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

The way QEMU is started has been changed to use '-device' and
the new style '-drive' syntax. This needs to be mirrored in
the hotplug code, requiring addition of two new APIs.

* src/qemu/qemu_monitor.h, src/qemu/qemu_monitor.c: Define APIs
  qemuMonitorAddDevice() and qemuMonitorAddDrive()
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h:
  Implement the new monitor APIs

To allow for better code reuse from hotplug methods, the code for
generating PCI/USB hostdev arg values is split out into separate
methods

* qemu/qemu_conf.h, qemu/qemu_conf.c: Introduce new APis for
  qemuBuildPCIHostdevPCIDevStr, qemuBuildUSBHostdevUsbDevStr
  and qemuBuildUSBHostdevDevStr

All the helper functions for building command line arguments
now return a 'char *', instead of acepting a 'char **' or
virBufferPtr argument

* qemu/qemu_conf.c: Standardize syntax for building args
* qemu/qemu_conf.h: Export all functions for building args
* qemu/qemu_driver.c: Update for changed syntax for building
  NIC/hostnet args

* src/qemu/qemu_driver.c (qemudLogReadFD): Don't pass a negative
offset (from a preceding failed attempt to seek to EOF) to this use
of lseek.

* src/qemu/qemu_monitor_text.c (qemuMonitorTextGetAllPCIAddresses):
Use %s.
* src/storage/storage_backend_iscsi.c (virStorageBackendCreateIfaceIQN):
Likewise.
* tools/virsh.c (cmdSecretSetValue): Likewise.

Similar to the race fixed by
be34c3c7, make sure
to wait around for KVM to release the resources from
a hot-detached PCI device before attempting to
rebind that device to the host driver.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

The QEMU driver contained code to generate a -device string for piix4-ide, but
wasn't using it. This change removes this string generation. It also adds a
comment explaining why IDE and FDC controllers don't generate -device strings.

The change also generates an error if a sata controller is specified for a QEMU
domain, as this isn't supported.

* src/qemu/qemu_conf.c: Remove VIR_DOMAIN_CONTROLLER_TYPE_IDE handler in
  qemuBuildControllerDevStr(). Ignore IDE and FDC controllers. Error if
  SATA controller is discovered. Add comments.

On RHEL-5 the qemu-kvm binary is located in /usr/libexec.
To reduce confusion for people trying to run upstream libvirt
on RHEL-5 machines, make the qemu driver look in /usr/libexec
for the qemu-kvm binary.

To make this work, I modified virFindFileInPath to handle an
absolute path correctly.  I also ran into an issue where
NULL was sometimes being passed for the file parameter
to virFindFileInPath; it didn't crash prior to this patch
since it was building paths like /usr/bin/(null).  This
is non-standard behavior, though, so I added a NULL
check at the beginning.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

If you shutdown libvirtd while a domain with PCI
devices is running, then try to restart libvirtd,
libvirtd will crash.

This happens because qemuUpdateActivePciHostdevs() is calling
pciDeviceListSteal() with a dev of 0x0 (NULL), and then trying
to dereference it.  This patch fixes it up so that
qemuUpdateActivePciHostdevs() steals the devices after first
Get()'ting them, avoiding the crash.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* src/qemu/qemu_monitor_text.c (qemuMonitorTextAttachDrive): Most other
failures in this function would "goto cleanup", but one mistakenly
returned directly, skipping the cleanup and resulting in a leak.
In addition, iterating the "try_command" loop would clobber, and
thus leak, the "cmd" allocated on the first iteration,
so be careful to free it in addition to "reply" beforehand.

The KVM build of QEMU includs the thread ID of each vCPU in the
'query-cpus' output. This is required for pinning guests to
particular host CPUs

* src/qemu/qemu_monitor_json.c: Extract 'thread_id' from CPU info

* src/util/json.c, src/util/json.h: Declare returned strings
  to be const
* src/qemu/qemu_monitor.c: Wire up JSON mode for qemuMonitorGetPtyPaths
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h: Fix
  const correctness. Add missing error message in the function
  qemuMonitorJSONGetAllPCIAddresses. Add implementation of the
  qemuMonitorGetPtyPaths function calling 'query-chardev'.

