QEMU has possibility to call madvise(.., MADV_REMOVE) in some
cases. Expose this feature to users by new element/attribute
discard.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
All the code now just uses the virHashTablePtr type directly.
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Enable the TPM CRB to be specified in the domain XML. This
now allows to describe the TPM device like this:
<tpm model='tpm-crb'>
<backend type='passthrough'>
<device path='/dev/tpm0'/>
</backend>
</tpm>
Extend the XML schema to also allow tpm-crb.
Extend the documentation.
Add a test case for testing the XML parser and formatter.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Currently it is not used in backing chains and does not seem that we
will need to use it so return it back to the disk definition. Thankfully
most accesses are done via the accessors.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Add a function named virDomainObjCheckIsActive in src/conf/domain_conf.c.
It calls virDomainObjIsActive, raises error if necessary and returns.
There is a lot of occurence of this pattern and it will save 3 lines on
each call.
Signed-off-by: Clementine Hayat <clem@lse.epita.fr>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
In 2ada9ef146 we've tried to turn virDomainChrSourceDef into
virObject. Well, this requires 'virObject' member to be stored on
the first position of the struct. This adjustment is missing in
the original commit leading to all sorts of funny memleaks and
data corruptions.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Rather than VIR_ALLOC, use the New function for allocation. We
already use the Free function anyway.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
The new controller will not yet be used automatically by
libvirt, but at this point it's already possible to configure
a guest to use it.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
For some reason we've decided to silently translate the disk
detect_zeroes mode if it would be invalid. Extract the
logic so that it does not need to be copypasta'd across the code base.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Make the function more usable by returning the full disk definition and
fix the only caller for the new semantics. The new name for the function
is virDomainDiskDefParse.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Move out formatting of 'startuPolicy' which is a property of the disk
out of the <source> element. Extracting the code formating the content
and attributes will also allow reuse in other parts of the code.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
If the user tries to define a domain that has
<controller type='usb' model='none'/>
and also some USB devices, we report an error:
error: internal error: No free USB ports
Which is technically still correct for a domain with no USB ports.
Change it to:
USB is disabled for this domain, but USB devices are present in the domain XML
https://bugzilla.redhat.com/show_bug.cgi?id=1347550
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Pretty much any reasonable compiler would do this automatically,
but there's no harm in being explicit about it.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
When calling virDomainDefCompatibleDevice to check a new device during
device update, we need to pass the original device which is going to be
updated in addition to the new device. Otherwise, the function can
report false conflicts.
The new argument is currently ignored by virDomainDefCompatibleDevice,
but this will change in the following patch.
https://bugzilla.redhat.com/show_bug.cgi?id=1546971
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The controller model is slightly unusual in that the default value is
-1, not 0. As a result the default value is not covered by any of the
existing enum cases. This in turn means that any switch() statements
that think they have covered all cases, will in fact not match the
default value at all. In the qemuDomainDeviceCalculatePCIConnectFlags()
method this has caused a serious mistake where we fallthrough from the
SCSI controller case, to the VirtioSerial controller case, and from
the USB controller case to the IDE controller case.
By adding explicit enum constant starting at -1, we can ensure switches
remember to handle the default case.
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Commit 7e62c4cd26 (first appearing in libvirt-3.9.0 as a resolution
to rhbz #1343919) added a "generated" attribute to virMacAddr that was
set whenever a mac address was auto-generated by libvirt. This
knowledge was used in a single place - when trying to match a NetDef
from the Domain to Delete with user-provided XML. Since the XML parser
always auto-generates a MAC address for NetDefs when none is provided,
it was previously impossible to make a search where the MAC address
isn't significant, but the addition of the "generated" attribute made
it possible for the search function to ignore auto-generated MACs.
This implementation had a problem though - it was adding a field to a
"low level" struct - virMacAddr - which is used in other places with
the assumption that it contains exactly a 6 byte MAC address and
nothing else. In particular, virNWFilterSnoopEthHdr uses virMacAddr as
part of the definition of an ethernet packet header, whose layout must
of course match an actual ethernet packet. Adding the extra bools into
virNWFilterSnoopEthHdr caused the nwfilter driver's "IP discovery via
DHCP packet snooping" functionality to mysteriously stop working.
In order to fix that behavior, and prevent potential future similar
odd behavior, this patch moves the "generated" member out of
virMacAddr (so that it is again really is just a MAC address) into
virDomainNetDef, and sets it only when virDomainNetGenerateMAC() is
called from virDomainNetDefParseXML() (which is the only time we care
about it).
