This patch sets or unsets the IFF_VNET_HDR flag depending on what device
is used in the VM. The manipulation of the flag is done in the open
function and is only fatal if the IFF_VNET_HDR flag could not be cleared
although it has to be (or if an ioctl generally fails). In that case the
macvtap tap is closed again and the macvtap interface torn.

* src/qemu/qemu_conf.c src/qemu/qemu_conf.h: pass qemuCmdFlags to
  qemudPhysIfaceConnect()
* src/util/macvtap.c src/util/macvtap.h: add vnet_hdr boolean to
  openMacvtapTap(), and private function configMacvtapTap()
* src/qemu/qemu_driver.c: add extra qemuCmdFlags when calling
  qemudPhysIfaceConnect()

For __virExec() this is a semantic NOP except for when fork()
fails. __virExec() would previously forget to restore the signal mask
in this case; virFork() corrects this behavior.

virFileCreate() and virDirCreate() gain the code to reset the logging
and properly deal with the signal handling race condition.

This also removes a log message that had a typo ("cannot fork o create
file '%s'") - this error is now logged in a more generic manner in
virFork() (more generic, but really just as informative, since the
fact that it's forking to create a file is immaterial to the fact that
it simply can't fork)

* src/util/util.c: use the generic virFork() in the 3 functions

virFork() contains bookkeeping that must be done any time a process
forks. Currently this includes:

1) Call virLogLock() prior to fork() and virLogUnlock() just after,
   to avoid a deadlock if some other thread happens to hold that lock
   during the fork.

2) Reset the logging hooks and send all child process log messages to
   stderr.

3) Block all signals prior to fork(), then either a) reset the signal
   mask for the parent process, or b) clear the signal mask for the
   child process.

Note that the signal mask handling in __virExec erroneously fails to
restore the signal mask when fork() fails. virFork() fixes this
problem.

Other than this, it attempts to behave as closely to fork() as
possible (including preserving errno for the caller), with a couple
exceptions:

1) The return value is 0 (success) or -1 (failure), while the pid is
   returned via the pid_t* argument. Like fork(), if pid < 0 there is
   no child process, otherwise both the child and the parent will
   return to the caller, and both should look at the return value,
   which will indicate if some of the extra processing outlined above
   encountered an error.

2) If virFork() returns with pid < 0 or with a return value < 0
   indicating an error condition, the error has already been
   reported. You can log an additional message if you like, but it
   isn't necessary, and may be awkwardly extraneous.

Note that virFork()'s child process will *never* call _exit() - if a
child process is created, it will return to the caller.

* util.c util.h: add virFork() function, based on what is currently
                 done in __virExec().

Support virtio-serial controller and virtio channel in QEMU backend.
Will output
the following for virtio-serial controller:

-device
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x4,max_ports=16,vectors=4

and the following for a virtio channel:

-chardev pty,id=channel0 \
-device
virtserialport,bus=virtio-serial0.0,chardev=channel0,name=org.linux-kvm.port.0

* src/qemu/qemu_conf.c: Add argument output for virtio
* tests/qemuxml2argvtest.c
  tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args: Add test for
  QEMU command line generation

Add support for virtio-serial by defining a new 'virtio' channel target type
and a virtio-serial controller. Allows the following to be specified in a
domain:

<controller type='virtio-serial' index='0' ports='16' vectors='4'/>
<channel type='pty'>
  <target type='virtio' name='org.linux-kvm.port.0'/>
  <address type='virtio-serial' controller='0' bus='0'/>
</channel>

* docs/schemas/domain.rng: Add virtio-serial controller and virtio
  channel type.
* src/conf/domain_conf.[ch]: Domain parsing/serialization for
  virtio-serial controller and virtio channel.
* tests/qemuxml2xmltest.c
  tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml: add domain xml
  parsing test
* src/libvirt_private.syms src/qemu/qemu_conf.c:
  virDomainDefAddDiskControllers() renamed to
  virDomainDefAddImplicitControllers()

Remove virDomainDevicePCIAddressEqual and virDomainDeviceDriveAddressEqual,
which are defined but not used anywhere.

* src/conf/domain_conf.[ch] src/libvirt_private.syms: Remove
  virDomainDevicePCIAddressEqual and virDomainDeviceDriveAddressEqual.

* src/qemu/qemu_driver.c: qemudStartVMDaemon() fix typo in comment

* src/node_device/node_device_linux_sysfs.c(get_virtual_functions_linux):
Return "ret", rather than always returning 0.

Currently we just error with ex. 'virbr0: No such device'.

Since we are using public API calls here, we need to ensure that any
raised error is properly saved and restored, since API entry points
always reset messages.

We were accessing the wrong private data structure, which would
cause a segfault.

virGetLastError returns NULL if no error has been set, not on
allocation error like virSetError assumed. Use virLastErrorObject
instead. This fixes virSetError when no error is currently stored.

The commands updated are SetMem, SetMaxMem, SetVcpus, and PinVcpu.

Rework and simplification of teardown of the macvtap device.

Basically all devices with the same MAC address and link device are kept
alive and not attempted to be torn down. If a macvtap device linked to a
physical interface with a certain MAC address 'M' is to be created it
will automatically fail if the interface is 'up'ed and another macvtap
with the same properties (MAC addr 'M', link dev) happens to be 'up'.
This will prevent the VM from starting or the device from being attached
to a running VM. Stale interfaces are assumed to be there for some
reason and not stem from libvirt.

