This patch provides support for a new watchdog action "inject-nmi" which
allows to define an inject of a non-maskable interrupt into a guest.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
The type='scsi' parameter of an address element is ignored
if placed within a hostdev section, and rejected by the XML
schema used by virt-xml-validate. Remove it from the doc,
and correct a typo in the remaining address arguments.
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>
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>
https://bugzilla.redhat.com/show_bug.cgi?id=1220527
This type of information defines attributes of a system
baseboard. With one exception: board type is yet not implemented
in qemu so it's not introduced here either.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Since the background for Admin API is merged upstream, we are bumping
the minor release version as discussed previously
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1021480
Seems the property has been deprecated for qemu, although seemingly ignored.
This patch enforces from a libvirt perspective that a scsi-block 'lun'
device should not provide the 'serial' property.
https://bugzilla.redhat.com/show_bug.cgi?id=1228007
When attaching a scsi volume lun via the attach-device --config or
--persistent options, there was no translation of the source pool
like there was for the live path, thus the attempt to modify the config
would fail since not enough was known about the disk.
This patch adds the support of queues attribute of the driver element
for vhost-user interface type. Example:
<interface type='vhostuser'>
<mac address='52:54:00:ee:96:6d'/>
<source type='unix' path='/tmp/vhost2.sock' mode='client'/>
<model type='virtio'/>
<driver queues='4'/>
</interface>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1207692
Signed-off-by: Maxime Leroy <maxime.leroy@6wind.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The guest firmware provides the same functionality as the pvpanic
device, and the relevant element should always be present in the
domain XML to reflect this fact, so add it after parsing the
definition if it wasn't there already.
The guest firmware provides the same functionality as the pvpanic
device, which is not available in QEMU on pSeries, so the domain
XML should be allowed to contain the <panic> element.
On the other hand, unlike the pvpanic device, the guest firmware
can't be configured, so report an error if an address has been
provided in the XML.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1182388
https://bugzilla.redhat.com/show_bug.cgi?id=998813
Like usb-serial, the pci-serial device allows a serial device to be
attached to PCI bus. An example XML looks like this:
<serial type='dev'>
<source path='/dev/ttyS2'/>
<target type='pci-serial' port='0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</serial>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Two new domain configuration XML elements are added to enable/disable
the protected key management operations for a guest:
<domain>
...
<keywrap>
<cipher name='aes|dea' state='on|off'/>
</keywrap>
...
</domain>
Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Some platforms, like aarch64, don't have APIC but GIC. So there's
no reason to have <apic/> feature turned on. However, we are
still missing <gic/> feature. This commit introduces the feature
to XML parser and formatter, adds documentation and updates RNG
schema.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
A new feature that can be turned on or off.
The QEMU machine vmport option allows to set the VMWare IO port
emulation. This emulation is useful for absolute pointer input when the
guest has vmware input drivers, and is enabled by default for kvm.
However it is unnecessary for Spice-enabled VM, since the agent already
handles absolute pointer and multi-monitors. Furthermore, it prevents
Spice from switching to relative input since the regular ps/2 pointer
driver is replaced by the vmware driver. It is thus advised to disable
vmport when using a Spice VM. This will permit the Spice client to
switch from absolute to relative pointer, as it may be required for
certain games or applications.
With iothreadid's allowing any 'id' value for an iothread_id, the
iothreadsched code needs a slight adjustment to allow for "any"
unsigned int value in order to create the bitmap of ids that will
have scheduler adjustments. Adjusted the doc description as well.
Remove the iothreadspin array from cputune and replace with a cpumask
to be stored in the iothreadids list.
Adjust the test output because our printing goes in order of the iothreadids
list now.
Adding a new XML element 'iothreadids' in order to allow defining
specific IOThread ID's rather than relying on the algorithm to assign
IOThread ID's starting at 1 and incrementing to iothreads count.
This will allow future patches to be able to add new IOThreads by
a specific iothread_id and of course delete any exisiting IOThread.
Each iothreadids element will have 'n' <iothread> children elements
which will have attribute "id". The "id" will allow for definition
of any "valid" (eg > 0) iothread_id value.
On input, if any <iothreadids> <iothread>'s are provided, they will
be marked so that we only print out what we read in.
On input, if no <iothreadids> are provided, the PostParse code will
self generate a list of ID's starting at 1 and going to the number
of iothreads defined for the domain (just like the current algorithm
numbering scheme). A future patch will rework the existing algorithm
to make use of the iothreadids list.
