Rename the virVirtualPortProfileParams struct to be
virNetDevVPortProfile, and rename the APIs to match
this prefix.

* src/util/network.c, src/util/network.h: Rename port profile
  APIs
* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/conf/network_conf.c, src/conf/network_conf.h,
  src/network/bridge_driver.c, src/qemu/qemu_hotplug.c,
  src/util/macvtap.c, src/util/macvtap.h: Update for
  renamed APIs/structs

Rename virBandwidth to virNetDevBandwidth, and virRate to
virNetDevBandwidthRate.

* src/util/network.c, src/util/network.h: Rename bandwidth
  structs and APIs
* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/conf/network_conf.c, src/conf/network_conf.h,
  src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/qemu/qemu_command.c, src/util/macvtap.c,
  src/util/macvtap.h, tools/virsh.c: Update for API changes.

The default console type may vary based on the OS type. ie a Xen
paravirt guests wants a 'xen' console, while a fullvirt guests
wants a 'serial' console.

A plain integer default console type in the capabilities does
not suffice. Instead introduce a callback that is passed the
OS type.

* src/conf/capabilities.h: Use a callback for default console
  type
* src/conf/domain_conf.c, src/conf/domain_conf.h: Use callback
  for default console type. Add missing LXC/OpenVZ console types.
* src/esx/esx_driver.c, src/libxl/libxl_conf.c,
  src/lxc/lxc_conf.c, src/openvz/openvz_conf.c,
  src/phyp/phyp_driver.c, src/qemu/qemu_capabilities.c,
  src/uml/uml_conf.c, src/vbox/vbox_tmpl.c,
  src/vmware/vmware_conf.c, src/xen/xen_hypervisor.c,
  src/xenapi/xenapi_driver.c: Set default console type callback

While Xen only has a single paravirt console, UML, and
QEMU both support multiple paravirt consoles. The LXC
driver can also be trivially made to support multiple
consoles. This patch extends the XML to allow multiple
<console> elements in the XML. It also makes the UML
and QEMU drivers support this config.

* src/conf/domain_conf.c, src/conf/domain_conf.h: Allow
  multiple <console> devices
* src/lxc/lxc_driver.c, src/xen/xen_driver.c,
  src/xenxs/xen_sxpr.c, src/xenxs/xen_xm.c: Update for
  internal API changes
* src/security/security_selinux.c, src/security/virt-aa-helper.c:
  Only label consoles that aren't a copy of the serial device
* src/qemu/qemu_command.c, src/qemu/qemu_driver.c,
  src/qemu/qemu_process.c, src/uml/uml_conf.c,
  src/uml/uml_driver.c: Support multiple console devices
* tests/qemuxml2xmltest.c, tests/qemuxml2argvtest.c: Extra
  tests for multiple virtio consoles. Set QEMU_CAPS_CHARDEV
  for all console /channel tests
* tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.args,
  tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args
  tests/qemuxml2argvdata/qemuxml2argv-console-virtio.args: Update
  for correct chardev syntax
* tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.args,
  tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.xml: New
  test file

To support "managed" mode of host PCI device, we record the original
states (unbind_from_stub, remove_slot, and reprobe) so that could
reattach the device to host with original driver. But there is no XML
for theses attrs, and thus after daemon is restarted, we lose the
original states. It's easy to reproduce:

    1) virsh start domain
    2) virsh attach-device dom hostpci.xml (in 'managed' mode)
    3) service libvirtd restart
    4) virsh destroy domain

    You will see the device won't be bound to the original driver
if there was one.

This patch is to solve the problem by introducing internal XML
(won't be dumped to user, only dumped to status XML). The XML is:
    <origstates>
      <unbind/>
      <remove_slot/>
      <reprobe/>
    </origstates>

Which will be child node of <hostdev><source>...</souce></hostdev>.
(only for PCI device).

A new struct "virDomainHostdevOrigStates" is introduced for the XML,
and the according members are updated when preparing the PCI device.
And function "qemuUpdateActivePciHostdevs" is modified to honor
the original states. Use of qemuGetPciHostDeviceList is removed
in function "qemuUpdateActivePciHostdevs", and the "managed" value of
the device config is honored by the change. This fixes another problem
alongside:

    qemuGetPciHostDeviceList set the device as "managed" force
    regardless of whether the device is configured as "managed='yes'"
    or not in XML, which is not right.