In the VM shutdown path, it's assuming that an interface name is always
available so that if the device type is DIRECT it can be torn down
using its name.

* src/util/macvtap.h src/libvirt_macvtap.syms: change of deleting routine
* src/util/macvtap.c: cleanups and change of deleting routine
* src/qemu/qemu_driver.c: change cleanup on shutdown
* src/qemu/qemu_conf.c: don't delete Macvtap in qemudPhysIfaceConnect()

The QEMU JSON monitor changed balloon commands to return/accept
bytes instead of kilobytes. Update libvirt to cope with this

* src/qemu/qemu_monitor_json.c: Expect/use bytes for ballooning

* src/openvz/openvz_conf.c (openvzLoadDomains): Diagnose failure of
virUUIDFormat.

* src/qemu/qemu_monitor_text.c (qemuMonitorTextAddUSBDisk): Free
command output buffer.

* src/qemu/qemu_driver.c (qemuInitPasswords): Free pass-phrase buffer.

* src/qemu/qemu_monitor_text.c (qemuMonitorTextAddDevice): Free the
device name buffer.

* src/vbox/vbox_tmpl.c (vboxDomainDumpXML): Free vboxCallback buffer
upon OOM.

* src/conf/node_device_conf.c (virNodeDevCapScsiHostParseXML):
Free the "nodes" buffer allocated by virXPathNodeSet.

* src/uml/uml_driver.c (umlMonitorCommand): This function would
sometimes return -1, yet fail to free the "reply" it had allocated.
Hence, no caller would know to free the corresponding argument.
When returning -1, be sure to free all allocated resources.

* src/vbox/vbox_tmpl.c (vboxDomainDumpXML): Free def.
Improved by Matthias Bolte.

* src/openvz/openvz_conf.c (openvzFreeDriver): Also free driver buffer.
Based on a suggestion from Matthias Bolte.

* src/storage/storage_backend_mpath.c (virStorageBackendIsMultipath):
The result of dm_get_next_target was never used (and isn't needed),
so don't store it.

Similar to the Set*Mem commands, this implementation was bogus and
misleading. Make it clear this is a hotplug only operation, and that the
hotplug piece isn't even implemented.

Also drop the overkill maxvcpus validation: we don't perform this check
at XML define time so clearly no one is missing it, and there is
always the risk that our info will be out of date, possibly preventing
legitimate CPU values.
Signed-off-by: NCole Robinson <crobinso@redhat.com>

SetMem and SetMaxMem are hotplug only APIs, any persistent config
changes are supposed to go via XML definition. The original implementation
of these calls were incorrect and had the nasty side effect of making
a psuedo persistent change that would be lost after libvirtd restart
(I didn't know any better).

Fix these APIs to rightly reject non running domains.
Signed-off-by: NCole Robinson <crobinso@redhat.com>

The plain QEMU tree does not include 'thread_id' in the JSON
output. Thus we need to treat it as non-fatal if missing.

* src/qemu/qemu_monitor_json.c: Treat missing thread_id as non-fatal

A typo in the check for the primary IDE controller could cause
a crash on restore depending on the exact guest config.

* src/qemu/qemu_conf.c: Fix s/video/controller/ typo & slot
  number typo

Current error reporting for JSON mode returns the full JSON
command string and full JSON error string. This is not very
user friendly, so this change makes the error report only
contain the basic command name, and friendly error message
description string. The full JSON data is logged instead.

* src/qemu/qemu_monitor_json.c: Always return the 'desc' field from
  the JSON error message to users.

When in JSON mode, QEMU requires that 'qmp_capabilities' is run as
the first command in the monitor. This is a no-op when run in the
text mode monitor

* src/qemu/qemu_driver.c: Run capabilities negotiation when
  connecting to the monitor
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h: Add
  support for the 'qmp_capabilities' command, no-op in text mode.

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

This part adds the helper code to setup and tear down macvtap devices
using direct communication with the device driver via netlink sockets.
The rather short messages received from the netlink layer are now
written into a dynamically allocated buffer

* src/util/macvtap.h src/util/macvtap.c: provides the new module
* po/POTFILES.in: the module contains translated strings

This part adds support to domain_conf.{c|h} for parsing the new
interface XML of type 'direct'. The parsed mode is now stored as
an int.
* src/conf/domain_conf.c src/conf/domain_conf.h: extend parsing code
* src/util/macvtap.h: empty header to not break compilation

This patch adds build support for libvirt checking for certain contents
of /usr/include/linux/if_link.h to see whether macvtap support is
compilable on that system. One can disable macvtap support in libvirt
via --without-macvtap passed to configure.
* configure.ac src/Makefile.am: new build support
* src/libvirt_macvtap.syms: list of exported symbols
* src/util/macvtap.c: empty module to not break compilation

The open function returned -1 in case of an error, but -1 maps
to VIR_DRV_OPEN_DECLINED instead of VIR_DRV_OPEN_ERROR.

The virRaiseError macro inside of virSecurityReportError expands to
virRaiseErrorFull and includes the __FILE__, __FUNCTION__ and __LINE__
information. But this three values are always the same for every call
to virSecurityReportError and do not reflect the actual error context.

Converting virSecurityReportError into a macro results in getting the
correct __FILE__, __FUNCTION__ and __LINE__ information.

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

If giving a lxc://  URI instead of lxc:/// the open method
would crash ona NULL pointer

* src/lxc/lxc_driver.c: Cope with a NULL URI path

* src/util/hostusb.c: The device path for a USB device wants the
  bus/device IDs in decimal not octal

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.