Allow the parent process to perform a bi-directional handshake
with the child process during fork/exec. The child process
will fork and do its initial setup. Immediately prior to the
exec(), it will stop & wait for a handshake from the parent
process. The parent process will spawn the child and wait
until the child reaches the handshake point. It will do
whatever extra setup work is required, before signalling the
child to continue.

The implementation of this is done using two pairs of blocking
pipes. The first pair is used to block the parent, until the
child writes a single byte. Then the second pair pair is used
to block the child, until the parent confirms with another
single byte.

* src/util/command.c, src/util/command.h,
  src/libvirt_private.syms: Add APIs to perform a handshake

To allow a client app to pass in custom XML during migration
of a guest it is neccessary to ensure the guest ABI remains
unchanged. The virDomainDefCheckABIStablity method accepts
two virDomainDefPtr structs and compares everything in them
that could impact the guest machine ABI

* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/libvirt_private.syms: Add virDomainDefCheckABIStablity
* src/conf/cpu_conf.c, src/conf/cpu_conf.h: Add virCPUDefIsEqual
* src/util/sysinfo.c, src/util/sysinfo.h: Add virSysinfoIsEqual

This introduces a new domain

  VIR_DOMAIN_EVENT_ID_CONTROL_ERROR

Which uses the existing generic callback

typedef void (*virConnectDomainEventGenericCallback)(virConnectPtr conn,
                                                     virDomainPtr dom,
                                                     void *opaque);

This event is intended to be emitted when there is a failure in
some part of the domain virtualization system. Whether the domain
continues to run/exist after the failure is an implementation
detail specific to the hypervisor.

The idea is that with some types of failure, hypervisors may
prefer to leave the domain running in a "degraded" mode of
operation. For example, if something goes wrong with the QEMU
monitor, it is possible to leave the guest OS running quite
happily. The mgmt app will simply loose the ability todo various
tasks. The mgmt app can then choose how/when to deal with the
failure that occured.
* daemon/remote.c: Dispatch of new event
* examples/domain-events/events-c/event-test.c: Demo catch
  of event
* include/libvirt/libvirt.h.in: Define event ID and callback
* src/conf/domain_event.c, src/conf/domain_event.h: Internal
  event handling
* src/remote/remote_driver.c: Receipt of new event from daemon
* src/remote/remote_protocol.x: Wire protocol for new event
* src/remote_protocol-structs: add new event for checks

Export a bunch of missing symbols and link the remote driver to gnulib.

This patch allows to modify interfaces of domain(qemu)
* src/conf/domain_conf.c src/conf/domain_conf.h src/libvirt_private.syms:
  (virDomainNetInsert)     : Insert a network device to domain definition.
  (virDomainNetIndexByMac) : Returns an index of net device in array.
  (virDomainNetRemoveByMac): Remove a NIC of passed MAC address.
* src/qemu/qemu_driver.c
  (qemuDomainAttachDeviceConfig): add codes for NIC.
  (qemuDomainDetachDeviceConfig): add codes for NIC.

This adds a streaming-video=filter|all|off attribute. It is used to change
the behavior of video stream detection in spice, the default is filter (the
default for libvirt is not to specify it - the actual default is defined in
libspice-server.so).

Usage:

    <graphics type='spice' autoport='yes'>
      <streaming mode='off'/>
    </graphics>

Tested with the above and with tests/qemuxml2argvtest.
Signed-off-by: NAlon Levy <alevy@redhat.com>

virRunWithHook is now unused, so we can drop it. Tested w/ raw + qcow2
volume creation and copying.

v2:
    Use opaque data to skip hook second time around
    Simply command building

v3:
    Drop explicit FindFileInPath

The migration protocol has support for a 'cookie' parameter which
is an opaque array of bytes as far as libvirt is concerned. Drivers
may use this for passing around arbitrary extra data they might
need during migration. The QEMU driver needs to do a few things:

 - Pass hostname/uuid to allow strict protection against localhost
   migration attempts
 - Pass SPICE/VNC server port from the target back to the source to
   allow seamless relocation of client sessions
 - Pass lock driver state from source to destination

This patch introduces the basic glue for handling cookies
but only includes the host/guest UUID & name.

* src/libvirt_private.syms: Export virXMLParseStrHelper
* src/qemu/qemu_migration.c, src/qemu/qemu_migration.h: Parsing
  and formatting of migration cookies
* src/qemu/qemu_driver.c: Pass in cookie parameters where possible
* src/remote/remote_protocol.h, src/remote/remote_protocol.x: Change
  cookie max length to 16384 bytes

Migration just seems to go from bad to worse. We already had to
introduce a second migration protocol when adding the QEMU driver,
since the one from Xen was insufficiently flexible to cope with
passing the data the QEMU driver required.

