The function doesn't check whether the request is made for active or
inactive domain.  Thus when the domain is not running it still tries
accessing non-existing cgroups (priv->cgroup, which is NULL).

I re-made the function in order for it to work the same way it's qemu
counterpart does.

Reproducer:
 1) Define an LXC domain
 2) Do 'virsh memtune <domain>'

Backtrace:
 Thread 6 (Thread 0x7fffec8c0700 (LWP 13387)):
 #0  0x00007ffff70edcc4 in virCgroupPathOfController (group=0x0, controller=3,
     key=0x7ffff75734bd "memory.limit_in_bytes", path=0x7fffec8bf750) at util/vircgroup.c:1764
 #1  0x00007ffff70e958c in virCgroupGetValueStr (group=0x0, controller=3,
     key=0x7ffff75734bd "memory.limit_in_bytes", value=0x7fffec8bf7c0) at util/vircgroup.c:705
 #2  0x00007ffff70e9d29 in virCgroupGetValueU64 (group=0x0, controller=3,
     key=0x7ffff75734bd "memory.limit_in_bytes", value=0x7fffec8bf810) at util/vircgroup.c:804
 #3  0x00007ffff70ee706 in virCgroupGetMemoryHardLimit (group=0x0, kb=0x7fffec8bf8a8)
     at util/vircgroup.c:1962
 #4  0x00005555557d590f in lxcDomainGetMemoryParameters (dom=0x7fffd40024a0,
     params=0x7fffd40027a0, nparams=0x7fffec8bfa24, flags=0) at lxc/lxc_driver.c:826
 #5  0x00007ffff72c28d3 in virDomainGetMemoryParameters (domain=0x7fffd40024a0,
     params=0x7fffd40027a0, nparams=0x7fffec8bfa24, flags=0) at libvirt.c:4137
 #6  0x000055555563714d in remoteDispatchDomainGetMemoryParameters (server=0x555555eb7e00,
     client=0x555555ebaef0, msg=0x555555ebb3e0, rerr=0x7fffec8bfb70, args=0x7fffd40024e0,
     ret=0x7fffd4002420) at remote.c:1895
 #7  0x00005555556052c4 in remoteDispatchDomainGetMemoryParametersHelper (server=0x555555eb7e00,
     client=0x555555ebaef0, msg=0x555555ebb3e0, rerr=0x7fffec8bfb70, args=0x7fffd40024e0,
     ret=0x7fffd4002420) at remote_dispatch.h:4050
 #8  0x00007ffff73b293f in virNetServerProgramDispatchCall (prog=0x555555ec3ae0,
     server=0x555555eb7e00, client=0x555555ebaef0, msg=0x555555ebb3e0)
     at rpc/virnetserverprogram.c:435
 #9  0x00007ffff73b207f in virNetServerProgramDispatch (prog=0x555555ec3ae0,
     server=0x555555eb7e00, client=0x555555ebaef0, msg=0x555555ebb3e0)
     at rpc/virnetserverprogram.c:305
 #10 0x00007ffff73a4d2c in virNetServerProcessMsg (srv=0x555555eb7e00, client=0x555555ebaef0,
     prog=0x555555ec3ae0, msg=0x555555ebb3e0) at rpc/virnetserver.c:165
 #11 0x00007ffff73a4e8d in virNetServerHandleJob (jobOpaque=0x555555ebc7e0, opaque=0x555555eb7e00)
     at rpc/virnetserver.c:186
 #12 0x00007ffff7187f3f in virThreadPoolWorker (opaque=0x555555eb7ac0) at util/virthreadpool.c:144
 #13 0x00007ffff718733a in virThreadHelper (data=0x555555eb7890) at util/virthreadpthread.c:161
 #14 0x00007ffff468ed89 in start_thread (arg=0x7fffec8c0700) at pthread_create.c:308
 #15 0x00007ffff3da26bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>
(cherry picked from commit f8c1cb90)

Conflicts:
	src/lxc/lxc_driver.c

As a consequence of the cgroup layout changes from commit 'cfed9ad4', the
lxcDomainGetSchedulerParameters[Flags]()' and lxcGetSchedulerType() APIs
failed to return data for a non running domain.  This can be seen through
a 'virsh schedinfo <domain>' command which returns:

Scheduler      : Unknown
error: Requested operation is not valid: cgroup CPU controller is not mounted

Prior to that change a non running domain would return:

Scheduler      : posix
cpu_shares     : 0
vcpu_period    : 0
vcpu_quota     : 0
emulator_period: 0
emulator_quota : 0

This patch will restore the capability to return configuration only data
for a non running domain regardless of whether cgroups are available.
(cherry picked from commit 38ada092)

The LXC, QEMU, and LibXL drivers have all merged their handling of
the attach/update/modify device APIs into one large

  'xxxxDomainModifyDeviceFlags'

which then does a 'switch()' based on the actual API being invoked.
While this saves some lines of code, it is not really all that
significant in the context of the driver API impls as a whole.