Add additional fields to let you specify the how to authenticate with a disk.
The secret to use may be referenced by a usage string or a UUID, i.e.:

<auth username='myuser'>
 <secret type='ceph' usage='secretname'/>
</auth>

or

<auth username='myuser'>
 <secret type='ceph' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/>
</auth>
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

This attribute says what to do with cdrom (or floppy) if
the source is missing. It accepts:
- mandatory - fail if missing for any reason (the default)
- requisite - fail if missing on boot up, drop if missing on
              migrate/restore/revert
- optional  - drop if missing at any start attempt.

However, this patch introduces only XML part of this new
functionality.

Add a test for the simple parts of my indentation changes, and
fix the fallout.

* tests/domainsnapshotxml2xmltest.c: New test.
* tests/Makefile.am (domainsnapshotxml2xmltest_SOURCES): Build it.
* src/conf/domain_conf.c (virDomainSnapshotDefFormat): Avoid NULL
deref, match documented order.
* src/conf/domain_conf.h (virDomainSnapshotDefFormat): Add const.
* tests/domainsnapshotxml2xmlout/all_parameters.xml: Tweak output.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: Likewise.
* tests/domainsnapshotxml2xmlout/full_domain.xml: Likewise.
* .gitignore: Exempt new binary.

<domainsnapshot> is the first public instance of <domain> being
used as a sub-element, although we have two other private uses
(runtime state, and migration cookie).  Although indentation has
no effect on XML parsing, using it makes the output more consistent.

This uses virBuffer auto-indentation to obtain the effect, for all
but the portions of <domain> that are not generated a line at a
time into the same virBuffer.  Further patches will clean up the
remaining problems.

* src/conf/domain_conf.h (virDomainDefFormatInternal): New prototype.
* src/conf/domain_conf.c (virDomainDefFormatInternal): Export.
(virDomainObjFormat, virDomainSnapshotDefFormat): Update callers.
* src/libvirt_private.syms (domain_conf.h): Add new export.
* src/qemu/qemu_migration.c (qemuMigrationCookieXMLFormat): Use
new function.
(qemuMigrationCookieXMLFormatStr): Update caller.

VirtFS allows the user to choose between path/handle based fs driver.
As of now, libvirt hardcoded path based driver only. This patch provides
a solution to allow user to choose between path/handle based fs driver.

Sample:

    <filesystem type='mount'>
      <driver type='handle'/>
      <source dir='/folder/to/share1'/>
      <target dir='mount_tag1'/>
    </filesystem>

    <filesystem type='mount'>
      <driver type='path'/>
      <source dir='/folder/to/share2'/>
      <target dir='mount_tag2'/>
    </filesystem>
Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

The previous optimizations lead to some follow-on cleanups.

* src/conf/domain_conf.c (virDomainSnapshotForEachChild)
(virDomainSnapshotForEachDescendant): Drop dead parameter.
(virDomainSnapshotActOnDescendant)
(virDomainSnapshotObjListNumFrom)
(virDomainSnapshotObjListGetNamesFrom): Update callers.
* src/qemu/qemu_driver.c (qemuDomainSnapshotNumChildren)
(qemuDomainSnapshotListChildrenNames, qemuDomainSnapshotDelete):
Likewise.
* src/conf/domain_conf.h: Update prototypes.

No one was using virDomainSnapshotHasChildren, but that was an
O(n) function.  Exposing and tracking a bit more metadata for each
snapshot will allow the same query to be made with an O(1) query
of the member field.  For single snapshot operations (create,
delete), callers can be trusted to maintain the metadata themselves,
but for reloading, we can't compute parents as we go since there
is no guarantee that parents were parsed before children, so we also
provide a function to refresh the relationships, and which can
be used to detect if the user has ignored our warnings and been
directly modifying files in /var/lib/libvirt/qemu/snapshot.  This
patch only adds metadata; later patches will actually use it.

This layout intentionally hardcodes the size of each snapshot struct,
by tracking sibling pointers, rather than having to deal with the
headache of yet more memory management by directly sticking a
dynamically sized child[] on each parent.

* src/conf/domain_conf.h (_virDomainSnapshotObj)
(_virDomainSnapshotObjList): Add members.
(virDomainSnapshotUpdateRelations, virDomainSnapshotDropParent):
New prototypes.
(virDomainSnapshotHasChildren): Delete.
* src/conf/domain_conf.c (virDomainSnapshotSetRelations)
(virDomainSnapshotUpdateRelations, virDomainSnapshotDropParent):
New functions.
(virDomainSnapshotHasChildren): Drop unused function.
* src/libvirt_private.syms (domain_conf): Update exports.

