Currently, only one log file is created by the libxl driver, with
all output from libxl for all domains going to this one file.
Create a per-domain log file based on domain name, making sifting
through the logs a bit easier. This required deferring libxl_ctx
allocation until starting the domain, which is fine since the
ctx is not used when the domain is inactive.
Tested-by: Dario Faggioli <dario.faggioli@citrix.com>
this patch introduce the console api in libxl driver for both pv and
hvm guest. and import and update the libxlMakeChrdevStr function
which was deleted in commit dfa1e1dd.
Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
The avail_vcpu bitmap has to be allocated before it can be used (using
the maximum allowed value for that). Then for each available VCPU the
bit in the mask has to be set (libxl_bitmap_set takes a bit position
as an argument, not the number of bits to set).
Without this, I would always only get one VCPU for guests created
through libvirt/libxl.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Although, having it depending on Xen >= 4.3 (by using the proper
libxl feature flag).
Xen currently implements a NUMA placement policy which is basically
the same as the 'interleaved' policy of `numactl', although it can
be applied on a subset of the available nodes. We therefore hardcode
"interleave" as 'numa_mode', and we use the newly introduced libxl
interface to figure out what nodes a domain spans ('numa_nodeset').
With this change, it is now possible to query the NUMA node
affinity of a running domain:
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// list
Id Name State
----------------------------------------------------
23 F18_x64 running
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// numatune 23
numa_mode : interleave
numa_nodeset : 1
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
domainGetNumaParameters has a string typed parameter, hence it
is necessary for the libxl driver to support this.
This change implements the connectSupportsFeature hook for the
libxl driver, advertising that VIR_DRV_FEATURE_TYPED_PARAM_STRING
is supported.
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Eric Blake <eblake@redhat.com>
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Use virDomainObjListRemoveLocked instead of virDomainObjListRemove, as
driver->domains is already taken by virDomainObjListForEach.
Above deadlock can be triggered when libvirtd is started after some
domain have been started by hand (in which case driver will not find
libvirt-xml domain config).
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
By providing the implementation of nodeGetCellsFreeMemory for
the driver. This is all just a matter of properly formatting, in
a way that libvirt like, what Xen provides via libxl_get_numainfo().
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// freecell --all
0: 25004 KiB
1: 105848 KiB
--------------------
Total: 130852 KiB
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
libxl supports the LIBXL_DISK_BACKEND_QDISK disk backend, where qemu
is used to provide the disk backend. This patch simply maps the
existing <driver name='qemu'/> to LIBXL_DISK_BACKEND_QDISK.
Specifying an unsupported disk format with the tap driver resulted in
a less than helpful error message
error: Failed to start domain test-hvm
error: internal error libxenlight does not support disk driver qed
Change the message to state that the qed format is not supported by
the tap driver, e.g.
error: Failed to start domain test-hvm
error: internal error libxenlight does not support disk format qed
with disk driver tap
While at it, check for unsupported formats in the other driver
backends.
libxl contains logic to determine an appropriate devid for new devices
that do not specify one in their configuration. For all device types
except NICs, the libxl driver allows libxl to determine devid. Do the
same for NICs.
Do not leave uninitialized variables, not all parameters are set in
libxlMake*.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
libxl uses some xenstore entries for hints in memory management
(especially when starting new domain). This includes dom0 memory limit
and Xen free memory margin, based on current system state. Entries are
created at first function usage, so force such call at daemon startup,
which most likely will be before any domain startup.
Also prevent automatic memory management if dom0_mem= option passed to
xen hypervisor - it is known to be incompatible with autoballoon.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
When creating a timer/event handler reference counting is used. So it could
be possible (in theory) that libxlDomainObjPrivateFree is called with
reference counting >1. The problem is that libxlDomainObjPrivateFree leave
the object in an invalid state with ctx freed (but still having dandling
pointer). This can lead timer/event handler to core.
This patch implements a dispose method for libxlDomainObjPrivate, and moves
freeing the libxl ctx to the dispose method, ensuring the ctx is valid while
the object's reference count is > 0.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Actually only those interface types are handled correctly so reject
others instead of ignoring settings (i.e. treating as bridge/ethernet
anyway).