Resolves: https://bugzilla.redhat.com/1529338
(It should also be applied to any maintenance branch that applies
commit 7e62c4cd26 and friends to resolve
https://bugzilla.redhat.com/1343919)
Signed-off-by: Laine Stump <laine@laine.org>
Rather than expecting callers to pass a virConnectPtr into the
virDomainDiskTranslateSourcePool() method, just acquire a connection
to the storage driver when needed.
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Now that we have the ability to easily open connections to secondary
drivers, eg network:///system, it is possible to reimplement the
virDomainNetResolveActualType method in terms of the public API. This
avoids the need to have the network driver provide a callback for it.
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Instead of storing separately whether the feature is enabled
or not and what resizing policy should be used, store both of
them in a single place.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Instead of storing separately whether the feature is enabled
or not and what driver should be used, store both of them in
a single place.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The virStorageTranslateDiskSourcePool method modifies a virDomainDiskDef
to resolve any storage pool reference. For some reason this was added
into the storage driver code, despite working entirely in terms of the
public APIs. Move it into the domain conf file and rename it to match the
object it modifies.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Currently the QEMU driver will call directly into the network driver
impl to modify resolve the atual type of NICs with type=network. It
has todo this before it has allocated the actual NIC. This introduces
a callback system to allow us to decouple the QEMU driver from the
network driver.
This is a short term step, as it ought to be possible to achieve the
same end goal by simply querying XML via the public network API. The
QEMU code in question though, has no virConnectPtr conveniently
available at this time.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Currently the QEMU driver will call directly into the network driver
impl to modify network device bandwidth for interfaces with
type=network. This introduces a callback system to allow us to decouple
the QEMU driver from the network driver.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Currently virt drivers will call directly into the network driver impl
to allocate domain interface devices where type=network. This introduces
a callback system to allow us to decouple the virt drivers from the
network driver.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The virt-aa-helper fails to parse the xmls with the memory/cpu
hotplug features or user assigned aliases. Set the features in
xmlopt->config for the parsing to succeed.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
As it turns out virDomainDeviceFindControllerModel was only ever
called for SCSI controllers using VIR_DOMAIN_CONTROLLER_TYPE_SCSI
as a parameter.
So rename to virDomainDeviceFindSCSIController and rather than
return a model, let's return a virDomainControllerDefPtr to let
the caller reference whatever it wants.
More info in the documentation, this is basically the XML parsing/formatting
support, schemas, tests and documentation for the new cputune/cachetune element
that will get used by following patches.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
VM drivers may need to store additional private data to the status XML
so that it can be restored after libvirtd restart. Since not everything
is needed add a callback infrastructure, where VM drivers can add only
stuff they need.
Note that the private data is formatted as a <privateData> sub-element
of the <disk> or <backingStore> <source> sub-element. This is done since
storing it out of band (in the VM private data) would require a complex
matching process to allow to put the data into correct place.
Introduce specific a target types with two models for the console
devices (sclp and sclplm) used in s390 and s390x guests, so isa-serial
is no more used for them.
This makes <serial> usable on s390 and s390x guests, with at most only
a single sclpconsole and one sclplmconsole devices usable in a single
guest (due to limitations in QEMU, which will enforce already at
runtime).
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1449265
Signed-off-by: Pino Toscano <ptoscano@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
We can finally introduce a specific target model for the pl011 device
used by mach-virt guests, which means isa-serial will no longer show
up to confuse users.
We make sure migration works in both directions by interpreting the
isa-serial target type, or the lack of target type, appropriately
when parsing the guest XML, and skipping the newly-introduced type
when formatting if for migration. We also verify that pl011 is not
used for non-mach-virt guests and add a bunch of test cases.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=151292
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
We can finally introduce a specific target model for the spapr-vty
device used by pSeries guests, which means isa-serial will no longer
show up to confuse users.
We make sure migration works in both directions by interpreting the
isa-serial target type, or the lack of target type, appropriately
when parsing the guest XML, and skipping the newly-introduced type
when formatting if for migration. We also verify that spapr-vty is
not used for non-pSeries guests and add a bunch of test cases.
This commit is best viewed with 'git show -w'.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1511421
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
This information will be used to select, and store in the guest
configuration in order to guarantee ABI stability, the concrete
(hypervisor-specific) model for serial devices.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
This attribute was used to decide whether to format the type
attribute of the <target> element, but the logic didn't take into
account all possible cases and as such could lead to unexpected
results. Moreover, it's one more thing to keep track of, and can
easily fall out of sync with other attributes.