Not too hard to wire up.  The trickiest part is realizing that
listing children of a snapshot cannot use SNAPSHOT_LIST_ROOTS,
and that we overloaded that bit to also mean SNAPSHOT_LIST_DESCENDANTS;
we use that bit to decide which iteration to use, but don't want
the existing counting/listing functions to see that bit.

* src/conf/domain_conf.h (virDomainSnapshotObjListNumFrom)
(virDomainSnapshotObjListGetNamesFrom): New prototypes.
* src/conf/domain_conf.c (virDomainSnapshotObjListNumFrom)
(virDomainSnapshotObjListGetNamesFrom): New functions.
* src/libvirt_private.syms (domain_conf.h): Export them.
* src/qemu/qemu_driver.c (qemuDomainSnapshotNumChildren)
(qemuDomainSnapshotListChildrenNames): New functions.

Previously libvirt's disk device XML only had a single attribute,
error_policy, to control both read and write error policy, but qemu
has separate options for controlling read and write. In one case
(enospc) a policy is allowed for write errors but not read errors.

This patch adds a separate attribute that sets only the read error
policy. If just error_policy is set, it will apply to both read and
write error policy (previous behavior), but if the new rerror_policy
attribute is set, it will override error_policy for read errors only.
Possible values for rerror_policy are "stop", "report", and "ignore"
("report" is the qemu-controlled default for rerror_policy when
error_policy isn't specified).

For consistency, the value "report" has been added to the possible
values for error_policy as well.

When support for was added for PCI multifunction cards (in commit
9f8baf, first included in libvirt 0.9.3), it was done by always
turning on the multifunction bit for all PCI devices. Since that time
it has been realized that this is not an ideal solution, and that the
multifunction bit must be selectively turned on. For example, see

  https://bugzilla.redhat.com/show_bug.cgi?id=728174

and the discussion before and after

  https://www.redhat.com/archives/libvir-list/2011-September/msg01036.html

This patch modifies multifunction support so that the multifunction=on
option is only added to the qemu commandline for a device if its PCI
<address> definition has the attribute "multifunction='on'", e.g.:

  <address type='pci' domain='0x0000' bus='0x00'
           slot='0x04' function='0x0' multifunction='on'/>

In practice, the multifunction bit should only be turned on if
function='0' AND other functions will be used in the same slot - it
usually isn't needed for functions 1-7 (although there are apparently
some exceptions, e.g. the Intel X53 according to the QEMU source
code), and should never be set if only function 0 will be used in the
slot. The test cases have been changed accordingly to illustrate.

With this patch in place, if a user attempts to assign multiple
functions in a slot without setting the multifunction bit for function
0, libvirt will issue an error when the domain is defined, and the
define operation will fail. In the future, we may decide to detect
this situation and automatically add multifunction=on to avoid the
error; even then it will still be useful to have a manual method of
turning on multifunction since, as stated above, there are some
devices that excpect it to be turned on for all functions in a slot.

A side effect of this patch is that attempts to use the same PCI
address for two different devices will now log an error (previously
this would cause the domain define operation to fail, but there would
be no log message generated). Because the function doing this log was
almost completely rewritten, I didn't think it worthwhile to make a
separate patch for that fix (the entire patch would immediately be
obsoleted).

While adding a new enum, I noticed a VIR_ENUM_DECL for a type that
doesn't exist. There is also of course no matching VIR_ENUM_IMPL for
it.

This patch was made in response to:

  https://bugzilla.redhat.com/show_bug.cgi?id=738095

In short, qemu's default for the rombar setting (which makes the
firmware ROM of a PCI device visible/not on the guest) was previously
0 (not visible), but they recently changed the default to 1
(visible). Unfortunately, there are some PCI devices that fail in the
guest when rombar is 1, so the setting must be exposed in libvirt to
prevent a regression in behavior (it will still require explicitly
setting <rom bar='off'/> in the guest XML).

rombar is forced on/off by adding:

  <rom bar='on|off'/>

inside a <hostdev> element that defines a PCI device. It is currently
ignored for all other types of devices.

