More fallout from commit d72ef888.  When reconnecting to running
domains, the libxl_ctx in libxlDomainObjPrivate was used before
initializing it, causing a segfault in libxl and consequently
crashing libvirtd.

Initialize the libxlDomainObjPrivate libxl_ctx in libxlReconnectDomain,
and while at it use this ctx in libxlReconnectDomain instead of the
driver-wide ctx.

https://bugzilla.redhat.com/show_bug.cgi?id=822052

When doing a live migration, if the destination fails for any
reason after the point in which files should be labeled, then
the cleanup of the destination would restore the labels to their
defaults, even though the source is still trying to continue
running with the image open.  Bug 822052 mentioned one source
of live migration failure - a mismatch in SELinux virt_use_nfs
settings (on for source, off for destination); but I found other
situations that would also trigger it (for example, having a
graphics device tied to port 5999 on the source, and a different
domain on the destination already using that port, so that the
destination cannot reuse the port).

In short, just as cleanup of the source on a successful migration
must not relabel files (because the destination would be crippled
by the relabel), cleanup of the destination on a failed migration
must not relabel files (because the source would be crippled).

* src/qemu/qemu_process.c (qemuProcessStart): Set flag to avoid
label restoration when cleaning up on failed migration.
Signed-off-by: NEric Blake <eblake@redhat.com>

Only compile securityselinuxhelper.c if xattr support was detected to
avoid this error:

securityselinuxhelper.c:34:24: fatal error: attr/xattr.h: No such file
or directory compilation terminated.

Since all SELinux tests depend upon the securityselinuxhelper library,
these test programs are now only build when xattr support is
available.

In commit f905cc99 a use of
uninitialized data was fixed based on a coverity report. It
turns out it was possible to trigger this issue by pointing
libvirt at non-existent certificate files, typically causing
a crash.

This adds a test case for that scenario. With the above
commit reverted, this new test case will crash with a SEGV.
With the fix applied, it passes, reporting a normal libvirt
error to the caller.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Introduced by commit e0139e30. virStorageVolDefFree free'ed the
pointers that are still used by the added volume object, this changes
it back to VIR_FREE.

Introduced by commit e0139e30:

1777 	    /* Updating pool metadata */

(40) Event var_deref_op: Dereferencing null pointer "newvol".
     Also see events: [assign_zero]

1778 	    pool->def->allocation += newvol->allocation;
1779 	    pool->def->available -= newvol->allocation;

Update the iSCSI storage pool example to include the secret

Update formatsecret docs to describe the various options and provide examples
in order to set up secrets for each type of secret.

Add more iSCSI examples including having a secret attached. There are 4 new
examples; one for each way to have an iSCSI - a network disk using virtio,
a passthrough network lun using scsi, a volume disk using "mode='host'",
and a volume disk using "mode='direct'"

Each of the modules handled reporting error messages from the secret fetching
slightly differently with respect to the error. Provide a similar message
for each error case and provide as much data as possible.

Following XML would fail :

    <disk type='network' device='lun'>
      <driver name='qemu' type='raw'/>
      <source protocol='iscsi' name='iqn.2013-07.com.example:iscsi/1'>
        <host name='example.com' port='3260'/>
      </source>
      <target dev='sda' bus='scsi'/>
    </disk>

With the message:

error: Failed to start domain iscsilun
error: Unable to get device ID 'iqn.2013-07.com.example:iscsi/1': No such fi

Cause was commit id '1f49b05a' which added 'virDomainDiskSourceIsBlockType'

When using virsh secret-list - if the secret types are cephx or iscsi,
then allow fetch/print of the usage information. Prior to the change
the following would print:

UUID                                 Usage
-----------------------------------------------------------
1b40a534-8301-45d5-b1aa-11894ebb1735 Unused
a5ba3efe-6adf-4a6a-b243-f010a043e314 Unused

Afterwards:

UUID                                 Usage
-----------------------------------------------------------
1b40a534-8301-45d5-b1aa-11894ebb1735 ceph ceph_example
a5ba3efe-6adf-4a6a-b243-f010a043e314 iscsi libvirtiscsi

If we reached cleanup: prior to allocating cpus, it was possible that
'nr_nodes' had a value, but cpus was NULL leading to a possible NULL
deref. Add a 'cpus' as an end condition to for loop

Daniel Berrange (correctly) pointed out that we should do a better
job of testing selinux labeling fallbacks on NFS disks that lack
labeling support.