On output, only print out the <iothreadids> if they were read in.
because network address is required by route, so
here we should add one avoid user misunderstand.
Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
The virNodeDeviceDettach API only works on PCI devices.
Originally added by commit 10d3272e, but the API never
supported USB devices.
Reported by: Martin Polednik <mpolednik@redhat.com>
This patch adds code that parses and formats configuration for memory
devices.
A simple configuration would be:
<memory model='dimm'>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
</target>
</memory>
A complete configuration of a memory device:
<memory model='dimm'>
<source>
<pagesize unit='KiB'>4096</pagesize>
<nodemask>1-3</nodemask>
</source>
<target>
<size unit='KiB'>524287</size>
<node>1</node>
</target>
</memory>
This patch preemptively forbids use of the <memory> device in individual
drivers so the users are warned right away that the device is not
supported.
To enable memory hotplug the maximum memory size and slot count need to
be specified. As qemu supports now other units than mebibytes when
specifying memory, use the new interface in this case.
Add a XML element that will allow to specify maximum supportable memory
and the count of memory slots to use with memory hotplug.
To avoid possible confusion and misuse of the new element this patch
also explicitly forbids the use of the maxMemory setting in individual
drivers's post parse callbacks. This limitation will be lifted when the
support is implemented.
I spent quite some time figuring that backingStore info
isn't included in the dom xml, unless guest is up and
running. Hopefully putting that in the doc should help.
Also, several people have complained that libvirt reports
a backing file as raw, even though they expected it to be
qcow2; where the culprit is usually the user forgetting to
create the file with qemu-img create -o backing_fmt=qcow2.
This patch adds that info to the doc.
Signed-off-by: Deepak C Shetty <deepakcs@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Midonet is an opensource virtual networking that over lays the IP
network between hypervisors. Currently, such networks can be made
with the openvswitch virtualport type.
This patch, defines the schema and documentation that will serve
as basis for the follow up patches that will add support to libvirt
for using Midonet virtual ports for its interfaces. The schema
definition requires that the port profile expresses its interfaceid
as part of the port profile. For that reason, this is part of the
patch too.
Signed-off-by: Antoni Segura Puimedon <toni+libvirt@midokura.com>
We're parsing memballoon status period as unsigned int, but when we're
trying to set it, both we and qemu use signed int. That means large
values will get wrapped around to negative one resulting in error.
Basically the same problem as commit e3a7b874 was dealing with when
updating live domain.
QEMU changed the accepted value to int64 in commit 1f9296b5, but even
values as INT_MAX don't make sense since the value passed means seconds.
Hence adding capability flag for this change isn't worth it.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1140958
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The version attribute in redirdev filters refers to the revision
of the device, not the version of the USB protocol.
Explicitly state that this is not the USB protocol and remove references
to those round version numbers that resemble USB protocol versions.
https://bugzilla.redhat.com/show_bug.cgi?id=1177237
To prevent a confusion about missing chardev argument in qemu
command line add a note about that behavior into documentation.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1129198
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
There was a mess in the way how we store unlimited value for memory
limits and how we handled values provided by user. Internally there
were two possible ways how to store unlimited value: as 0 value or as
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED. Because we chose to store memory
limits as unsigned long long, we cannot use -1 to represent unlimited.
It's much easier for us to say that everything greater than
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED means unlimited and leave 0 as valid
value despite that it makes no sense to set limit to 0.
Remove unnecessary function virCompareLimitUlong. The update of test
is to prevent the 0 to be miss-used as unlimited in future.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1146539
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Our documentation isn't 100% clear about hostdev 'managed' attribute usage,
because it only makes sense to use it with PCI devices, yet we format
this attribute to all hostdev devices. By adding a note into the docs,
we can possibly avoid confusion from customer's side and also avoid a solution
using ternary logic.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1155887
At least Xen supports backend drivers in another domain (aka "driver
domain"). This patch introduces an XML config option for specifying the
backend domain name for <disk> and <interface> devices. E.g.
<disk>
<backenddomain name='diskvm'/>
...
</disk>
<interface type='bridge'>
<backenddomain name='netvm'/>
...
</interface>
In the future, same option will be needed for USB devices (hostdev
objects), but for now libxl doesn't have support for PVUSB.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Add an XML attribute to allow disabling merge of rx buffers
on the host:
<interface ...>
...
