Every domain that grabs a domain object to work over should
reference it to make sure it won't disappear meanwhile.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is basically turning qemuDomObjEndAPI into a more general
function. Other drivers which gets a reference to domain objects may
benefit from this function too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
just as what b8e25c35d7 did, we
fall back to the ACPI method when the guest agent is unresponsive
in qemuDomainReboot().
Signed-off-by: YueWenyuan <yuewenyuan@huawei.com>
Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Because packets going through the egress from a bridge (where our
bandwidth limiting takes place) have no information about which
interface they came from, the QoS rules that we create instead
use the source MAC address of the packets to make their decisions
about which QDisc the packet should be in.
One flaw in this is that when a guest changed the MAC address it
used, packets from the guest would no longer be put into the
correct QDisc, but would instead be put in an "unprivileged"
class, resulting in the bandwidth "floor" (minimum guaranteed)
being no longer honored.
Now that libvirt has infrastructure to capture and respond to
RX_FILTER_CHANGE events from qemu (sent whenever a guest
interface modifies its MAC address, among other things), we can
notice when a guest MAC address changes, and update the QoS rules
accordingly, so that bandwidth floor is honored even after a
guest MAC address change.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
qemuDomainSetMemoryFlags() would allow to set the initial memory greater
than the <maxMemory> field. While the configuration would not work as
memory hotplug requires NUMA to be enabled and the
qemuDomainSetMemoryFlags() API does not work on NUMA guests this just
fixes a corner case.
The fix is still worth though as it allows to induce an invalid
configuration and make the VM vanish on libvirt restart.
Additionally this tweaks error message to be more accurate.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
This needs to specified in way too many places for a simple validation
check. The ostype/arch/virttype validation checks later in
DomainDefParseXML should catch most of the cases that this was covering.
https://bugzilla.redhat.com/show_bug.cgi?id=1209948
So we have this bug. The virConnectGetDomainCapabilities() API
performs a couple of checks before it produces any result. One of
the checks is if the architecture requested by user can be run by
the binary (again user provided). However, the check is pretty
dumb. It merely compares if the default binary architecture
matches the one provided by user. However, a qemu binary can run
multiple architectures. For instance: qemu-system-ppc64 can run:
ppc, ppcle, ppc64, ppc64le and ppcemb. The default is ppc64, so
if user requested something else, like ppc64le, the check would
have failed without obvious reason.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When a qemu domain is to be rebooted, from outside, at libvirt
level it looks like regular shutdown. To really restart the
domain, libvirt needs to issue reset command on the monitor once
SHUTDOWN event appeared. So, in order to differentiate bare
shutdown and reboot libvirt uses a variable within domain private
data. It's called fakeReboot. When the reboot API is called, the
variable is set, but when the shutdown API is called it must be
cleared out. But it was not for every possible case. So if user
called virDomainReboot(), and there was no ACPI daemon running
inside the guest (so guest didn't initiated shutdown sequence)
and then virDomainShutdown(mode=agent) was called bad thing
happened. We remembered the fakeReboot and instead of shutting
the domain down, we just rebooted it.
Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com>
Signed-off-by: Wang Yufei <james.wangyufei@huawei.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Rather than erroring out make the best attempt to retrieve other data if
disks are inaccessible or missing. The failure will still be logged
though.
Since the bulk stats API is called on multiple domains an error like
this makes the API unusable. This regression was introduced by commit
596a137134
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1209394
After set memory parameters for running domain, save the change to live
xml is needed otherwise it will disappear after restart libvirtd.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1211548
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Apparently for Xen-devel 'index' is a global and causes a build failure,
so just use the shortened 'idx' instead to avoid the conflict.
Signed-off-by: John Ferlan <jferlan@redhat.com>
QEMU does not abandon the mirror. The job carries on in the synchronised
phase and it might be either pivoted again or cancelled. The commit
hints that the described behavior was happening in a downstream version.
