Update the function's comment, which was missed when removing use of
the driver lock everywhere.

A small fix for the possiblitiy of jumping to an error path before
registering for domain events, preventing receiving important ones
like shutdown and death.

libxlDomEventsRegister better reflects its purpose: register for
domain events from libxl.

libxlDomainRestoreFlags acquires the driver lock while reading the
domain config from the save file and adding it to
libxlDriverPrivatePtr->domains.  But virDomainObjList provides
self-locking APIs, so remove the needless driver locking.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Handling the domain shutdown event within the event handler seems
a bit unfair to libxl's event machinery.  Domain "shutdown" could
take considerable time.  E.g. if the shutdown reason is reboot,
the domain must be reaped and then started again.

Spawn a shutdown handler thread to do this work, allowing libxl's
event machinery to go about its business.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Due to some misunderstanding of requirements libxl places on timer
handling, I introduced the half-brained idea of maintaining a list
of timeouts that the driver could force to expire before freeing a
libxlDomainObjPrivate (and hence libxl_ctx).  But testing all
the latest versions of Xen supported by the libxl driver (4.2.3,
4.3.1, 4.4.0 RC3), I see that libxl will handle this just fine and
there is no need to force expiration behind libxl's back.  Indeed it
may be harmful to do so.

This patch removes the timer list, allowing libxl to handle cleanup
of its timer registrations.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1058839

Commit f9f56340 for CVE-2014-0028 almost had the right idea - we
need to check the ACL rules to filter which events to send.  But
it overlooked one thing: the event dispatch queue is running in
the main loop thread, and therefore does not normally have a
current virIdentityPtr.  But filter checks can be based on current
identity, so when libvirtd.conf contains access_drivers=["polkit"],
we ended up rejecting access for EVERY event due to failure to
look up the current identity, even if it should have been allowed.

Furthermore, even for events that are triggered by API calls, it
is important to remember that the point of events is that they can
be copied across multiple connections, which may have separate
identities and permissions.  So even if events were dispatched
from a context where we have an identity, we must change to the
correct identity of the connection that will be receiving the
event, rather than basing a decision on the context that triggered
the event, when deciding whether to filter an event to a
particular connection.

If there were an easy way to get from virConnectPtr to the
appropriate virIdentityPtr, then object_event.c could adjust the
identity prior to checking whether to dispatch an event.  But
setting up that back-reference is a bit invasive.  Instead, it
is easier to delay the filtering check until lower down the
stack, at the point where we have direct access to the RPC
client object that owns an identity.  As such, this patch ends
up reverting a large portion of the framework of commit f9f56340.
We also have to teach 'make check' to special-case the fact that
the event registration filtering is done at the point of dispatch,
rather than the point of registration.  Note that even though we
don't actually use virConnectDomainEventRegisterCheckACL (because
the RegisterAny variant is sufficient), we still generate the
function for the purposes of documenting that the filtering
takes place.

Also note that I did not entirely delete the notion of a filter
from object_event.c; I still plan on using that for my upcoming
patch series for qemu monitor events in libvirt-qemu.so.  In
other words, while this patch changes ACL filtering to live in
remote.c and therefore we have no current client of the filtering
in object_event.c, the notion of filtering in object_event.c is
still useful down the road.

* src/check-aclrules.pl: Exempt event registration from having to
pass checkACL filter down call stack.
* daemon/remote.c (remoteRelayDomainEventCheckACL)
(remoteRelayNetworkEventCheckACL): New functions.
(remoteRelay*Event*): Use new functions.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Drop unused parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/domain_event.c (virDomainEventFilter): Delete unused
function.
* src/conf/network_event.c (virNetworkEventFilter): Likewise.
* src/libxl/libxl_driver.c: Adjust caller.
* src/lxc/lxc_driver.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/test/test_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/vbox/vbox_tmpl.c: Likewise.
* src/xen/xen_driver.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Coverity complains about default: label in libxl_driver.c not be able
to be reached. It's by design for the code and since it's not necessary
in the code nor does it elicit any compiler/make check warnings - just
remove it rather than adding a coverity[dead_error_begin] tag.