At the moment there is no clean method to determine whether or not the
rombar option is supported by QEMU - this patch uses the advice of a
QEMU developer to assume support for qemu-0.12+. There is currently a
patch in the works to put this information in the output of "qemu-kvm
-device pci-assign,?", but of course if we switch to keying off that,
we would lose support for setting rombar on all the versions of qemu
between 0.12 and whatever version gets that patch.

QEMU 0.13 introduced cache=unsafe for -drive, this patch exposes
it in the libvirt layer.

  * Introduced a new QEMU capability flag ($prefix_CACHE_UNSAFE),
    as even if $prefix_CACHE_V2 is set, we can't know if unsafe
    is supported.

  * Improved the reliability of qemu cache type detection.

A new element is introduced to XML that allows to control
state of virtual network interfaces in hypervisors.

Live modification of the link state allows networking tools
propagate topology changes to guest OS or testing of
scenarios in complex (virtual) networks.

This patch adds elements to XML grammars and parsing and generating
code.

I got confused when 'virsh domblkinfo dom disk' required the
path to a disk (which can be ambiguous, since a single file
can back multiple disks), rather than the unambiguous target
device name that I was using in disk snapshots.  So, in true
developer fashion, I went for the best of both worlds - all
interfaces that operate on a disk (aka block) now accept
either the target name or the unambiguous path to the backing
file used by the disk.

* src/conf/domain_conf.h (virDomainDiskIndexByName): Add
parameter.
(virDomainDiskPathByName): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainDiskIndexByName): Also allow
searching by path, and decide whether ambiguity is okay.
(virDomainDiskPathByName): New function.
(virDomainDiskRemoveByName, virDomainSnapshotAlignDisks): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainBlockPeek)
(qemuDomainAttachDeviceConfig, qemuDomainUpdateDeviceConfig)
(qemuDomainGetBlockInfo, qemuDiskPathToAlias): Likewise.
* src/qemu/qemu_process.c (qemuProcessFindDomainDiskByPath):
Likewise.
* src/libxl/libxl_driver.c (libxlDomainAttachDeviceDiskLive)
(libxlDomainDetachDeviceDiskLive, libxlDomainAttachDeviceConfig)
(libxlDomainUpdateDeviceConfig): Likewise.
* src/uml/uml_driver.c (umlDomainBlockPeek): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainBlockPeek): Likewise.
* docs/formatsnapshot.html.in: Update documentation.
* tools/virsh.pod (domblkstat, domblkinfo): Likewise.
* docs/schemas/domaincommon.rng (diskTarget): Tighten pattern on
disk targets.
* docs/schemas/domainsnapshot.rng (disksnapshot): Update to match.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: Update test.

Adds an optional element to <domainsnapshot>, which will be used
to give user control over external snapshot filenames on input,
and specify generated filenames on output.

For now, no driver accepts this element; that will come later.

<domainsnapshot>
  ...
  <disks>
    <disk name='vda' snapshot='no'/>
    <disk name='vdb' snapshot='internal'/>
    <disk name='vdc' snapshot='external'>
      <driver type='qcow2'/>
      <source file='/path/to/new'/>
    </disk>
  </disks>
  <domain>
    ...
    <devices>
      <disk ...>
        <driver name='qemu' type='raw'/>
        <target dev='vdc'/>
        <source file='/path/to/old'/>
      </disk>
    </devices>
  </domain>
</domainsnapshot>

* src/conf/domain_conf.h (_virDomainSnapshotDiskDef): New type.
(_virDomainSnapshotDef): Add new elements.
(virDomainSnapshotAlignDisks): New prototype.
* src/conf/domain_conf.c (virDomainSnapshotDiskDefClear)
(virDomainSnapshotDiskDefParseXML, disksorter)
(virDomainSnapshotAlignDisks): New functions.
(virDomainSnapshotDefParseString): Parse new fields.
(virDomainSnapshotDefFree): Clean them up.
(virDomainSnapshotDefFormat): Output them.
* src/libvirt_private.syms (domain_conf.h): Export new function.
* docs/schemas/domainsnapshot.rng (domainsnapshot, disksnapshot):
Add more xml.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: New test.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: Update.