* src/qemu/qemu_monitor_text.c (qemuMonitorCommandWithHandler):
Always free *reply, upon failure.

Certain hypervisors (like qemu/kvm) map the PCI bar(s) on
the host when doing device passthrough.  This can lead to a race
condition where the hypervisor is still cleaning up the device while
libvirt is trying to re-attach it to the host device driver.  To avoid
this situation, we look through /proc/iomem, and if the hypervisor is
still holding onto the bar (denoted by the string in the matcher variable),
then we can wait around a bit for that to clear up.

v2: Thanks to review by DV, make sure we wait the full timeout per-device
Signed-off-by: NChris Lalancette <clalance@redhat.com>

Fix a small problem with the qemu memory stats parsing algorithm.  If qemu
reports a stat that libvirt does not recognize, skip past it so parsing can
continue.  This corrects a potential infinite loop in the parsing code that can
only be triggered if new statistics are added to qemu.

* src/qemu/qemu_monitor_text.c: qemuMonitorParseExtraBalloonInfo add a
  skip for extra ','

* src/qemu/qemu_conf.c (qemuBuildDriveStr): Use "%s".
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONGetGuestPCIAddress):
(qemuMonitorJSONGetGuestDriveAddress): Likewise.

The loop looking for the controller associated with a SCI drive had
an off by one, causing it to miss the last controller.

* src/qemu/qemu_driver.c: Fix off-by-1 in searching for SCSI
  drive hotplug

The hotplug code in QEMU was leaking memory because although the
inner device object was being moved into the main virDomainDefPtr
config object, the outer container virDomainDeviceDefPtr was not.

 * src/qemu/qemu_driver.c: Clarify code to show that the inner
   device object is owned by the main domain config upon
   successfull attach.

Add the ability to turn off dynamic management of file permissions
for libvirt guests.

* qemu/libvirtd_qemu.aug: Support 'dynamic_ownership' flag
* qemu/qemu.conf: Document 'dynamic_ownership' flag.
* qemu/qemu_conf.c: Load 'dynamic_ownership' flag
* qemu/test_libvirtd_qemu.aug: Test 'dynamic_ownership' flag

The hotplug code was not correctly invoking the security driver
in error paths. If a hotplug attempt failed, the device would
be left with VM permissions applied, rather than restored to the
original permissions. Also, a CDROM media that is ejected was
not restored to original permissions. Finally there was a bogus
call to set hostdev permissions in the hostdev unplug code

* qemu/qemu_driver.c: Fix security driver usage in hotplug/unplug

If there is a problem with VM startup, PCI devices may be left
assigned to pci-stub / pci-back. Adding a call to reattach
host devices in the cleanup path is required.

* qemu/qemu_driver.c: qemuDomainReAttachHostDevices() when
  VM startup fails

Remove all the QEMU driver calls for setting file ownership and
process uid/gid. Instead wire in the QEMU DAC security driver,
stacking it ontop of the primary SELinux/AppArmour driver.

* qemu/qemu_driver.c: Switch over to new DAC security driver

This new security driver is responsible for managing UID/GID changes
to the QEMU process, and any files/disks/devices assigned to it.

* qemu/qemu_conf.h: Add flag for disabling automatic file permission
  changes
* qemu/qemu_security_dac.h, qemu/qemu_security_dac.c: New DAC driver
  for QEMU guests
* Makefile.am: Add new files

* qemu/qemu_conf.h: Add securityPrimaryDriver and
  securitySecondaryDriver fields to 'struct qemud_driver'
* Makefile.am: Add new files
* qemu/qemu_security_stacked.c, qemu/qemu_security_stacked.h: A
  simple stacked security driver

Pulling the disk labelling code out of the exec hook, and into
libvirtd will allow it to access shared state in the daemon. It
will also make debugging & error reporting easier / more reliable.

