https://bugzilla.redhat.com/show_bug.cgi?id=1289391

Rather than pass the whole drive string (which contained the alias),
pass only the alias for the qemuMonitorDriveDel call in the error
path when adding a host device in the monitor fails.

When building the command line alias and for SCSI Host Device deletion,
use the common API to build the alias

Introduce a common API to generate the alias for a host device

Completion of fix for:
    https://bugzilla.redhat.com/show_bug.cgi?id=1336225

Similar to the other disk types, add the qemuMonitorDriveDel in the failure
to add/hotplug a SCSI disk.

Partial fix for:
    https://bugzilla.redhat.com/show_bug.cgi?id=1336225

Similar to the other disk types, add the qemuMonitorDriveDel in the failure
to add/hotplug a USB.

Added a couple of other formatting changes just to have a less cluttered look

Move QEMU_DRIVE_HOST_PREFIX into the qemu_alias.c to dissuade future
callers from using it. Create qemuAliasDiskDriveSkipPrefix in order
to handle the current consumers that desire to check if an alias has
the drive- prefix and "get beyond it" in order to get the disk alias.

Rather than open code build the drive alias command in multiple places,
use the helper to ensure consistency.

Since we already have a function that will generate the drivestr from
the alias, let's use it and remove the qemuDeviceDriveHostAlias.

Move the QEMU_DRIVE_HOST_PREFIX definition into qemu_alias.h

Also alter qemuAliasFromDisk to use the QEMU_DRIVE_HOST_PREFIX instead
of "drive-%s".

The qemuDomainSnapshotCreateSingleDiskActive open coded generating the
disk drive alias. Let's use the common function.

Rather than pass the disks[i]->info.alias to qemuMonitorSetDrivePassphrase
and then generate the "drive-%s" alias from that, let's use qemuAliasFromDisk
prior to the call to generate the drive alias and then pass that along
thus removing the need to generate the alias from the monitor code.

Modify the error/exit path to match what was done for Virtio and SCSI.
If nothing else it'll have a consistent look'n'feel

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.