There are a few extra exceptions that weren't being accounted for when
creating the alias for a controller. This resulted in 1) incorrect
status XML, and 2) exceptions/printfs of what *should* have been
directly available in the controller alias when constructing device
commandline arguments:
1) The primary (and only) IDE controller on a 440FX machinetype is
hardcoded to be "ide" in qemu.
2) The primary SATA controller on a 440FX machinetype is also
hardcoded to be "ide" in qemu.
3) On machinetypes that don't support multiple PCI buses, the PCI bus
is hardcoded in qemu to have the name "pci".
4) The first usb master controller is "usb", all others are the normal
"usb%d". (note that usb controllers that are not a "master" will have
the same index, and thus alias, as the master).
We needed to pass in the full domainDef and qemuCaps in order to
properly make the decisions about these exceptions.
Since libvirt doesn't call to update the new balloon size in qemu add
code that will handle tweaking of the size of the current balloon
statistic until qemu reports the new size using the event.
Coverity notes that ->ifname is used after the VIR_FREE done in the
code path after the call to virNetDevMacVLanDeleteWithVPortProfile
by a call to virNetDevOpenvswitchRemovePort.
Since the ->ifname will be VIR_FREE()'d eventually in virDomainNetDefFree
just remove the extraneous VIR_FREE here.
When originally added, the Openvswitch code wasn't present and checks
were made for non NULL prior to use.
Coverity complains that in the error paths both the < 0 condition and
the success path after the qemuDomainObjExitMonitor failure will end
up going to cleanup. So just use ignore_value in this error path to
resolve the complaint.
A further fix for:
https://bugzilla.redhat.com/show_bug.cgi?id=1113474
Since there is no possibility that any type of macvtap will work if
the parent physdev it's attached to is offline, we should bring the
physdev online at the same time as the macvtap. When taking the
macvtap offline, it's also necessary to take the physdev offline for
macvtap passthrough mode (because the physdev has the same MAC address
as the macvtap device, so could potentially cause problems with
misdirected packets during migration, as outlined in commits 829770
and 879c13). We can't set the physdev offline for other macvtap modes
1) because there may be other macvtap devices attached to the same
physdev (and/or the host itself may be using the device) in the other
modes whereas passthrough mode is exclusive to one macvtap at a time,
and 2) there's no practical reason to do so anyway.
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.
virnetdevopenvswitch.h declares a few functions that can be called to
add ports to and remove them from OVS bridges, and retrieve the
migration data for a port. It does not contain any data definitions
that are used by domain_conf.h. But for some reason, domain_conf.h
virnetdevopenvswitch.h should be directly #including it. This adds a
few lines to the project, but saves all the files that don't need it
from the extra computing, and makes the dependencies more clear cut.
Use the utilities introduced in the previous patches so the qemu
driver is able to create tap devices that are bound (and unbound
on domain destroyal) to Midonet virtual ports.
Signed-off-by: Antoni Segura Puimedon <toni+libvirt@midokura.com>
As there are two possible approaches to define a domain's memory size -
one used with legacy, non-NUMA VMs configured in the <memory> element
and per-node based approach on NUMA machines - the user needs to make
sure that both are specified correctly in the NUMA case.
To avoid this burden on the user I'd like to replace the NUMA case with
automatic totaling of the memory size. To achieve this I need to replace
direct access to the virDomainMemtune's 'max_balloon' field with
two separate getters depending on the desired size.
The two sizes are needed as:
1) Startup memory size doesn't include memory modules in some
hypervisors.
2) After startup these count as the usable memory size.
Note that the comments for the functions are future aware and document
state that will be present after a few later patches.
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>
Commit f7afeddc added code to report to systemd an array of interface
indexes for all tap devices used by a guest. Unfortunately it not only
didn't add code to report the ifindexes for macvtap interfaces
(interface type='direct') or the tap devices used by type='ethernet',
it ended up sending "-1" as the ifindex for each macvtap or hostdev
interface. This resulted in a failure to start any domain that had a
macvtap or hostdev interface (or actually any type other than
"network" or "bridge").
This patch does the following with the nicindexes array:
1) Modify qemuBuildInterfaceCommandLine() to only fill in the
nicindexes array if given a non-NULL pointer to an array (and modifies
the test jig calls to the function to send NULL). This is because
there are tests in the test suite that have type='ethernet' and still
have an ifname specified, but that device of course doesn't actually
exist on the test system, so attempts to call virNetDevGetIndex() will
fail.