<model type='virtio'/>
<driver ...>
<host mrg_rxbuf='off'/>
</driver>
</interface>
https://bugzilla.redhat.com/show_bug.cgi?id=1186886
In order for QEMU vCPU (and other) threads to run with RT scheduler,
libvirt needs to take care of that so QEMU doesn't have to run privileged.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1178986
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Change the wording in the device-address-part of the docmunentation since
the ccw bus address support added to the optional address parameter of
virsh attach-disk for S390.
Signed-off-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
It is only usable for NETWORK and BRIDGE type interfaces.
Error out when trying to start a domain where the custom
tap device path is specified for interfaces of other types,
or when the daemon is not privileged.
Note that this cannot be checked at definition time, because
the comparison is against actual type.
https://bugzilla.redhat.com/show_bug.cgi?id=1147195
It is only supported for virtio adapters.
Silently drop it if it was specified for other models,
as is done for other virtio attributes.
Also mention this in the documentation.
https://bugzilla.redhat.com/show_bug.cgi?id=1147195
https://bugzilla.redhat.com/show_bug.cgi?id=1170492
In one of our previous commits (dc8b7ce7) we've done a functional
change even though it was intended as pure refactor. The problem is,
that the following XML:
<vcpu placement='static' current='2'>6</vcpu>
<cputune>
<emulatorpin cpuset='1-3'/>
</cputune>
<numatune>
<memory mode='strict' placement='auto'/>
</numatune>
gets translated into this one:
<vcpu placement='auto' current='2'>6</vcpu>
<cputune>
<emulatorpin cpuset='1-3'/>
</cputune>
<numatune>
<memory mode='strict' placement='auto'/>
</numatune>
We should not change the vcpu placement mode. Moreover, we're doing
something similar in case of emulatorpin and iothreadpin. If they were
set, but vcpu placement was auto, we've mistakenly removed them from
the domain XML even though we are able to set them independently on
vcpus.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Ploop is a pseudo device which makeit possible to access
to an image in a file as a block device. Like loop devices,
but with additional features, like snapshots, write tracker
and without double-caching.
It used in PCS for containers and in OpenVZ. You can manage
ploop devices and images with ploop utility
(http://git.openvz.org/?p=ploop).
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
QEMU supports feature specification with -cpu host and we just skip
using that. Since QEMU developers themselves would like to use this
feature, this patch modifies the code to work.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1178850
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
It was brought to my attention that some -boot options may not
work with UEFI. For instance, rebootTimeout is very SeaBIOS
specific,splash logo is not implemented yet on OVMF, and so on.
We should document this limitation at least.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add the possibility to have more than one IP address configured for a
domain network interface. IP addresses can also have a prefix to define
the corresponding netmask.
Since libvirt.h was split into multiple files and similarly
docs/libvirt-libvirt.html, docs/hvsupport.html have bad hyperlinks. The
same happens for all the html.in files that used <code class='docref'>
tag, because page.xsl has no idea where to point the link that's found.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Add attribute to set vgamem_mb parameter of QXL device for QEMU. This
value sets the size of VGA framebuffer for QXL device. Default value in
QEMU is 8MB so reuse it also in libvirt to not break things.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1076098
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The vram attribute was introduced to set the video memory but it is
usable only for few hypervisors excluding QEMU/KVM and the old XEN
driver. Only in case of QEMU the vram was used for QXL.
This patch updates the documentation to reflect current code in libvirt
and also changes the cases when we will set the default vram attribute.
It also fixes existing strange default value for VGA devices 9MB to 16MB
because the video ram should be rounded to power of two.
The change of default value could affect migrations but I found out that
QEMU always round the video ram to power of two internally so it's safe
to change the default value to the next closest power of two and also
silently correct every domain XML definition. And it's also safe because
we don't pass the value to QEMU.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1076098
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
To be able to express some use cases of the RBD backing with libvirt, we
need to be able to specify a config file for the RBD client to qemu as
that is one of the commonly used options.
Some storage systems have internal support for snapshots. Libvirt should
be able to select a correct snapshot when starting a VM.
This patch adds a XML element to select a storage source snapshot for
the RBD protocol which supports this feature.
The docs describing the <host> element that are under the <source>
element in the XML document were incorrectly placed under the <disk>
element. Move them to the correct place.
To track state of virtio channels this patch adds a new output-only
attribute called 'state' to the <target> element of virtio channels.
This will be later populated with the guest state of the channel.