It turns out that this protocol still has some flaws that we
need to address. The current sequence is

 *  Src: DumpXML
          - Generate XML to pass to dst

 *  Dst: Prepare
          - Get ready to accept incoming VM
          - Generate optional cookie to pass to src

 *  Src: Perform
          - Start migration and wait for send completion
          - Kill off VM if successful, resume if failed

 *  Dst: Finish
          - Wait for recv completion and check status
          - Kill off VM if unsuccessful

The problems with this are:

 - Since the first step is a generic 'DumpXML' call, we can't
   add in other migration specific data. eg, we can't include
   any VM lease data from lock manager plugins
 - Since the first step is a generic 'DumpXML' call, we can't
   emit any 'migration begin' event on the source, or have
   any hook that runs right at the start of the process
 - Since there is no final step on the source, if the Finish
   method fails to receive all migration data & has to kill
   the VM, then there's no way to resume the original VM
   on the source

This patch attempts to introduce a version 3 that uses the
improved 5 step sequence

 *  Src: Begin
          - Generate XML to pass to dst
          - Generate optional cookie to pass to dst

 *  Dst: Prepare
          - Get ready to accept incoming VM
          - Generate optional cookie to pass to src

 *  Src: Perform
          - Start migration and wait for send completion
          - Generate optional cookie to pass to dst

 *  Dst: Finish
          - Wait for recv completion and check status
          - Kill off VM if failed, resume if success
          - Generate optional cookie to pass to src

 *  Src: Confirm
          - Kill off VM if success, resume if failed

The API is designed to allow both input and output cookies
in all methods where applicable. This lets us pass around
arbitrary extra driver specific data between src & dst during
migration. Combined with the extra 'Begin' method this lets
us pass lease information from source to dst at the start of
migration

Moving the killing of the source VM out of Perform and
into Confirm, means we can now recover if the dst host
can't successfully Finish receiving migration data.

Only in drivers which use virDomainObj, drivers that query hypervisor
for domain status need to be updated separately in case their hypervisor
supports this functionality.

The reason is also saved into domain state XML so if a domain is not
running (i.e., no state XML exists) the reason will be lost by libvirtd
restart. I think this is an acceptable limitation.

And drop the now unused virExecDaemonize

The same code for queueing, flushing, and deregistering events exists
in multiple drivers, which will soon use these common functions.

v2:
    Adjust libvirt_private.syms
    isDispatching bool fixes
    NONNULL tagging

v3:
    Add requireTimer parameter to virDomainEventStateNew

This structure will be used to unify lots of duplicated event handling code
across the state drivers.

v2:
    Check for state == NULL in StateFree
    Add NONNULL tagging
    Use bool for isDispatching
Signed-off-by: NCole Robinson <crobinso@redhat.com>

Actually execs the argv/env we've generated, replacing the current process.
Kind of has a limited usage, but allows us to use virCommand in LXC
driver to launch the 'init' process

Similar to virCommandArgAddFormat. We will use this shortly.

v2:
    Convert virCommandEnvAddPair to use the new function

Users often edit XML file stored in configuration directory
thinking of modifying a domain/network/pool/etc. Thus it is wise
to let them know they are using the wrong way and give them hint.

Some configuration setups for guests are allowed, but strongly
discouraged and unsupportable in production systems. Introduce
a concept of 'tainting' to virDomainObjPtr to allow such setups
to be identified. Drivers can then log warnings at suitable
times

* src/conf/domain_conf.c, src/conf/domain_conf.h: Declare taint
  flags and add parsing/formatting of domain status XML

Match the fact that we have virAsprintf and virVasprintf.

* src/util/buf.h (virBufferVasprintf): New prototype.
* src/util/buf.c (virBufferAsprintf): Move guts...
(virBufferVasprintf): ...to new function.
* src/libvirt_private.syms (buf.h): Export it.
* bootstrap.conf (gnulib_modules): Add stdarg, for va_copy.

We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose.  Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.

global rename performed with:

$ git grep -l virBufferVSprintf \
  | xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'

then revert the changes in ChangeLog-old.

Support changes of disks by MODIFY_CONFIG for qemu.

This patch includes patches for qemu's disk to support
virDomainAt(De)tachDeviceFlags with VIR_DOMAIN_DEVICE_MODIFY_CONFIG.