2) Even then, only add an entry to the nicindexes array for
appropriate types, and to do so for all appropriate types ("network",
"bridge", and "direct"), but only if the ifname is known (since that
is required to call virNetDevGetIndex().
libvirt was unconditionally calling virNetDevBandwidthClear() for
every interface (and network bridge) of a type that supported
bandwidth, whether it actually had anything set or not. This doesn't
hurt anything (unless ifname == NULL!), but is wasteful.
This patch makes sure that all calls to virNetDevBandwidthClear() are
qualified by checking that the interface really had some bandwidth
setup done, and checks for a null ifname inside
virNetDevBandwidthClear(), silently returning success if it is null
(as well as removing the ATTRIBUTE_NONNULL from that function's
prototype, since we can't guarantee that it is never null,
e.g. sometimes a type='ethernet' interface has no ifname as it is
provided on the fly by qemu).
Export the required helpers and add backend code to hotplug RNG devices.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1161024
This way the device is in vmdef only if ret = 0 and the caller
(qemuDomainAttachDeviceFlags) does not free it.
Otherwise it might get double freed by qemuProcessStop
and qemuDomainAttachDeviceFlags if the domain crashed
in monitor after we've added it to vm->def.
Do the allocation first, then add the actual device.
The second part should never fail. This is good
for live hotplug where we don't want to remove the device
on OOM after the monitor command succeeded.
The only change in behavior is that on failure, the
vmdef->consoles array is freed, not just the first console.
Depending on the context, either error out if the domain
has disappeared in the meantime, or just ignore the value
to allow marking the function as ATTRIBUTE_RETURN_CHECK.
https://bugzilla.redhat.com/show_bug.cgi?id=1161024
If the domain crashed while we were in monitor,
we cannot rely on the REALLOC done on live definition,
since vm->def now points to the persistent definition.
Skip adding the attached devices to domain definition
if the domain crashed.
In AttachChrDevice, the chardev was already added to the
live definition and freed by qemuProcessStop in the case
of a crash. Skip the device removal in that case.
Also skip audit if the domain crashed in the meantime.
https://bugzilla.redhat.com/show_bug.cgi?id=1161024
In the device type-specific functions, exit early
if the domain has disappeared, because the cleanup
should have been done by qemuProcessStop.
Check the return value in processDeviceDeletedEvent
and qemuProcessUpdateDevices.
Skip audit and removing the device from live def because
it has already been cleaned up.
https://bugzilla.redhat.com/show_bug.cgi?id=1165993
So, there are still plenty of vNIC types that we don't know how to set
bandwidth on. Let's warn explicitly in case user has requested it
instead of pretending everything was set.
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.
We can change vnc password by using virDomainUpdateDeviceFlags API with
live flag. But it can't be changed with config flag. Error is reported as
below.
error: Operation not supported: persistent update of device 'graphics' is not supported
This patch supports the graphics arguments changed with config flag.
Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
It's not supported to change some graphics arguments with '--live'.
Replace some error code VIR_ERR_INTERNAL_ERROR and VIR_ERR_INVALID_ARG
with VIR_ERR_OPERATION_UNSUPPORTED.
Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
We now have a qemuInterfaceStartDevices() which does the final
activation needed for the host-side tap/macvtap devices that are used
for qemu network connections. It will soon make sense to have the
converse qemuInterfaceStopDevices() which will undo whatever was done
during qemuInterfaceStartDevices().
A function to "stop" a single device has also been added, and is
called from the appropriate place in qemuDomainDetachNetDevice(),
although this is currently unnecessary - the device is going to
immediately be deleted anyway, so any extra "deactivation" will be for
naught. The call is included for completeness, though, in anticipation
that in the future there may be some required action that *isn't*
nullified by deleting the device.
This patch is a part of a more complete fix for:
https://bugzilla.redhat.com/show_bug.cgi?id=1081461
Currently, MAC registration occurs during device creation, which is
early enough that, during live migration, you end up with duplicate
MAC addresses on still-running source and target devices, even though
the target device isn't actually being used yet.
This patch proposes to defer MAC registration until right before
the guest can actually use the device -- In other words, right
before starting guest CPUs.