Since 1.2.8 it's possible to use OVMF on domains. Moreover, it's
possible to have libvirt create NVRAM file per domain. Later,
when domain is undefined, the file is removed too. However,
things are a bit complicated when domain's transient. There's no
undefine to transient domains. There are two options: 1) leave
the file behind and let mgmt app remove it. 2) remove it
automatically as domain dies.
But, in some scenarios mgmt app may want to preserve the file,
copy it somewhere safe, and then copy it back when the domain is
starting again. And this wouldn't be possible with case 2). So,
even though case 1) leaves some files behind (possibly undeleted
for a long time), the files themselves are small (128K each). And
data loss is worse than full disk, isn't it?
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We still default to bhyveloader(1) if no explicit bootloader
configuration is supplied in the domain.
If the /domain/bootloader looks like grub-bhyve and the user doesn't
supply /domain/bootloader_args, we make an intelligent guess and try
chainloading the first partition on the disk (or a CD if one exists,
under the assumption that for a VM a CD is likely an install source).
Caveat: Assumes the HDD boots from the msdos1 partition. I think this is
a pretty reasonable assumption for a VM. (DrvBhyve with Bhyveload
already assumes that the first disk should be booted.)
I've tested both HDD and CD boot and they seem to work.
Modify the structure _virDomainBlockIoTuneInfo to support these the new
options.
Change the initialization of the variable expectedInfo in qemumonitorjsontest.c
to avoid compiling problem.
Add documentation about the new xml options
Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com>
CPU numa topology implicitly allows memory specification in 'KiB'.
Enabling this to accept the 'unit' in which memory needs to be specified.
This now allows users to specify memory in units of choice, and
lists the same in 'KiB' -- just like other 'memory' elements in XML.
<numa>
<cell cpus='0-3' memory='1024' unit='MiB' />
<cell cpus='4-7' memory='1024' unit='MiB' />
</numa>
Also augment test cases to correctly model NUMA memory specification.
This adds the tag 'unit="KiB"' for memory attribute in NUMA cells.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add documentation to explain how compat-mode can be invoked with libvirt
running on PowerPC architecture.
It also mentions that this change is available libvirt 1.2.11 onwards.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Extending the iothread disk support from pci to pci and ccw.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
This new attribute will control whether or not libvirt will pay
attention to guest notifications about changes to network device mac
addresses and receive filters. The default for this is 'no' (for
security reasons). If it is set to 'yes' *and* the specified device
model and connection support it (currently only macvtap+virtio) then
libvirt will watch for NIC_RX_FILTER_CHANGED events, and when it
receives one, it will issue a query-rx-filter command, retrieve the
result, and modify the host-side macvtap interface's mac address and
unicast/multicast filters accordingly.
The functionality behind this attribute will be in a later patch. This
patch merely adds the attribute to the top-level of a domain's
<interface> as well as to <network> and <portgroup>, and adds
documentation and schema/xml2xml tests. Rather than adding even more
test files, I've just added the net attribute in various applicable
places of existing test files.
This patch adds parsing/formatting code as well as documentation for
shared memory devices. This will currently be only accessible in QEMU
using it's ivshmem device, but is designed as generic as possible to
allow future expansion for other hypervisors.
In the devices section in the domain XML users may specify:
- For shmem device using a server:
<shmem name='shmem0'>
<server path='/tmp/socket-ivshmem0'/>
<size unit='M'>32</size>
<msi vectors='32' ioeventfd='on'/>
</shmem>
- For ivshmem device not using an ivshmem server:
<shmem name='shmem1'>
<size unit='M'>32</size>
</shmem>
Most of the configuration is made optional so it also allows
specifications like:
<shmem name='shmem1/>
<shmem name='shmem2'>
<server/>
</shmem>
Signed-off-by: Maxime Leroy <maxime.leroy@6wind.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Add options for tuning segment offloading:
<driver>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/>
</driver>
which control the respective host_ and guest_ properties
of the virtio-net device.
For the tap backend the default is specified and the same should be
done for the vhost attribute.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
For tuning the network, alternative devices
for creating tap and vhost devices can be specified via:
<backend tap='/dev/net/tun' vhost='/dev/net-vhost'/>
https://bugzilla.redhat.com/show_bug.cgi?id=1101574
Add an option 'iothreadpin' to the <cpuset> to allow for setting the
CPU affinity for each IOThread.
