When we added the default USB controller into domain XML, we efficiently
broke migration to older versions of libvirt that didn't support USB
controllers at all (0.9.4 and earlier) even for domains that don't use
anything that the older libvirt can't provide. We still want to present
the default USB controller in any XML seen by a user/app but we can
safely remove it from the domain XML used during migration. If we are
migrating to a new enough libvirt, it will add the controller XML back,
while older libvirt won't be confused with it although it will still
tell qemu to create the controller.

Similar approach can be used in the future whenever we find out we
always enabled some kind of device without properly advertising it in
domain XML.

Always use appropriate qemuDomain{,Def}Format wrapper since it may do
some additional magic based on the flags.

Commit 4c82f09e added a capability check for qemu per-device io
throttling, but only applied it to domain startup.  As mentioned
in the previous commit (98cec052), the user can still get an 'internal
error' message during a hotplug attempt, when the monitor command
doesn't exist.  It is confusing to allow tuning on inactive domains
only to then be rejected when starting the domain.

* src/qemu/qemu_driver.c (qemuDomainSetBlockIoTune): Reject
offline tuning if online can't match it.

If you have a qemu build that lacks the blockio tune monitor command,
then this command:

$ virsh blkdeviotune rhel6u2 hda --total_bytes_sec 1000
error: Unable to change block I/O throttle
error: internal error Unexpected error

fails as expected (well, the error message is lousy), but the next
dumpxml shows that the domain was modified anyway.  Worse, that means
if you save the domain then restore it, the restore will likely fail
due to throttling being unsupported, even though no throttling should
even be active because the monitor command failed in the first place.

* src/qemu/qemu_driver.c (qemuDomainSetBlockIoTune): Check for
error before making modification permanent.

These two functions are called from main() on all platforms, and
always return success on platforms that don't support libnl. They
still log an error message, though, which doesn't make sense - they
should just be NOPs on those platforms. (Per a suggestion during
review, I've turned the logs into debug messages rather than removing
them completely).

Error: STRING_NULL:
/libvirt/src/node_device/node_device_linux_sysfs.c:80:
string_null_argument: Function "saferead" does not terminate string "*buf".
/libvirt/src/util/util.c:101:
string_null_argument: Function "read" fills array "*buf" with a non-terminated string.
/libvirt/src/node_device/node_device_linux_sysfs.c:87:
string_null: Passing unterminated string "buf" to a function expecting a null-terminated string.

Error: STRING_NULL:
/libvirt/src/util/uuid.c:273:
string_null_argument: Function "getDMISystemUUID" does not terminate string "*dmiuuid".
/libvirt/src/util/uuid.c:241:
string_null_argument: Function "saferead" fills array "*uuid" with a non-terminated string.
/libvirt/src/util/util.c:101:
string_null_argument: Function "read" fills array "*buf" with a non-terminated string.
/libvirt/src/util/uuid.c:274:
string_null: Passing unterminated string "dmiuuid" to a function expecting a null-terminated string.
/libvirt/src/util/uuid.c:138:
var_assign_parm: Assigning: "cur" = "uuidstr". They now point to the same thing.
/libvirt/src/util/uuid.c:164:
string_null_sink_loop: Searching for null termination in an unterminated array "cur".

Error: RESOURCE_LEAK:
/libvirt/tests/qemuxml2argvtest.c:47:
alloc_arg: Calling allocation function "virAlloc" on "ret".
/libvirt/src/util/memory.c:101:
alloc_fn: Storage is returned from allocation function "calloc".
/libvirt/src/util/memory.c:101:
var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/libvirt/tests/qemuxml2argvtest.c:54:
leaked_storage: Variable "ret" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/libvirt/src/qemu/qemu_driver.c:6968:
alloc_fn: Calling allocation function "calloc".
/libvirt/src/qemu/qemu_driver.c:6968:
var_assign: Assigning: "nodeset" =  storage returned from "calloc(1UL, 1UL)".
/libvirt/src/qemu/qemu_driver.c:6977:
noescape: Variable "nodeset" is not freed or pointed-to in function "virTypedParameterAssign".
/libvirt/src/qemu/qemu_driver.c:6997:
leaked_storage: Variable "nodeset" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/libvirt/src/vmx/vmx.c:2431:
alloc_fn: Calling allocation function "calloc".
/libvirt/src/vmx/vmx.c:2431:
var_assign: Assigning: "networkName" =  storage returned from "calloc(1UL, 1UL)".
/libvirt/src/vmx/vmx.c:2495:
leaked_storage: Variable "networkName" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/nodeinfo.c:629: alloc_fn: Calling allocation function "fopen".
/builddir/build/BUILD/libvirt-0.9.10/src/nodeinfo.c:629: var_assign: Assigning: "cpuinfo" =  storage returned from "fopen("/proc/cpuinfo", "r")".
/builddir/build/BUILD/libvirt-0.9.10/src/nodeinfo.c:638: leaked_storage: Variable "cpuinfo" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/test/test_driver.c:1041: alloc_arg: Calling allocation function "virXPathNodeSet" on "devs".
/builddir/build/BUILD/libvirt-0.9.10/src/util/xml.c:621: alloc_arg: "virAllocN" allocates memory that is stored into "*list".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:129: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:129: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(count, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/util/xml.c:625: noescape: Variable "*list" is not freed or pointed-to in function "memcpy".
/builddir/build/BUILD/libvirt-0.9.10/src/test/test_driver.c:1098: leaked_storage: Variable "devs" going out of scope leaks the storage it points to.