While I'm at it, lxc_driver.c and nodeinfo.c have the same design, so I
removed the default labels and the existing coverity tags.

I noticed that we allow virDomainGetVcpusFlags even for read-only
connections, but that with a flag, it can require guest agent
interaction.  It is feasible that a malicious guest could
intentionally abuse the replies it sends over the guest agent
connection to possibly trigger a bug in libvirt's JSON parser,
or withhold an answer so as to prevent the use of the agent
in a later command such as a shutdown request.  Although we
don't know of any such exploits now (and therefore don't mind
posting this patch publicly without trying to get a CVE assigned),
it is better to err on the side of caution and explicitly require
full access to any domain where the API requires guest interaction
to operate correctly.

I audited all commands that are marked as conditionally using a
guest agent.  Note that at least virDomainFSTrim is documented
as needing a guest agent, but that such use is unconditional
depending on the hypervisor (so the existing domain:fs_trim ACL
should be sufficient there, rather than also requirng domain:write).
But when designing future APIs, such as the plans for obtaining
a domain's IP addresses, we should copy the approach of this patch
in making interaction with the guest be specified via a flag, and
use that flag to also require stricter access checks.

* src/libvirt.c (virDomainGetVcpusFlags): Forbid guest interaction
on read-only connection.
(virDomainShutdownFlags, virDomainReboot): Improve docs on agent
interaction.
* src/remote/remote_protocol.x
(REMOTE_PROC_DOMAIN_SNAPSHOT_CREATE_XML)
(REMOTE_PROC_DOMAIN_SET_VCPUS_FLAGS)
(REMOTE_PROC_DOMAIN_GET_VCPUS_FLAGS, REMOTE_PROC_DOMAIN_REBOOT)
(REMOTE_PROC_DOMAIN_SHUTDOWN_FLAGS): Require domain:write for any
conditional use of a guest agent.
* src/xen/xen_driver.c: Fix clients.
* src/libxl/libxl_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Ever since ACL filtering was added in commit 76397360 (v1.1.1), a
user could still use event registration to obtain access to a
domain that they could not normally access via virDomainLookup*
or virConnectListAllDomains and friends.  We already have the
framework in the RPC generator for creating the filter, and
previous cleanup patches got us to the point that we can now
wire the filter through the entire object event stack.

Furthermore, whether or not domain:getattr is honored, use of
global events is a form of obtaining a list of networks, which
is covered by connect:search_domains added in a93cd08f (v1.1.0).
Ideally, we'd have a way to enforce connect:search_domains when
doing global registrations while omitting that check on a
per-domain registration.  But this patch just unconditionally
requires connect:search_domains, even when no list could be
obtained, based on the following observations:
1. Administrators are unlikely to grant domain:getattr for one
or all domains while still denying connect:search_domains - a
user that is able to manage domains will want to be able to
manage them efficiently, but efficient management includes being
able to list the domains they can access.  The idea of denying
connect:search_domains while still granting access to individual
domains is therefore not adding any real security, but just
serves as a layer of obscurity to annoy the end user.
2. In the current implementation, domain events are filtered
on the client; the server has no idea if a domain filter was
requested, and must therefore assume that all domain event
requests are global.  Even if we fix the RPC protocol to
allow for server-side filtering for newer client/server combos,
making the connect:serach_domains ACL check conditional on
whether the domain argument was NULL won't benefit older clients.
Therefore, we choose to document that connect:search_domains
is a pre-requisite to any domain event management.

Network events need the same treatment, with the obvious
change of using connect:search_networks and network:getattr.