The iothreadspin will mimic the vcpupin with respect to being able to
assign each iothread to a specific CPU, although iothreads ids start
at 1 while vcpu ids start at 0. This matches the iothread naming scheme.
At the beginning when I was inventing <loader/> attributes and
<nvram/> I've introduced this @readonly attribute to the loader
element. It accepted values 'on' and 'off'. However, later, during the
review process, that has changed to 'yes' and 'no', but the example
XML snippet wasn't updated, so while the description is correct, the
example isn't.
Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When using split UEFI image, it may come handy if libvirt manages per
domain _VARS file automatically. While the _CODE file is RO and can be
shared among multiple domains, you certainly don't want to do that on
the _VARS file. This latter one needs to be per domain. So at the
domain startup process, if it's determined that domain needs _VARS
file it's copied from this master _VARS file. The location of the
master file is configurable in qemu.conf.
Temporary, on per domain basis the location of master NVRAM file can
be overridden by this @template attribute I'm inventing to the
<nvram/> element. All it does is holding path to the master NVRAM file
from which local copy is created. If that's the case, the map in
qemu.conf is not consulted.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Up to now, users can configure BIOS via the <loader/> element. With
the upcoming implementation of UEFI this is not enough as BIOS and
UEFI are conceptually different. For instance, while BIOS is ROM, UEFI
is programmable flash (although all writes to code section are
denied). Therefore we need new attribute @type which will
differentiate the two. Then, new attribute @readonly is introduced to
reflect the fact that some images are RO.
Moreover, the OVMF (which is going to be used mostly), works in two
modes:
1) Code and UEFI variable store is mixed in one file.
2) Code and UEFI variable store is separated in two files
The latter has advantage of updating the UEFI code without losing the
configuration. However, in order to represent the latter case we need
yet another XML element: <nvram/>. Currently, it has no additional
attributes, it's just a bare element containing path to the variable
store file.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add a new disk "driver" attribute "iothread" to be parsed as the thread
number for the disk to use. In order to more easily facilitate the usage
and configuration of the iothread, a "zero" for the attribute indicates
iothreads are not supported for the device and a positive value indicates
the specific thread to try and use.
Introduce XML to allowing adding iothreads to the domain. These can be
used by virtio-blk-pci devices in order to assign a specific thread to
handle the workload for the device. The iothreads are the official
implementation of the virtio-blk Data Plane that's been in tech preview
for QEMU.
QEMU 2.1 added support for the kvm=off option to the -cpu command,
allowing the KVM hypervisor signature to be hidden from the guest.
This enables disabling of some paravirualization features in the
guest as well as allowing certain drivers which test for the
hypervisor to load. Domain XML syntax is as follows:
<domain type='kvm>
...
<features>
...
<kvm>
<hidden state='on'/>
</kvm>
</features>
...
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The 'min_guarantee' is used by VMware ESX and OpenVZ drivers,
with qemu however, libvirt should report error when starting a domain,
because this element is not used.
Resolves https://bugzilla.redhat.com/show_bug.cgi?id=1122455
Commit 4cf53158 tried to set up unique labels per disk in the
example, but ended up choosing strings that don't correspond
to the usual choice of bus types. Tweak the strings once again.
* docs/formatdomain.html.in: Use preferred names.
Signed-off-by: Eric Blake <eblake@redhat.com>
Introduce a new structure to handle an iSCSI host device based on the
existing virDomainHostdevSubsysSCSI by adding a "protocol='iscsi'" to
the <source/> element. The existing scsi_host subsystem RNG was modified
to read an optional "protocol='adapter'", although it won't be written
out nor is it documented as an option (by choice).
The new hostdev structure mimics the existing <disk/> element for an
iSCSI device (network) device. New XML is:
<hostdev mode='subsystem' type='scsi' managed='yes'>
<source protocol='iscsi' name='iqn.1992-01.com.example'>
<host name='example.org' port='3260'/>
<auth username='myname'>
<secret type='iscsi' usage='mycluster_myname'/>
</auth>
</source>
<address type='drive' controller='0' bus='0' target='2' unit='5'/>
</hostdev>
The controller element will mimic the existing scsi_host code insomuch
as when 'lsi' and 'virtio-scsi' are used.
Jiri Moskovcak reported on IRC that the documentation on valid
<disk> was confusing because it didn't have unique dev='...'
entries.
* docs/formatdomain.html.in: Use unique names.