Also allow <script/> in 'ethernet' (which should be the only
script-allowing type). Keep <script/> allowed in bridge to be compatible
with legacy 'xen' driver.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
The legacy xen toolstack will set pygrub as the bootloader if not
specified. For compatibility, do the same in the libxl driver
iff not using direct kernel boot.
Currently, the libxl driver reports a connection type of "xenlight".
To be compatible with the legacy Xen driver, it should return "Xen".
Note: I noticed this while testing the libxl driver on OpenStack.
After switching my Xen compute nodes to use the libxl stack, I
could no longer launch instances on those nodes since
hypervisor_type was reported as "xenlight" instead of "xen".
libxl expects the event handler to free the event passed to it. From
libxl_event.h:
event becomes owned by the application and must be freed, either
by event_occurs or later
Xen 4.3 fixes a mistake in the libxl event handler signature where the
event owned by the application was defined as const. Detect this and
define the libvirt libxl event handler signature appropriately.
This resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=851411https://bugzilla.redhat.com/show_bug.cgi?id=955500
The first problem was that virFileOpenAs was returning fd (-1) in one
of the error cases rather than ret (-errno), so the caller thought
that the error was EPERM rather than ENOENT.
The second problem was that some log messages in the general purpose
qemuOpenFile() function would always say "Failed to create" even if
the caller hadn't included O_CREAT (i.e. they were trying to open an
existing file).
This fixes virFileOpenAs to jump down to the error return (which
returns ret instead of fd) in the previously mentioned incorrect
failure case of virFileOpenAs(), removes all error logging from
virFileOpenAs() (since the callers report it), and modifies
qemuOpenFile to appropriately use "open" or "create" in its log
messages.
NB: I seriously considered removing logging from all callers of
virFileOpenAs(), but there is at least one case where the caller
doesn't want virFileOpenAs() to log any errors, because it's just
going to try again (qemuOpenFile()). We can't simply make a silent
variation of virFileOpenAs() though, because qemuOpenFile() can't make
the decision about whether or not it wants to retry until after
virFileOpenAs() has already returned an error code.
Likewise, I also considered changing virFileOpenAs() to return -1 with
errno set on return, and may still do that, but only as a separate
patch, as it obscures the intent of this patch too much.
The LXC, QEMU, and LibXL drivers have all merged their handling of
the attach/update/modify device APIs into one large
'xxxxDomainModifyDeviceFlags'
which then does a 'switch()' based on the actual API being invoked.
While this saves some lines of code, it is not really all that
significant in the context of the driver API impls as a whole.
This merger of the handling of different APIs creates pain when
wanting to automated analysis of the code and do things which
are specific to individual APIs. The slight duplication of code
from unmerged the API impls, is preferrable to allow for easier
automated analysis.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the virGetHostname() API has a bogus virConnectPtr
parameter. This is because virtualization drivers directly
reference this API in their virDriverPtr tables, tieing its
API design to the public virConnectGetHostname API design.
This also causes problems for access control checks since
these must only be done for invocations from the public
API, not internal invocation.
Remove the bogus virConnectPtr parameter, and make each
hypervisor driver provide a dedicated function for the
driver API impl. This will allow access control checks
to be easily inserted later.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
libxlBuildDomainConfig() was disposing the libxl_domain_config object
on error, only to have it disposed again by libxlBuildDomainConfig()'s
caller, which resulted in a segfault. Leave disposing of the config
object to it's owner.
this patch fix the wrong sequence for fd and timeout register. the sequence
was right in dfa1e1dd for fd register, but it changed in e0622ca2.
in this patch, set priv, xl_priv in info and increase info->priv ref count
before virEventAddHandle. if do this after virEventAddHandle, the fd
callback or fd deregister maybe got the empty priv, xl_priv or wrong ref
count.
after apply this patch, test more than 100 rounds passed compare to fail
within 3 rounds without this patch. each round includes define -> start ->
destroy -> create -> suspend -> resume -> reboot -> shutdown -> save ->
resotre -> dump -> destroy -> create -> setmem -> setvcpus -> destroy.
Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
Ensure that all drivers implementing public APIs use a
naming convention for their implementation that matches
the public API name.
eg for the public API virDomainCreate make sure QEMU
uses qemuDomainCreate and not qemuDomainStart
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Detected by a simple Shell script:
for i in $(git ls-files -- '*.[ch]'); do
awk 'BEGIN {
fail=0
}
/# *include.*\.h/{
match($0, /["<][^">]*[">]/)
arr[substr($0, RSTART+1, RLENGTH-2)]++
}
END {
for (key in arr) {
if (arr[key] > 1) {
fail=1
printf("%d %s\n", arr[key], key)
}
}
if (fail == 1)
exit 1
}' $i
if test $? != 0; then
echo "Duplicate header(s) in $i"
fi
done;
A later patch will add the syntax-check to avoid duplicate
headers.
This patch refactors various places to allow removing of the
defaultConsoleTargetType callback from the virCaps structure.
A new console character device target type is introduced -
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_NONE - to mark that no type was
specified in the XML. This type is at the end converted to the standard
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL. Other types that are
different from this default have to be processed separately in the
device post parse callback.
Use the virDomainXMLConf structure to hold this data and tweak the code
to avoid semantic change.
Without configuration the KVM mac prefix is used by default. I chose it
as it's in the privately administered segment so it should be usable for
any purposes.
This patch adds instrumentation that will allow hypervisor drivers to
fill and validate domain and device definitions after parsed by the XML
parser.
With this patch, after the XML is parsed, a callback to the driver is
issued requesting to fill and validate driver specific details of the
configuration. This allows to use sensible defaults and checks on a per
driver basis at the time the XML is parsed.
Two callback pointers are stored in the new virDomainXMLConf object:
* virDomainDeviceDefPostParseCallback (devicesPostParseCallback)
- called for a single device parsed and for every single device in a
domain config. A virDomainDeviceDefPtr is passed along with the
domain definition and virCaps.
* virDomainDefPostParseCallback, (domainPostParseCallback)
- A callback that is meant to process the domain config after it's
parsed. A virDomainDefPtr is passed along with virCaps.
Both types of callbacks support arbitrary opaque data passed for the
callback functions.
Errors may be reported in those callbacks resulting in a XML parsing
failure.
This patch is the result of running:
for i in $(git ls-files | grep -v html | grep -v \.po$ ); do
sed -i -e "s/virDomainXMLConf/virDomainXMLOption/g" -e "s/xmlconf/xmlopt/g" $i
done
and a few manual tweaks.
The virCaps structure gathered a ton of irrelevant data over time that.
The original reason is that it was propagated to the XML parser
functions.
This patch aims to create a new data structure virDomainXMLConf that
will contain immutable data that are used by the XML parser. This will
allow two things we need:
1) Get rid of the stuff from virCaps
2) Allow us to add callbacks to check and add driver specific stuff
after domain XML is parsed.
This first attempt removes pointers to private data allocation functions
to this new structure and update all callers and function that require
them.
1. The virObjectLock() call was unconditional, but Unlock was conditional
on vm being valid. Removed the check
2. A call to virDomainEventNewFromObj() isn't guaranteed to return an
event - that check needs to be made prior to libxlDomainEventQueue()
of the event. Did not add libxlDriverLock/Unlock around the call since
some callers already have lock taken
3. Need to initialize fd = -1 in libxlDoDomainSave() since we can jump
to cleanup before it's set.
4. Missing break;'s in libxlDomainModifyDeviceFlags() for case
LIBXL_DEVICE_UPDATE. The default: case would report an error
To enable virCapabilities instances to be reference counted,
turn it into a virObject. All cases of virCapabilitiesFree
turn into virObjectUnref
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The duplicate VM checking should be done atomically with
virDomainObjListAdd, so shoud not be a separate function.
Instead just use flags to indicate what kind of checks are
required.
This pair, used in virDomainCreateXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainRestoreFlags:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, true)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainDefineXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 0) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
0, NULL)))
goto cleanup;
As a step towards making virDomainObjList thread-safe turn it
into an opaque virObject, preventing any direct access to its
internals.
As part of this a new method virDomainObjListForEach is
introduced to replace all existing usage of virHashForEach
Since libxl provides the domain ID in the event handler callback,
find the domain object based on the ID. This approach prevents
processing the callback on a domain that has already been reaped.
