This part adds support for qemu making a macvtap tap device available
via file descriptor passed to qemu command line. This also attempts to
tear down the macvtap device when a VM terminates. This includes support
for attachment and detachment to/from running VM.
* src/qemu/qemu_conf.[ch] src/qemu/qemu_driver.c: add support in the
  QEmu driver

Current PCI addresses are allocated at time of VM startup.
To make them truely persistent, it is neccessary to do this
at time of virDomainDefine/virDomainCreate. The code in
qemuStartVMDaemon still remains in order to cope with upgrades
from older libvirt releases

* src/qemu/qemu_driver.c: Rename existing qemuAssignPCIAddresses
  to qemuDetectPCIAddresses. Add new qemuAssignPCIAddresses which
  does auto-allocation upfront. Call qemuAssignPCIAddresses from
  qemuDomainDefine and qemuDomainCreate to assign PCI addresses that
  can then be persisted. Don't clear PCI addresses at shutdown if
  they are intended to be persistent

The old text mode monitor prompts for a password when disks are
encrypted. This interactive approach doesn't work for JSON mode
monitor. Thus there is a new 'block_passwd' command that can be
used.

* src/qemu/qemu_driver.c: Split out code for looking up a disk
  secret from findVolumeQcowPassphrase, into a new method
  getVolumeQcowPassphrase. Enhance qemuInitPasswords() to also
  set the disk encryption password via the monitor
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  support for the 'block_passwd' monitor command.

Since c26cb923, the dname
parameter has been ignored by these two functions.  Use it.
* src/qemu/qemu_driver.c (qemudDomainMigratePrepareTunnel): Honor dname
parameter once again.
(qemudDomainMigratePrepare2): Likewise.

All other libvirt functions use array first and then number of elements
in that array. Let's make cpuDecode follow this rule.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NChris Lalancette <clalance@redhat.com>

With QEMU >= 0.12 the host and guest side of disks no longer have
the same naming convention. Specifically the host side will now
get a 'drive-' prefix added to its name. The 'info blockstats'
monitor command returns the host side name, so it is neccessary
to strip this off when looking up stats since libvirt stores the
guest side name !

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Move 'drive-' prefix
  string to a defined constant
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_text.c: Strip
  off 'drive-' prefix (if found) when looking up disk stats

Currently the timeout for reading startup output is 3 seconds. If the
host is under any sort of load, we can easily trigger this. Lets bump
it to 30 seconds.

Since the polling loop checks to see if the process has died, we shouldn't
erroneously hit this timeout if qemu bombs (only if it is stuck in some
infinite loop).

The timeout errors were unconditionally being overwritten by the less
helpful 'unable to start guest' error.

Use the ATTRIBUTE_NONNULL annotation to mark some virConnectPtr
args as mandatory non-null so the compiler can warn of mistakes

* src/conf/domain_event.h: All virConnectPtr args must be non-null
* src/qemu/qemu_conf.h: qemudBuildCommandLine and
  qemudNetworkIfaceConnect() must be given non-null connection
* tests/qemuxml2argvtest.c: Provide a non-null (dummy) connection to
  qemudBuildCommandLine()

The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in cpu_conf.{h,c} and update all callers to
match

The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in node_device_conf.{h,c} and update all callers to
match

All callers now pass a NULL virConnectPtr into the USB/PCi device
iterator functions. Therefore the virConnectPtr arg can now be
removed from these functions

* src/util/hostusb.h, src/util/hostusb.c: Remove virConnectPtr
  from usbDeviceFileIterate
* src/util/pci.c, src/util/pci.h: Remove virConnectPtr arg from
  pciDeviceFileIterate
* src/qemu/qemu_security_dac.c, src/security/security_selinux.c: Update
  to drop redundant virConnectPtr arg

* src/qemu/qemu_conf.c: Fix ',' vs '.' typo in floppy disk arg

The QEMU flags are commonly stored as a signed or unsigned int,
allowing only 31 flags. This limit is rather close, so to aid
future patches, change it to a 64-bit int

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h, src/qemu/qemu_driver.c,
  tests/qemuargv2xmltest.c, tests/qemuhelptest.c, tests/qemuxml2argvtest.c:
  Use 'unsigned long long' for QEMU flags

The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in security_driver.{h,c} and update all callers to
match

The security driver was mistakenly initialized before the QEMU
config file was loaded. This prevents it being turned off again.
The capabilities XML was also getting the wrong security driver
name, due to the stacked driver arrangement.