In order to distinguish disk snapshots from system checkpoints, a
new state value that is only valid for snapshots is helpful.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_LAST): New placeholder.
* src/conf/domain_conf.h (virDomainSnapshotState): New enum mapping.
(VIR_DOMAIN_DISK_SNAPSHOT): New internal enum value.
* src/conf/domain_conf.c (virDomainState): Use placeholder.
(virDomainSnapshotState): Extend mapping by one for use in snapshot.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Handle new state.
(virDomainObjSetState, virDomainStateReasonToString)
(virDomainStateReasonFromString): Avoid compiler warnings.
* tools/virsh.c (vshDomainState, vshDomainStateReasonToString):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new functions.
* docs/schemas/domainsnapshot.rng: Tighten state definition.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: New test.

As discussed here:
https://www.redhat.com/archives/libvir-list/2011-August/msg00361.html
https://www.redhat.com/archives/libvir-list/2011-August/msg00552.html

Adds snapshot attribute and transient sub-element:

<devices>
  <disk type=... snapshot='no|internal|external'>
    ...
    <transient/>
  </disk>
</devices>

* docs/schemas/domaincommon.rng (snapshot): New define.
(disk): Add snapshot and persistent attributes.
* docs/formatdomain.html.in: Document them.
* src/conf/domain_conf.h (virDomainDiskSnapshot): New enum.
(_virDomainDiskDef): New fields.
* tests/qemuxml2argvdata/qemuxml2argv-disk-transient.xml: New
test of rng, no args counterpart until qemu support is complete.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.args: New
file, snapshot attribute does not affect args.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.xml: Likewise.
* tests/qemuxml2argvtest.c (mymain): Run new test.

Just like VM saved state images (virsh save), snapshots MUST
track the inactive domain xml to detect any ABI incompatibilities.

The indentation is not perfect, but functionality comes before form.

Later patches will actually supply a full domain; for now, this
wires up the storage to support one, but doesn't ever generate one
in dumpxml output.

Happily, libvirt.c was already rejecting use of VIR_DOMAIN_XML_SECURE
from read-only connections, even though before this patch, there was
no information to be secured by the use of that flag.

And while we're at it, mark the libvirt snapshot metadata files
as internal-use only.

* src/libvirt.c (virDomainSnapshotGetXMLDesc): Document flag.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Add member.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Update signature.
* src/conf/domain_conf.c (virDomainSnapshotDefFree): Clean up.
(virDomainSnapshotDefParseString): Optionally parse domain.
(virDomainSnapshotDefFormat): Output full domain.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML)
(esxDomainSnapshotGetXMLDesc): Update callers.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML)
(vboxDomainSnapshotGetXMLDesc): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotLoad, qemuDomainSnapshotGetXMLDesc)
(qemuDomainSnapshotWriteMetadata): Likewise.
* docs/formatsnapshot.html.in: Rework doc example.
Based on a patch by Philipp Hahn.

Redefining a qemu snapshot requires a bit of a tweak to the common
snapshot parsing code, but the end result is quite nice.

Be careful that redefinitions do not introduce circular parent
chains.  Also, we don't want to allow conversion between online
and offline existing snapshots.  We could probably do some more
validation for snapshots that don't already exist to make sure
they are even feasible, by parsing qemu-img output, but that
can come later.

* src/conf/domain_conf.h (virDomainSnapshotParseFlags): New
internal flags.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString): Alter
signature to take internal flags.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML): Update caller.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Support
new public flags.

Filtering for roots is pretty easy to do.

* src/conf/domain_conf.h (virDomainSnapshotObjListGetNames)
(virDomainSnapshotObjListNum): Update prototype.
* src/conf/domain_conf.c (virDomainSnapshotObjListCopyNames)
(virDomainSnapshotObjListGetNames, virDomainSnapshotObjListCount)
(virDomainSnapshotObjListNum): Support filtering.
* src/qemu/qemu_driver.c (qemuDomainSnapshotNum)
(qemuDomainSnapshotListNames): Update callers.

Similar to the last patch in isolating the filtering from the
client actions, so that clients don't have to reinvent the
filtering.

* src/conf/domain_conf.h (virDomainSnapshotForEachChild): New
prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainSnapshotActOnChild)
(virDomainSnapshotForEachChild): New functions.
(virDomainSnapshotCountChildren): Delete.
(virDomainSnapshotHasChildren): Simplify.
* src/qemu/qemu_driver.c (qemuDomainSnapshotReparentChildren)
(qemuDomainSnapshotDelete): Likewise.

