, it could set
NOCOW flag per file:
for raw file images, handle 'nocow' in libvirt code; for non-raw file images,
pass 'nocow=on' option to qemu-img, and let qemu-img to handle that (requires
qemu-img version >= 2.1).

Signed-off-by: Chunyan Liu <cyliu@suse.com>
2014-07-16 13:35:20 +02:00
Eric Blake
06cf86e94b docs: mention more about older capability feature bits
Our documentation for features was rather sparse; this fleshes out
more of the details for other existing capabilities (and cost me
some time trawling git history).

* docs/formatcaps.html.in: Document it feature bits.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-07-14 06:11:34 -06:00
Peter Krempa
500f80a595 doc: Document that snapshot name of block-backed disk isn't autogenerated
Libvirt generates external snapshot target file names for file backed
storage but not for block backed storage. Document the limitation.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1032363
2014-07-14 09:26:26 +02:00
Ján Tomko
3701b51984 Document the need to free vir*Ptr objects
https://bugzilla.redhat.com/show_bug.cgi?id=994731
2014-07-09 09:22:20 +02:00
Peter Krempa
5bd3c73bdf audit: Audit smartcard devices 2014-07-07 12:56:45 +02:00
Peter Krempa
994cc31444 audit: Add auditing for serial/parallel/channel/console character devs
Add startup auditing and also hotplug auditing for said devices.
2014-07-07 12:56:45 +02:00
Michele Paolino
14f71959b6 docs: formatdomain.html fixes
Fixed some XML tags in the formatdomain page.

Signed-off-by: Michele Paolino <m.paolino@virtualopensystems.com>
2014-07-04 18:28:39 +02:00
Michele Paolino
7ab2f81889 docs: Fix broken link in the HACKING page
The link to the page "how to get your code into an open source
project" has been fixed.

Signed-off-by: Michele Paolino <m.paolino@virtualopensystems.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-07-04 18:28:24 +02:00
John Ferlan
f1aa00b4e7 formatdomain: Fix issues found describing auth
Fix a couple of typos ('chap' should have been 'iscsi' and there was
a stray 'iqn.2013-07.com.example:iscsi-pool' entry.  Clean up the
description of the <auth> element for the disk
2014-07-03 17:39:15 -04:00
Michal Privoznik
614581f32b Introduce domain_capabilities
This new module holds and formats capabilities for emulator. If you
are about to create a new domain, you may want to know what is the
host or hypervisor capable of. To make sure we don't regress on the
XML, the formatting is not something left for each driver to
implement, rather there's general format function.

The domain capabilities is a lockable object (even though the locking
is not necessary yet) which uses reference counter.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-07-03 12:22:37 +02:00
Ján Tomko
058d89b9df Introduce virBufferCheckError
Check if the buffer is in error state and report an error if it is.

This replaces the pattern:
if (virBufferError(buf)) {
    virReportOOMError();
    goto cleanup;
}
with:

if (virBufferCheckError(buf) < 0)
    goto cleanup;

Document typical buffer usage to favor this.
Also remove the redundant FreeAndReset - if an error has
been set via virBufferSetError, the content is already freed.
2014-07-03 10:41:15 +02:00
Mike Perez
d950494129 qemu: Add cmd_per_lun, max_sectors to virtio-scsi
This introduces two new attributes "cmd_per_lun" and "max_sectors" same
with the names QEMU uses for virtio-scsi. An example of the XML:

<controller type='scsi' index='0' model='virtio-scsi' cmd_per_lun='50'
max_sectors='512'/>

The corresponding QEMU command line:

-device virtio-scsi-pci,id=scsi0,cmd_per_lun=50,max_sectors=512,
bus=pci.0,addr=0x3

Signed-off-by: Mike Perez <thingee@gmail.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2014-07-02 09:43:17 +02:00
Daniel Veillard
b083528e56 Release of libvirt-1.2.6 2014-07-02 13:50:18 +08:00
Eric Blake
9b291bbe20 docs: publish correct enum values
We publish libvirt-api.xml for others to use, and in fact, the
libvirt-python bindings use it to generate python constants that
correspond to our enum values.  However, we had an off-by-one bug
that any enum that relied on C's rules for implicit initialization
of the first enum member to 0 got listed in the xml as having a
value of 1 (and all later members of the enum were equally
botched).