If the command returns false there are two possible options:
1) qemu did not reach the point where it would ask the block job to
pivot
2) pivotting failed in the actual qemu coroutine
If either of those would happen we return failure and reset the
condition that waits for the block job to complete. This makes the API
fail but in case where qemu would actually abandon the mirror the fact
is notified via the event and handled asynchronously.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1202704
qemuDomainBlockJobImpl become an unmaintainable mess over the years of
adding new stuff to it. This patch starts splitting up individual
functions from it until it can be killed entirely.
In bulk this will add lines of code rather than delete them but it will
be traded for maintainability.
Previously we checked that the vcpu we are trying to set is in range of
the number of threads presented by qemu. The problem is that if the VM
is offline the count is 0. Since the condition subtracted 1 from the
count the number would overflow and the check would never trigger.
Change the condition for more sensible ones with specific error
messages.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1208434
This patch adds checks for empty bitmaps right after the calls of
virBitmapParse. These only include spots where set API's are called and
where domain's XML is parsed.
Also, it partially reverts commit 983f5a which added a check for
invalid nodeset "0,^0" into virBitmapParse function. This change broke
the logic, as an empty bitmap should not cause an error.
https://bugzilla.redhat.com/show_bug.cgi?id=1210545
Future IOThread setting patches would copy the code anyway, so create
and generalize the adding of pindef for the vcpu and the pinning of the
thread into their own APIs.
Future IOThread setting patches would copy the code anyway, so create
and generalize a delete cgroup and pindef for the vcpu into its own API.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Future IOThread setting patches would copy the code anyway, so create
and generalize the add the vcpu to a cgroup into its own API.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Support for drive-reopen was never present in the upstream code so we
don't need to pause the VM when doing the block pivot. Kill all the
code related to this semi-upstream artifact.
Currently we check qemuCaps before starting the block job. But qemuCaps
isn't available on a stopped domain, which means we get a misleading
error message in this case:
# virsh domstate example
shut off
# virsh blockjob example vda
error: unsupported configuration: block jobs not supported with this QEMU binary
Move the qemuCaps check into the block job so that we are guaranteed the
domain is running.
Signed-off-by: Michael Chapman <mike@very.puzzling.org>
https://bugzilla.redhat.com/show_bug.cgi?id=1206479
As described in virDomainBlockCopy() parameters description, the
VIR_DOMAIN_BLOCK_COPY_GRANULARITY parameter may require the value to
have some specific attributes (e.g. be a power of two or fall within a
certain range). And in qemu, a power of two is required. However, our
code does not check that and let qemu operation fail. Moreover, the
virsh man page is not as exact as it could be in this respect.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
virDomainHasDiskMirror() currently detects only jobs that add the mirror
elements. Since some operations like migration are interlocked by
existing block jobs on the given domain the check needs to be
instrumented to check regular jobs too.
This patch renames virDomainHasDiskMirror to virDomainHasDiskBlockjob
and adds an argument that allows to select that it returns true only for
block copy jobs as those interlock making the domain persistent.
Other two uses trigger on any block job type.
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
If any disk of a VM was involved in a (copy) block job we refused to do
a snapshot. As not only copy jobs interlock snapshots and the
interlocking is applicable to individual disks only we can make the
check in a more individual fashion and interlock all block job types
supported by libvirt.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1203628
In the order of appearance:
* MAX_LISTEN - never used
added by 23ad665c (qemud) and addec57 (lock daemon)
* NEXT_FREE_CLASS_ID - never used, added by 07d1b6b
* virLockError - never used, added by eb8268a4
* OPENVZ_MAX_ARG, CMDBUF_LEN, CMDOP_LEN
unused since the removal of ADD_ARG_LIT in d8b31306
* QEMU_NB_PER_CPU_STAT_PARAM - unused since 897808e
* QEMU_CMD_PROMPT, QEMU_PASSWD_PROMPT - unused since 1dc10a7
* TEST_MODEL_WORDSIZE - unused since c25c18f7
* TEMPDIR - never used, added by 714bef5
* NSIG - workaround around old headers
added by commit 60ed1d2
unused since virExec was moved by commit 02e8691
* DO_TEST_PARSE - never used, added by 9afa006
* DIFF_MSEC, GETTIMEOFDAY - unused since eee6eb6
When the synchronous pivot option is selected, libvirt would not update
the backing chain until the job was exitted. Some applications then
received invalid data as their job serialized first.