Signed-off-by: Eric Blake <eblake@redhat.com>
A future patch is going to wire up qemu active block commit jobs;
but as they have similar events and are canceled/pivoted in the
same way as block copy jobs, it is easiest to track all bookkeeping
for the commit job by reusing the <mirror> element. This patch
adds domain XML to track which job was responsible for creating a
mirroring situation, and adds a job='copy' attribute to all
existing uses of <mirror>. Along the way, it also massages the
qemu monitor backend to read the new field in order to generate
the correct type of libvirt job (even though it requires a
future patch to actually cause a qemu event that can be reported
as an active commit). It also prepares to update persistent XML
to match changes made to live XML when a copy completes.
* docs/schemas/domaincommon.rng: Enhance schema.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (_virDomainDiskDef): Add a field.
* src/conf/domain_conf.c (virDomainBlockJobType): String conversion.
(virDomainDiskDefParseXML): Parse job type.
(virDomainDiskDefFormat): Output job type.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Distinguish
active from regular commit.
* src/qemu/qemu_driver.c (qemuDomainBlockCopy): Set job type.
(qemuDomainBlockPivot, qemuDomainBlockJobImpl): Clean up job type
on completion.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-mirror-old.xml:
Update tests.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-disk-active-commit.xml: New
file.
* tests/qemuxml2xmltest.c (mymain): Drive new test.
Signed-off-by: Eric Blake <eblake@redhat.com>
Doing a blockcopy operation across a libvirtd restart is not very
robust at the moment. In particular, we are clearing the <mirror>
element prior to telling qemu to finish the job. Also, thanks to the
ability to request async completion, the user can easily regain
control prior to qemu actually finishing the effort, and they should
be able to poll the domain XML to see if the job is still going.
A future patch will fix things to actually wait until qemu is done
before modifying the XML to reflect the job completion. But since
qemu issues identical BLOCK_JOB_COMPLETE events regardless of whether
the job was cancelled (kept the original disk) or completed (pivoted
to the new disk), we have to track which of the two operations were
used to end the job. Furthermore, we'd like to avoid attempts to
end a job where we are already waiting on an earlier request to qemu
to end the job. Likewise, if we miss the qemu event (perhaps because
it arrived during a libvirtd restart), we still need enough state
recorded to be able to determine how to modify the domain XML once
we reconnect to qemu and manually learn whether the job still exists.
Although this patch doesn't actually fix the problem, it is a
preliminary step that makes it possible to track whether a job
has already begun steps towards completion.
* src/conf/domain_conf.h (virDomainDiskMirrorState): New enum.
(_virDomainDiskDef): Convert bool mirroring to new enum.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Handle new values.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Adjust
client.
* src/qemu/qemu_driver.c (qemuDomainBlockPivot)
(qemuDomainBlockJobImpl): Likewise.
* docs/schemas/domaincommon.rng (diskMirror): Expose new values.
* docs/formatdomain.html.in (elementsDisks): Document it.
* tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml: Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
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>
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.
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.
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>
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>
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
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>
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>
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>
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>
<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>
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>
When the default was changed from kvm to vfio, the documentation for
hostdev and interface was changed, but the documentation in <network>
was forgotten.
Also document when the default was changed from "always kvm" to "vfio
if available, else kvm" (1.0.5).
Recent autotest/virt-test testing on f20 discovered an anomaly in how
the bandwidth options are documented and used. This was discovered due
to a bug fix in the /sbin/tc utility found in iproute-3.11.0.1 (on f20)
in which overflow was actually caught and returned as an error. The fix
was first introduced in iproute-3.10 (search on iproute2 commit 'a303853e').
The autotest/virt-test test for virsh domiftune was attempting to send
the largest unsigned integer value (4294967295) for maximum value
testing. The libvirt xml implementation was designed to manage values
in kilobytes thus when this value was passed to /sbin/tc, it (now)
properly rejected the 4294967295kbps value.
Investigation of the problem discovered that formatdomain.html.in and
formatnetwork.html.in described the elements and property types slightly
differently, although they use the same code - virNetDevBandwidthParseRate()
(shared by portgroups, domains, and networks xml parsers). Rather than
have the descriptions in two places, this patch will combine and reword
the description under formatnetwork.html.in and have formatdomain.html.in
link to that description.
This documentation faux pas was continued into the virsh man page where
the bandwidth description for both 'attach-interface' and 'domiftune'
did not indicate the format of each value, thus leading to the test using
largest unsigned integer value assuming "bps" rather than "kbps", which
ultimately was wrong.
