Andrea Bolognani [Tue, 29 Mar 2022 09:43:36 +0000 (11:43 +0200)]
meson: Use dicts to initialize cfg_data objects
Instead of creating an empty object and then setting keys one
at a time, it is possible to pass a dict object to
configuration_data(). This is nicer because it doesn't require
repeating the name of the cfg_data object over and over.
There is one exception: the 'conf' object, where we store values
that are used directly by C code. In that case, using a dict
object is not feasible for two reasons: first of all, replacing
the set_quoted() calls would result in awkward code with a lot
of calls to format(); moreover, since code that modifies it is
sprinkled all over the place, refactoring it would probably
make things more complicated rather than simpler.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Andrea Bolognani [Mon, 28 Mar 2022 13:26:11 +0000 (15:26 +0200)]
qemu: Use real defaults for user and group in qemu.conf
The default values used by the library are determined at configure
time based on a number of factors, and we should reflect them in
the installed configuration file to make the comments it contains
more useful.
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/263 Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Andrea Bolognani [Mon, 28 Mar 2022 15:24:47 +0000 (17:24 +0200)]
util: Improve macOS workaround
Since the workaround is specific to macOS, only disable compiler
warnings when building on that platform.
While at it, update the comment to reflect the fact that the
workaround is needed for all versions of the OS, including the
modern ones that we currently target.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Recent refactor (v8.1.0-217-ga193f4bef6) generalized job related enums
and functions by changing "qemu" prefix to "vir" and moving them to
src/hypervisor/domain_job.[ch]. This was in most cases a good thing, but
async job phases are driver specific and the corresponding functions
remained in src/qemu/qemu_domainjob.[ch], but still their prefix was
changed to "vir". Let's change it back to "qemu".
Signed-off-by: Jiri Denemark <jdenemar@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Michal Privoznik [Wed, 30 Mar 2022 11:54:50 +0000 (13:54 +0200)]
virsh: Fix integer overflow in allocpages
I've came across an aarch64 system which supports hugepages up to
16GiB of size. However, I was unable to allocate them using
virsh allocpages. This is because cmdAllocpages() uses
vshCommandOptScaledInt(), which scales passed value into bytes,
but since the virNodeAllocPages() expects size in KiB the
variable holding bytes is then divided by 1024. However, the
limit for the biggest value passed to vshCommandOptScaledInt() is
UINT_MAX which is now obviously wrong, as it needs to be UINT_MAX
* 1024.
The same bug is in completer. But here, let's use ULLONG_MAX so
that we don't have to care about it anymore.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Jonathon Jongsma [Tue, 29 Mar 2022 19:24:36 +0000 (14:24 -0500)]
qemu: fix hotplug for multiqueue vdpa net device
While commit a5e659f0 removed the restriction against multiple queues
for the vdpa net device, there were some missing pieces. Configuring a
device statically and then starting the domain worked as expected, but
hotplugging a device didn't have the expected multiqueue support
enabled. Add the missing bits.
Consider the following device xml:
<interface type="vdpa">
<mac address="00:11:22:33:44:03" />
<source dev="/dev/vhost-vdpa-0" />
<model type="virtio" />
<driver queues='2' />
</interface>
Without this patch, hotplugging the above XML description resulted in
the following:
{"execute":"netdev_add","arguments":{"type":"vhost-vdpa","vhostdev":"/dev/fdset/0","id":"hostnet1"},"id":"libvirt-392"}
{"execute":"device_add","arguments":{"driver":"virtio-net-pci","netdev":"hostnet1","id":"net1","mac":"00:11:22:33:44:03","bus":"pci.5","addr":"0x0"},"id":"libvirt-393"}
With the patch, hotplugging results in the following:
{"execute":"netdev_add","arguments":{"type":"vhost-vdpa","vhostdev":"/dev/fdset/0","queues":2,"id":"hostnet1"},"id":"libvirt-392"}
{"execute":"device_add","arguments":{"driver":"virtio-net-pci","mq":true,"vectors":6,"netdev":"hostnet1","id":"net1","mac":"00:11:22:33:44:03","bus":"pci.5","addr":"0x0"},"id":"libvirt-393"}
John Levon [Tue, 29 Mar 2022 17:38:11 +0000 (18:38 +0100)]
fix documentation for sockets topology
In 0895a0e, it was noted that the "sockets" value in the topology
section of capabilities reflects not the number of sockets per NUMA
node, not the total number.
