Implement a compressed save image format for qemu.  While ideally
we would have the choice between compressed/non-compressed
available to the libvirt API, unfortunately there is no "flags"
parameter to the virDomainSave() API.  Therefore, implement this
as a qemu.conf option.  gzip, bzip2, and lzma are implemented, and
it should be very easy to implement additional compression
methods.

One open question is if/how we should detect the compression
binaries.  One way to do it is to do compile-time setting of the
paths (via configure.in), but that doesn't seem like a great thing
to do.  My preferred solution is not to detect at all;
when we go to run the commands that need them, if they
aren't available, or aren't available in one of the standard paths,
then we'll fail.  That's also the solution implemented in this patch.

In the future, we'll have a more robust (managed) save/restore API,
at which time we can expose this functionality properly in the API.

V2: get rid of redundant dd command and just use >> to append data.
V3: Add back the missing pieces for the enum and bumping the save version.
V4: Make the compressed field in the save_header an int.
    Implement LZMA compression.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

PCI device assignment is only supported in KVM's fork of qemu, so we
should really detect its availability and give a nice error if its
not supported.

* src/qemu_conf.[ch]: introduce QEMUD_CMD_FLAG_PCIDEVICE indicating
  that the -pcidevice command line option is available

* tests/*: update the tests

* docs/schemas/*.rng: the comments were wrong
* src/qemu_conf.c: typo in an error message

With hotplug, we're going to want to pass a tapfd name rather than an
actual file descriptor, so prepare the way by passing a string tapfd to
qemuBuildHostNetStr().

* src/qemu_conf.h: qemuBuildHostNetStr() takes a string tapfd now

* src/qemu_conf.c: pass qemuBuildHostNetStr() a string rather than an
  actual file descriptor

* src/qemu_driver.c: update qemudDomainAttachNetDevice() for change

* src/qemu_conf.h: export qemudNetworkIfaceConnect()

* src/qemu_conf.c: move vnet_hdr logic into qemudNetworkIfaceConnect()
  since we need it for hotplug too

By probing for qemu machine types, we increased the time of a
GetCapabilities call from 100us to a whopping 60ms.

This patch takes the approach of only probing for machine types
when the mtime of the emulator binary changed since the last time
the capabilities were generated.

* src/capabilities.h: cache the emulator binary mtime

* src/qemu_conf.c: add qemudGetOldMachines() to copy the machine
  types from the old caps struct if the mtime for the binary hasn't
  changed

* src/qemu_conf.h, src/qemu_driver.c: pass the old caps pointer to
  qemudCapsInit()

Not all possible emulators are actually in the capabilities, so if we
don't find the supplied emulator we should probe it directly for machine
types.

* src/qemu_driver.c: add qemudCanonicalizeMachineDirect() to directly
  probe an emulator for the canonical machine type

In qemu-0.11 there is a 'pc-0.10' machine type which allows you to run
guests with a machine which is compatible with the pc machine in
qemu-0.10 - e.g. using the original PCI class for virtio-blk and
virtio-console and disabling MSI support in virtio-net. The idea here
is that we don't want to suprise guests by changing the hardware when
qemu is updated.

I've just posted some patches for qemu-0.11 which allows libvirt to
canonicalize the 'pc' machine alias to the latest machine version.

This patches makes us use that so that when a guest is configured to
use the 'pc' machine type, we resolve that to 'pc-0.11' machine and
save that in the guest XML.

See also:

  https://fedoraproject.org/wiki/Features/KVM_Stable_Guest_ABI

* src/qemu_conf.c: add qemudCanonicalizeMachine() to canonicalize
  the machine type according to the machine aliases in capabilities

* src/qemu_driver.c: parse aliases in qemudParseMachineTypesStr()

A subsequent commit will add a "canonical" field to this structure,
this patch basically just prepares the way for that.

The new type is added, along with virCapabilitiesAlloc/FreeMachines()
helpers and a whole bunch of code to make the transition.

One quirk is that virCapabilitiesAddGuestDomain() and
virCapabilitiesAddGuest() take ownership of the machine list rather
than duping it. This makes sense to avoid needless copying.

* src/capabilities.h: add the virCapsGuestMachine struct and use it
  in virCapsGuestDomainInfo, add prototypes for new functions and
  update the AddGuest() prototypes

* src/capabilities.c: add code for allocating and freeing the new
  type, change the machines parameter to AddGuest() etc.