Add a new character device backend called 'spiceport' that uses
spice's channel for communications and apart from spicevmc can be used
as a backend for any character device from libvirt's point of view.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Some grammar fixes.
s/namespace,set/namespace, set
s/container being allowed/container are allowed
s/the <code>uid/The <code>uid
Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Add a new <timer> for the HyperV reference time counter enlightenment
and the iTSC reference page for Windows guests.
This feature provides a paravirtual approach to track timer events for
the guest (similar to kvmclock) with the option to use real hardware
clock on systems with a iTSC with compensation across various hosts.
It doesn't make sense to fail if the SCSI host device is specified
as "shareable" explicitly between domains (NB, it works if and only
if the device is specified as "shareable" for *all* domains,
otherwise it fails).
To fix the problem, this patch introduces an array for virSCSIDevice
struct, which records all the names of domain which are using the
device (note that the recorded domains must specify the device as
shareable). And the change on the data struct brings on many
subsequent changes in the code.
Prior to this patch, the "shareable" tag didn't work as expected,
it actually work like "non-shareable". So this patch also added notes
in formatdomain.html to declare the fact.
* src/util/virscsi.h:
- Remove virSCSIDeviceGetUsedBy
- Change definition of virSCSIDeviceGetUsedBy and virSCSIDeviceListDel
- Add virSCSIDeviceIsAvailable
* src/util/virscsi.c:
- struct virSCSIDevice: Change "used_by" to be an array; Add
"n_used_by" as the array count
- virSCSIDeviceGetUsedBy: Removed
- virSCSIDeviceFree: frees the "used_by" array
- virSCSIDeviceSetUsedBy: Copy the domain name to avoid potential
memory corruption
- virSCSIDeviceIsAvailable: New
- virSCSIDeviceListDel: Change the logic, for device which is already
in the list, just remove the corresponding entry in "used_by". And
since it's only used in one place, we can safely removing the code
to find out the dev in the list first.
- Copyright updating
* src/libvirt_private.sys:
- virSCSIDeviceGetUsedBy: Remove
- virSCSIDeviceIsAvailable: New
* src/qemu/qemu_hostdev.c:
- qemuUpdateActiveScsiHostdevs: Check if the device existing before
adding it to the list;
- qemuPrepareHostdevSCSIDevices: Error out if the not all domains
use the device as "shareable"; Also don't try to add the device
to the activeScsiHostdevs list if it already there; And make
more sensible error w.r.t the current "shareable" value in
driver->activeScsiHostdevs.
- qemuDomainReAttachHostScsiDevices: Change the logic according
to the changes on helpers.
Signed-off-by: Osier Yang <jyang@redhat.com>
spice-server offers an API to disable file transfer messages
on the agent channel between the client and the guest.
This is supported in qemu through the disable-agent-file-xfer option.
This patch exposes this option to libvirt.
Adds a new element 'filetransfer', with one property,
'enable', which accepts a boolean.
Default is enabled, for backward compatibility.
Depends on the capability exported in the first patch of the series.
Signed-off-by: Francesco Romani <fromani@redhat.com>
The linux kernel recently added support for paravirtual spinlock
handling to avoid performance regressions on overcomitted hosts. This
feature needs to be turned in the hypervisor so that the guest OS is
notified about the possible support.
This patch adds a new feature "paravirt-spinlock" to the XML and
supporting code to enable the "kvm_pv_unhalt" pseudo CPU feature in
qemu.
https://bugzilla.redhat.com/show_bug.cgi?id=1008989
Prefer using VFIO (if available) to the legacy KVM device passthrough.
With this patch a PCI passthrough device without the driver configured
will be started with VFIO if it's available on the host. If not legacy
KVM passthrough is checked and error is reported if it's not available.
Since 76b644c when the support for RAM filesystems was introduced,
libvirt accepted the following XML:
<source usage='1024' unit='KiB'/>
This was parsed correctly and internally stored in bytes, but it
was formatted as (with an extra 's'):
<source usage='1024' units='KiB'/>
When read again, this was treated as if the units were missing,
meaning libvirt was unable to parse its own XML correctly.
The usage attribute was documented as being in KiB, but it was not
scaled if the unit was missing. Transient domains still worked,
because this was balanced by an extra 'k' in the mount options.