Unfortunately, the fix was applied to the wrong place: the domain XML
format documentation, not that for the capabilities output. And, in
fact, the domain XML interprets "sockets" as the total number, not a
per-node value.
Back out this change in favour of a note in the capabilities
documentation instead.
Fixes: 0895a0e75d13874254218e16dc66dcad673671d3 Suggested-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: John Levon <john.levon@nutanix.com>
Michal Privoznik [Mon, 28 Mar 2022 11:29:19 +0000 (13:29 +0200)]
virfile: Report error when changing pipe size fails
When changing the size of pipe that virFileWrapperFdNew() creates
we start at 1MiB and if that fails because it's above the system
wide limit we get EPERM and continue with half of the size.
However, we might get another error in which case we should
report proper system error and return failure from
virFileWrapperFdNew().
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Peter Krempa [Mon, 21 Mar 2022 14:17:47 +0000 (15:17 +0100)]
qemu: command: Override device definition according to the namespace config
Apply the user-requested changes to the device definition as requested
by the <qemu:deviceOverride> element from the custom qemu XML namespace.
Closes: https://gitlab.com/libvirt/libvirt/-/issues/287 Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Peter Krempa [Mon, 21 Mar 2022 11:02:53 +0000 (12:02 +0100)]
docs: drvqemu: Document overriding of device properties
Upcoming patches will add possibility to override configuration of a
device with custom properties as a more versatile replacement to using
QEMU's '-set' parameter, which doesn't work when we use JSON to
instantiate devices.
Describe the XML used for the override as well as expectations of
upstream support in case something breaks.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Claudio Fontana [Fri, 25 Mar 2022 15:10:19 +0000 (16:10 +0100)]
virfile: set pipe size in virFileWrapperFdNew to improve throughput
currently the only user of virFileWrapperFdNew is the qemu driver;
virsh save is very slow with a default pipe size.
This change improves throughput by ~400% on fast nvme or ramdisk.
Best value currently measured is 1MB, which happens to be also
the kernel default for the pipe-max-size.
Signed-off-by: Claudio Fontana <cfontana@suse.de> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Michal Privoznik [Mon, 21 Mar 2022 12:33:06 +0000 (13:33 +0100)]
qemu_tpm: Do async IO when starting swtpm emulator
When vTPM is secured via virSecret libvirt passes the secret
value via an FD when swtpm is started (arguments --key and
--migration-key). The writing of the secret into the FDs is
handled via virCommand, specifically qemu_tpm calls
virCommandSetSendBuffer()) and then virCommandRunAsync() spawns a
thread to handle writing into the FD via
virCommandDoAsyncIOHelper. But the thread is not created unless
VIR_EXEC_ASYNC_IO flag is set, which it isn't. In order to fix
it, virCommandDoAsyncIO() must be called.
The credit goes to Marc-André Lureau
<marcandre.lureau@redhat.com> who has done all the debugging and
proposed fix in the bugzilla.
Paolo Bonzini [Thu, 24 Mar 2022 09:48:39 +0000 (10:48 +0100)]
qemu: add support for tsc.on_reboot element
QEMU 7.0.0 adds a new property tsc-clear-on-reset to x86 CPU, corresponding
to Libvirt's <tsc on_reboot="clear"/> element. Plumb it in the validation,
command line handling and tests.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Paolo Bonzini [Thu, 24 Mar 2022 09:48:38 +0000 (10:48 +0100)]
domain: add tsc.on_reboot element
Some versions of Windows hang on reboot if their TSC value is greater
than 2^54. The workaround is to reset the TSC to a small value. Add
to the domain configuration an attribute for this. It can be used
by QEMU and in principle also by ESXi, which has a property called
monitor_control.enable_softResetClearTSC as well.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Paolo Bonzini [Thu, 24 Mar 2022 09:36:56 +0000 (10:36 +0100)]
tests: add dependencies to meson declaration
Make sure that all tests are run after the helpers and mocks are
(re)built. This enables for example using "meson test" as the
command line passed to "git bisect run".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Paolo Bonzini [Thu, 24 Mar 2022 10:53:04 +0000 (11:53 +0100)]
meson: do not look for libparted if not requested
libparted_dep is not used if -Dstorage_disk=disabled. Do not
bother looking for this library if the disk storage backend was
not requested.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
These enums are essentially the same and always sorted in the
same order in every hypervisor with jobs. They can be generalized
by using the qemu enums as the main ones as they are the most
extensive.