Also, similar to the xl implementation, ignore the SUSPEND shutdown
reason. By calling libxl_domain_suspend(), we know a shutdown
event with SUSPEND reason will be generated, but it can be safely
ignored since any subsequent cleanup will be done by the callers.
libxlDoDomainSave() was removing non-persistent domains, but
required callers to have the virDomainObj locked. Callers could
potentially unlock an already freed virDomainObj. Move this
logic to the callers of libxlDoDomainSave().
I've noticed that libxl can invoke timeout reregister/modify hooks
after returning from libxl_ctx_free. Explicitly remove the
timeouts before freeing the libxl ctx to avoid executing hooks on
stale objects.
It is possible to destroy and cleanup a VM, resulting in freeing the
libxlDomainObjPrivate object and associated libxl ctx, before all fds and
timeouts have been deregistered and destroyed.
Fix this race by incrementing the reference count on libxlDomainObjPrivate
for each fd and timeout registration. Only when all fds and timeouts are
deregistered and destroyed will the libxlDomainObjPrivate be destroyed.
The libxl driver is racy in it's interactions with libxl and libvirt's
event loop. The event loop can invoke callbacks after libxl has
deregistered the event, and possibly access freed data associated with
the event.
This patch fixes the race by converting libxlDomainObjPrivate to a
virObjectLockable, and locking it while executing libxl upcalls and
libvirt event loop callbacks.
Note that using the virDomainObj lock is not satisfactory since it may
be desirable to hold the virDomainObj lock even when libxl events such
as reading and writing to xenstore need processed.
xen-unstable changeset 26469 makes changes wrt modifying and deregistering
timeouts.
First, timeout modify callbacks will only be invoked with an
abs_t of {0,0}, i.e. make the timeout fire immediately. Prior to this
commit, timeout modify callbacks were never invoked.
Second, timeout deregister hooks will no longer be called.
This patch makes changes in the libvirt libxl driver that should be
compatible before and after changeset 26469.
While at it, fix a potential overflow in the timeout register callback.
Commit dfa1e1dd added functions whose definitions do not conform
to the style used in the libxl driver. Change these functions to
be consistent throughout the driver.
The virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Convert the host capabilities and domain config structs to
use the virArch datatype. Update the parsers and all drivers
to take account of datatype change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The libxl driver ignored boot devices in the domain config,
preventing PXE booting HVM domains. This patch accounts for
user-specified boot devices when building the libxl domain
configuration.
Based on a patch originally authored by Daniel De Graaf
http://lists.xen.org/archives/html/xen-devel/2012-05/msg00565.html
This patch converts the Xen libxl driver to support only Xen >= 4.2.
Support for Xen 4.1 libxl is dropped since that version of libxl is
designated 'technology preview' only and is incompatible with Xen 4.2
libxl. Additionally, the default toolstack in Xen 4.1 is still xend,
for which libvirt has a stable, functional driver.
Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virStateInitialize method and several cgroups methods were
using an 'int privileged' parameter or similar for dual-state
values. These are better represented with the bool type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
For S390, the default console target type cannot be of type 'serial'.
It is necessary to at least interpret the 'arch' attribute
value of the os/type element to produce the correct default type.
Therefore we need to extend the signature of defaultConsoleTargetType
to account for architecture. As a consequence all the drivers
supporting this capability function must be updated.
Despite the amount of changed files, the only change in behavior is
that for S390 the default console target type will be 'virtio'.
N.B.: A more future-proof approach could be to to use hypervisor
specific capabilities to determine the best possible console type.
For instance one could add an opaque private data pointer to the
virCaps structure (in case of QEMU to hold capsCache) which could
then be passed to the defaultConsoleTargetType callback to determine
the console target type.
Seems to be however a bit overengineered for the use case...
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
virDomainVcpuPinAdd does a realloc on vcpupin_list if the new vcpu pin
definition doesn't fit into the array. The list is an array of pointers
but the function definition didn't support returning the changed pointer
to the caller if it was realloced. This caused segfaults if realloc
would change the base pointer.
