This idea was first suggested by Daniel Veillard here:
https://www.redhat.com/archives/libvir-list/2011-October/msg00353.html

Now that I am about to add more complexity to snapshot listing, it
makes sense to avoid code duplication and special casing for domain
listing (all snapshots) vs. snapshot listing (descendants); adding
a metaroot reduces the number of code lines by having the domain
listing turn into a descendant listing of the metaroot.

Note that this has one minor pessimization - if we are going to list
ALL snapshots without filtering, then virHashForeach is more efficient
than recursing through the child relationships; restoring that minor
optimization will occur in the next patch.

* src/conf/domain_conf.h (_virDomainSnapshotObj)
(_virDomainSnapshotObjList): Repurpose some fields.
(virDomainSnapshotDropParent): Drop unused parameter.
* src/conf/domain_conf.c (virDomainSnapshotObjListGetNames)
(virDomainSnapshotObjListCount): Simplify.
(virDomainSnapshotFindByName, virDomainSnapshotSetRelations)
(virDomainSnapshotDropParent): Match new field semantics.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotReparentChildren, qemuDomainSnapshotDelete):
Adjust clients.

The word size there is 64 bit not 8.

This patch adds common code to list domains in fashion used by
virListAllDomains with all currently supported flags. The header file
also contains macros that group filters together that are used to
shorten filter conditions.

This patch stores existence of the image in the object. At start of the
daemon the state is checked and then updated in key moments in domain
lifecycle.

This patch wires up the RPC protocol handlers for
virConnectListAllDomains(). The RPC generator has no support for the way
how virConnectListAllDomains() returns the results so the handler code
had to be done manually.

The new api is handled by REMOTE_PROC_CONNECT_LIST_ALL_DOMAINS, with
number 273 and marked with high priority.

This patch adds export of the new API function
virConnectListAllDomains() to the libvirt-python bindings. The
virConnect object now has method "listAllDomains" that takes only the
flags parameter and returns a python list of virDomain object
corresponding to virDomainPtrs returned by the underlying api.

The implementation is done manually as the generator does not support
wrapping list of virDomainPtrs into virDomain objects.

This patch adds a new public api that lists domains. The new approach is
different from those used before. There are key points to this:

1) The list is acquired atomically and contains both active and inactive
domains (guests). This eliminates the need to call two different list
APIs, where the state might change in between the calls.

2) The returned list consists of virDomainPtrs instead of names or ID's
that have to be converted to virDomainPtrs anyways using separate calls
for each one of them. This is more convenient and saves hypervisor calls.

3) The returned list is auto-allocated. This saves a lot of hassle for
the users.

4) Built in support for filtering. The API call supports various
filtering flags that modify the output list according to user needs.

Available filter groups:
    Domain status:
    VIR_CONNECT_LIST_DOMAINS_ACTIVE, VIR_CONNECT_LIST_DOMAINS_INACTIVE

    Domain persistence:
    VIR_CONNECT_LIST_DOMAINS_PERSISTENT,
    VIR_CONNECT_LIST_DOMAINS_TRANSIENT

    Domain state:
    VIR_CONNECT_LIST_DOMAINS_RUNNING, VIR_CONNECT_LIST_DOMAINS_PAUSED,
    VIR_CONNECT_LIST_DOMAINS_SHUTOFF, VIR_CONNECT_LIST_DOMAINS_OTHER

    Existence of managed save image:
    VIR_CONNECT_LIST_DOMAINS_MANAGEDSAVE,
    VIR_CONNECT_LIST_DOMAINS_NO_MANAGEDSAVE

    Auto-start option:
    VIR_CONNECT_LIST_DOMAINS_AUTOSTART,
    VIR_CONNECT_LIST_DOMAINS_NO_AUTOSTART

    Existence of snapshot:
    VIR_CONNECT_LIST_DOMAINS_HAS_SNAPSHOT,
    VIR_CONNECT_LIST_DOMAINS_NO_SNAPSHOT

5) The python binding returns a list of domain objects that is very neat
to work with.

The only problem with this approach is no support from code generators
so both RPC code and python bindings had to be written manually.

*include/libvirt/libvirt.h.in: - add API prototype
                               - clean up whitespace mistakes nearby
*python/generator.py: - inhibit generation of the bindings for the new
                        api
*src/driver.h: - add driver prototype
               - clean up some whitespace mistakes nearby
*src/libvirt.c: - add public implementation
*src/libvirt_public.syms: - export the new symbol

print debug info "container support is enabled"
when host support the user or net namespace.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

kill the "return 0;" code, it will cause memory leak.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Introduced in commit 1f8c33b6.