The fix is simple - since we add one to the previous value when
encountering an enum without an initializer, the previous value
must start at -1 so that the first enum member is assigned 0.

The python generator code has had the off-by-one ever since DV
first wrote it years ago, but most of our public enums were immune
because they had an explicit = 0 initializer.  The only affected
enums are:
- virDomainEventGraphicsAddressType (such as
VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV4), since commit 987e31e
(libvirt v0.8.0)
- virDomainCoreDumpFormat (such as VIR_DOMAIN_CORE_DUMP_FORMAT_RAW),
since commit 9fbaff0 (libvirt v1.2.3)
- virIPAddrType (such as VIR_IP_ADDR_TYPE_IPV4), since commit
03e0e79 (not yet released)

Thanks to Nehal J Wani for reporting the problem on IRC, and
for helping me zero in on the culprit function.

* docs/apibuild.py (CParser.parseEnumBlock): Fix implicit enum
values.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-26 15:25:05 -06:00
Laine Stump
69db5f921a interface: report link state for bonds and vlans too
The interface state for bonds and vlans does seem to reflect the state
of the underlying physical devices, at least in some cases, so it
makes sense to allow reporting it (netcf now does).

The link state/speed for bridge devices is meaningless though, so we
don't even look for it.
2014-06-20 11:43:19 +03:00
Laine Stump
a341fc731d interface: allow reordering of elements in xml
The interface xml schema was written with strict rules about the
ordering of the elements. This was never intentional, but just due to
omission of <interleave> in the appropriate places. This patch just
adds in <interleave> wherever there is more than one element, and
re-indents everything else appropriately.
2014-06-19 07:56:27 -06:00
Jincheng Miao
d98a60c225 docs: fix some typos in formatdomain.html
In section "Block / character devices" of "Host device assignment",
the description of hostdev element has some error:

For a block device, the type should be "storage", not "block";
For a character device, the type should be "misc", not "char".

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
2014-06-19 07:54:09 -06:00
Michal Privoznik
02129b7c0e virCaps: expose pages info
There are two places where you'll find info on page sizes. The first
one is under <cpu/> element, where all supported pages sizes are
listed. Then the second one is under each <cell/> element which refers
to concrete NUMA node. At this place, the size of page's pool is
reported. So the capabilities XML looks something like this:

<capabilities>

  <host>
    <uuid>01281cda-f352-cb11-a9db-e905fe22010c</uuid>
    <cpu>
      <arch>x86_64</arch>
      <model>Westmere</model>
      <vendor>Intel</vendor>
      <topology sockets='1' cores='1' threads='1'/>
      ...
      <pages unit='KiB' size='4'/>
      <pages unit='KiB' size='2048'/>
      <pages unit='KiB' size='1048576'/>
    </cpu>
    ...
    <topology>
      <cells num='4'>
        <cell id='0'>
          <memory unit='KiB'>4054408</memory>
          <pages unit='KiB' size='4'>1013602</pages>
          <pages unit='KiB' size='2048'>3</pages>
          <pages unit='KiB' size='1048576'>1</pages>
          <distances/>
          <cpus num='1'>
            <cpu id='0' socket_id='0' core_id='0' siblings='0'/>
          </cpus>
        </cell>
        <cell id='1'>
          <memory unit='KiB'>4071072</memory>
          <pages unit='KiB' size='4'>1017768</pages>
          <pages unit='KiB' size='2048'>3</pages>
          <pages unit='KiB' size='1048576'>1</pages>
          <distances/>
          <cpus num='1'>
            <cpu id='1' socket_id='0' core_id='0' siblings='1'/>
          </cpus>
        </cell>
        ...
      </cells>
    </topology>
    ...
  </host>

  <guest/>

</capabilities>

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-19 15:10:49 +02:00
Eric Blake
b50e104923 blockjob: don't remove older-style mirror XML
Commit 7c6fc39 introduced a regression in the XML produced for older
clients.  The argument at the time was that clients shouldn't be
depending on output-only data for something that is only going to
be triggered for a transient guest; but John Ferlan reported that
the automated testsuite was such a client.  It's better to be safe
than sorry by guaranteeing back-compat cruft.  Note that later
patches will be using <mirror> for active block commit, but there
we don't have to worry about back-compat.

