Save and managedsave both use migration to file. This patch reuses
qemuMigrationIsAllowed to check if the migration could happen before
trying.

Qemu doesn't support migration on guests with host devices. This patch
adds a check to ensure migration is safe before actually doing so.

This patch exports qemuMigrationIsAllowed and adds a new parameter to it
to denote if it's a remote migration or a local migration. Local
migrations are used in snapshots and saving of the machine state and
have fewer restrictions. This patch also adjusts callers of the function
and tweaks some error messages to be more universal.

Currently there is no way to detect it via QMP and requesting "-sandbox
off" works correctly even if it was compiled out, so this will work
unless someone both requests the sandbox in qemu.conf and builds QEMU
without the support for it.

Interfaces keeps a class_id, which is an ID from which bridge
part of QoS settings is derived. We need to store class_id
in domain status file, so we can later pass it to
virNetDevBandwidthUnplug.

Currently, we are only keeping a inactive XML configuration
in status dir. This is no longer enough as we need to keep
this class_id attribute so we don't overwrite old entries
when the daemon restarts. However, since there has already
been release which has just <network/> as root element,
and we want to keep things compatible, detect that loaded
status file is older one, and don't scream about it.

Network should be notified if we plug in or unplug an
interface, so it can perform some action, e.g. set/unset
network part of QoS. However, we are doing this in very
early stage, so iface->ifname isn't filled in yet. So
whenever we want to report an error, we must use a different
identifier, e.g. the MAC address.

This will be used whenever a NIC with guaranteed throughput is to
be plugged into a bridge. It will adjust the average throughput of
non guaranteed NICs (classid 1:2) to meet new requirements.

These set bridge part of QoS when bringing domain's interface up.
Long story short, if there's a 'floor' set, a new QoS class is created.
ClassID MUST be unique within the bridge and should be kept for
unplug phase.

These classes can borrow unused bandwidth. Basically,
only egress qdsics can have classes, therefore we can
do this kind of traffic shaping only on host's outgoing,
that is domain's incoming traffic.

This is however supported only on domain interfaces with
type='network'. Moreover, target network needs to have at least
inbound QoS set. This is required by hierarchical traffic shaping.

From now on, the required attribute for <inbound/> is either 'average'
(old) or 'floor' (new). This new attribute can be used just for
interfaces type of network (<interface type='network'/>) currently.

Stochastic Fairness Queuing (SFQ) is queuing discipline
(qdisc) which doesn't really shape any traffic but 'just'
re-arrange packets in sending buffer so no stream starve.
The goal is to ensure fairness. There is basically only one
configuration parameter (perturb) which is set to advised
value of 10.

Network adapters of type 'routed' is a special case. Other adapters
have 'network' parameter in prlctl's output instead.

Routed network adapters should be connected to 'routed' network
from libvirt's view.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Historically if traffic from the adapter is routed to LAN without
NAT, it isn't connected to any virtual networks, but has a 'type'
instead. Sinse libvirt has special virtual network type for such case,
let's add pseudo network 'routed' to fit libvirt's API well.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Fill bridge name and mac for bridged network and
DHCP server parameter for host-only network.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Parallels Cloud Server uses virtual networks model for network
configuration. It uses own tools for virtual network management.
So add network driver, which will be responsible for listing
virtual networks and performing different operations on them
(in consequent patched).

This patch only allows listing virtual network names, without
any parameters like DHCP server settings.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

This macro will be used in another file in the next
patch, so move it to common header file.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Allow changing network interfaces in domain configuration.

ifname is used as iterface identifier: if there is interface
with some ifname in old config and there are no interfaces with
such name in the new config - issue prlctl command to delete
the network interface. And vice versa - if interface with
some ifname exists only in new config - issue prlctl command
to create it.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Parse network interfaces info from prlctl output.

Parallels Cloud Server uses virtual networks model for
network configuration: You can add network adapter to
VM and connect it to some predefined virtual network.

Fill type, mac, network name and linkstate fields of
virDomainNetDef structure.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

When the disk snapshot part of an external system checkpoint fails the
memory image is retained. This patch adds code to remove the image in
such case.

In case the snapshot code isn't able to restart CPUs after an external
checkpoint we would leak a copy of the domains XML definition. This
patch fixes the cleanup path.