This patch removes polling to wait for the ABORT/PIVOT job completion
and replaces it with a condition. If a synchronous operation is
requested the update of the XML is executed in the job of the caller of
the synchronous request. Otherwise the monitor event callback uses a
separate worker to update the backing chain with a new job.
This is a regression since 1a92c71910
When the ABORT job is finished synchronously you get the following call
stack:
#0 qemuBlockJobEventProcess
#1 qemuDomainBlockJobImpl
#2 qemuDomainBlockJobAbort
#3 virDomainBlockJobAbort
While previously or while using the _ASYNC flag you'd get:
#0 qemuBlockJobEventProcess
#1 processBlockJobEvent
#2 qemuProcessEventHandler
#3 virThreadPoolWorker
Later on I'll be adding a condition that will allow to synchronise a
SYNC block job abort. The approach will require this code to be called
from two different places so it has to be extracted into a helper.
Commit 1a92c719 moved code to handle block job events to a different
function that is executed in a separate thread. The caller of
processBlockJob handles locking and unlocking of @vm, so the we should
not do it in the function itself.
The block copy API takes the speed in bytes/s rather than MiB/s that was
the prior approach in virDomainBlockRebase. We correctly converted the
speed to bytes/s in the old API but we still called the common helper
virDomainBlockCopyCommon with the unadjusted variable.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1207122
When getting info on NUMA parameters for domain,
virCgroupGetCpusetMems() may be called. However, as of 43b67f2e
the call is guarded by check if memory controller is present.
Even though it may be not obvious instantly, NUMA parameters are
stored under cpuset controller. Therefore the check needs to look
like this:
if (!virCgroupHasController(priv->cgroup,
VIR_CGROUP_CONTROLLER_CPUSET) ||
virCgroupGetCpusetMems(priv->cgroup, &nodeset) < 0) {
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Blockcopy to non-file destination is not supported according the code,
but a 'goto endjob' is missed after checking the destination.
This leads to calling drive-mirror with wrong parameters.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1206406
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
We don't have to modify cpuset.mems on hosts without NUMA. It also
fixes an error message that you get instead of success if you trying
update vcpus of a guest on a host without NUMA.
error: internal error: NUMA isn't available on this host
Signer-off-by: Pavel Hrdina <phrdina@redhat.com>
We should call virDomainLiveConfigHelperMethod ASAP because this
function transfers VIR_DOMAIN_AFFECT_CURRENT to VIR_DOMAIN_AFFECT_LIVE
or VIR_DOMAIN_AFFECT_CONFIG. All other additional checks for those two
flags should consider that the user give us VIR_DOMAIN_AFFECT_CURRENT.
Remove the unnecessary check whether the domain is live in case of
VIR_DOMAIN_VCPU_GUEST because this check is done by
virDomainLiveConfigHelperMethod.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
While debugging the support for responding to qemu RX_FILTER_CHANGED
events, I had changed the "ignoring this event" log message from
VIR_DEBUG to VIR_WARN, but forgot to change it back before
pushing. Since many guest OSes make enough changes to multicast lists
and/or promiscuous mode settings to trigger this message, it's
starting to show up as a red herring in bug reports.
Add a few helpers that allow to operate with memory device definitions
on the domain config and use them to implement memory device coldplug in
the qemu driver.
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.
Wikipedia's list of common misspellings [1] has a machine-readable
version. This patch fixes those misspellings mentioned in the list
which don't have multiple right variants (as e.g. "accension", which can
be both "accession" and "ascension"), such misspellings are left
untouched. The list of changes was manually re-checked for false
positives.