Coverity logs:

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_inotify.c:103: alloc_fn: Calling allocation function "xenDaemonLookupByUUID".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xend_internal.c:2534: alloc_fn: Storage is returned from allocation function "virGetDomain".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:191: alloc_arg: "virAlloc" allocates memory that is stored into "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:210: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xend_internal.c:2534: var_assign: Assigning: "ret" = "virGetDomain(conn, name, uuid)".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xend_internal.c:2541: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_inotify.c:103: var_assign: Assigning: "dom" =  storage returned from "xenDaemonLookupByUUID(conn, rawuuid)".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_inotify.c:126: leaked_storage: Variable "dom" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2742: alloc_fn: Calling allocation function "fopen".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2742: var_assign: Assigning: "cpuinfo" =  storage returned from "fopen("/proc/cpuinfo", "r")".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2763: noescape: Variable "cpuinfo" is not freed or pointed-to in function "xenHypervisorMakeCapabilitiesInternal".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2574:45: noescape: "xenHypervisorMakeCapabilitiesInternal" does not free or save its pointer parameter "cpuinfo".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2768: leaked_storage: Variable "cpuinfo" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2752: alloc_fn: Calling allocation function "fopen".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2752: var_assign: Assigning: "capabilities" =  storage returned from "fopen("/sys/hypervisor/properties/capabilities", "r")".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2763: noescape: Variable "capabilities" is not freed or pointed-to in function "xenHypervisorMakeCapabilitiesInternal".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2574:60: noescape: "xenHypervisorMakeCapabilitiesInternal" does not free or save its pointer parameter "capabilities".
/builddir/build/BUILD/libvirt-0.9.10/src/xen/xen_hypervisor.c:2768: leaked_storage: Variable "capabilities" going out of scope leaks the storage it points to.

Coverity logs:

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:523: alloc_fn: Calling allocation function "fopen".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:523: var_assign: Assigning: "fd" =  storage returned from "fopen(local_file, "rb")".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:540: noescape: Variable "fd" is not freed or pointed-to in function "fread".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:542: noescape: Variable "fd" is not freed or pointed-to in function "feof".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:575: leaked_storage: Variable "fd" going out of scope leaks the storage it points to.
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:585: leaked_storage: Variable "fd" going out of scope leaks the storage it points to.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2088: alloc_fn: Calling allocation function "phypVolumeLookupByName".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2026: alloc_fn: Storage is returned from allocation function "virGetStorageVol".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:724: alloc_arg: "virAlloc" allocates memory that is stored into "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:753: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2026: var_assign: Assigning: "vol" = "virGetStorageVol(pool->conn, pool->name, volname, key)".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2030: return_alloc: Returning allocated memory "vol".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2088: leaked_storage: Failing to save storage allocated by "phypVolumeLookupByName(pool, voldef->name)" leaks it.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2725: alloc_fn: Calling allocation function "phypGetStoragePoolLookUpByUUID".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2689: alloc_fn: Storage is returned from allocation function "virGetStoragePool".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:592: alloc_arg: "virAlloc" allocates memory that is stored into "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:610: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2689: var_assign: Assigning: "sp" = "virGetStoragePool(conn, pools[i], uuid)".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2694: return_alloc: Returning allocated memory "sp".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2725: leaked_storage: Failing to save storage allocated by "phypGetStoragePoolLookUpByUUID(conn, def->uuid)" leaks it.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2719: alloc_fn: Calling allocation function "phypStoragePoolLookupByName".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2254: alloc_fn: Storage is returned from allocation function "virGetStoragePool".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:592: alloc_arg: "virAlloc" allocates memory that is stored into "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:610: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2254: return_alloc_fn: Directly returning storage allocated by "virGetStoragePool".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2719: leaked_storage: Failing to save storage allocated by "phypStoragePoolLookupByName(conn, def->name)" leaks it.