* src/lxc/lxc_container.c (lxcContainerGetSubtree): Avoid TAB.

when libvirt_lxc trigger oom error in lxcContainerGetSubtree
we should free the alloced memory for mounts.

so when lxcContainerGetSubtree failed,we should do some
memory cleanup in lxcContainerUnmountSubtree.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

we alloc the memory for format in lxcContainerMountDetectFilesystem
but without free it in lxcContainerMountFSBlockHelper.

this patch just call VIR_FREE to free it.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

as we support qed format as well.

as we are missing:
attach-disk: --type can accept 'lun' too, not just cdrom or floppy.
attach-disk: --target specify logical device name, not path
attach-interface: --target silently drops strings with vnet* prefix

With latest changes to qemu-ga success on some commands is not reported
anymore, e.g. guest-shutdown or guest-suspend-*. However, errors are
still being reported. Therefore, we need to find different source of
indication if operation was successful. Events.

for agent ref count and qemuProcessHandleAgentDestroy

Operating on a list of snapshot objects looks so much simpler.
In particular, since the helper function already trimmed out
irrelevant entries, we no longer have quite so many special cases
on finding the first snapshot to operate on.  Also, vshTreePrint
no longer has a generic callback struct; both clients now pass
something different according to their own needs.

* tools/virsh.c (cmdSnapshotList): Use previous patches.
(vshTreeArrayLookup): Rename...
(vshNodeListLookup): ...now that it only has one client.
(cmdNodeListDevices): Adjust caller.

This patch is based on the fallback code out of cmdSnapshotList,
with tweaks to keep the snapshot objects around rather than just
their name, and to remove unwanted elements before returning.
It looks forward to a future patch when we add a way to list all
snapshot objects at once, and the next patch will simplify
cmdSnapshotList to take advantage of this factorization.

* tools/virsh.c (vshSnapshotList, vshSnapshotListFree): New functions.

Commit 6e769eba made it a runtime error if libvirt was compiled
without yajl support but targets a new enough qemu.  But enough
users are hitting this on self-compiled libvirt that it is worth
erroring out at compilation time, rather than an obscure failure
when trying to use the built executable.

* configure.ac: If qemu is requested and -version works, require
yajl when qemu version is new enough.
* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags): Add
comment.

If we do ./autogen.sh && ./configure, then later try ./autogen.sh --system,
configure isn't invoked with the requested params. Instead
config.status --recheck is run.

The return status of virInterfaceDefParseBridge() was not being
checked, potentially resulting in the creation of a broken
interface.

When libpcap is not available, the NWFilter driver provides a
no-op stub for the DHCP snooping initialization. This was
mistakenly returning '-1' instead of '0', so the entire driver
initialization failed

To facilitate future troubleshooting add a bunch more debugging
statements into important startup parts of libvirt

'boot' tag shouldn't be exclusive with 'kernel', 'initrd', and 'cmdline',
though the boot sequence doesn't make sense when the guest boots from
kernel directly. But it's useful if booting from kernel is to install
a newguest, even if it's not to install a guest, there is no hurt. And
on the other hand, we allow 'boot' and the kernel tags when parsing.

Add a new parameter --memory-only for 'virsh dump' command. So
the user can decide the vmcore's format.

This patch updates qemu driver to allow the client to choose the
vmcore's format: memory only or including device state.

dump-guest-memory is a new dump mechanism, and it can work when the
guest uses host devices. This patch adds a API to use this new
monitor command.
We will always use json mode if qemu's version is >= 0.15, so I
don't implement the API for text mode.

If we lock the qemu_driver, we should call qemuDomainObjBeginJobWithDriver()
not qemuDomainObjBeginJob().

Detected by valgrind:

==16217== 1 errors in context 1 of 12:
==16217== Invalid read of size 1
==16217==    at 0x4A07804: __GI_strlen (mc_replace_strmem.c:284)
==16217==    by 0x3019F167F6: xdr_string (in /lib64/libc-2.12.so)
==16217==    by 0x3033709E8D: xdr_remote_nonnull_string (remote_protocol.c:31)
==16217==    by 0x303370E5CB: xdr_remote_domain_update_device_flags_args (remote_protocol.c:2028)
==16217==    by 0x30337197D1: virNetMessageEncodePayload (virnetmessage.c:341)
==16217==    by 0x30337135E1: virNetClientProgramCall (virnetclientprogram.c:327)
==16217==    by 0x30336F1EFD: callWithFD (remote_driver.c:4586)
==16217==    by 0x30336F1F7B: call (remote_driver.c:4607)
==16217==    by 0x30336F42F2: remoteDomainUpdateDeviceFlags (remote_client_bodies.h:2865)
==16217==    by 0x30336D46E5: virDomainUpdateDeviceFlags (libvirt.c:9457)
==16217==    by 0x41AEE8: cmdChangeMedia (virsh.c:15249)
==16217==    by 0x413CB4: vshCommandRun (virsh.c:18669)
==16217==  Address 0x4ec5e25 is 0 bytes after a block of size 293 alloc'd
==16217==    at 0x4A04A28: calloc (vg_replace_malloc.c:467)
==16217==    by 0x303364F1DB: virAllocN (memory.c:129)
==16217==    by 0x41A844: vshPrepareDiskXML (virsh.c:15043)
==16217==    by 0x41AECC: cmdChangeMedia (virsh.c:15246)
==16217==    by 0x413CB4: vshCommandRun (virsh.c:18669)
==16217==    by 0x423973: main (virsh.c:20261)