* src/qemu/qemu_driver.c: Fix initialization order and capabilities
  model name

It was used for error reporting only.

It was used for error reporting only.

It was used for error reporting only.

It was used for error reporting only.

It was used for error reporting only.

It was used for error reporting only.

Implementation of domain{Attach,Detach}DeviceFlags handlers
in the drivers.

When restoring from a saved guest image, the XML would already
contain the PCI slot ID of the IDE controller & video card.
The attempt to explicitly reserve this upfront would thus fail
everytime.

* src/qemu/qemu_conf.c: Reserve IDE controller / video card
  slot at time of need, rather than upfront

If the primary security driver (SELinux/AppArmour) was disabled
then the secondary QEMU DAC security driver was also disabled.
This is mistaken, because the latter must be active at all times

* src/qemu/qemu_driver.c: Ensure DAC driver is always active

To allow devices to be hot(un-)plugged it is neccessary to ensure
they all have a unique device aliases. This fixes the hotplug
methods to assign device aliases before invoking the monitor
commands which need them

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Expose methods
  for assigning device aliases for disks, host devices and
  controllers
* src/qemu/qemu_driver.c: Assign device aliases when hotplugging
  all types of device
* tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address-device.args,
  tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.args:
  Update for changed hostdev naming scheme

This patch re-arranges the QEMU device alias assignment code to
make it easier to call into the same codeblock when performing
device hotplug. The new code has the ability to skip over already
assigned names to facilitate hotplug

* src/qemu/qemu_driver.c: Call qemuAssignDeviceNetAlias()
  instead of qemuAssignNetNames
* src/qemu/qemu_conf.h: Export qemuAssignDeviceNetAlias()
  instead of qemuAssignNetNames
* src/qemu/qemu_driver.c: Merge the legacy disk/network alias
  assignment code into the main methods

The current way of assigning names to the host network backend and
NIC device in QEMU was over complicated, by varying naming scheme
based on the NIC model and backend type. This simplifies the naming
to simply be 'net0' and 'hostnet0', allowing code to easily determine
the host network name and vlan based off the primary device alias
name 'net0'. This in turn allows removal of alot of QEMU specific
code from the XML parser, and makes it easier to assign new unique
names for NICs that are hotplugged

* src/conf/domain_conf.c, src/conf/domain_conf.h: Remove hostnet_name
  and vlan fields from virNetworkDefPtr
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h, src/qemu/qemu_driver.c:
  Use a single network alias naming scheme regardless of NIC type
  or backend type. Determine VLANs from the alias name.
* tests/qemuxml2argvdata/qemuxml2argv-net-eth-names.args,
  tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.args,
  tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.args: Update
  for new simpler naming scheme

The QEMU 0.12.x tree has the -netdev command line argument, but not
corresponding monitor command. We can't enable the former, without
the latter since it will break hotplug/unplug.

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Disable -netdev usage
  until 0.13 at earliest
* tests/qemuxml2argvtest.c: Add test for -netdev syntax
* tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.args,
  tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.xml: Test
  data files for -netdev syntax

PCI disk, disk controllers, net devices and host devices need to
have PCI addresses assigned before they are hot-plugged

* src/qemu/qemu_conf.c: Add APIs for ensuring a device has an
  address and releasing unused addresses
* src/qemu/qemu_driver.c: Ensure all devices have addresses
  when hotplugging.

The current QEMU code allocates PCI addresses incrementally starting
at 4. This is not satisfactory because the user may have given some
addresses in their XML config, which need to be skipped over when
allocating addresses to remaining devices.

It is thus neccessary to maintain a list of already allocated PCI
addresses and then only allocate ones that remain unused. This is
also required for domain device hotplug to work properly later.

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Add APIs for creating
  list of existing PCI addresses, and allocating new addresses.
  Refactor address assignment to use this code
* src/qemu/qemu_driver.c: Pull PCI address assignment up into the
  qemuStartVMDaemon() method, as a prelude to moving it into the
  'define' method. Update list of allocated addresses when connecting
  to a running VM at daemon startup.
* tests/qemuxml2argvtest.c, tests/qemuargv2xmltest.c,
  tests/qemuxml2xmltest.c: Remove USB product test since all
  passthrough is done based on address
* tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-product.args,
  tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-product.xml: Kil
  unused data files

Since QEMU startup uses the new -device argument, the hotplug
code needs todo the same. This converts disk, network and
host device hotplug to use the device_add command

* src/qemu/qemu_driver.c: Use new device_add monitor APIs
  whereever possible