* src/access/viraccessperm.h
(VIR_ACCESS_PERM_CONNECT_SEARCH_DOMAINS)
(VIR_ACCESS_PERM_CONNECT_SEARCH_NETWORKS): Document additional
effect of the permission.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Add new parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/object_event_private.h (virObjectEventStateRegisterID):
Likewise.
* src/conf/object_event.c (_virObjectEventCallback): Track a filter.
(virObjectEventDispatchMatchCallback): Use filter.
(virObjectEventCallbackListAddID): Register filter.
* src/conf/domain_event.c (virDomainEventFilter): New function.
(virDomainEventStateRegister, virDomainEventStateRegisterID):
Adjust callers.
* src/conf/network_event.c (virNetworkEventFilter): New function.
(virNetworkEventStateRegisterID): Adjust caller.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER_ANY)
(REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY): Generate a
filter, and require connect:search_domains instead of weaker
connect:read.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventRegisterAny)
(testConnectNetworkEventRegisterAny): Update callers.
* src/remote/remote_driver.c (remoteConnectDomainEventRegister)
(remoteConnectDomainEventRegisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventRegisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventRegisterAny): Likewise.
* src/qemu/qemu_driver.c (qemuConnectDomainEventRegister)
(qemuConnectDomainEventRegisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventRegisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventRegisterAny): Likewise.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventRegisterAny): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Ever since their introduction (commit 1509b802 in v0.5.0 for
virConnectDomainEventRegister, commit 44457238 in v0.8.0 for
virConnectDomainEventDeregisterAny), the event deregistration
functions have been documented as returning 0 on success;
likewise for older registration (only the newer RegisterAny
must return a non-zero callbackID).  And now that we are
adding virConnectNetworkEventDeregisterAny for v1.2.1, it
should have the same semantics.

Fortunately, all of the stateful drivers have been obeying
the docs and returning 0, thanks to the way the remote_driver
tracks things (in fact, the RPC wire protocol is unable to
send a return value for DomainEventRegisterAny, at least not
without adding a new RPC number).  Well, except for vbox,
which was always failing deregistration, due to failure to
set the return value to anything besides its initial -1.

But for local drivers, such as test:///default, we've been
returning non-zero numbers; worse, the non-zero numbers have
differed over time.  For example, in Fedora 12 (libvirt 0.8.2),
calling Register twice would return 0 and 1 [the callbackID
generated under the hood]; while in Fedora 20 (libvirt 1.1.3),
it returns 1 and 2 [the number of callbacks registered for
that event type].  Since we have changed the behavior over
time, and since it differs by local vs. remote, we can safely
argue that no one could have been reasonably relying on any
particular behavior, so we might as well obey the docs, as well
as prepare callers that might deal with older clients to not be
surprised if the docs are not strictly followed.

For consistency, this patch fixes the code for all drivers,
even though it only makes an impact for vbox and for local
drivers.  By fixing all drivers, future copy and paste from
a remote driver to a local driver is less likely to
reintroduce the bug.

Finally, update the testsuite to gain some coverage of the
issue for local drivers, including the first test of old-style
domain event registration via function pointer instead of
event id.

* src/libvirt.c (virConnectDomainEventRegister)
(virConnectDomainEventDeregister)
(virConnectDomainEventDeregisterAny): Clarify docs.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventDeregister)
(libxlConnectDomainEventDeregisterAny): Match documentation.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventDeregister)
(lxcConnectDomainEventDeregisterAny): Likewise.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventDeregister)
(testConnectDomainEventDeregisterAny)
(testConnectNetworkEventDeregisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventDeregister)
(umlConnectDomainEventDeregisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxConnectDomainEventRegister)
(vboxConnectDomainEventDeregister)
(vboxConnectDomainEventDeregisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventDeregister)
(xenUnifiedConnectDomainEventDeregisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventDeregisterAny): Likewise.
* tests/objecteventtest.c (testDomainCreateXMLOld): New test.
(mymain): Run it.
(testDomainCreateXML): Check return values.
Signed-off-by: NEric Blake <eblake@redhat.com>

By actually removing the <vcpupin> element (from within the
<cputune> section) from the XML, rather than jus update it with
a fully set vcpu affinity mask.
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>

And use it to implement libxlDomainPinVcpu(), similarly to what
happens in the QEMU driver. This way, it is possible to both
query and change the vcpu affinity of a persistent but not
running domain.