This merger of the handling of different APIs creates pain when
wanting to automated analysis of the code and do things which
are specific to individual APIs. The slight duplication of code
from unmerged the API impls, is preferrable to allow for easier
automated analysis.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The individual hypervisor drivers were directly referencing
APIs in virnodesuspend.c in their virDriverPtr struct. Separate
these methods, so there is always a wrapper in the hypervisor
driver. This allows the unused virConnectPtr args to be removed
from the virnodesuspend.c file. Again this will ensure that
ACL checks will only be performed on invocations that are
directly associated with public API usage.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The individual hypervisor drivers were directly referencing
APIs in src/nodeinfo.c in their virDriverPtr struct. Separate
these methods, so there is always a wrapper in the hypervisor
driver. This allows the unused virConnectPtr args to be
removed from the nodeinfo.c file. Again this will ensure that
ACL checks will only be performed on invocations that are
directly associated with public API usage.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the virGetHostname() API has a bogus virConnectPtr
parameter. This is because virtualization drivers directly
reference this API in their virDriverPtr tables, tieing its
API design to the public virConnectGetHostname API design.

This also causes problems for access control checks since
these must only be done for invocations from the public
API, not internal invocation.

Remove the bogus virConnectPtr parameter, and make each
hypervisor driver provide a dedicated function for the
driver API impl. This will allow access control checks
to be easily inserted later.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

Ensure that all drivers implementing public APIs use a
naming convention for their implementation that matches
the public API name.

eg for the public API   virDomainCreate make sure QEMU
uses qemuDomainCreate and not qemuDomainStart
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of calling virCgroupForDomain every time we need
the virCgrouPtr instance, just do it once at Vm startup
and cache a reference to the object in virLXCDomainObjPrivatePtr
until shutdown of the VM. Removing the virCgroupPtr from
the LXC driver state also means we don't have stale mount
info, if someone mounts the cgroups filesystem after libvirtd
has been started
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virCgroupMounted method is badly named, since a controller can be
mounted, but disabled in the current object. Rename the method to be
virCgroupHasController. Also make it tolerant to a  NULL virCgroupPtr
and out-of-range controller index, to avoid duplication of these
checks in all callers
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently when getting an instance of virCgroupPtr we will
create the path in all cgroup controllers. Only at the virt
driver layer are we attempting to filter controllers. This
is bad because the mere act of creating the dirs in the
controllers can have a functional impact on the kernel,
particularly for performance.

Update the virCgroupForDriver() method to accept a bitmask
of controllers to use. Only create dirs in the controllers
that are requested. When creating cgroups for domains,
respect the active controller list from the parent cgroup
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Move the xmlopt and caps arguments to the end of the argument list.

This patch adds instrumentation that will allow hypervisor drivers to
fill and validate domain and device definitions after parsed by the XML
parser.

With this patch, after the XML is parsed, a callback to the driver is
issued requesting to fill and validate driver specific details of the
configuration. This allows to use sensible defaults and checks on a per
driver basis at the time the XML is parsed.

Two callback pointers are stored in the new virDomainXMLConf object:
* virDomainDeviceDefPostParseCallback (devicesPostParseCallback)
  - called for a single device parsed and for every single device in a
    domain config. A virDomainDeviceDefPtr is passed along with the
    domain definition and virCaps.

* virDomainDefPostParseCallback, (domainPostParseCallback)
  - A callback that is meant to process the domain config after it's
  parsed.  A virDomainDefPtr is passed along with virCaps.

Both types of callbacks support arbitrary opaque data passed for the
callback functions.

Errors may be reported in those callbacks resulting in a XML parsing
failure.

This patch is the result of running:

for i in $(git ls-files | grep -v html | grep -v \.po$ ); do
  sed -i -e "s/virDomainXMLConf/virDomainXMLOption/g" -e "s/xmlconf/xmlopt/g" $i
done

and a few manual tweaks.

The sysinfo code used by QEMU is trivially portable to the
LXC driver

This reverts commit c9c87376.

Now that we force all containers to have a root filesystem,
there is no way the host's /dev is ever exposed
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When the container has the same '/dev' mount as host (no chroot),
calling domainShutdown(WithFlags) shouldn't shutdown the host it is
running on.

The virDomainGetSecurityLabel method is currently (mistakenly)
showing the label of the libvirt_lxc process:

...snip...
Security model: selinux
Security DOI:   0
Security label: system_u:system_r:virtd_t:s0-s0:c0.c1023 (permissive)

when it should be showing the init process label

...snip...
Security model: selinux
Security DOI:   0
Security label: system_u:system_r:svirt_t:s0:c724,c995 (permissive)

The virCaps structure gathered a ton of irrelevant data over time that.
The original reason is that it was propagated to the XML parser
functions.

This patch aims to create a new data structure virDomainXMLConf that
will contain immutable data that are used by the XML parser. This will
allow two things we need:

1) Get rid of the stuff from virCaps

2) Allow us to add callbacks to check and add driver specific stuff
after domain XML is parsed.