This one's nasty.  Ever since we fixed virHashForEach to prevent
nested hash iterations for safety reasons (commit fba550f6),
virDomainSnapshotDelete with VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN
has been broken for qemu: it deletes children, while leaving
grandchildren intact but pointing to a no-longer-present parent.
But even before then, the code would often appear to succeed to
clean up grandchildren, but risked memory corruption if you have
a large and deep hierarchy of snapshots.

For acting on just children, a single virHashForEach is sufficient.
But for acting on an entire subtree, it requires iteration; and
since we declared recursion as invalid, we have to switch to a
while loop.  Doing this correctly requires quite a bit of overhaul,
so I added a new helper function to isolate the algorithm from the
actions, so that callers do not have to reinvent the iteration.

Note that this _still_ does not handle CHILDREN correctly if one
of the children is the current snapshot; that will be next.

* src/conf/domain_conf.h (_virDomainSnapshotDef): Add mark.
(virDomainSnapshotForEachDescendant): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainSnapshotMarkDescendant)
(virDomainSnapshotActOnDescendant)
(virDomainSnapshotForEachDescendant): New functions.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiscardChildren):
Replace...
(qemuDomainSnapshotDiscardDescenent): ...with callback that
doesn't nest hash traversal.
(qemuDomainSnapshotDelete): Use new function.

- create a new "redirdev" element for this purpose

So that devices can be attached to hubs. Example, to attach to first
port of a usb-hub on port 1.

      <hub type='usb'>
         <address type='usb' bus='0' port='1'/>
      </hub>

      <input type='mouse' type='usb'>
         <address type='usb' bus='0' port='1.1'/>
      </hub>

also add a test entry

domain parsing and serialization code, qemu driver backend and
a couple of test

Companion controllers take an extra 'master' attribute to associate
them.

Also add tests for this

Expand the domain and the QEmu driver code
Adds a couple of tests

The model by default is piix3-uchi.

Example:
<controller type='usb' index='0' model='ich9-ehci'/>

List is: piix3-uhci piix4-uhci ehci ich9-ehci1 ich9-uhci1 ich9-uhci2
ich9-uhci3 vt82c686b-uhci pci-ohci

Since we are about to add USB controller support let's remove the
ambiguity

Newer QEMU introduced cache=directsync for -drive, this patchset
is to expose it in libvirt layer.

  * Introduced a new QEMU capability flag ($prefix_CACHE_DIRECTSYNC),
    As even $prefix_CACHE_V2 is set, we can't known if directsync
    is supported.

Audit all changes to the qemu vm->current_snapshot, and make them
update the saved xml file for both the previous and the new
snapshot, so that there is always at most one snapshot with
<active>1</active> in the xml, and that snapshot is used as the
current snapshot even across libvirtd restarts.

This patch does not fix the case of virDomainSnapshotDelete(,CHILDREN)
where one of the children is the current snapshot; that will be later.

* src/conf/domain_conf.h (_virDomainSnapshotDef): Alter member
type and name.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString)
(virDomainSnapshotDefFormat): Update clients.
* docs/schemas/domainsnapshot.rng: Tighten rng.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad): Reload current
snapshot.
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDiscard): Track current snapshot.

In some versions of qemu, both virtio-blk-pci and virtio-net-pci
devices can have an event_idx setting that determines some details of
event processing. When it is enabled, it "reduces the number of
interrupts and exits for the guest". qemu will automatically enable
this feature when it is available, but there may be cases where this
new feature could actually make performance worse (NB: no such case
has been found so far).

As a safety switch in case such a situation is encountered in the
field, this patch adds a new attribute "event_idx" to the <driver>
element of both disk and interface devices. event_idx can be set to
"on" (to force event_idx on in case qemu has it disabled by default)
or "off" (for force event_idx off). In the case that event_idx support
isn't present in qemu, the attribute is ignored (this on the advice of
the qemu developer).

docs/formatdomain.html.in: document the new flag (marking it as
   "don't mess with this!"
docs/schemas/domain.rng: add event_idx in appropriate places
src/conf/domain_conf.[ch]: add event_idx to parser and formatter
src/libvirt_private.syms: export
   virDomainVirtioEventIdx(From|To)String
src/qemu/qemu_capabilities.[ch]: detect and report event_idx in
   disk/net
src/qemu/qemu_command.c: add event_idx parameter to qemu commandline
    when appropriate.
tests/qemuxml2argvdata/qemuxml2argv-event_idx.args,
tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml,
tests/qemuxml2argvtest.c,
tests/qemuxml2xmltest.c: test cases for event_idx.