* qemu/qemu_driver.c: Move initial disk labelling calls up into
  libvirtd. Add cleanup of disk labels upon failure

If a VM fails to start, we can't simply free the security label
strings, we must call the domainReleaseSecurityLabel() method
otherwise the reserved 'mcs' level will be leaked in SElinux

* src/qemu/qemu_driver.c: Invoke domainReleaseSecurityLabel()
  when domain fails to start

The current security driver architecture has the following
split of logic

 * domainGenSecurityLabel

    Allocate the unique label for the domain about to be started

 * domainGetSecurityLabel

    Retrieve the current live security label for a process

 * domainSetSecurityLabel

    Apply the previously allocated label to the current process
    Setup all disk image / device labelling

 * domainRestoreSecurityLabel

    Restore the original disk image / device labelling.
    Release the unique label for the domain

The 'domainSetSecurityLabel' method is special because it runs
in the context of the child process between the fork + exec.

This is require in order to set the process label. It is not
required in order to label disks/devices though. Having the
disk labelling code run in the child process limits what it
can do.

In particularly libvirtd would like to remember the current
disk image label, and only change shared image labels for the
first VM to start. This requires use & update of global state
in the libvirtd daemon, and thus cannot run in the child
process context.

The solution is to split domainSetSecurityLabel into two parts,
one applies process label, and the other handles disk image
labelling. At the same time domainRestoreSecurityLabel is
similarly split, just so that it matches the style. Thus the
previous 4 methods are replaced by the following 6 new methods

 * domainGenSecurityLabel

    Allocate the unique label for the domain about to be started
    No actual change here.

 * domainReleaseSecurityLabel

   Release the unique label for the domain

 * domainGetSecurityProcessLabel

   Retrieve the current live security label for a process
   Merely renamed for clarity.

 * domainSetSecurityProcessLabel

   Apply the previously allocated label to the current process

 * domainRestoreSecurityAllLabel

    Restore the original disk image / device labelling.

 * domainSetSecurityAllLabel

    Setup all disk image / device labelling

The SELinux and AppArmour drivers are then updated to comply with
this new spec. Notice that the AppArmour driver was actually a
little different. It was creating its profile for the disk image
and device labels in the 'domainGenSecurityLabel' method, where as
the SELinux driver did it in 'domainSetSecurityLabel'. With the
new method split, we can have consistency, with both drivers doing
that in the domainSetSecurityAllLabel method.

NB, the AppArmour changes here haven't been compiled so may not
build.

The QEMU driver is doing 90% of the calls to check for static vs
dynamic labelling. Except it is forgetting todo so in many places,
in particular hotplug is mistakenly assigning disk labels. Move
all this logic into the security drivers themselves, so the HV
drivers don't have to think about it.

* src/security/security_driver.h: Add virDomainObjPtr parameter
  to virSecurityDomainRestoreHostdevLabel and to
  virSecurityDomainRestoreSavedStateLabel
* src/security/security_selinux.c, src/security/security_apparmor.c:
  Add explicit checks for VIR_DOMAIN_SECLABEL_STATIC and skip all
  chcon() code in those cases
* src/qemu/qemu_driver.c: Remove all checks for VIR_DOMAIN_SECLABEL_STATIC
  or VIR_DOMAIN_SECLABEL_DYNAMIC. Add missing checks for possibly NULL
  driver entry points.

* src/lxc/lxc_container.c src/lxc/lxc_controller.c src/lxc/lxc_driver.c
  src/network/bridge_driver.c src/qemu/qemu_driver.c
  src/uml/uml_driver.c: virFileMakePath returns 0 for success, or the
  value of errno on failure, so error checking should be to test
  if non-zero, not if lower than 0

The test expected all environment variables copied in qemudBuildCommandLine
to have known values. So all of them have to be either set to a known value
or be unset. SDL_VIDEODRIVER and QEMU_AUDIO_DRV are not handled at all but
should be handled. Unset both, otherwise the test will fail if they are set
in the testing environment.

* src/qemu/qemu_conf.c: add a comment about copied environment variables
  and qemuxml2argvtest
* tests/qemuxml2argvtest.c: unset SDL_VIDEODRIVER and QEMU_AUDIO_DRV

Invoking the virConnectGetCapabilities() method causes the QEMU
driver to rebuild its internal capabilities object. Unfortunately
it was forgetting to register the custom domain status XML hooks
again.

To avoid this kind of error in the future, the code which builds
capabilities is refactored into one single method, which can be
called from all locations, ensuring reliable rebuilds.

* src/qemu/qemu_driver.c: Fix rebuilding of capabilities XML and
  guarentee it is always consistent