As the consensus in:
https://www.redhat.com/archives/libvir-list/2012-July/msg01692.html,
this patch is to destroy conf/virdomainlist.[ch], folding the
helpers into conf/domain_conf.[ch].
* src/Makefile.am:
- Various indention fixes incidentally
- Add macro DATATYPES_SOURCES (datatypes.[ch])
- Link datatypes.[ch] for libvirt_lxc
* src/conf/domain_conf.c:
- Move all the stuffs from virdomainlist.c into it
- Use virUnrefDomain and virUnrefDomainSnapshot instead of
virDomainFree and virDomainSnapshotFree, which are defined
in libvirt.c, and we don't want to link to it.
- Remove "if" before "free" the object, as virObjectUnref
is in the list "useless_free_options".
* src/conf/domain_conf.h:
- Move all the stuffs from virdomainlist.h into it
- s/LIST_FILTER/LIST_DOMAINS_FILTER/
* src/libxl/libxl_driver.c:
- s/LIST_FILTER/LIST_DOMAINS_FILTER/
- no (include "virdomainlist.h")
* src/libxl/libxl_driver.c: Likewise
* src/lxc/lxc_driver.c: Likewise
* src/openvz/openvz_driver.c: Likewise
* src/parallels/parallels_driver.c: Likewise
* src/qemu/qemu_driver.c: Likewise
* src/test/test_driver.c: Likewise
* src/uml/uml_driver.c: Likewise
* src/vbox/vbox_tmpl.c: Likewise
* src/vmware/vmware_driver.c: Likewise
* tools/virsh-domain-monitor.c: Likewise
* tools/virsh.c: Likewise
Switch virDomainObjPtr to use the virObject APIs for reference
counting. The main change is that virObjectUnref does not return
the reference count, merely a bool indicating whether the object
still has any refs left. Checking the return value is also not
mandatory.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
Introduce new members in the virMacAddr 'class'
- virMacAddrSet: set virMacAddr from a virMacAddr
- virMacAddrSetRaw: setting virMacAddr from raw 6 byte MAC address buffer
- virMacAddrGetRaw: writing virMacAddr into raw 6 byte MAC address buffer
- virMacAddrCmp: comparing two virMacAddr
- virMacAddrCmpRaw: comparing a virMacAddr with a raw 6 byte MAC address buffer
then replace raw MAC addresses by replacing
- 'unsigned char *' with virMacAddrPtr
- 'unsigned char ... [VIR_MAC_BUFLEN]' with virMacAddr
and introduce usage of above functions where necessary.
This patch adds support for listing all domains into drivers that use
the common virDomainObj implementation: libxl, lxc, openvz, qemu, test,
uml, vmware.
For drivers that don't support managed save images the guests are
treated as if they had none, so filtering guests that do have such an
image on this driver succeeds and produces 0 results.
This patch stores existence of the image in the object. At start of the
daemon the state is checked and then updated in key moments in domain
lifecycle.
When the last reference to a virConnectPtr is released by
libvirtd, it was possible for a deadlock to occur in the
virDomainEventState functions. The virDomainEventStatePtr
holds a reference on virConnectPtr for each registered
callback. When removing a callback, the virUnrefConnect
function is run. If this causes the last reference on the
virConnectPtr to be released, then virReleaseConnect can
be run, which in turns calls qemudClose. This function has
a call to virDomainEventStateDeregisterConn which is intended
to remove all callbacks associated with the virConnectPtr
instance. This will try to grab a lock on virDomainEventState
but this lock is already held. Deadlock ensues
Thread 1 (Thread 0x7fcbb526a840 (LWP 23185)):
Since each callback associated with a virConnectPtr holds a
reference on virConnectPtr, it is impossible for the qemudClose
method to be invoked while any callbacks are still registered.
Thus the call to virDomainEventStateDeregisterConn must in fact
be a no-op. Thus it is possible to just remove all trace of
virDomainEventStateDeregisterConn and avoid the deadlock.
* src/conf/domain_event.c, src/conf/domain_event.h,
src/libvirt_private.syms: Delete virDomainEventStateDeregisterConn
* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
src/qemu/qemu_driver.c, src/uml/uml_driver.c: Remove
calls to virDomainEventStateDeregisterConn