* src/libvirt_private.syms: export the new helpers

* src/qemu_conf.c: update all the machine type code to use the new
  struct

* src/xen_internal.c: ditto

* tests/testutilsqemu.c: ditto

Currently we hardcode the QEMU machine types. We should really just
parse the output of 'qemu -M ?' so the lists don't get out of sync.

xenner doesn't support '-M ?', so we still need to hardcode that.

The horrible (const char *const *) is removed in a subsequent patch.

* src/qemu_conf.c: kill the arch_info*machines tables, retain the
  hardcoded xenner machine type, add qemudProbeMachineTypes() to
  run and parse 'qemu -M ?' and use it in qemudCapsInitGuest()

There's no need for the hasbase/hasaltbase confusion, just store the
first binary path found in a variable.

* src/qemu_conf.c: kill hasbase/hasaltbase logic in qemudCapsInitGuest()

 * qemud/libvirtd_qemu.aug, qemud/test_libvirtd_qemu.aug,
   src/qemu.conf: Add 'cgroups_controllers' and 'cgroups_device_acl'
   parameters
 * src/qemu_conf.h, src/qemu_conf.c: Load & parse configuration params
   for cgroups
 * src/qemu_driver.c: Only use cgroups controllers that are activated,
   and use configured device whitelist instead of default, if set.

If the qemu binary supports "-no-kvm" and/or "-no-kqemu", they should
always be added for plain "qemu" domains.  Previously, we omitted them
whenever the host and guest architectures implied that they would be
disabled automatically, but that logic was flawed in some cases
(such as i686 and x86_64).
* src/qemu_conf.c: fix the conditions for adding "-no-kvm" and/or "-no-kqemu"

Implement basic NIC hotplug support using the 'host_net_add' and
'pci_add' qemu monitor commands.

For now, we don't support 'bridge' or 'network' types.

Also, if pci_add fails, we currently fail to remove the backend
which we added.

Finally, NIC hot-unplug support is missing.

* src/qemu_driver.c: add qemudDomainAttachNetDevice()

* src/qemu_conf.[ch]: export qemuBuildNicStr(), qemuBuildHostNetStr()
  and qemuAssignNames()

* src/libvirt_private.syms: export virDomainNetTypeToString()

Currently, an interface's vlan number corresponds to its index in
the table of network interfaces. That is no longer true when we
allow devices to be removed.

To fix this, we store the vlan number in the domain's state XML
so that it survives libvirtd restarts.

* src/domain_conf.h: add vlan number to virDomainNetDef

* src/domain_conf.c: store it in XML as <state vlan='N'/>, defaulting
  to -1 if this is state saved by a previous version of libvirt

* src/qemu_conf.c: assign vlan numbers before starting qemu

We need these so that we can remove the devices via the monitor.

* src/domain_conf.h: add nic_name and hostnet_name to virDomainNetDef

* src/domain_conf.c: free nic_name and hostnet_name

* src/qemu_conf.c: add qemuAssignNetNames(), use it if qemu has
  support for the param and pass the names on the command line

* tests/qemuxml2argv*: add a test for this

Add QEMUD_CMD_FLAG_NET_NAME to indicate that '-net ...,name=foo' is
supported and QEMUD_CMD_FLAG_HOST_NET_ADD to indicate that the
'host_net_add' monitor command is available.

Set both these flags if the qemu version is greater than 0.10.0.
Checking via the '-help' output would not work for the monitor command
and even for the command line arg, it would be quite fragile.

* src/qemu_conf.h: add new flags as aliases of QEMUD_CMD_FLAG_0_10

* src/qemu_conf.c: set QEMUD_CMD_FLAG_0_10 for versions >= 0.10.0

* tests/qemuhelptest.c: set QEMUD_CMD_FLAG_0_10 for the appropriate
  qemu versions

Re-factor this code so that it can be used for NIC hotplug
too. The awkward prefix and type_sep arguments are needed to
allow us to do "host_net_add tap vlan=..."

* src/qemu_conf.c: factor the net backend string formatting
  code into its own function

Re-factor this code so that it can be used for NIC hotplug
too. The awkward arguments are needed to allow use to do
"pci_add auto nic macaddr=..."

* src/qemu_conf.c: factor the nic string formatting code into
  its own function

* configure.in: Add --with-qemu-user and --with-qemu-group args
* libvirt.spec.in: use 'qemu' for user/group for Fedora >= 12
* qemud/libvirtd_qemu.arg, qemud/test_libvirtd_qemu.aug,
  src/qemu.conf: Add 'user' and 'group' args for configuration
* src/Makefile.am: Create %localstatedir/cache/libvirt/qemu
* src/qemu_conf.c, src/qemu_conf.h: Load user/group from config
* src/qemu_driver.c: Change user ID/group ID when launching QEMU
  guests. Change user/group ownership on disks/usb/pci devs.
  Put memory dumps in %localstatedir/cache/libvirt/qemu
* src/util.c, src/util.h: Add convenient APIs for converting
  username/groupname to user ID / group ID

by running this command:
git ls-files -z | xargs -0 perl -pi -0777 -e 's/\n\n+$/\n/'
This is in preparation for a more strict make syntax-check
rule that will detect trailing blank lines.