Error: RESOURCE_LEAK:
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2270: alloc_fn: Calling allocation function "phypStoragePoolLookupByName".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2254: alloc_fn: Storage is returned from allocation function "virGetStoragePool".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:592: alloc_arg: "virAlloc" allocates memory that is stored into "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: alloc_fn: Storage is returned from allocation function "calloc".
/builddir/build/BUILD/libvirt-0.9.10/src/util/memory.c:101: var_assign: Assigning: "*((void **)ptrptr)" = "calloc(1UL, size)".
/builddir/build/BUILD/libvirt-0.9.10/src/datatypes.c:610: return_alloc: Returning allocated memory "ret".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2254: return_alloc_fn: Directly returning storage allocated by "virGetStoragePool".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2270: var_assign: Assigning: "sp" =  storage returned from "phypStoragePoolLookupByName(vol->conn, vol->pool)".
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2324: leaked_storage: Variable "sp" going out of scope leaks the storage it points to.
/builddir/build/BUILD/libvirt-0.9.10/src/phyp/phyp_driver.c:2327: leaked_storage: Variable "sp" going out of scope leaks the storage it points t

Related coverity log:

Error: FORWARD_NULL:
/builddir/build/BUILD/libvirt-0.9.10/python/libvirt-override.c:355:
assign_zero: Assigning: "params" = 0.
/builddir/build/BUILD/libvirt-0.9.10/python/libvirt-override.c:458:
var_deref_model: Passing null variable "params" to function
"getPyVirTypedParameter", which dereferences it. (The dereference is assumed on
the basis of the 'nonnull' parameter attribute.)

On 32-bit platforms, gcc warns that the comparison between a long
and (ULLONG_MAX/1024/1024) is always false; throwing in a type
conversion shuts up the warning.

* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Shut gcc up.

configure.ac: check for libnl-3 in addition to libnl-1

src/Makefile.am: link against libnl when needed

src/util/virnetlink.c:
support libnl3 api.  To minimize impact on code flow, wrap the
differences under the virNetlink* namespace.

Unfortunately libnl3 moves netlink/msg.h to
/usr/include/libnl3/netlink/msg.h, so the LIBNL_CFLAGS need to be added
to a bunch of places where they weren't needed with libnl1.
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

On cygwin, <rpc/rpc.h> lives in a different directory than
/usr/include, so anything that uses it must modify CFLAGS.  This
previously tripped up just 'make check', but now that we build
all test programs unconditionally, it also trips up 'make'.

* tests/Makefile.am (virnetmessagetest_CFLAGS): Find rpc headers.

Add function virJSONValueObjectKeysNumber, virJSONValueObjectGetKey
and virJSONValueObjectGetValue, which allow you to iterate over all
fields of json object: you can get number of fields and then get
name and value, stored in field with that name by index.
Signed-off-by: NDmitry Guryanov <dguryanov@parallels.com>

qemuDomainNetsRestart indents with 3 spaces.

This patch is to correct it.
Signed-off-by: NLi Zhang <zhlcindy@linux.vnet.ibm.com>

The code uses long long for pid_t now.
It fails on mingw64 without this change.

Fix a few more places where pid_t is printed with wrong type

The recent push to use correct scaling terms (kB for 1000, KiB for
1024 - such as commit 9dfdeadc) missed some places in virsh.

* tools/virsh.c (prettyCapacity, cmdDominfo, cmdFreecell)
(cmdNodeinfo, cmdNodeMemStats, cmdMigrateSetMaxSpeed)
(cmdBlockCopy, cmdBlockPull, cmdBlockJob): Use KiB, not kB, when
referring to multiples of 1024.
* tests/virshtest.c: Update expected output to match.

https://bugzilla.redhat.com/show_bug.cgi?id=817244 mentions that
unlike most other tools, where --help or --version prevent all
further parsing of all later options, virsh was strange in that
--version stopped parsing but --help tried to plow on to the end.
There was no rationale for this original implementation (since
2005!), so I think we can safely conform to common usage patterns.