* src/conf/domain_conf.c (virDomainDiskDefFormat): Restore old
style output when necessary.
* docs/schemas/domaincommon.rng: Validate back-compat style.
* docs/formatdomain.html.in: Update the documentation.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-mirror-old.xml:
Update tests.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-16 13:48:00 -06:00
Michal Privoznik
16ebf10f34 nodedev: Introduce <pci-express/> to PCI devices
This new element is there to represent PCI-Express capabilities
of a PCI devices, like link speed, number of lanes, etc.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-16 17:40:49 +02:00
Michal Privoznik
0311ef3d65 node_device: Expose link state & speed
While exposing the info under <interface/> in previous patch works, it
may work only in cases where interface is configured on the host.
However, orchestrating application may want to know the link state and
speed even in that case. That's why we ought to expose this in nodedev
XML too:

virsh # nodedev-dumpxml net_eth0_f0_de_f1_2b_1b_f3
<device>
  <name>net_eth0_f0_de_f1_2b_1b_f3</name>
  <path>/sys/devices/pci0000:00/0000:00:19.0/net/eth0</path>
  <parent>pci_0000_00_19_0</parent>
  <capability type='net'>
    <interface>eth0</interface>
    <address>f0🇩🇪f1:2b:1b:f3</address>
    <link speed='1000' state='up'/>
    <capability type='80203'/>
  </capability>
</device>

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 10:59:39 +02:00
Michal Privoznik
3db89662c2 virInterface: Expose link state & speed
Currently it is not possible to determine the speed of an interface
and whether a link is actually detected from the API. Orchestrating
platforms want to be able to determine when the link has failed and
where multiple speeds may be available which one the interface is
actually connected at. This commit introduces an extension to our
interface XML (without implementation to interface driver backends):

  <interface type='ethernet' name='eth0'>
    <start mode='none'/>
    <mac address='aa:bb:cc:dd:ee:ff'/>
    <link speed='1000' state='up'/>
    <mtu size='1492'/>
    ...
  </interface>

Where @speed is negotiated link speed in Mbits per second, and state
is the current NIC state (can be one of the following:  "unknown",
"notpresent", "down", "lowerlayerdown","testing", "dormant", "up").

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 09:13:32 +02:00
Wangrui (K)
350f816a00 docs: fix a typo in hacking.html.in
Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 08:53:03 -06:00
Eric Blake
7c6fc3948e conf: alter disk mirror xml output
Now that we track a disk mirror as a virStorageSource, we might
as well update the XML to theoretically allow any type of
mirroring destination (not just a local file).  A later patch
will also be reusing <mirror> to track the block commit of the
top layer of a chain, which is another case where libvirt needs
to update the backing chain after the job is finally pivoted,
and since backing chains can have network backing files as the
destination to commit into, it makes more sense to display that
in the XML.

This patch changes output-only XML; it was already documented
that <mirror> does not affect a domain definition at this point
(because qemu doesn't provide persistent bitmaps yet).  Any
application that was starting a block copy job with older libvirt
and then relying on the domain XML to determine if it was
complete will no longer be able to access the file= and format=
attributes of mirror that were previously used.  However, this is
not going to be a problem in practice: the only time a block copy
job works is on a transient domain, and any app that is managing
a transient domain probably already does enough of its own
bookkeeping to know which file it is mirroring into without
having to re-read it from the libvirt XML.  The one thing that
was likely to be used in a mirroring job was the ready=
attribute, which is unchanged.  Meanwhile, I made sure the schema
and parser still accept the old format, even if we no longer
output it, so that upgrading from an older version of libvirt is
seamless.