This patch:
Changes the parser to use 'units' instead of 'unit', as the latter
was never documented (fixing persistent domains) and some programs
(libvirt-glib, libvirt-sandbox) already parse the 'units' attribute.
Removes the extra 'k' from the tmpfs mount options, which is needed
because now we parse our own XML correctly.
Changes the default input unit to KiB to match documentation, fixing:
https://bugzilla.redhat.com/show_bug.cgi?id=1015689
qemu/KVM also supports a tftp URL while specifying the cdrom ISO image.
The xml should be as following:
<disk type='network' device='cdrom'>
<source protocol='tftp' name='/url/path'>
<host name='host.name' port='69'/>
</source>
</disk>
Signed-off-by: Aline Manera <alinefm@br.ibm.com>
The ftps protocol is another protocol supported by qemu/KVM while specifying
the cdrom ISO image.
The xml should be as following:
<disk type='network' device='cdrom'>
<source protocol='ftps' name='/url/path'>
<host name='host.name' port='990'/>
</source>
</disk>
Signed-off-by: Aline Manera <alinefm@br.ibm.com>
The https protocol is also accepted by qemu/KVM when specifying the cdrom ISO
image.
The xml should be as following:
<disk type='network' device='cdrom'>
<source protocol='https' name='/url/path'>
<host name='host.name' port='443'/>
</source>
</disk>
Signed-off-by: Aline Manera <alinefm@br.ibm.com>
Mention that user namespace can be enabled using the UID/GID
mapping schema.
Fix typo in link anchor for container args in domain XML docs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
According to VMWare's documentation 'cdrom-raw' is an acceptable value
for deviceType for a CD-ROM drive. The documentation states that the VMX
configuration for a CD-ROM deviceType is as follows:
ide|scsi(n):(n).deviceType = "cdrom-raw|atapi-cdrom|cdrom-image"
From the documentation it appears the following is true:
- cdrom-image = Provides the ISO to the VM
- atapi-cdrom = Provides a NEC emulated ATAPI CD-ROM on top of the host
CD-ROM
- cdrom-raw = Passthru for a host CD-ROM drive. Allows CD-R burning from
within the guest.
A CD-ROM prior to this patch would always provide an 'atapi-cdrom' is
modeled as:
<disk type='block' device='cdrom'>
<source dev='/dev/scd0'/>
<target dev='hda' bus='ide'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
This patch allows the 'device' attribute to be set to 'lun' for a raw
acccess CD-ROM such as:
<disk type='block' device='lun'>
<source dev='/dev/scd0'/>
<target dev='hda' bus='ide'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
This corresponds to '-sd' and '-drive if=sd' on the qemu command line.
Needed for many ARM boards which don't provide any other way to
pass in storage.
Add an attribute named 'removable' to the 'target' element of disks,
which controls the removable flag. For instance, on a Linux guest it
controls the value of /sys/block/$dev/removable. This option is only
valid for USB disks (i.e. bus='usb'), and its default value is 'off',
which is the same behaviour as before.
To achieve this, 'removable=on' (or 'off') is appended to the '-device
usb-storage' parameter sent to qemu when adding a USB disk via
'-disk'. A capability flag QEMU_CAPS_USB_STORAGE_REMOVABLE was added
to keep track if this option is supported by the qemu version used.
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=922495
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
<controller type='pci' index='0' model='pci-root'>
<pcihole64 unit='KiB'>1048576</pcihole64>
</controller>
It can be used to adjust (or disable) the size of the 64-bit
PCI hole. The size attribute is in kilobytes (different unit
can be specified on input), but it gets rounded up to
the nearest GB by QEMU.
Disabling it will be needed for guests that crash with the
64-bit PCI hole (like Windows XP), see:
https://bugzilla.redhat.com/show_bug.cgi?id=990418
The ftp protocol is already recognized by qemu/KVM so add this support to
libvirt as well.
The xml should be as following:
<disk type='network' device='cdrom'>
<source protocol='ftp' name='/url/path'>
<host name='host.name' port='21'/>
</source>
</disk>
Signed-off-by: Aline Manera <alinefm@br.ibm.com>
QEMU/KVM already allows a HTTP URL for the cdrom ISO image so add this support
to libvirt as well.
The xml should be as following:
<disk type='network' device='cdrom'>
<source protocol='http' name='/url/path'>
<host name='host.name' port='80'/>
</source>
</disk>
Signed-off-by: Aline Manera <alinefm@br.ibm.com>