Other devices can be added incrementally.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

* /src/conf/domain_conf.c
(virDomainDiskIndexByName): returns array index of disk in vmdef.
(virDomainDiskRemoveByName): removes a disk which has the name in vmdef.
* src/qemu/qemu_driver.c
(qemuDomainAttachDeviceConfig): add support for Disks.
(qemuDomainDetachDeviceConfig): add support for Disks.

This patch adds functions for modify domain's persistent definition.
To do error recovery in easy way, we use a copy of vmdef and update it.

The whole sequence will be:

  make a copy of domain definition.

  if (flags & MODIFY_CONFIG)
      update copied domain definition
  if (flags & MODIF_LIVE)
      do hotplug.
  if (no error)
      save copied one to the file and update cached definition.
  else
      discard copied definition.

This patch is mixuture of Eric Blake's work and mine.
From: Eric Blake <eblake@redhat.com>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

(virDomainObjCopyPersistentDef): make a copy of persistent vm definition
(qemuDomainAttach/Detach/UpdateDeviceConfig) : callbacks. now empty
(qemuDomainModifyDeviceFlags): add support for MODIFY_CONFIG and MODIFY_CURRENT

This adds several tests for remaining hash APIs (custom
hasher/comparator functions are not covered yet, though).

All tests pass both before and after the "Simplify hash implementation".

This will be used in the ESX driver event handling.

mingw lacks the counterpart to PTHREAD_MUTEX_INITIALIZER, so the
best we can do is portably expose once-only runtime initialization.

* src/util/threads.h (virOnceControlPtr): New opaque type.
(virOnceFunc): New callback type.
(virOnce): New prototype.
* src/util/threads-pthread.h (virOnceControl): Declare.
(VIR_ONCE_CONTROL_INITIALIZER): Define.
* src/util/threads-win32.h (virOnceControl)
(VIR_ONCE_CONTROL_INITIALIZER): Likewise.
* src/util/threads-pthread.c (virOnce): Implement in pthreads.
* src/util/threads-win32.c (virOnce): Implement in WIN32.
* src/libvirt_private.syms: Export it.

Make: passed
Make check: passed
Make syntax-check: passed

this is the commit to introduce the function to create new character
device definition for the domain as advised by Cole Robinson
<crobinso@redhat.com>.

The function is used on the relevant places and also new tests has
been added.
Signed-off-by: NMichal Novotny <minovotn@redhat.com>

This extends the SPICE XML to allow variable compression settings for audio,
images and streaming:
    <graphics type='spice' port='5901' tlsPort='-1' autoport='yes'>
        <image compression='auto_glz'/>
        <jpeg compression='auto'/>
        <zlib compression='auto'/>
        <playback compression='on'/>
    </graphics>

All new elements are optional.

This patch adds support for the evaluation of TCP flags in nwfilters.

It adds documentation to the web page and extends the tests as well.
Also, the nwfilter schema is extended.

The following are some example for rules using the tcp flags:

<rule action='accept' direction='in'>
    <tcp state='NONE' flags='SYN/ALL' dsptportstart='80'/>
</rule>
<rule action='drop' direction='in'>
    <tcp state='NONE' flags='SYN/ALL'/>
</rule>

Also related new functions' declaration, and expose the new introduced
functions in libvirt_private.syms.

v1 - v2:
  Don't expose "virAllocVar" in libvirt_private.syms

* src/Makefile.am src/libvirt_private.syms configure.ac: share and
  reuse the sexpr routines from sexpr.h of the old xen driver
* src/libxl/libxl_driver.c: implements libxlDomainXMLFromNative and
  libxlDomainXMLToNative

This patch intentionally doesn't change indentation, in order to
make it easier to review the real changes.

* src/util/util.h (VIR_FILE_OP_RETURN_FD, virFileOperationHook):
Delete.
(virFileOperation): Rename...
(virFileOpenAs): ...and reduce parameters.
* src/util/util.c (virFileOperationNoFork, virFileOperation):
Rename and simplify.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Adjust caller.
* src/storage/storage_backend.c (virStorageBackendCreateRaw):
Likewise.
* src/libvirt_private.syms: Reflect rename.

* src/util/util.h (virSetInherit): New prototype.
* src/util/util.c (virSetCloseExec): Move guts...
(virSetInherit): ...to new function, and allow clearing.
* src/libvirt_private.syms (util.h): Export it.

Sometimes, an asynchronous helper is started (such as a compressor
or iohelper program), but a later error means that we want to
abort that child.  Make this easier.

Note that since daemons and virCommandRunAsync can't mix, the only
time virCommandFree can reap a process is if someone did
virCommandRunAsync for a non-daemon and didn't stash the pid.