Signed-off-by: Kristina Hanicova <khanicov@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The prealloc-threads is property of memory-backend class which is
parent to the other three classes memory-backend-{ram,file,memfd}.
Therefore the property is present for all, or none if QEMU is
older than v5.0.0-rc0~75^2~1^2~3 which introduced the property.
Anyway, the .reserve property is the same story, and we chose
memory-backend-file to detect it, so stick with our earlier
decision and use the same backend to detect this new property.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Michal Privoznik [Mon, 21 Mar 2022 15:49:25 +0000 (16:49 +0100)]
conf: Introduce memory allocation threads
Since its v5.0.0 release QEMU is capable of specifying number of
threads used to allocate memory. It defaults to 1, which may be
too low for humongous guests with gigantic pages.
In general, on QEMU cmd line level it is possible to use
different number of threads per each memory-backend-* object, in
practical terms it's not useful. Therefore, use <memoryBacking/>
to set guest wide value and let all memory devices 'inherit' it,
silently. IOW, don't introduce per device knob because that would
only complicate things for a little or no benefit.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Erik Skultety [Tue, 22 Mar 2022 11:31:49 +0000 (12:31 +0100)]
ci: integration: Rename all Avocado standard stream log files to *.log
By default, stdout/stderr Avocado test log files do not have any file
extension which confuses GitLab's web UI to mangle the MIME type for
these and so the browser will never offer the option to open such file
from in a text editor rather than dowloading it.
Since GitLab sets a proper MIME for .txt and .log file extensions,
rename all Avocado log files without an extension to *.log . This pairs
nicely with the coredumpctl info file which we already name as
'coredumpctl.txt' because of this.
Signed-off-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Erik Skultety [Mon, 21 Mar 2022 17:05:16 +0000 (18:05 +0100)]
ci: integration: Collect stack traces with coredumpctl
Some Red Hat-like distros have cores limited with a soft limit of 0
which means that neither a stack trace nor a core file will be
available. Since we want the stack trace we need to set the core limit
with systemd globally to unlimited/infinity.
Signed-off-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Erik Skultety [Mon, 21 Mar 2022 12:51:53 +0000 (13:51 +0100)]
ci: Define the integration job tag dynamically via a variable
Custom runners are private to a project, so naturally forks cannot run
any workloads on these. The integration test suite which requires
access to our custom runner is naturally disabled on forks and can be
enabled by setting LIBVIRT_CI_INTEGRATION=1.
The problem is that the current integration jobs definitions have tags
statically defined as 'redhat-vm-host'. If users are going to supply
their own private runners for their forks, they can define whatever
tags they want with it and so unless they add 'redhat-vm-host' to their
own runner's tags, the pipeline won't run.
To solve this, define the integration job tag using a variable. The
repo config will use the value defined in the job for the variable
while users can override the value easily on a project/pipeline level
thanks to GitLab's CI variable precedence [1].
The updateLock is a R/W lock held by anything which needs to read or
modify the rules associated with an NWFilter.
APIs for defining/undefining NW filters rules hold a write lock on
updateLock.
APIs for creating/deleting NW filter bindings hold a read lock on
updateLock, which prevents define/undefine taking place concurrently.
The problems arise when we attempt to creating two NW filter bindings in
parallel.
Thread 1 can acquire the mutex for filter A
Thread 2 can acquire the mutex for filter B
Consider if filters A and B both reference filters C and D, but in
different orders:
Filter A
-> filter C
-> filter D
Filter B
-> filter D
-> filter C
Thread 1 will try to acquire locks in order A, C, D while thread 1 will
try to acquire in order A, D, C. Deadlock can still occur.
