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

First 'poll' can't return EWOULDBLOCK, and second, we're checking errno
so far away from the poll() call that we've probably already trashed the
original errno value.

In addition to keepalive responses, we also need to send keepalive
requests from client IO loop to properly detect dead connection in case
a libvirt API is called from the main loop, which prevents any timers to
be called.

We don't need to add or remove filters when client object is already
locked anymore. There's no reason to keep the *Locked variants of those
APIs.

The previous commit removed the only usage of ``all'' parameter in
virKeepAliveStopInternal, which was actually the only reason for having
virKeepAliveStopInternal. This effectively reverts most of commit
6446a9e2.

When a libvirt API is called from the main event loop (which seems to be
common in event-based glib apps), the client IO loop would properly
handle keepalive requests sent by a server but will not actually send
them because the main event loop is blocked with the API. This patch
gets rid of response timer and the thread which is processing keepalive
requests is also responsible for queueing responses for delivery.

This makes it possible to create and queue new calls while we are
running IO loop.

Add virKeepAliveTimeout and virKeepAliveTrigger APIs that can be used to
set poll timeouts and trigger keepalive timer. virKeepAliveTrigger
checks if it is called to early and does nothing in that case.

The code that needs to be run every keepalive interval of inactivity was
only called from a timer and thus from the main event loop. We will need
to call the code directly from another place.

As we never drop non-blocking calls, the return value that used to
indicate a call was dropped is no longer needed.

As non-blocking calls are no longer dropped, we don't really need to
care that much about their fate and wait for the thread with the buck
to process them. If another thread has the buck, we can just push a
non-blocking call to the queue and be done with it.

So far, we were dropping non-blocking calls whenever sending them would
block. In case a client is sending lots of stream calls (which are not
supposed to generate any reply), the assumption that having other calls
in a queue is sufficient to get a reply from the server doesn't work. I
tried to fix this in b1e374a7 but
failed and reverted that commit.

With this patch, non-blocking calls are never dropped (unless the
connection is being closed) and will always be sent.

Normally, when every call has a thread associated with it, the thread
may get the buck and be in charge of sending all calls until its own
call is done. When we introduced non-blocking calls, we had to add
special handling of new non-blocking calls. This patch uses event loop
to send data if there is no thread to get the buck so that any
non-blocking calls left in the queue are properly sent without having to
handle them specially. It also avoids adding even more cruft to client
IO loop in the following patches.

With this change in, non-blocking calls may see unpredictable delays in
delivery when the client has no event loop registered. However, the only
non-blocking calls we have are keepalives and we already require event
loop for them, which makes this a non-issue until someone introduces new
non-blocking calls.

When analyzing our debug log, I'm always confused about what each of the
pointers mean. Let's be explicit.

'make dist' was depending on *protocol-structs files, which are
stored in git but in turn depended on generated files.  We still
want to ship the protocol-structs files, but by renaming the
tests to something not matching a file name, we separate 'make
check' (which depends on the generated file) from 'make dist'
(which only depends on the git files).  After all, the tarball
should never depend on a generated file not stored in git.

I found one more case of a git file depending on a generated
file, in a bogus virkeycode.c listing; but at least this one
had no associated rules so it never broke 'make dist'.

Reported by Wen Congyang.  Latent bug has been present since
commit 62dee6fa, but only recently exposed by commit 7bff56a0.

* src/Makefile.am ($(srcdir)/util/virkeycode.c): Drop useless
dependency.
(BUILT_SOURCES): ...and build virkeymaps.h sooner.
(PROTOCOL_STRUCTS): Rather than depend on the struct file...
(check-local): ...convert things into a phony target of...
(check-protocol): ...a new check.
($(srcdir)/remote_protocol-struct): Rename to isolate the distributed
file from the conditional test.
(PDWTAGS): Deal with rename.  Swap to compare 'expected actual'.

Otherwise, 'make dist' gives multiple warnings like:

libvirt.pot:20814: warning: internationalized messages should not contain the `\r' escape sequence

* tools/virsh.c (vshAskReedit): Avoid \r in _().