* tools/virsh.c (main): Drop useless 'help' variable.

The ATTRIBUTE_NONNULL(m) macro normally resolves to the gcc builtin
__attribute__((__nonnull__(m))). The effect of this in gcc is
unfortunately only to make gcc believe that "m" can never possibly be
NULL, *not* to add in any checks to guarantee that it isn't ever NULL
(i.e. it is an optimization aid, *not* something to verify code
correctness.) - see the following gcc bug report for more details:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17308

Static source analyzers such as clang and coverity apparently can use
ATTRIBUTE_NONNULL(), though, to detect dead code (in the case that the
arg really is guaranteed non-NULL), as well as situations where an
obviously NULL arg is given to the function.

https://bugzilla.redhat.com/show_bug.cgi?id=815270 is a good example
of a bug caused by erroneous application of ATTRIBUTE_NONNULL().
Several people spent a long time staring at this code and not finding
the problem, because the problem wasn't in the function itself, but in
the prototype that specified ATTRIBUTE_NONNULL() for an arg that
actually *wasn't* always non-NULL, and caused a segv when dereferenced
(even though the code that dereferenced the pointer was inside an if()
that checked for a NULL pointer, that code was optimized out by gcc).

There may be some very small gain to be had from the optimizations
that can be inferred from ATTRIBUTE_NONNULL(), but it seems safer to
err on the side of generating code that behaves as expected, while
turning on the attribute for static analyzers.

Once lxcContainerSetStdio is invoked, logging will not work as
expected in libvirt_lxc. So make sure this is the last thing to
be called, in particular after setting the security process label

The virLogSetFromEnv call was done too late in startup to
catch many log messages (eg from security driver initialization).
To assist debugging also explicitly log the security details
at startup

The driver->securityDriverName field may be NULL, if automatic
probing is used to determine security driver. This meant that
unless selinux was explicitly requested in lxc.conf, it was
not being sent to the libvirt_lxc process.

The driver->securityManager field is guaranteed non-NULL, since
there will always be the 'none' security driver present if
nothing else exists. So use that to set the driver name for
libvirt_lxc
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the libvirt_lxc process uses VIR_DOMAIN_XML_INACTIVE
when loading the XML for the container. This means it loses
any dynamic data such as the, just allocated, SELinux label.

Further there is an inconsistency in the libvirt LXC driver
whereby it saves the live config XML and then later overwrites
the file with the live status XML instead. Add a comment about
this for future reference.

* src/lxc/lxc_controller.c: Remove VIR_DOMAIN_XML_INACTIVE
  when loading XML
* src/lxc/lxc_driver.c: Add comment about inconsistent
  config file formats
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Otherwise, a string such as _("Don't use \"" VAR "\".") would
complain about unmarked diagnostics.

* cfg.mk (sc_libvirt_unmarked_diagnostics): Handle \" in message.

Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

This works with newer qemu that doesn't allow escaping spaces.
It's backwards compatible as well.
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

In fact, the 'tapfd' is always NULL, the function 'virNetDevTapCreate()' hasn't
assign 'fd' to 'tapfd', when the function 'virNetDevSetMAC()' is failed then
goto 'error' label, finally, the VIR_FORCE_CLOSE() will deref a NULL 'tapfd'.

* util/virnetdevtap.c (virNetDevTapCreateInBridgePort): fix a NULL pointer derefing.

* How to reproduce?

$ cat > /tmp/net.xml <<EOF
<network>
  <name>test</name>
  <forward mode='nat'/>
  <bridge name='br1' stp='off' delay='1' />
  <mac address='00:00:00:00:00:00'/>
  <ip address='192.168.100.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.100.2' end='192.168.100.254' />
    </dhcp>
  </ip>
</network>
EOF

$ virsh net-define /tmp/net.xml

$ virsh net-start test
error: Failed to start network brTest
error: End of file while reading data: Input/output error
Signed-off-by: NAlex Jia <ajia@redhat.com>

The previous storage patch missed an instance affected by the struct
member rename.  It also had some botched whitespace detected by
'make check'.

* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSIFindPoolSources): Adjust to new struct.
* src/conf/storage_conf.c (virStoragePoolSourceFormat): Fix
indentation.

It doesn't break out the "for" loop even if duplicate pool is
found, and thus the "matchpool" could be overriden as NULL again
if there is different pool afterwards.

To address the problem in libvirt-user list:

https://www.redhat.com/archives/libvirt-users/2012-April/msg00150.html