Think we can sort the list of filters before acquiring locks on all of
them ? Nope, we allow arbitrary recursion:
Filter A
-> filter C
-> filter E
-> filter F
-> filter H
-> filter K
-> filter D
-> filter G
-> filter I
So we can't tell from looking at 'A' which filters we're going to
need to lock. We can only see the first level of filters references
and we need to lock those before we can see the second level of
filters, etc.
We could probably come up with some cleverness to address this but
it isn't worth the time investment. It is simpler to just keep the
process of creating NW filter bindings totally serialized.
Using two separate locks for this serialization though is pointless.
Every code path which gets a read(updateLock) will go on to hold
updateMutex. It is simpler to just hold write(updateLock) and
get rid of updateMutex. At that point we don't need updateLock
to be a R/W lock, it can be a plain mutex.
Thus this patch gets rid of the current updateLock and updateMutex
and introduces a new top level updateMutex.
This has a secondary benefit of introducing fairness into the
locking. With a POSIX R/W lock, you get writer starvation if
you have lots of readers. IOW, if we call virNWFilterBIndingCreate
and virNWFilterBindingDelete in a tight loop from a couple of
threads, we can prevent virNWFilterDefine from ever acquiring
a write lock.
Getting rid of the R/W lock gives us FIFO lock acquisition
preventing starvation of any API call servicing.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
In case we are snapshotting at least one 'manual' disk we will pause the
VM and keep it paused.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1866400 Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Peter Krempa [Fri, 4 Mar 2022 14:50:19 +0000 (15:50 +0100)]
conf: snapshot: Introduce 'manual' mode for snapshot of a disk
The idea of the manual mode is to allow a synchronized snapshot in cases
when the storage is outsourced to an unmanaged storage provider which
requires cooperation with snapshotting.
The mode will instruct the hypervisor to pause along when the other
components are snapshotted and the 'manual' disk can be snapshotted
along. This increases latency of the snapshot but allows them in
otherwise impossible situations.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
The code parsing thue query-cpu-definitions response will short-circuit
the for loop in the case where usable=yes, resulting in us failing to
parse the CPU deprecation flag.
IOW, we only reported deprecations in domain capabilities for CPU models
which were not runnable on the host.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
In the not so distant past, the lock ordering in
virNWFilterLockIface() was as follows: global mutex ifaceMapLock
was acquired, then internal representation of given interface was
looked up in a hash table (or created brand new if none was
found), the global lock was released and the lock of the
interface was acquired.
But this was mistakenly changed as the function was rewritten to
use automatic mutexes, because now the global lock is held
throughout the whole run of the function and thus the interface
specific lock is acquired with the global lock held. This results
in a deadlock.
Fixes: dd8150c48dcf94e8d3b0481be08eeef822b98b02 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Tested-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com>
qemu_process: Be nicer to killing QEMU when probing caps
The qemuProcessQMPStop() function is intended to kill this dummy
QEMU process we started only for querying capabilities.
Nevertheless, it may be not plain QEMU binary we executed, but
in fact it may be a memcheck tool (e.g. valgrind) that executes
QEMU later. By switching to virProcessKillPainfully() we allow
this wrapper tool to exit gracefully.
Another up side is that virProcessKillPainfully() reports an
error so no need for us to VIR_ERROR() ourselves.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
ci: only run integration tests if $LIBVIRT_CI_INTEGRATION=1 is set
Right now the jobs have no rules so they will always be created in
a pipeline. If the user's fork has no runner configured, then the
jobs will never be able to execute and the pipeline will not finish.
Even on upstream, there might be times the runner has to be taken
offline for maint work, or unexpectedly fail. We need a quick way
to disable the integration tests if we decide we don't want to
have pipelines queued until the runner comes back online.