* tests/securityselinuxhelper.c (includes): Makefile already
guaranteed xattr support.  Add additional headers.
(init_syms): New function, borrowing from vircgroupmock.c.
(setfilecon_raw, getfilecon_raw): Fake NFS failure.
(statfs): Fake an NFS mount point.
(security_getenforce, security_get_boolean_active): Don't let host
environment affect test.
* tests/securityselinuxlabeldata/nfs.data: New file.
* tests/securityselinuxlabeldata/nfs.xml: New file.
* tests/securityselinuxlabeltest.c (testSELinuxCreateDisks)
(testSELinuxDeleteDisks): Setup and cleanup for fake NFS mount.
(testSELinuxCheckLabels): Test handling of SELinux NFS denial.
Fix memory leak.
(testSELinuxLabeling): Avoid infinite loop on dirty tree.
(mymain): Add new test.

https://bugzilla.redhat.com/show_bug.cgi?id=924153

Commit 904e05a2 (v0.9.9) added a per-<disk> seclabel element with
an attribute relabel='no' in order to try and minimize the
impact of shutdown delays when an NFS server disappears.  The idea
was that if a disk is on NFS and can't be labeled in the first
place, there is no need to attempt the (no-op) relabel on domain
shutdown.  Unfortunately, the way this was implemented was by
modifying the domain XML so that the optimization would survive
libvirtd restart, but in a way that is indistinguishable from an
explicit user setting.  Furthermore, once the setting is turned
on, libvirt avoids attempts at labeling, even for operations like
snapshot or blockcopy where the chain is being extended or pivoted
onto non-NFS, where SELinux labeling is once again possible.  As
a result, it was impossible to do a blockcopy to pivot from an
NFS image file onto a local file.

The solution is to separate the semantics of a chain that must
not be labeled (which the user can set even on persistent domains)
vs. the optimization of not attempting a relabel on cleanup (a
live-only annotation), and using only the user's explicit notation
rather than the optimization as the decision on whether to skip
a label attempt in the first place.  When upgrading an older
libvirtd to a newer, an NFS volume will still attempt the relabel;
but as the avoidance of a relabel was only an optimization, this
shouldn't cause any problems.

In the ideal future, libvirt will eventually have XML describing
EVERY file in the backing chain, with each file having a separate
<seclabel> element.  At that point, libvirt will be able to track
more closely which files need a relabel attempt at shutdown.  But
until we reach that point, the single <seclabel> for the entire
<disk> chain is treated as a hint - when a chain has only one
file, then we know it is accurate; but if the chain has more than
one file, we have to attempt relabel in spite of the attribute,
in case part of the chain is local and SELinux mattered for that
portion of the chain.

* src/conf/domain_conf.h (_virSecurityDeviceLabelDef): Add new
member.
* src/conf/domain_conf.c (virSecurityDeviceLabelDefParseXML):
Parse it, for live images only.
(virSecurityDeviceLabelDefFormat): Output it.
(virDomainDiskDefParseXML, virDomainChrSourceDefParseXML)
(virDomainDiskSourceDefFormat, virDomainChrDefFormat)
(virDomainDiskDefFormat): Pass flags on through.
* src/security/security_selinux.c
(virSecuritySELinuxRestoreSecurityImageLabelInt): Honor labelskip
when possible.
(virSecuritySELinuxSetSecurityFileLabel): Set labelskip, not
norelabel, if labeling fails.
(virSecuritySELinuxSetFileconHelper): Fix indentation.
* docs/formatdomain.html.in (seclabel): Document new xml.
* docs/schemas/domaincommon.rng (devSeclabel): Allow it in RNG.
* tests/qemuxml2argvdata/qemuxml2argv-seclabel-*-labelskip.xml:
* tests/qemuxml2argvdata/qemuxml2argv-seclabel-*-labelskip.args:
* tests/qemuxml2xmloutdata/qemuxml2xmlout-seclabel-*-labelskip.xml:
New test files.
* tests/qemuxml2argvtest.c (mymain): Run the new tests.
* tests/qemuxml2xmltest.c (mymain): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Use the new semantics of vshStringToArray to avoid leaking the array of
volumes to be deleted. The array would be leaked in case the first
volume was found in the domain definition. Also refactor the code a bit
to sanitize naming of variables hoding arrays and dimensions of the
arrays.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=996050

Explicitly let the user know about the unknown pool type.

At a slightly larger memory expense allow stealing of items from the
string array returned from vshStringToArray and turn the result into a
string list compatible with virStringSplit. This will allow to use the
common dealloc function.

This patch also fixes a few forgotten checks of return from
vshStringToArray and one memory leak.

If there's no hard_limit set and domain uses VFIO we still must lock the
guest memory (prerequisite from qemu). Hence, we should compute the
amount to be locked from max_balloon.

Since 16bcb3 we have a regression. The hard_limit is set
unconditionally. By default the limit is zero. Hence, if user hasn't
configured any, we set the zero in cgroup subsystem making the kernel
kill the corresponding qemu process immediately. The proper fix is to
set hard_limit iff user has configured any.

Another program gains --help/--version :)

* tools/virt-pki-validate.in: Add option parsing.  Update
documentation to match.
* tools/Makefile.am (virt-pki-validate): Substitute version.
Signed-off-by: NEric Blake <eblake@redhat.com>

We were failing to autoprobe which schema to use for several
top-level XML elements.

* tools/virt-xml-validate.in (TYPE): Recognize <domainsnapshot>,
<filter>, and <secret>.
Signed-off-by: NEric Blake <eblake@redhat.com>

All good tools should have --help and --version output :)

Furthermore, we want to ensure a failed exit if xmllint fails,
or even for 'virt-xml-validate > /dev/full'.

