Also includes unittests for node device lifecycle events API

Add node device event handling infrastructure to node_device_event.[ch]

Node device lifecycle event API entry points for registering and
deregistering node deivce events, as well as types of events
associated with node device.
These entry points will be used for implementing asynchronous
lifecycle events.

Node device API:
virConnectNodeDeviceEventRegisterAny
virConnectNodeDeviceEventDeregisterAny
virNodeDeviceEventLifecycleType which has events CREATED and DELETED

As commit id 'e2b86f58' notes, when mode=agent possibly setting the
fake reboot flag to true wouldn't be necessary; however, it doesn't
"force" the issue by just ensuring the fake reboot is false, so this
patch adds the explicit setting for the reboot path.

More investigation and details can be found in commit id '8be502fd'
as well as in the archives at:

  https://www.redhat.com/archives/libvir-list/2015-April/msg00715.html

Conditional setting of the fake reboot flag should only happen for
the acpi mode shutdown path; however, for the agent mode shutdown,
the fake reboot should be cleared. This patch will essentially revert
commit id '8be502fd', but adds an explicit setting of the flag to false
when using mode=agent while also only conditionally setting the reboot
flag if the guest went away. This also avoids an issue where a shutdown
with reboot semantics is done from agent mode which sets the reboot
flag followed by a shutdown from within the guest which would result
in a reboot due to the fake reboot flag being set. The change will
also properly handle the cases described in the following archive post:

  https://www.redhat.com/archives/libvir-list/2015-April/msg00715.html

Commit id '44304c6e' added the API libxlDomainAttachControllerDevice
inside a conditional LIBXL_HAVE_PVUSB, but called that function outside
the conditional in libxlDomainAttachDeviceLive.

Similarly, the API libxlDomainDetachControllerDevice was added inside a
conditional LIBXL_HAVE_PVUSB, but called outside the conditional in
libxlDomainDetachDeviceLive.

This patch adds the conditional LIBXL_HAVE_PVUSB around those two calls
from within the switch.

Commit id '7d3b2eb5' missed a closing parenthesis on the ignore_value
macro, causing the failure

Prior to commit 2737aaaf, we allowed every client to connect successfully,
however, if accepting a client would eventually lead to an overcommit of the
limits, we would disconnect it immediately with "Too many active clients,
dropping connection from...". Recent changes refactored the code in a way, that
it is not possible for the client-related callback to be dispatched and the
client to be accepted if the limits wouldn't permit to do so, therefore a check
if a connection should be dropped due to limits violation has become a dead
code that could be removed.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

Commit 2737aaaf changed our policy for accepting new clients in a way, that
instead of accepting new clients only to disconnect them immediately, since
that would overcommit the limit, we temporarily disable polling for the
dedicated file descriptor, so any new connection will queue on the socket.
Commit 8b1f0469 then added the possibility to change the limits during runtime
but it didn't re-enable polling for the previously disabled file descriptor,
thus any new connection would still continue to queue on the socket. This patch
forces an update of the services each time the limits were changed in some way.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1357776Signed-off-by: NErik Skultety <eskultet@redhat.com>

So far, virNetServerCheckLimits was only used to possibly re-enable accepting
new clients that might have previously been disabled due to client limits
violation (max_clients, max_anonymous_clients). This patch refactors
virNetServerAddClient, which is currently the only place where the services get
disabled, in order to use the virNetServerCheckLimits helper instead of
checking the limits by itself.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

Since virNetServerAddClient checks for the limits in order to temporarily
suspend the services, thus not accepting any more clients, there is no reason
why virNetServerCheckLimits, which is only responsible for re-enabling
previously disabled services according to the limits, could not do both. To be
able to do that however, it needs to be moved up in the file since it's static
(and because it's just a helper and there's only one caller it should remain
 static).
Signed-off-by: NErik Skultety <eskultet@redhat.com>

The original naming was just a leftover that should have been fixed in commit
8b1f0469.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

Introduce libxl hook and use it for start, prepare, started,
stop, stopped, migrate events.

In case of error, libxlReconnectDomain may call
virDomainObjListRemoveLocked. However it has no local reference on
the domain object, leading to segfault. Get a reference to the domain
object at the start of the function and release it at the end to avoid
problems.

This commit also factorizes code between the error and normal ends.

The migrate hook will affect the migrated guest definition. Allow
these domains be marked as tainted in the libxl driver.

To sync with virDomainControllerModelUSB, we add two models
in qemuControllerModelUSB 'qusb1' and 'qusb2', but those
models are not supported in qemu driver. So add check in
device post parse to report errors if 'qusb1' and 'qusb2'
are specified.
Signed-off-by: NChunyan Liu <cyliu@suse.com>

libxl configuration files conversion can now handle USB controllers.
When parting libxl config file, USB controllers with type PV are
ignored as those aren't handled.
Signed-off-by: NChunyan Liu <cyliu@suse.com>

When hotplugging a USB device, check if there is an available controller
and port, if not, automatically create a USB controller of version
2.0 and 8 ports.
Signed-off-by: NChunyan Liu <cyliu@suse.com>

Support USB controller hot-plug and hot-unplug.

 #virsh attach-device dom usbctrl.xml
 #virsh detach-device dom usbctrl.xml
 usbctrl.xml example:
 <controller type='usb' index='0' model='qusb2'>
Signed-off-by: NChunyan Liu <cyliu@suse.com>

To support USB Controller in xen guest domains, just add
USB controller in domain config xml as following:
<controller type='usb' model='qusb2' ports='4'/>
Signed-off-by: NChunyan Liu <cyliu@suse.com>

According to libxl implementation, it supports pvusb
controller of version 1.1 and version 2.0, and it
supports two types of backend, 'pvusb' (dom0 backend)
and 'qusb' (qemu backend). But currently pvusb backend
is not checked in yet.

To match libxl support, extend usb controller schema
to support two more models: qusb1 (qusb, version 1.1)
and 'qusb2' (qusb version 2.0).
Signed-off-by: NChunyan Liu <cyliu@suse.com>

Construct the query string by using virBufferTrim rather than having to
remember to add a space and simplify cleanup path.

Use a temporary pointer rather than always recalculating the index in a
very verbose way.

Add a structure to store the data and use a single array of the
structures rather than having 3 separate arrays with shared indexes.

Let's cleanly differentiate what wiping a volume does for ploop and
other volumes so it's more readable what is done for each one instead of
branching out multiple times in different parts of the same function.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Some functions use volume specification merely to use the target path
from it.  Let's change it to pass the path only so that it can be used
for other files than just volumes.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

This is done in order to call them in next patches from each other and
definitions would be missing otherwise.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

When reset was called from a domain that crashed we didn't change the
crashed state into a paused one which could confuse users.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1269575Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Commit 0c56d943 forgot to return false in the cmdConnect command
after the clean up made there.

Before (assuming you don't have uri alias for 'asdf'):
  $ virsh connect asdf
  error: failed to connect to the hypervisor

  $ echo $?
  0

After (with the same assumption):
  $ virsh connect asdf
  error: failed to connect to the hypervisor
  error: no connection driver available for asdf

  $ echo $?
  1

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1356461Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Until now we simply errored out when the translation from pool+volume
failed.  However, we should instead check whether that disk is needed or
not since there is an option for that.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1168453Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

There is an error reset following the function and check for
startupPolicy before that.  Let's reflect those things inside that
function so that future code doesn't have to be that complex.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>