Now that we have VIR_DOMAIN_CHR_SERIAL_TARGET_TYPE_NONE, we can
use that value to signal that no specific target type has been
configured for the serial device and as such the attribute should
not be formatted at all. All other values are now formatted.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
This is the first step in getting rid of the assumption that
isa-serial is the default target type for serial devices.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Rather than picking apart the two pieces we need/want (path, hosts,
and auth)- let's allocate/use a virStorageSourcePtr for iSCSI storage.
The end result is that qemuBuildSCSIiSCSIHostdevDrvStr doesn't need
to "fake" one for the qemuBuildNetworkDriveStr call.
Starting from qemu 2.11, the `-device vmcoreinfo` will create a fw_cfg
entry for a guest to store dump details, necessary to process kernel
dump with KASLR enabled and providing additional kernel details.
In essence, it is similar to -fw_cfg name=etc/vmcoreinfo,file=X but in
this case it is not backed by a file, but collected by QEMU itself.
Since the device is a singleton and shouldn't use additional hardware
resources, it is presented as a <feature> element in the libvirt
domain XML.
The device is arm/x86 only for now (targets that support fw_cfg+dma).
Related to:
https://bugzilla.redhat.com/show_bug.cgi?id=1395248
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
This is similar to the virDomainQemuMonitorCommand API, it can change
the domain state in a way that libvirt may not understand.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Most of the time it's okay to leave this up to negotiation between
the guest and the host, but in some situations it can be useful to
manually decide the behavior, especially to enforce its availability.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1308743
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
This function works over domain definition and not domain object.
Its name is thus misleading.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
When coverage build is enabled, gcc complains about it:
In file included from qemu/qemu_agent.h:29:0,
from qemu/qemu_driver.c:47:
qemu/qemu_driver.c: In function 'qemuDomainSetInterfaceParameters':
./conf/domain_conf.h:3397:1: error: inlining failed in call to
'virDomainNetTypeSharesHostView': call is unlikely and code size would
grow [-Werror=inline]
virDomainNetTypeSharesHostView(const virDomainNetDef *net)
^
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
They have to be unique within the domain. As usual, backwards
compatibility takes its price. In this particular situation we
have a device that is represented twice in a domain and so is its
alias.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
If driver that is calling the parse supports user supplied
aliases, they can be parsed even for inactive XMLs. However, to
avoid any clashes with aliases that libvirt generates, the user
ones have to have "ua-" prefix.
Note, that some drivers don't have notion of device aliases at
all. Also, in order to support user supplied aliases some extra
checks need to be done (e.g. during hotplug). Therefore we can't
just enable this feature for all the drivers. Thus we need a flag
that drivers set to tell parsing code that they can handle user
supplied device aliases.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There is one limitation for using this API, when the guest is started
with all actions set to "destroy" we put "-no-reboot" on the QEMU
command line. That cannot be changed while QEMU is running and
the QEMU process is always terminated no matter what is configured
for any action.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1460677
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
There is no need to have two different enums where one has the same
values as the other one with some additions.
Currently for on_poweroff and on_reboot we allow only subset of actions
that are allowed for on_crash. This was covered in parse time using
two different enums. Now to make sure that we don't allow setting
actions that are not supported we need to check it while validating
domain config.
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1497410
The comment in virNetDevTapInterfaceStats() implementation for
Linux states that packets transmitted by domain are received by
the host and vice versa. Well, this is true but not for all types
of interfaces. For instance, for macvtaps when TAP device is
hooked right onto a physical device any packet that domain sends
looks also like a packet sent to the host. Therefore, we should
allow caller to chose if the stats returned should be straight
copy or swapped.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Small wrapper to lookup interface in domain definition by its
name.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
qemu 2.7.0 introduces multiqueue virtio-blk(commit 2f27059).
This patch introduces a new attribute "queues". An example of
the XML:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' queues='4'/>
The corresponding QEMU command line:
-device virtio-blk-pci,scsi=off,num-queues=4,id=virtio-disk0
Signed-off-by: Lin Ma <lma@suse.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Add an optional virTristateBool haveTLS to virStorageSource to
manage whether a storage source will be using TLS.
Sample XML for a VxHS disk:
<disk type='network' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source protocol='vxhs' name='eb90327c-8302-4725-9e1b-4e85ed4dc251' tls='yes'>
<host name='192.168.0.1' port='9999'/>
</source>
<target dev='vda' bus='virtio'/>
</disk>
Additionally add a tlsFromConfig boolean to control whether the TLS
setting was due to domain configuration or qemu.conf global setting
in order to decide whether to Format the haveTLS setting for either
a live or saved domain configuration file.
Update the qemuxml2xmltest in order to add a test to show the proper
parsing.
Also update the docs to describe the tls attribute.