In face, before this patch, we have:
 # virsh list --all
  Id    Name                           State
 ----------------------------------------------------
  5     debian_32                      running
  -     fedora20_64                    shut off
 # virsh vcpupin fedora20_64 0 2-4 --current
 error: this function is not supported by the connection driver: virDomainPinVcpuFlags

After (same situation as above):
 # virsh vcpupin  fedora20_64 0 2-4 --current
 # virsh vcpupin  fedora20_64 0
 VCPU: CPU Affinity
 ----------------------------------
    0: 2-4
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>

So that it is possible to query vcpu related information of
a persistent but not running domain, like it is for the QEMU
driver.

In fact, before this patch, we have:
 # virsh list --all
  Id    Name                           State
 ----------------------------------------------------
  5     debian_32                      running
  -     fedora20_64                    shut off
 # virsh vcpuinfo fedora20_64
 error: this function is not supported by the connection driver: virDomainGetVcpuPinInfo

After (same situation as above, i.e., fedora20_64 not running):
 # virsh vcpuinfo fedora20_64
 VCPU:           0
 CPU:            N/A
 State:          N/A
 CPU time        N/A
 CPU Affinity:   yyyyyyyy

 VCPU:           1
 CPU:            N/A
 State:          N/A
 CPU time        N/A
 CPU Affinity:   yyyyyyyy
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>

by, in libxlDomainGetNumaParameters(), calling libxl_bitmap_init() as soon as
possible, which avoids getting to 'cleanup:', where libxl_bitmap_dispose()
happens, without having initialized the nodemap, and hence crashing after some
invalid free()-s:

 # ./daemon/libvirtd -v
 *** Error in `/home/xen/libvirt.git/daemon/.libs/lt-libvirtd': munmap_chunk(): invalid pointer: 0x00007fdd42592666 ***
 ======= Backtrace: =========
 /lib64/libc.so.6(+0x7bbe7)[0x7fdd3f767be7]
 /lib64/libxenlight.so.4.3(libxl_bitmap_dispose+0xd)[0x7fdd2c88c045]
 /home/xen/libvirt.git/daemon/.libs/../../src/.libs/libvirt_driver_libxl.so(+0x12d26)[0x7fdd2caccd26]
 /home/xen/libvirt.git/src/.libs/libvirt.so.0(virDomainGetNumaParameters+0x15c)[0x7fdd4247898c]
 /home/xen/libvirt.git/daemon/.libs/lt-libvirtd(+0x1d9a2)[0x7fdd42ecc9a2]
 /home/xen/libvirt.git/src/.libs/libvirt.so.0(virNetServerProgramDispatch+0x3da)[0x7fdd424e9eaa]
 /home/xen/libvirt.git/src/.libs/libvirt.so.0(+0x1a6f38)[0x7fdd424e3f38]
 /home/xen/libvirt.git/src/.libs/libvirt.so.0(+0xa81e5)[0x7fdd423e51e5]
 /home/xen/libvirt.git/src/.libs/libvirt.so.0(+0xa783e)[0x7fdd423e483e]
 /lib64/libpthread.so.0(+0x7c53)[0x7fdd3febbc53]
 /lib64/libc.so.6(clone+0x6d)[0x7fdd3f7e1dbd]
Signed-off-by: NDario Faggili <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>

Starting from commit 2e82c18c in Xen (will be included in Xen 4.4)
both libxl_get_max_cpus() and libxl_get_max_nodes() start returning
a proper libxl error code, in case of failure. This patch fixes
this in the libxl driver.

Note that, although it is now basically impossible for them to return
0, that would, theoretically, still be wrong. Also, checking that the
returned value is '<= 0' makes the code correct for both Xen 4.4 and
Xen 4.3 (and 4.2), and that is why we go for it (rather than
just '< 0').
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The virDomainEvent class is kept as it indicates what meta informations
are valid for the children classes. This may be useful in the future.