* docs/schemas/domaincommon.rng (diskMirror): Alter definition.
* src/conf/domain_conf.c (virDomainDiskDefParseXML): Parse two
styles of mirror elements.
(virDomainDiskDefFormat): Output new style.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror-old.xml: New
file, copied from...
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: ...here
before modernizing.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-mirror-old*: New
files.
* tests/qemuxml2xmltest.c (mymain): Test both styles.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-06 11:48:09 -06:00
Michal Privoznik
1c70277886 nodedev: Export NUMA node locality for PCI devices
A PCI device can be associated with a specific NUMA node. Later, when
a guest is pinned to one NUMA node the PCI device can be assigned on
different NUMA node. This makes DMA transfers travel across nodes and
thus results in suboptimal performance. We should expose the NUMA node
locality for PCI devices so management applications can make better
decisions.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-06 15:10:57 +02:00
Martin Kletzander
3de462fe9a Remove unnecessary empty first lines
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-06-06 10:52:05 +02:00
Michal Privoznik
e9f4729a01 formatcaps: Rework and add stubs to document
At the moment we are missing even basic documentation on our
capabilities XML. Without demand on completeness, I'm
reorganizing the document structure and adding very basic
documentation to two major components of the capabilities XML.
These stubs are intended to be enhanced in the future.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-05 13:58:19 +02:00
Michal Privoznik
8ba0a58f8d virCaps: Expose distance between host NUMA nodes
If user or management application wants to create a guest,
it may be useful to know the cost of internode latencies
before the guest resources are pinned. For example:

<capabilities>

  <host>
    ...
    <topology>
      <cells num='2'>
        <cell id='0'>
          <memory unit='KiB'>4004132</memory>
          <distances>
            <sibling id='0' value='10'/>
            <sibling id='1' value='20'/>
          </distances>
          <cpus num='2'>
            <cpu id='0' socket_id='0' core_id='0' siblings='0'/>
            <cpu id='2' socket_id='0' core_id='2' siblings='2'/>
          </cpus>
        </cell>
        <cell id='1'>
          <memory unit='KiB'>4030064</memory>
          <distances>
            <sibling id='0' value='20'/>
            <sibling id='1' value='10'/>
          </distances>
          <cpus num='2'>
            <cpu id='1' socket_id='0' core_id='0' siblings='1'/>
            <cpu id='3' socket_id='0' core_id='2' siblings='3'/>
          </cpus>
        </cell>
      </cells>
    </topology>
    ...
  </host>
  ...
</capabilities>

We can see the distance from node1 to node0 is 20 and within nodes 10.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-04 09:35:55 +02:00
Daniel Veillard
e604b59d79 Release of libvirt-1.2.5
* docs/news.html.in: update for release
* po/*.po*: updated ukrainian localization and regenerated
2014-06-02 09:47:05 +08:00
Roman Bogorodskiy
ca50df8eec docs: bhyve driver documentation improvements
- Document 'domxml-to-native' command
- Mention that the nmdm console support needs an appropriate
  kernel module loaded
2014-06-01 20:36:13 +04:00
Olivia Yin
61b1c681e0 change machine name ppce500v2 to ppce500
ppce500v2 is not machine supported by official release of QEMU.
It should be replaced by ppce500.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
2014-05-27 08:48:57 +02:00
Ján Tomko
00622f3be1 docs: add a serial device with a seclabel example 2014-05-19 08:47:03 +02:00
Michal Privoznik
0f1a0fff0e apibuild: Disallow 'returns' return description
Our documentation generator is a bit messy, to say the least. For
instance, the description to return values of a function is
searched within C comment. Currently, all lines that start with
'returns' or 'Returns' are viewed as return value description.
However, there are some valid uses where the 'returns' word is in
the middle of a sentence describing function behavior not the
return value. And there are no places where 'returns' is used to
describe return values.  For instance:
virDomainDetachDeviceFlags, virConnectNetworkEventRegisterAny and
virDomainGetDiskErrors. This leads to HTML documemtation being
generated incorrectly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-05-13 08:51:11 +02:00
James Shubin
4fddfeefaf docs: mention vagrant-libvirt in apps.html
Doc patch for apps.html as per: http://libvirt.org/apps.html#add

Disclaimer: I've contributed patches to the project that this commit
adds.