* tools/virt-xml-validate.in: Add option parsing.  Output errors
to stderr.  Update documentation to match.
* tools/Makefile.am (virt-xml-validate): Substitute version.
Signed-off-by: NEric Blake <eblake@redhat.com>

From: Dario Faggioli <dario.faggioli@citrix.com>

Starting from Xen 4.2, libxl has all the bits and pieces in place
for retrieving an adequate amount of information about the host
NUMA topology. It is therefore possible, after a bit of shuffling,
to arrange those information in the way libvirt wants to present
them to the outside world.

Therefore, with this patch, the <topology> section of the host
capabilities is properly populated, when running on Xen, so that
we can figure out whether or not we're running on a NUMA host,
and what its characteristics are.

[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// capabilities
<capabilities>
  <host>
    <cpu>
    ....
    <topology>
      <cells num='2'>
        <cell id='0'>
          <memory unit='KiB'>6291456</memory>
          <cpus num='8'>
            <cpu id='0' socket_id='1' core_id='0' siblings='0-1'/>
            <cpu id='1' socket_id='1' core_id='0' siblings='0-1'/>
            <cpu id='2' socket_id='1' core_id='1' siblings='2-3'/>
            <cpu id='3' socket_id='1' core_id='1' siblings='2-3'/>
            <cpu id='4' socket_id='1' core_id='9' siblings='4-5'/>
            <cpu id='5' socket_id='1' core_id='9' siblings='4-5'/>
            <cpu id='6' socket_id='1' core_id='10' siblings='6-7'/>
            <cpu id='7' socket_id='1' core_id='10' siblings='6-7'/>
          </cpus>
        </cell>
        <cell id='1'>
          <memory unit='KiB'>6881280</memory>
          <cpus num='8'>
            <cpu id='8' socket_id='0' core_id='0' siblings='8-9'/>
            <cpu id='9' socket_id='0' core_id='0' siblings='8-9'/>
            <cpu id='10' socket_id='0' core_id='1' siblings='10-11'/>
            <cpu id='11' socket_id='0' core_id='1' siblings='10-11'/>
            <cpu id='12' socket_id='0' core_id='9' siblings='12-13'/>
            <cpu id='13' socket_id='0' core_id='9' siblings='12-13'/>
            <cpu id='14' socket_id='0' core_id='10' siblings='14-15'/>
            <cpu id='15' socket_id='0' core_id='10' siblings='14-15'/>
          </cpus>
        </cell>
      </cells>
    </topology>
  </host>
  ....

When the daemon is compiled with firewalld support but the DBus message
bus isn't started in the system, the initialization of the nwfilter
driver fails even if there are fallback options.

On hosts that don't have the DBus service running or installed the new
systemd cgroups code failed with hard error instead of falling back to
"manual" cgroup creation.

Use the new helper to check for the system bus and use the fallback code
in case it isn't available.

Some systems may not use DBus in their system. Add a method to check if
the system bus is available that doesn't print error messages so that
code can later check for this condition and use an alternative approach.

Coverity reported a memleak in the test added in 7efd5fd1. In case
the code will be broken and the code will actually parse a faulty bitmap
the resulting pointer would be leaked. Free it although that shouldn't
ever happen.

Each new VM requires a new connection from libvirtd to virtlockd.
The default max clients limit in virtlockd of 20 is thus woefully
insufficient. virtlockd sockets are only accessible to matching
users, so there is no security need for such a tight limit. Make
it configurable and default to 1024.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In one of my previous patches I am removing the hard_limit heuristic to
guess the correct value if none set. However, it turned out, this limit
is hard to guess even for users. We should advise them to not set the
limit as their domains may be OOM killed. Sigh.

This function is to guess the correct limit for maximal memory
usage by qemu for given domain. This can never be guessed
correctly, not to mention all the pains and sleepless nights this
code has caused. Once somebody discovers algorithm to solve the
Halting Problem, we can compute the limit algorithmically. But
till then, this code should never see the light of the release
again.

One has to refresh the pool to get the correct pool info after
adding/removing/resizing a volume, this updates the pool metadata
(allocation, available) after those operation are done.

Similar to how other objects arrange their parse APIs. This will be
used by the test driver.

Right now things are split a bit between parsing from a relative file
path or parsing from inline XML. Unify it. This will simplify upcoming
bits.

Passing virConnectPtr is redundant, just pass testConnPtr and simplify
certain callers.

The function that parses custom driver XML was getting pretty unruly,
split the object parsing into their own functions. Rename some variables
to be consistent across each function. This should be functionally
identical.

Currently the virConnectBaselineCPU API does not expose the CPU features
that are part of the CPU's model.  This patch adds a new flag,
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, that causes the API to explicitly
list all features that are part of that model.
Signed-off-by: NDon Dugger <donald.d.dugger@intel.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Rather than inlining gl_WARN_ADD loads of time, we can shave about
17k size off of the configure script by delaying it to a cleanup
shell loop.

* m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Track a
list of things to check, rather than inlining multiple checks.
Signed-off-by: NEric Blake <eblake@redhat.com>