This aims at providing some consistency with other domain events

Leave virDomainEventRegister and its Deregister brother as these are
legacy functions only for domain lifecycle events.

Most of our code base uses space after comma but not before;
fix the remaining uses before adding a syntax check.

* src/libxl/libxl_driver.c: Consistently use commas.
* src/xen/xend_internal.c: Likewise.
* src/xen/xs_internal.c: Likewise.
* src/xenapi/xenapi_driver.c: Likewise.
* src/xenapi/xenapi_utils.c: Likewise.
* src/xenxs/xen_sxpr.c: Likewise.
* src/xenxs/xen_xm.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

This allows its error messages to be more specific.

ifdef LIBXL_HAVE_DOMAIN_CREATE_RESTORE_PARAMS hides a multi-line body
for a brace-less else.  Add braces to ensure proper logic is applied.

Without this fix, new domains cannot be started.  Both
libxl_domain_create_new and libxl_domain_create_restore are called when
starting a new domain leading to this error:
libxl: error: libxl.c:324:libxl__domain_rename: domain with name "guest" already exists.
libxl: error: libxl_create.c:800:initiate_domain_create: cannot make domain: -6

Rather than casting the virBitmap pointer to uint8_t* and then using
the structure contents as a byte array, use the virBitmap API to determine
the bitmap size and test each bit.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>

This reverts commit 394d6e0a.
The real problem is accessing the virtBitmap structure as a byte
array, which was correctly identified and fixed by Jeremy Fitzhardinge

https://www.redhat.com/archives/libvir-list/2013-October/msg01257.html

in recently xen commit: 7051d5c8, there is a api changes in
libxl_domain_create_restore.
Author: Andrew Cooper <andrew.cooper3@citrix.com>
Date:   Thu Oct 10 12:23:10 2013 +0100

    tools/migrate: Fix regression when migrating from older version of Xen

use the macro LIBXL_HAVE_DOMAIN_CREATE_RESTORE_PARAMS in libxl.h
in order to make libvirt could compile with old and new xen.

the params checkpointed_stream is useful if libvirt libxl driver
support migration. for new, set it as zero.
Signed-off-by: NBamvor Jian Zhang <bjzhang@suse.com>

According to the following valgrind output, there seems to be a
invalid limit for the iterator (captured on Fedora 19):

==3945== Invalid read of size 1
==3945==    at 0x1E1FA410: libxlVmStart (libxl_driver.c:475)
==3945==    by 0x1E1FAD9A: libxlDomainCreateWithFlags (libxl_driver.c:2633)
==3945==    by 0x5187D46: virDomainCreate (libvirt.c:9439)
==3945==    by 0x13BAA6: remoteDispatchDomainCreateHelper (remote_dispatch.h:2910)
==3945==    by 0x51DE5B9: virNetServerProgramDispatch (virnetserverprogram.c:435)
==3945==    by 0x51D93E7: virNetServerHandleJob (virnetserver.c:165)
==3945==    by 0x50F5BF4: virThreadPoolWorker (virthreadpool.c:144)
==3945==    by 0x50F5670: virThreadHelper (virthreadpthread.c:161)
==3945==    by 0x8046C52: start_thread (pthread_create.c:308)
==3945==    by 0x8758E1C: clone (clone.S:113)
==3945==  Address 0x23424d81 is 0 bytes after a block of size 1 alloc'd
==3945==    at 0x4A08121: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==3945==    by 0x50B1F8C: virAllocN (viralloc.c:189)
==3945==    by 0x1E1FA3CA: libxlVmStart (libxl_driver.c:468)
==3945==    by 0x1E1FAD9A: libxlDomainCreateWithFlags (libxl_driver.c:2633)
==3945==    by 0x5187D46: virDomainCreate (libvirt.c:9439)
==3945==    by 0x13BAA6: remoteDispatchDomainCreateHelper (remote_dispatch.h:2910)
==3945==    by 0x51DE5B9: virNetServerProgramDispatch (virnetserverprogram.c:435)
==3945==    by 0x51D93E7: virNetServerHandleJob (virnetserver.c:165)
==3945==    by 0x50F5BF4: virThreadPoolWorker (virthreadpool.c:144)
==3945==    by 0x50F5670: virThreadHelper (virthreadpthread.c:161)
==3945==    by 0x8046C52: start_thread (pthread_create.c:308)
==3945==    by 0x8758E1C: clone (clone.S:113)
==3945==