Signed-off-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: Laine Stump <laine@laine.org>
qemuNetworkIfaceConnect() used to have a special case for
actualType='network' (a network with forward mode of route, nat, or
isolated) to call the libvirt public API to retrieve the bridge being
used by a network. That is no longer necessary - since all network
types that use a bridge and tap device now get the bridge name stored
in the ActualNetDef, we can just always use
virDomainNetGetActualBridgeName() instead.
(an audit of the two callers to qemuNetworkIfaceConnect() confirms
that it is never called for any other type of network, so the dead
code in the else statement (logging an internal error if it is called
for any other type of network) is eliminated in the process.)
Since virNetworkFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Coverity complained that because the cfg->macFilter call checked
net->ifname != NULL before calling ebtablesRemoveForwardAllowIn, then
the virNetDevOpenvswitchRemovePort call should have the same check.
However, if I move the ebtables call prior to the check for TYPE_DIRECT
(where there is a VIR_FREE(net->ifname)), then it seems Coverity is
happy. Since firewall info is tacked on last during setup, removing
it in the opposite order of initialization seems to be natural anyway
Ethernet interfaces in libvirt currently do not support bandwidth setting.
For example, following xml file for an interface will not apply these
settings to corresponding qdiscs.
<interface type="ethernet">
<mac address="02:36:1d:18:2a:e4"/>
<model type="virtio"/>
<script path=""/>
<target dev="tap361d182a-e4"/>
<bandwidth>
<inbound average="984" peak="1024" burst="64"/>
<outbound average="2000" peak="2048" burst="128"/>
</bandwidth>
</interface>
Signed-off-by: Anirban Chakraborty <abchak@juniper.net>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Hotplugging and hotunplugging char devices is only supported through
'-device' and the check for device capability should be independently.
Coverity also complains about 'tmpChr->info.alias' could be NULL and we
are dereferencing it but it somehow only in this case don't recognize
that the value is set by 'qemuAssignDeviceChrAlias' so it's clearly
false positive. Add sa_assert to make coverity happy.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
In qemuDomainDetachControllerDevice if the info.alias already exists
a call to qemuAssignDeviceControllerAlias would overwrite the existing
so avoid this possibility.
Prior patch removed the need for the virConnectPtr in the unplug
detach host path which caused ripple effect to remove in multiple
callers. The previous patch just left things as ATTRIBUTE_UNUSED -
this patch will remove the variable.
https://bugzilla.redhat.com/show_bug.cgi?id=1141732
Introduced by commit id '8f76ad99' the logic to detach a scsi_host
device (SCSI or iSCSI) fails when attempting to remove the 'drive'
because as I found in my investigation - the DelDevice takes care of
that for us.
The investigation turned up commits to adjust the logic for the
qemuMonitorDelDevice and qemuMonitorDriveDel processing for interfaces
(commit id '81f76598'), disk bus=VIRTIO,SCSI,USB (commit id '0635785b'),
and chr devices (commit id '55b21f9b'), but nothing with the host devices.
This commit uses the model for the previous set of changes and applies
it to the hostdev path. The call to qemuDomainDetachHostSCSIDevice will
return to qemuDomainDetachThisHostDevice handling either the audit of
the failure or the wait for the removal and then call into
qemuDomainRemoveHostDevice for the event, removal from the domain hostdev
list, and audit of the removal similar to other paths.
NOTE: For now the 'conn' param to +qemuDomainDetachHostSCSIDevice is left
as ATTRIBUTE_UNUSED. Removing requires a cascade of other changes to be
left for a future patch.
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>
Request erroring out from the backing chain traveller and drop qemu's
internal backing chain integrity tester.
The backing chain traveller reports errors by itself with possibly more
detail than qemuDiskChainCheckBroken ever could.
We also need to make sure that we reconnect to existing qemu instances
even at the cost of losing the backing chain info (this really should be
stored in the XML rather than reloaded from disk, but that needs some
work).
https://bugzilla.redhat.com/show_bug.cgi?id=1095636
When starting up the domain the domain's NICs are allocated. As of
1f24f682 (v1.0.6) we are able to use multiqueue feature on virtio
NICs. It breaks network processing into multiple queues which can be
processed in parallel by different host CPUs. The queues are, however,
created by opening /dev/net/tun several times. Unfortunately, only the
first FD in the row is labelled so when turning the multiqueue feature
on in the guest, qemu will get AVC denial. Make sure we label all the
FDs needed.