Both these problems can be addressed by requiring a environment
variable to be set
LIBVIRT_CI_INTEGRATION=1
This can be done in the GitLab repo CI settings for permanent
enablement. Alternatively it can be set for individual
scheduled jobs, or using a push option
git push -o ci.variable=LIBVIRT_CI_INTEGRATION=1
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com>
Although we split out jobs across many files, the template / job
namespace is global, so we should use something more specific
than '.tests' as the template name.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com>
Michal Privoznik [Fri, 18 Mar 2022 10:36:47 +0000 (11:36 +0100)]
virnwfilterobj: Don't use virObjectLockGuard() with virNWFilterObj
While its name would suggest that virNWFilterObj is an actual
virObject it is not. It's a plain structure (with virMutex as its
first member). Therefore, when locking the struct
virObjectLockGuard() can' be used and virLockGuardLock() must be
used instead.
Spotted-by: Martin Kletzander <mkletzan@redhat.com> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com>
qemu: use qemuDomainSaveStatus() and remove qemuDomainObjSaveStatus()
It does not make sense to have both of these, since one of them
is only a wrapper for the other one. I decided to preserve the
more general one, which requires only virDomainObj and rewrote it
a bit, so that it pulls the qemu driver from privateData.
conf: fix inverted parameters in hash iterator callbacks
virHashTableForEach unhelpfully has payload/key args in
its callback reversed compared to g_hash_table_foreach.
When converting from one to the other the semantics
change but you don't get a compile error
Reviewed-by: Erik Skultety <eskultet@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Tim Wiederhake [Thu, 17 Mar 2022 10:30:16 +0000 (11:30 +0100)]
esx_stream: Fix NULL dereferences
A wrong reordering caused "priv" to be derefenced before the NULL-check
in esxStreamSend and esxStreamRecvFlags.
Fixes: 12e19f172d2a908eec2a4557202ff764cdbb951e Signed-off-by: Tim Wiederhake <twiederh@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Erik Skultety [Tue, 5 Oct 2021 09:02:24 +0000 (11:02 +0200)]
gitlab-ci: Introduce new 'integration_tests' pipeline stage
This stage will download build artifacts from both the libvirt and
libvirt-perl (multi-project CI) builds, install all them on the custom
runners and configures libvirt debug logging on the runners prior to
executing the actual test suite. In case of a failure, libvirt and
Avocado logs will be saved and published as pipeline artifacts.
Signed-off-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Erik Skultety [Tue, 5 Oct 2021 09:01:34 +0000 (11:01 +0200)]
ci: manifest: Publish RPMs as artifacts on CentOS Stream and Fedoras
We're already building libvirt in the containers already, if we publish
the build in form of, say, RPMs, later stages of the pipeline can
consume the RPMs instead of re-building libvirt from scratch.
Signed-off-by: Erik Skultety <eskultet@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Andrea Bolognani [Wed, 26 Jan 2022 14:09:52 +0000 (15:09 +0100)]
meson: Check for os-release's ID_LIKE in addition to ID
This makes it possible to reduce the number of cases we have to
consider, because 'sles' declares itself to be like 'suse' and
both 'rhel' and 'centos' declare themselves to be like 'fedora'.
We have to move the check for Ubuntu before the one for Debian,
however, because 'ubuntu' declares itself to be like 'debian'
and it would end up with the wrong defaults otherwise.
Suggested-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Andrea Bolognani [Thu, 27 Jan 2022 14:20:31 +0000 (15:20 +0100)]
spec: Move virkey* manual pages from -daemon to -client
The documentation included in these manual pages is mostly useful
to users of the 'send-key' virsh command, and the virsh manual
page refers to them, so it makes more sense to install them along
with virsh instead of libvirtd.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
I introduced support for these vim plugins several years ago
but have since moved away from them. These days developers
are likely better served by lsp-based tooling, which doesn't
require additional per-project configuration.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
The files marked as export-ignore here are not going to be
included in the tarball produced by 'meson dist' when using
meson >= 0.60.
Older versions of meson excluded a small subset of these files
automatically, but since we have more control now we can be
more aggressive and leave out anything that doesn't make sense
in a release tarball.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
conf: use a hash table for storing nwfilter object list
The current use of an array for nwfilter objects requires
the caller to iterate over all elements to find a filter,
and also requires locking each filter.
Switching to a pair of hash tables enables O(1) lookups
both by name and uuid, with no locking required.
Reviewed-by: Ján Tomko <jtomko@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>