Related: https://bugzilla.redhat.com/show_bug.cgi?id=1013045Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

No need to check if privileged when reading hostsysinfo, since
that check was already done in libxlDriverShouldLoad().  The
libxl driver fails to load if not privileged.

John Ferlan reported the following Coverity warning:

In libxlDomainCoreDump() Coverity has noted a FORWARD_NULL reference:

2004 	    if ((flags & VIR_DUMP_CRASH) && !vm->persistent) {
2005 	        virDomainObjListRemove(driver->domains, vm);

(20) Event assign_zero: 	Assigning: "vm" = "NULL".
Also see events: 	[var_deref_model]

2006 	        vm = NULL;
2007 	    }
2008
2009 	    ret = 0;
2010
2011 	cleanup_unpause:

(21) Event var_deref_model: 	Passing null pointer "vm" to function
     "virDomainObjIsActive(virDomainObjPtr)", which dereferences it. [details]
Also see events: 	[assign_zero]

2012 	    if (virDomainObjIsActive(vm) && paused) {
2013 	        if (libxl_domain_unpause(priv->ctx, dom->id) != 0) {
2014 	            virReportError(VIR_ERR_INTERNAL_ERROR,

Removing the vm from domain obj list and setting it to NULL can be
done in the previous 'if (flags & VIR_DUMP_CRASH)' conditional.  Fix
the Coverity warning by ensuring vm is not NULL before testing if it
is still active.

Change source file copyright notice to prevailing libvirt style.

Similar to the QEMU and LXC drivers, add a helper function to
lookup a domain, and use it instead of much copy and paste.

Now that most fields of libxlDriverPrivate struct are immutable
or self-locking, there is no need to acquire the driver lock in
much of the libxl driver.

Move the libxl driver lock/unlock functions from libxl_driver.c
to libxl_conf.h so they can be used by other source files.

The libxlDriverPrivate struct contains an variety of data with
varying access needs. Similar to the QEMU and LXC drivers,
move all the static config data into a dedicated libxlDriverConfig
object. The only locking requirement is to hold the driver lock
while obtaining an instance of libxlDriverConfig. Once a reference
is held on the config object, it can be used completely lockless
since it is immutable.

libxlDomainGetInfo() uses the driver-wide libxl ctx when
it would be more appropriate to use the per-domain ctx
associated with the domain.  Switch to using the per-domain
libxl ctx.

libxl version info is static data as far as the libxl driver
is concerned, so retrieve this info when the driver is initialized
and stash it in the libxlDriverPrivate object.  Subsequently use
the stashed info instead of repeatedly calling libxl_get_version_info().

Detect early on in libxl driver initialization if the driver
should be loaded at all, avoiding needless initialization steps
that only have to be undone later.  While at it, move the
detection to a helper function to improve readability.

After detecting that the driver should be loaded, subsequent
failures such as initializing the log stream, allocating libxl
ctx, etc. should be treated as failure to initialize the driver.

Create libxl_domain.[ch] and move all functions operating on
libxlDomainObjPrivate to these files.  This will be useful for
future patches that e.g. add job support for libxlDomainObjPrivate.

Detecting whether or not to autoballoon is configuration related,
so move the code to libxl_conf.

More fallout from commit d72ef888.  When reconnecting to running
domains, the libxl_ctx in libxlDomainObjPrivate was used before
initializing it, causing a segfault in libxl and consequently
crashing libvirtd.

Initialize the libxlDomainObjPrivate libxl_ctx in libxlReconnectDomain,
and while at it use this ctx in libxlReconnectDomain instead of the
driver-wide ctx.