Moreover, the default label of /dev/net/tun doesn't allow
attaching a queue:
type=AVC msg=audit(1399622478.790:893): avc: denied { attach_queue }
for pid=7585 comm="qemu-kvm"
scontext=system_u:system_r:svirt_t:s0:c638,c877
tcontext=system_u:system_r:virtd_t:s0-s0:c0.c1023
tclass=tun_socket
And as suggested by SELinux maintainers, the tun FD should be labeled
as svirt_t. Therefore, we don't need to adjust any range (as done
previously by Guannan in ae368ebf) rather set the seclabel of the
domain directly.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Pass the source of the changed media instead of a complete disk
definition.
Note that the @disk argument now contains what @olddisk would contain.
The new source is passed as a virStorageSource struct.
When we are changing media (or doing other hotplug operations) we need
to setup cgroups, locking and seclabels on the new disk. This is a
multi-step process where every piece can fail. To simplify dealing with
this introduce qemuDomainPrepareDisk that similarly to
qemuDomainPrepareDiskChainElement initializes/tears down a whole new
disk to be used with the domain.
Additionally the function supports passing a different source struct for
media changes of cdroms that will be refactored later.
Currently, qemu driver uses qemuTranslateDiskSourcePool()
to translate disk volume information. This function is
general enough and could be used for other drivers as well,
so move it to conf/domain_conf.c along with its helpers.
- qemuTranslateDiskSourcePool: move to storage/storage_driver.c
and rename to virStorageTranslateDiskSourcePool,
- qemuAddISCSIPoolSourceHost: move to storage/storage_driver.c
and rename to virStorageAddISCSIPoolSourceHost,
- qemuTranslateDiskSourcePoolAuth: move to storage/storage_driver.c
and rename to virStorageTranslateDiskSourcePoolAuth,
- Update users of qemuTranslateDiskSourcePool to use a
new name.
During a QEMU live migration several warning messages about job
handling could be written to syslog on the destination host:
"entering monitor without asking for a nested job is dangerous"
The messages are written because the job handling during migration
uses hard coded asyncJob values in several places that are incorrect.
This patch passes the required asyncJob value around and prevents
the warnings as well as any issues that the warnings may be referring
to.
https://bugzilla.redhat.com/show_bug.cgi?id=1130089
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Otherwise this beautiful error would be overwritten when
the function is called with a really high rate number:
2014-07-28 12:51:47.920+0000: 2304: error : virCommandWait:2399 :
internal error: Child process (/sbin/tc class add dev vnet0 parent 1:
classid 1:1 htb rate 4294968kbps) unexpected exit status 1: Illegal "rate"
Usage: ... qdisc add ... htb [default N] [r2q N]
default minor id of class to which unclassified packets are sent {0}
r2q DRR quantums are computed as rate in Bps/r2q {10}
debug string of 16 numbers each 0-3 {0}
... class add ... htb rate R1 [burst B1] [mpu B] [overhead O]
[prio P] [slot S] [pslot PS]
[ceil R2] [cburst B2] [mtu MTU] [quantum Q]
rate rate allocated to this class (class can still borrow)
burst max bytes burst which can be accumulated during idle period {computed}
mpu minimum packet size used in rate computations
overhead per-packet size overhead used in rate computations
linklay adapting to a linklayer e.g. atm
ceil definite upper class rate (no borrows) {rate}
cburst burst but for ceil {computed}
mtu max packet size we create rate map for {1600}
prio priority of leaf; lowe
https://bugzilla.redhat.com/show_bug.cgi?id=1043735
Create the structures and API's to hold and manage the iSCSI host device.
This extends the 'scsi_host' definitions added in commit id '5c811dce'.
A future patch will add the XML parsing, but that code requires some
infrastructure to be in place first in order to handle the differences
between a 'scsi_host' and an 'iSCSI host' device.
Split virDomainHostdevSubsysSCSI further. In preparation for having
either SCSI or iSCSI data, create a union in virDomainHostdevSubsysSCSI
to contain just a virDomainHostdevSubsysSCSIHost to describe the
'scsi_host' host device
I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.
As we are doing with the enum structures, a cleanup in "src/qemu/"
directory was done now. All the enums that were defined in the
header files were converted to typedefs in this directory. This
patch includes all the adjustments to remove conflicts when you do
this kind of change. "Enum-to-typedef"'s conversions were made in
"src/qemu/qemu_{capabilities, domain, migration, hotplug}.h".