This first attempt removes pointers to private data allocation functions
to this new structure and update all callers and function that require
them.

otherwise we crash with

 #0  virUSBDeviceListFind (list=0x0, dev=dev@entry=0x8193d70) at util/virusb.c:526
 #1  0xb1a4995b in virLXCPrepareHostdevUSBDevices (driver=driver@entry=0x815d9a0, name=0x815dbf8 "debian-700267", list=list@entry=0x81d8f08) at lxc/lxc_hostdev.c:88
 #2  0xb1a49fce in virLXCPrepareHostUSBDevices (def=0x8193af8, driver=0x815d9a0) at lxc/lxc_hostdev.c:261
 #3  virLXCPrepareHostDevices (driver=driver@entry=0x815d9a0, def=0x8193af8) at lxc/lxc_hostdev.c:328
 #4  0xb1a4c5b1 in virLXCProcessStart (conn=0x817d3f8, driver=driver@entry=0x815d9a0, vm=vm@entry=0x8190908, autoDestroy=autoDestroy@entry=false, reason=reason@entry=VIR_DOMAIN_RUNNING_BOOTED)
     at lxc/lxc_process.c:1068
 #5  0xb1a57e00 in lxcDomainStartWithFlags (dom=dom@entry=0x815e460, flags=flags@entry=0) at lxc/lxc_driver.c:1014
 #6  0xb1a57fc3 in lxcDomainStart (dom=0x815e460) at lxc/lxc_driver.c:1046
 #7  0xb79c8375 in virDomainCreate (domain=domain@entry=0x815e460) at libvirt.c:8450
 #8  0x08078959 in remoteDispatchDomainCreate (args=0x81920a0, rerr=0xb65c21d0, client=0xb0d00490, server=<optimized out>, msg=<optimized out>) at remote_dispatch.h:1066
 #9  remoteDispatchDomainCreateHelper (server=0x80c4928, client=0xb0d00490, msg=0xb0d005b0, rerr=0xb65c21d0, args=0x81920a0, ret=0x815d208) at remote_dispatch.h:1044
 #10 0xb7a36901 in virNetServerProgramDispatchCall (msg=0xb0d005b0, client=0xb0d00490, server=0x80c4928, prog=0x80c6438) at rpc/virnetserverprogram.c:432
 #11 virNetServerProgramDispatch (prog=0x80c6438, server=server@entry=0x80c4928, client=0xb0d00490, msg=0xb0d005b0) at rpc/virnetserverprogram.c:305
 #12 0xb7a300a7 in virNetServerProcessMsg (msg=<optimized out>, prog=<optimized out>, client=<optimized out>, srv=0x80c4928) at rpc/virnetserver.c:162
 #13 virNetServerHandleJob (jobOpaque=0xb0d00510, opaque=0x80c4928) at rpc/virnetserver.c:183
 #14 0xb7924f98 in virThreadPoolWorker (opaque=opaque@entry=0x80a94b0) at util/virthreadpool.c:144
 #15 0xb7924515 in virThreadHelper (data=0x80a9440) at util/virthreadpthread.c:161
 #16 0xb7887c39 in start_thread (arg=0xb65c2b70) at pthread_create.c:304
 #17 0xb77eb78e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

when adding a domain with a usb device. This is Debian bug

    http://bugs.debian.org/700267

To enable locking to be introduced to the security manager
objects later, turn virSecurityManager into a virObjectLockable
class
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To enable virCapabilities instances to be reference counted,
turn it into a virObject. All cases of virCapabilitiesFree
turn into virObjectUnref
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Rename all the usbDeviceXXX and usbXXXDevice APIs to have a
fixed virUSBDevice name prefix

The duplicate VM checking should be done atomically with
virDomainObjListAdd, so shoud not be a separate function.
Instead just use flags to indicate what kind of checks are
required.

This pair, used in virDomainCreateXML:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, false)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
                                   NULL)))
     goto cleanup;

This pair, used in virDomainRestoreFlags:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, true)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
                                   VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
                                   NULL)))
     goto cleanup;

This pair, used in virDomainDefineXML:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 0) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, false)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   0, NULL)))
     goto cleanup;

As a step towards making virDomainObjList thread-safe turn it
into an opaque virObject, preventing any direct access to its
internals.

As part of this a new method virDomainObjListForEach is
introduced to replace all existing usage of virHashForEach

The APIs names for accessing the domain list object are
very inconsistent. Rename them all to have a standard
virDomainObjList prefix.

It was possible to call VIR_FREE in cleanup prior to initialization

The use of switch statements inside a bounded for loop resulted in some
false positives regarding the "default:" label which cannot be reached
since each of the other case statements use the possible for loop values.

The  virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virDomainLxcOpenNamespace method needs to open every file
in /proc/$INITPID/ns and return the open file descriptor to the
client application.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Mark virDomainLxcEnterNamespace as skipped in python binding
and remove reference to lxcDomainOpenNamespace which doesn't
arrive until a later patch

This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.

The actual APIs are

  int virDomainLxcOpenNamespace(virDomainPtr domain,
                                int **fdlist,
                                unsigned int flags);

  int virDomainLxcEnterNamespace(virDomainPtr domain,
                                 unsigned int nfdlist,
                                 int *fdlist,
                                 unsigned int *noldfdlist,
                                 int **oldfdlist,
                                 unsigned int flags);

which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.

NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>