[1] https://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Issue #1 - A call to virBitmapNew did not check if the allocation
failed which could lead to a NULL dereference
Issue #2 - When deleting the pin entries from the config file, the
code loops from the number of elements down to the "new" vcpu count;
however, the pin id values are numbered 0..n-1 not 1..n, so the "first"
pin attempt would never work. Luckily the check was for whether the
incoming 'n' (vcpu id) matched the entry in the array from 0..arraysize
rather than a dereference of the 'n' entry
The function needs a pointer to the network to get list of DHCP
leases. The pointer is obtained via virNetworkLookupByName() which
requires callers to free the returned network once no longer needed.
Otherwise it's leaked.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1199182 documents that
after a series of disk snapshots into existing destination images,
followed by active commits of the top image, it is possible for
qemu 2.2 and earlier to end up tracking a different name for the
image than what it would have had when opening the chain afresh.
That is, when starting with the chain 'a <- b <- c', the name
associated with 'b' is how it was spelled in the metadata of 'c',
but when starting with 'a', taking two snapshots into 'a <- b <- c',
then committing 'c' back into 'b', the name associated with 'b' is
now the name used when taking the first snapshot.
Sadly, older qemu doesn't know how to treat different spellings of
the same filename as identical files (it uses strcmp() instead of
checking for the same inode), which means libvirt's attempt to
commit an image using solely the names learned from qcow2 metadata
fails with a cryptic:
error: internal error: unable to execute QEMU command 'block-commit': Top image file /tmp/images/c/../b/b not found
even though the file exists. Trying to teach libvirt the rules on
which name qemu will expect is not worth the effort (besides, we'd
have to remember it across libvirtd restarts, and track whether a
file was opened via metadata or via snapshot creation for a given
qemu process); it is easier to just always directly ask qemu what
string it expects to see in the first place.
As a safety valve, we validate that any name returned by qemu
still maps to the same local file as we have tracked it, so that
a compromised qemu cannot accidentally cause us to act on an
incorrect file.
* src/qemu/qemu_monitor.h (qemuMonitorDiskNameLookup): New
prototype.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskNameLookup):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorDiskNameLookup): New function.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskNameLookup)
(qemuMonitorJSONDiskNameLookupOne): Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit)
(qemuDomainBlockJobImpl): Use it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Only selected fields from the disk source were copied when cold updating
source in a CDROM drive. When such drive was backed by a network file
this resulted into corruption of the definition:
<disk type='network' device='cdrom'>
<driver name='qemu' type='raw' cache='none'/>
<source protocol='gluster' name='gluster-vol1(null)'>
<host name='localhost'/>
</source>
<target dev='vdc' bus='virtio'/>
<readonly/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
</disk>
Update the whole source instead of cherry-picking elements.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1166024
By querying the qemu guest agent with the QMP command
"guest-network-get-interfaces" and converting the received JSON
output to structured objects.
Although "ifconfig" is deprecated, IP aliases created by "ifconfig"
are supported by this API. The legacy syntax of an IP alias is:
"<ifname>:<alias-name>". Since we want all aliases to be clubbed
under parent interface, simply stripping ":<alias-name>" suffices.
Note that IP aliases formed by "ip" aren't visible to "ifconfig",
and aliases created by "ip" do not have any specific name. But
we are lucky, as qemu guest agent detects aliases created by both.
src/qemu/qemu_agent.h:
* Define qemuAgentGetInterfaces
src/qemu/qemu_agent.c:
* Implement qemuAgentGetInterface
src/qemu/qemu_driver.c:
* New function qemuGetDHCPInterfaces
* New function qemuDomainInterfaceAddresses
src/remote_protocol-sructs:
* Define new structs
tests/qemuagenttest.c:
* Add new test: testQemuAgentGetInterfaces
Test cases for IP aliases, 0 or multiple ipv4/ipv6 address(es)
Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>
Patch 51f9f03a4c introduces a regression
where if a blockCommit operation fails the disk is still marked as being
part of a block job but can't be unmarked later.