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.
A future patch will add two-phase block commit jobs; as the
mechanism for managing them is similar to managing a block copy
job, existing errors should be made generic enough to occur
for either job type.
* src/conf/domain_conf.c (virDomainHasDiskMirror): Update
comment.
* src/qemu/qemu_driver.c (qemuDomainDefineXML)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemuDomainBlockCopy): Update error
message.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Some of the APIs already return int since they can produce errors that
need to be propagated. For consistency reasons, this patch changes the
rest of the APIs to also return int even though they do not fail or
report any errors.
In general, we should only remove a backend after seeing DEVICE_DELETED
event for a corresponding frontend.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
In general, we should only remove a backend after seeing DEVICE_DELETED
event for a corresponding frontend. This doesn't make any difference for
disks attached using -drive or drive_add since QEMU automatically
removes their backends but it's still better to make our code
consistent. And it may start making difference in case we switch to
attaching disks using -blockdev.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
[1] reported that we are removing network's backend too early. I didn't
really get the reproducer but libvirt behaves strangely when a guest
does not confirm the removal, e.g., it does not support PCI hotplug. In
such case, detaching a network device leaves its frontend in place but
removes the backend, which makes the device unusable for the guest.
Moreover attaching the same device again succeeds and both the guest and
libvirt will see two network interfaces attached but only one of them is
actually working.
I checked with Paolo Bonzini and he confirmed we should only remove a
backend after seeing DEVICE_DELETED event for a corresponding frontend.
[1] https://www.redhat.com/archives/libvir-list/2014-March/msg01740.html
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
In "src/conf/domain_conf.h" there are many enum declarations. The
cleanup in this header filer was started, but it wasn't enough and
there are many other files that has enum variables declared. So, the
commit was starting to be big. This commit finish the cleanup in this
header file and in other files that has enum variables, parameters,
or functions declared.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/domain_conf.h" there are many enumerations (enum)
declarations to be converted as a typedef too. As mentioned before,
it's better to use a typedef for variable types, function types and
other usages. I think this file has most of those enum declarations
at "src/conf/". So, me and Eric Blake plan to keep the cleanups all
over the source code. This time, most of the files changed in this
commit are related to part of one file: "src/conf/domain_conf.h".
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
If QEMU supports DEVICE_DELETED event, we always call
qemuDomainRemoveDevice from the event handler. However, we will need to
push this call away from the main event loop and begin a job for it (see
the following commit), we need to make sure the device is fully removed
by the original thread (and within its existing job) in case the
DEVICE_DELETED event arrives before qemuDomainWaitForDeviceRemoval times
out.
Without this patch, device removals would be guaranteed to never finish
before the timeout because the could would be blocked by the original
job being still active.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The commit 84c59ffa improved the way we change ejectable media.
If for any reason the first "eject" didn't open the tray we
should return with error.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Move sharable PCI handling functions to domain_addr.[ch], and
change theirs prefix from 'qemu' to 'vir':
- virDomainPCIAddressAsString;
- virDomainPCIAddressBusSetModel;
- virDomainPCIAddressEnsureAddr;
- virDomainPCIAddressFlagsCompatible;
- virDomainPCIAddressGetNextSlot;
- virDomainPCIAddressReleaseSlot;
- virDomainPCIAddressReserveAddr;
- virDomainPCIAddressReserveNextSlot;
- virDomainPCIAddressReserveSlot;
- virDomainPCIAddressSetFree;
- virDomainPCIAddressSetGrow;
- virDomainPCIAddressSlotInUse;
- virDomainPCIAddressValidate;
The only change here is function names, the implementation itself
stays untouched.
Extract common allocation code from DomainPCIAddressSetCreate
into virDomainPCIAddressSetAlloc.
This uses the new QEMU_CAPS_HOST_PCI_MULTIDOMAIN capability when
present, for -devivce pci-assign, -device vfio-pci, and -pcidevice.
While creating tests for this new functionality, I noticed that the
xmls for two existing tests had erroneously specified an
until-now-ignored domain="0x0002", so I corrected those two tests, and
also added two failure tests to be sure that we alert users who
attempt to use a non-zero domain with a qemu that doesn't support it.