False positive, but it breaks the build with gcc-4.6.3.

qemu/qemu_migration.c:2931:37: error: 'offline' may be used
uninitialized in this function [-Werror=uninitialized]
qemu/qemu_migration.c:2887:10: note: 'offline' was declared here

This patch changes how parameters are passed to dnsmasq.  Instead of
being on the command line, the parameters are put into a file (one
parameter per line) and a commandline --conf-file= specifies the
location of the file.  The file is located in the same directory as
the leases file.

Putting the dnsmasq parameters into a configuration file
allows them to be examined and more easily understood than
examining the command lines displayed by "ps ax".  This is
especially true when a number of networks have been started.

When the use of dnsmasq was originally done, the required command line
was simple, but it has gotten more complicated over time and will
likely become even more complicated in the future.

Note: The test conf files have all been renamed .conf instead of
.argv, and tests/networkxml2xmlargvdata was moved to
tests/networkxml2xmlconfdata.

The DHCPv6 support includes IPV6 dhcp-range and dhcp-host for one
IPv6 subnetwork on one interface.  This support will only work
if dnsmasq version >= 2.64; otherwise an error occurs if
dhcp-range or dhcp-host is specified for an IPv6 address.

Essentially, this change provides the same DHCP support for IPv6
that has been available for IPv4.

With dnsmasq >= 2.64, support for the RA service is also now provided
by dnsmasq (radvd is no longer used/started). (Although at least one
version of dnsmasq prior to 2.64 "supported" IPv6 Router
Advertisement, there were bugs (fixed in 2.64) that rendered it
unusable.)

Documentation and the network schema has been updated
to reflect the new support.

virNetworkDefUpdateForward requires separate functions to parse and
clear a virNetworkForwardDef by itself, but they were previously just
inlined in the virNetworkDef parse and free functions. This patch
makes them into separate functions.

The attributes of a <network> element's <forward> element were
previously stored directly in the virNetworkDef object, but
virNetworkUpdateForward() needs to operate on a <forward> in
isolation, so this patchs pulls out all those attributes into a
separate virNetworkForwardDef struct (and shortens their names
appropriately). This new object is contained in the virNetworkDef, not
pointed to by it, so there is no extra memory management.

This patch makes no functional changes, it only changes, e.g.,
"nForwardIfs" to "forward.nifs".

The other clear functions in network_conf.c that clear out arrays of
sub-objects do so by using the n[itemname]s value as a counter going
down to 0. Make this one consistent. There's no functional value, just
makes the style more consistent with the rest of the file.

This makes some function names and arg lists for consistent with other
parse functions in network_conf.c. While modifying
virNetworkIPParseXML(), also change its "error" label to "cleanup",
since the code at that label is executed on success as well as
failure.

These three functions are very similar - none allow a MODIFY
operation; you can only add or delete.

The biggest difference between them (other than the data itself) is in
the criteria for determining a match, and whether or not multiple
matches are possible:

1) for HOST records, it's considered a match if the IP address or any
of the hostnames of an existing record matches.

2) for SRV records, it's a match if all of
domain+service+protocol+target *which have been specified* are
matched.

3) for TXT records, there is only a single field to match - name
(value can be the same for multiple records, and isn't considered a
search term), so by definition there can be no ambiguous matches.

In all three cases, if any matches are found, ADD will fail; if
multiple matches are found, it means the search term was ambiguous,
and a DELETE will fail.

The upper level code in bridge_driver.c is already implemented for
these functions - appropriate conf files will be re-written, and
dnsmasq will be SIGHUPed or restarted as appropriate.

Since there is only a single virNetworkDNSDef for any virNetworkDef,
and it's trivial to determine whether or not it contains any real
data, it's much simpler (and fits more uniformly with the parse
function calling sequence of the parsers for many other objects that
are subordinates of virNetworkDef) if virNetworkDef *contains* an
virNetworkDNSDef rather than pointing to one.

Since it is now just a part of another object rather than its own
object, it no longer makes sense to have a *Free() function, so that
is changed to a *Clear() function.

More importantly though, ParseXML and Clear functions are needed for
the individual items contained in a virNetworkDNSDef (srv, txt, and
host records), but none of them have a *Clear(), and only two of the
three had *ParseXML() functions (both of which used a non-uniform
arglist). Those problems are cleared up by this patch - it splits the
higher-level Clear function into separate functions for each of the
three, creates a parse for txt records, and cleans up the srv and host
parsers, so we now have all the utility functions necessary to
implement virNetworkDefUpdateDNS(Host|Srv|Txt).