As pointed out by jtomko in his review of the IOThreads pinning code:
http://www.redhat.com/archives/libvir-list/2015-March/msg00495.html
there are some comments sprinkled in indicating IOThreads were using
the same structure as the VcpuPin code...
This is the first patch of a few that will change the virDomainVcpuPin*
structures and code to just virDomainPin* - starting with the data
structure naming...
During his review of the iothreads pin setting code, Pavel noted that
there was a potential memory leak with respect to how the newVcpuPin
is handled and the goto endjob's in failure paths which would not free
the memory. For reference, See:
http://www.redhat.com/archives/libvir-list/2015-March/msg00415.html
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.
Surprisingly we did not grab a VM job when a block job finished and we'd
happily rewrite the backing chain data. This made it possible to crash
libvirt when queueing two backing chains tightly and other badness.
To fix it, add yet another handler to the helper thread that handles
monitor events that require a job.
Now that qemuDomainBlocksStatsGather provides functions of both
qemuMonitorGetBlockStatsParamsNumber and qemuMonitorGetBlockStatsInfo we
can reuse it and kill a lot of code.
Additionally as a bonus qemuDomainBlockStatsFlags will now support
summary statistics so add a statement to the virsh man page about that.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1142636
In the LXC driver, if the disk path is not provided the API returns
total statistics for all disks of the domain. With the new text monitor
implementation this can be now done in the qemu driver too.
Add code that wil total the stats for all disks if the path is not
provided.
Extract the code to look up the disk alias and return the block stats
struct so that it can be reused later in qemuDomainBlockStatsFlags.
The function uses qemuMonitorGetAllBlockStatsInfo instead of
qemuMonitorGetBlockStatsInfo.
By adding a call and check of return of virBitmapToData to the
IOThreads code, my Coverity checker lets me know qemuDomainHelperGetVcpus
also needs to check the status...
Depending on the flags passed, either attempt to return the active/live
IOThread data for the domain or the config data.
The active/live path will call into the Monitor in order to get the
IOThread data and then correlate the thread_id's returned from the
monitor to the currently running system/threads in order to ascertain
the affinity for each iothread_id.
The config path will map each of the configured IOThreads and return
any configured iothreadspin data
Signed-off-by: John Ferlan <jferlan@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>
When the domain's source disk type is network, if source protocol is rbd
or sheepdog, the 'if().. break' will end the current case, which lead to
miss check the driver type is raw or qcow2. Libvirt will allow to create
internal snapshot for a running domain with raw format disk which based
on rbd storage.
While both protocols support internal snapshots of the disk qemu is not
able to use it as it requires some place to store the memory image. The
check if the disk is backed by a qcow2 image needs to be executed
always.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1179533
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Previously when a domain would get stuck in a domain job due to a
programming mistake we'd report the following control state:
$ virsh domcontrol domain
occupied (1424343406.150s)
The timestamp is invalid as the monitor was not entered for that domain.
We can use that to detect that the domain has an active job and report a
better error instead:
$ virsh domcontrol domain
error: internal (locking) error
We have two different places that needs to be updated while touching
code for allocation spice ports. Add a bool option to
'qemuProcessSPICEAllocatePorts' function to switch between true and fake
allocation so we can use this function also in qemu_driver to generate
native domain definition.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The problem here was that when opening a channel, we were checking
whether the channel given is alias (can't be NULL for running domain) or
it's name, which can be NULL (for example with spicevmc). In case of
such domain qemuDomainOpenChannel() made the daemon crash.
STREQ_NULLABLE() is safe to use since the code in question is wrapped in
"if (name)" and is more readable, so use that instead of checking for
non-NULL "vm->def->channels[i]->target.name".
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
NUMA enabled guest configuration explicitly specifies memory sizes for
individual nodes. Allowing the virDomainSetMemoryFlags API (and friends)
to change the total doesn't make sense as the individual node configs
are not updated in that case.
Forbid use of the API in case NUMA is specified.
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().