* src/util/command.h (virCommandAbort): New prototype.
* src/util/command.c (_virCommand): Add new field.
(virCommandRunAsync, virCommandWait): Track whether pid was used.
(virCommandFree): Reap child if caller did not request pid.
(virCommandAbort): New function.
* src/libvirt_private.syms (command.h): Export it.
* tests/commandtest.c (test19): New test.

Child processes don't always reach _exit(); if they die from a
signal, then any messages should still be accurate.  Most users
either expect a 0 status (thankfully, if status==0, then
WIFEXITED(status) is true and WEXITSTATUS(status)==0 for all
known platforms) or were filtering on WIFEXITED before printing
a status, but a few were missing this check.  Additionally,
nwfilter_ebiptables_driver was making an assumption that works
on Linux (where WEXITSTATUS shifts and WTERMSIG just masks)
but fails on other platforms (where WEXITSTATUS just masks and
WTERMSIG shifts).

* src/util/command.h (virCommandTranslateStatus): New helper.
* src/libvirt_private.syms (command.h): Export it.
* src/util/command.c (virCommandTranslateStatus): New function.
(virCommandWait): Use it to also diagnose status from signals.
* src/security/security_apparmor.c (load_profile): Likewise.
* src/storage/storage_backend.c
(virStorageBackendQEMUImgBackingFormat): Likewise.
* src/util/util.c (virExecDaemonize, virRunWithHook)
(virFileOperation, virDirCreate): Likewise.
* daemon/remote.c (remoteDispatchAuthPolkit): Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesExecCLI):
Likewise.

The ref count was assigned to 1 at creation, then never modified again
until it was decremented just before freeing the object.

* src/conf/domain_conf.h (_virDomainSnapshotObj): Delete unused
field.
(virDomainSnapshotObjUnref): Delete unused prototype.
* src/libvirt_private.syms: Likewise.
* src/conf/domain_conf.c (virDomainSnapshotObjNew)
(virDomainSnapshotObjListDataFree): Update users.
(virDomainSnapshotObjUnref): Delete.

* Correct the documentation for cgroup: the swap_hard_limit indicates
  mem+swap_hard_limit.
* Change cgroup private apis to: virCgroupGet/SetMemSwapHardLimit
Signed-off-by: NNikunj A. Dadhania <nikunj@linux.vnet.ibm.com>

The virSetNonBlock() API only allows enabling non-blocking
operations. It doesn't allow turning blocking back on. Add
a new API to allow arbitrary toggling.

* src/libvirt_private.syms, src/util/util.h
  src/util/util.c: Add virSetBlocking

This is the part allowing to dynamically resize the debug log
buffer from it's default 64kB size. The buffer is now dynamically
allocated.
It adds a new API virLogSetBufferSize() which resizes the buffer
If passed a zero size, the buffer is deallocated and we do the small
optimization of not formatting messages which are not output anymore.
On the daemon side, it just adds a new option log_buffer_size to
libvirtd.conf and call virLogSetBufferSize() if needed
* src/util/logging.h src/util/logging.c src/libvirt_private.syms:
  make buffer dynamic and add virLogSetBufferSize() internal API
* daemon/libvirtd.conf: document the new log_buffer_size option
* daemon/libvirtd.c: read and use the new log_buffer_size option

Although the cgroup device ACL controller path can be worked out
by researching the code, it is more efficient to include that
information directly in the audit message.

* src/util/cgroup.h (virCgroupPathOfController): New prototype.
* src/util/cgroup.c (virCgroupPathOfController): Export.
* src/libvirt_private.syms: Likewise.
* src/qemu/qemu_audit.c (qemuAuditCgroup): Use it.

Not all applications have an existing event loop they need
to integrate with. Forcing them to implement the libvirt
event loop integration APIs is an undue burden. This just
exposes our simple poll() based implementation for apps
to use. So instead of calling

   virEventRegister(....callbacks...)

The app would call

   virEventRegisterDefaultImpl()

And then have a thread somewhere calling

    static bool quit = false;
    ....
    while (!quit)
      virEventRunDefaultImpl()

* daemon/libvirtd.c, tools/console.c,
  tools/virsh.c: Convert to public event loop APIs
* include/libvirt/libvirt.h.in, src/libvirt_private.syms: Add
  virEventRegisterDefaultImpl and virEventRunDefaultImpl
* src/util/event.c: Implement virEventRegisterDefaultImpl
  and virEventRunDefaultImpl using poll() event loop
* src/util/event_poll.c: Add full error reporting
* src/util/virterror.c, include/libvirt/virterror.h: Add
  VIR_FROM_EVENTS