Vagrant-Libvirt is an excellent way to use vagrant with libvirt. This
way you can benefit from the vagrant features, while not loosing access
to the familiar (and useful) tools such as virsh and virt-manager.

Development currently at:

https://github.com/pradels/vagrant-libvirt/

although recent contributors include:

https://github.com/sciurus/vagrant-libvirt/

and:

https://github.com/purpleidea/vagrant-libvirt/

see git log for more details.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-12 15:50:59 -06:00
Chunyan Liu
99f50208c9 update documentation of <interface type='hostdev'>
<interface type='hostdev' managed='yes'> is supported, but
nowhere mentions 'managed' in <interface type='hostdev'> syntax.
Update documentation to cover it.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
2014-05-12 14:52:50 -06:00
Chen Hanxiao
4ae8369a4b docs: fix a typo in formatdomain
s/virual/virtual

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2014-05-06 06:58:44 +02:00
Martin Kletzander
6d105946a9 typos: fix s/it/is/ where applicable
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-05-05 11:49:36 +02:00
Daniel Veillard
791fb3f668 Release of libvirt-1.2.4
* docs/news.html.in libvirt.spec.in: updates for release
* po/*.po*: fetched new localization and regenerated
2014-05-04 14:41:29 +08:00
Chen Hanxiao
6c19f0de49 docs: update docs for setting the QEMU BIOS path
commit ddf2dfa1f7
provided a way to determine which bios files to use.
But we need to update related docs.

disccussed at:
http://www.redhat.com/archives/libvir-list/2012-June/msg01286.html

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-04-29 10:18:12 +02:00
Roman Bogorodskiy
6d0a617568 docs: document nmdm type console
* Add nmdm type device to domain format documnetation
* Add a section about nmdm console usage to the bhyve driver
  documentation
2014-04-24 19:57:11 +04:00
Jiri Denemark
a2e369bc00 conf: Output disk backing store details in domain XML
The XML for quite a longish backing chain is shown below:

  <disk type='network' device='disk'>
    <driver name='qemu' type='qcow2'/>
    <source protocol='nbd' name='bar'>
      <host transport='unix' socket='/var/run/nbdsock'/>
    </source>
    <backingStore type='block' index='1'>
      <format type='qcow2'/>
      <source dev='/dev/HostVG/QEMUGuest1'/>
      <backingStore type='file' index='2'>
        <format type='qcow2'/>
        <source file='/tmp/image2.qcow'/>
        <backingStore type='file' index='3'>
          <format type='qcow2'/>
          <source file='/tmp/image3.qcow'/>
          <backingStore type='file' index='4'>
            <format type='qcow2'/>
            <source file='/tmp/image4.qcow'/>
            <backingStore type='file' index='5'>
              <format type='qcow2'/>
              <source file='/tmp/image5.qcow'/>
              <backingStore type='file' index='6'>
                <format type='raw'/>
                <source file='/tmp/Fedora-17-x86_64-Live-KDE.iso'/>
                <backingStore/>
              </backingStore>
            </backingStore>
          </backingStore>
        </backingStore>
      </backingStore>
    </backingStore>
    <target dev='vdb' bus='virtio'/>
  </disk>

Various disk types and formats can be mixed in one chain. The
<backingStore/> empty element marks the end of the backing chain and it
is there mostly for future support of parsing the chain provided by a
user. If it's missing, we are supposed to probe for the rest of the
chain ourselves, otherwise complete chain was provided by the user. The
index attributes of backingStore elements can be used to unambiguously
identify a specific part of the image chain.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2014-04-24 16:06:13 +02:00
Nehal J Wani
3d5c29a17c Fix typos in src/*
Fix minor typos in source comments

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-04-21 16:49:08 -06:00