Signed-off-by: Ashish Mittal <Ashish.Mittal@veritas.com>
Signed-off-by: John Ferlan <jferlan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1439991
Whenever a device is being updated via
virDomainUpdateDeviceFlags() API, we parse the device XML and
ideally run some generic checks to validate the configuration
(e.g. if device defines per-device boot order but the domain has
os/boot element already). Well, that's the theory - due to a
missing check we've jumped early from that check function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Will be needed for future patches to pull the default video type
setting out of XML parsing routines.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
To handle setting a default heads value. Convert callers that were
doing it by hand
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
In order to ensure that the default protocol is RAW, explicitly
assigning VIR_DOMAIN_CHR_TCP_PROTOCOL_RAW = 0.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Some failures of the post parse callback can be tolerated. This is
specifically desired when loading the configs of existing VMs. In such
case the post parse callback should not really be modifying anything
in the definition.
This patch adds a parse flag VIR_DOMAIN_DEF_PARSE_ALLOW_POST_PARSE_FAIL
which will allow the callbacks to report non-fatal failures by returning
a positive return value. In such case the field 'postParseFailed' in the
domain definition is set to true, to notify the drivers that the
callback failed and possibly needs to be re-run.
Some drivers use def-specific private data across callbacks (e.g.
qemuCaps in the qemu driver). Currently it's mostly allocated in every
single callback. This is rather wasteful, given that every single call
to the device callback allocates it.
The new callback will allocate the data (if not provided externally) and
then use it for the VM, address and device post parse callbacks.
Add yet another post parse callback, which is executed prior the real
one without @parseOpaque. This is meant to set basics before
@parseOpaque (in case of the qemu driver qemuCaps) can be allocated.
This callback will allow to optimize passing of custom parseOpaque
through the callbacks.
It is more related to a domain as we might use it even when there is
no systemd and it does not use any dbus/systemd functions. In order
not to use code from conf/ in util/ pass machineName in cgroups code
as a parameter. That also fixes a leak of machineName in the lxc
driver and cleans up and de-duplicates some code.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The original name didn't hint at the fact that PHBs are
a pSeries-specific concept.
Suggested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
The virDomainDeviceInfo struct is defined in device_conf,
so generic functions that operate on it should also be
defined there rather than in domain_conf.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
pSeries guests will soon need the new information; luckily,
we can figure it out automatically most of the time, so
users won't have to worry about it.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
Adding it to the virDomainControllerPCIModelName enumeration
is enough for existing code to handle it, so parsing and
formatting will work without further tweaking.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
It comes very handy to have source path for chardevs. We already
have such function: virDomainAuditChardevPath() but it's static
and has name not suitable for exposing. Moreover, while exposing
it change its name slightly to virDomainChrSourceDefGetPath.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Users may want to run the init command of a container as a special
user / group. This is achieved by adding <inituser> and <initgroup>
elements. Note that the user can either provide a name or an ID to
specify the user / group to be used.
This commit also fixes a side effect of being able to run the command
as a non-root user: the user needs rights on the tty to allow shell
job control.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Some containers may want the application to run in a special directory.
Add <initdir> element in the domain configuration to handle this case
and use it in the lxc driver.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
When running an application container, setting environment variables
could be important.
The newly introduced <initenv> tag in domain configuration will allow
setting environment variables to the init program.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Add support for vgaconf driver configuration. In domain xml it looks like
this:
<video>
<driver vgaconf='io|on|off'>
<model .../>
</video>
It was added with bhyve gop video in mind to allow users control how the
video device is exposed to the guest, specifically, how VGA I/O is
handled.
One can refer to the bhyve manual page to get more detailed description
of the possible VGA configuration options:
https://www.freebsd.org/cgi/man.cgi?query=bhyve&manpath=FreeBSD+12-current
The relevant part could be found using the 'vgaconf' keyword.
Also, add some tests for this new feature.
Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
virDomainXMLOption gains driver specific callbacks for parsing and
formatting save cookies.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
While checking for ABI stability, drivers might pose additional
checks that are not valid for general case. For instance, qemu
driver might check some memory backing attributes because of how
qemu works. But those attributes may work well in other drivers.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add a new <ioapic> element with a driver attribute.
Possible values are qemu and kvm. With 'qemu', the I/O
APIC can be put in the userspace even for KVM domains.
https://bugzilla.redhat.com/show_bug.cgi?id=1427005
... with VIR_NET_GENERATED_MACV???_PREFIX, which is defined in
util/virnetdevmacvlan.h.
Since VIR_NET_GENERATED_PREFIX is used for plain tap devices, it is
renamed to VIR_NET_GENERATED_TAP_PREFIX and moved to virnetdev.h