This reverts

  commit c16b4c43
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Fri May 11 15:09:27 2012 +0100

    Avoid LXC pivot root in the root source is still /

This commit broke setup of /dev, because the code which
deals with setting up a private /dev and /dev/pts only
works if you do a pivotroot.

The original intent of avoiding the pivot root was to
try and ensure the new root has a minimumal mount
tree. The better way todo this is to just unmount the
bits we don't want (ie old /proc & /sys subtrees.
So apply the logic from

  commit c529b47a
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Fri May 11 11:35:28 2012 +0100

    Trim /proc & /sys subtrees before mounting new instances

to the pivot_root codepath as well

Tell the user what CPU mode value is wrong

Libvirt updates the configuration of SPICE server only when something
changes. This is unfortunate when the user wants to disconnect a
existing spice session when the connected attribute is already
"disconnect".

This patch modifies the conditions for calling the password updater to
be called when nothing changes, but the connected attribute is already
"disconnect".

There is a little easter egg in virsh: one can easily clone
an object (domain, network, ...). Just 'virsh edit' change the name
and remove <uuid>. And then, in the end when reporting success
the new name was printed out.
However, with recent edit rewrite we lost the final part and are
still printing the original name out.

When printing reedit options we make stdin raw. However,
this results in stdout being raw as well. Therefore we need
to return carriage when doing new line. Unfortunately,
'\r' cannot be part of internationalized messages hence
we must move them to formatting string which then in turn
become huge and disarranged. To solve this, a new function
is introduced which takes variable string arguments and
prepend each with "\r\n" just before printing.

While unescaping the commands the commands passed through to the monitor
function qemuMonitorUnescapeArg() initialized lenght of the input string
to strlen()+1 which is fine for alloc but not for iteration of the
string.

This patch fixes the off-by-one error and drops the pointless check for
a single trailing slash that is automaticaly handled by the default
branch of switch.

The attach-disk command used with parameter --cache created an invalid
XML snippet as the beginning of the <driver> element was not printed
when used solely with --cache and no other attribute to driver.

commit 52d064f4 added
VIR_NETWORK_XML_INACTIVE in order to allow suppressing the
auto-generated list of VFs in network definitions, and a --inactive
flag to virsh net-dumpxml to take advantage of the flag. However, it
missed out on two opportunities:

1) Use INACTIVE to get the current config of the network as it
   exists on disk, rather than the currently active config.

2) Add INACTIVE to the flags used for the virsh net-edit command, so
   that it won't include the forward-pool interfaces that were
   autogenerated, and so that a re-edit of the network prior to
   restarting it will show any other edits made since the last restart
   of the network. (prior to this patch, if you edited a network a 2nd
   time without restarting, all of the previous edits would magically
   disappear).

In order to fit with the new #define-based generic edit function in
virsh.c, a new function vshNetworkGetXMLDesc() was added. This
function first tries to call virNetworkGetXMLDesc with the INACTIVE
flag added, then retries without if the first attempt fails (in the
manner expected when the server doesn't support it).

A core use case of the hook scripts is to be able to do things
to a guest's network configuration. It is possible to hook into
the 'start' operation for a QEMU guest which runs just before
the guest is started. The TAP devices will exist at this point,
but the QEMU process will not. It can be desirable to have a
'started' hook too, which runs once QEMU has started.

If libvirtd is restarted it will re-populate firewall rules,
but there is no QEMU hook to trigger for existing domains.
This is solved with a 'reconnect' hook.

Finally, if attaching to an external QEMU process there needs
to be an 'attach' hook script.

This all also applies to the LXC driver

* docs/hooks.html.in: Document new operations
* src/util/hooks.c, src/util/hooks.c: Add 'started', 'reconnect'
  and 'attach' operations for QEMU. Add 'prepare', 'started',
  'release' and 'reconnect' operations for LXC
* src/lxc/lxc_driver.c: Add hooks for 'prepare', 'started',
  'release' and 'reconnect' operations
* src/qemu/qemu_process.c: Add hooks for 'started', 'reconnect'
  and 'reconnect' operations