There are no functional changes in this patch apart from adding the
monitor type to the state XML.

The patch mostly consists of switching to use virDomainChrDef every
where to describe the monitor.

* src/domain_conf.h: replace monitorpath with monitor_chr

* src/domain_conf.c: handle parsing the monitor type and initializing
  monitor chr

* src/qemu_conf.[ch]: make qemudBuildCommandLine take a
  virDomainChrDefPtr and use that to build the -monitor parameter

* src/qemu_driver.c: split pty specific and common code from
  qemudOpenMonitor, have qemudStartVMDaemon() initialize monitor_chr

* tests/qemuxml2argvtest.c: update for qemudBuildCommandLine() change

	* src/qemu_conf.c, src/qemu_conf.h: Use -vga or -std-vga
	when starting guests if video card is present
	* tests/qemuhelptest.c: Change to use constants instead
	of hardcoded hex numbers, and add VGA support
	* tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl-fullscreen.xml,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.args,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.xml,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.args,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.xml,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.xml,
	tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml,
	tests/qemuxml2argvdata/qemuxml2argv-input-xen.xml: Add <video>
	element for testing graphics adapter
	* tests/qemuxml2argvtest.c: Add QEMUD_CMD_FLAG_VGA flag
	* tests/qemuxml2xmltest.c: Add missing graphics-vnc-sasl/tls tests

* src/qemu_conf.c: when connecting an interface if it reference
  an undefined network, then we used to raise an internal error.

* src/qemu_conf.c: patch from C.J. Adams-Collier adding support
  for arm emulation if qemu-system-arm is present
daniel

* qemud/qemud.c src/conf.c src/conf.h src/qemu_conf.c src/xen_unified.c
  src/xm_internal.c tests/conftest.c tests/xmconfigtest.c: extend
  the configuration parser for VMX syntax, patch by Matthias Bolte
Daniel

Rather than numerous instances of:

emulator = vm->def->emulator;
if (!emulator)
    emulator = virDomainDefDefaultEmulator(conn, vm->def, driver->caps);
if (!emulator)
    return -1;

Set this value at XML parse time in the domain config, so we can depend on
it for all future emulator accesses. There were unchecked accesses in the
qemu driver that were tripping up on this if no emulator was specified in
the XML, see:

http://www.redhat.com/archives/libvir-list/2008-October/msg00602.html

Certain drivers always need an 'emulator' specified in the XML (qemu and lxc
at least). Store this info in capabilities.

We will eventually use this to move default emulator handling out of
drivers and into domain_conf.*

Qemu < 0.10.0 did not support it, and virt-* tools now try to add this by
default, so it's extra important we ensure the option exists.

New function qemudParseHelpStr was being called with arguments in the
wrong order, so command flags == kvm_version :/

Signed-off-by: NMark McLoughlin <markmc@redhat.com>

The KVM version string can be one of the following:

  - qemu-kvm-x.y.z in stable releases
  - kvm-XX for kvm versions up to kvm-85
  - qemu-kvm-devel-XX for kvm version kvm-86 and later

There are only a few of places where we need to detect
differences between KVM versions based on 0.9.1:

  1) VNET_HDR introduced in kvm-74

  2) -incoming tcp introduced in kvm-79

  3) -incoming exec introduced in kvm-80

  4) -incoming stdio in all earlier kvm versions

With qemu-kvm-0.10.x, we can now assume that (1) is available
if it's a KVM release, (2) and (3) is always available and
(4) is never available.

So, from now on we should only need to check the qemu version
number and the "is_kvm" flag for detecting feature availability.
We only need the KVM version number for older releases.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>

This patch is purely re-factoring without any functional changes
to make way for the next patch.

The main thing achieved by the refactoring is that we now have
easier access to the parenthesised string that KVM folks seem
to delight in changing.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>

* src/qemu_conf.c docs/schemas/domain.rng
  tests/capabilityschemadata/caps-qemu-kvm.xml: PPC Qemu Machine Type
  changed from g3bw to g3beige some time ago, patch by Thomas Baker
Daniel