This shortens the name of the structs for srv and txt, and their
instances in virNetworkDNSDef, to be more compact and uniform with the
naming of the dns host array. It also changes the type of ntxts, etc
from unsigned int to size_t, so that they can be used directly as args
to VIR_*_ELEMENT.

The already-written backend functions for virNetworkUpdate that add
and delete items into lists within the a network were already debugged
to work properly, but future such functions will use
VIR_(INSERT|DELETE)_ELEMENT instead, so these are changed for
uniformity.

I noticed when writing the backend functions for virNetworkUpdate that
I was repeating the same sequence of memmove, VIR_REALLOC, nXXX-- (and
messed up the args to memmove at least once), and had seen the same
sequence in a lot of other places, so I decided to write a few
utility functions/macros - see the .h file for full documentation.

The intent is to reduce the number of lines of code, but more
importantly to eliminate the need to check the element size and
element count arithmetic every time we need to do this (I *always*
make at least one mistake.)

VIR_INSERT_ELEMENT: insert one element at an arbitrary index within an
  array of objects. The size of each object is determined
  automatically by the macro using sizeof(*array). The new element's
  contents are copied into the inserted space, then the original copy
  of contents are 0'ed out (if everything else was
  successful). Compile-time assignment and size compatibility between
  the array and the new element is guaranteed (see explanation below
  [*])

VIR_INSERT_ELEMENT_COPY: identical to VIR_INSERT_ELEMENT, except that
  the original contents of newelem are not cleared to 0 (i.e. a copy
  is made).

VIR_APPEND_ELEMENT: This is just a special case of VIR_INSERT_ELEMENT
  that "inserts" one past the current last element.

VIR_APPEND_ELEMENT_COPY: identical to VIR_APPEND_ELEMENT, except that
  the original contents of newelem are not cleared to 0 (i.e. a copy
  is made).

VIR_DELETE_ELEMENT: delete one element at an arbitrary index within an
  array of objects. It's assumed that the element being deleted is
  already saved elsewhere (or cleared, if that's what is appropriate).

All five of these macros have an _INPLACE variant, which skips the
memory re-allocation of the array, assuming that the caller has
already done it (when inserting) or will do it later (when deleting).

Note that VIR_DELETE_ELEMENT* can return a failure, but only if an
invalid index is given (index + amount to delete is > current array
size), so in most cases you can safely ignore the return (that's why
the helper function virDeleteElementsN isn't declared with
ATTRIBUTE_RETURN_CHECK). A warning is logged if this ever happens,
since it is surely a coding error.

[*] One initial problem with the INSERT and APPEND macros was that,
due to both the array pointer and newelem pointer being cast to void*
when passing to virInsertElementsN(), any chance of type-checking was
lost. If we were going to move in newelem with a memmove anyway, we
would be no worse off for this. However, most current open-coded
insert/append operations use direct struct assignment to move the new
element into place (or just populate the new element directly) - thus
use of the new macros would open a possibility for new usage errors
that didn't exist before (e.g. accidentally sending &newelemptr rather
than newelemptr - I actually did this quite a lot in my test
conversions of existing code).

But thanks to Eric Blake's clever thinking, I was able to modify the
INSERT and APPEND macros so that they *do* check for both assignment
and size compatibility of *ptr (an element in the array) and newelem
(the element being copied into the new position of the array). This is
done via clever use of the C89-guaranteed fact that the sizeof()
operator must have *no* side effects (so an assignment inside sizeof()
is checked for validity, but not actually evaluated), and the fact
that virInsertElementsN has a "# of new elements" argument that we
want to always be 1.

When restarting CPUs after an external snapshot, the restarting function
was called without the appropriate async job type. This caused that a
new sync job wasn't created and allowed races in the monitor.

If some hard disk is not found in new domain configuration, it
should be removed.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

New VM will have default values for all parameters, like
cpu number, we have to change its configuration as provided
by xml definition, given to parallelsDomainDefineXML.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Implement creation of new disks - if a new disk found
in configuration, find a volume by disk path and
actually create a disk image by issuing prlctl command.
If it's successfully finished - remove the file with volume
definition.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

Add function for convertion bus from libvirt's numeric constant
to a name, used in a parallels command-line tools.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>