conf: clarify what is returned for actual bandwidth and vlan

In practice, if a virDomainNetDef has a virDomainActualNetDef
allocated, the ActualNetDef will *always* contain the bandwidth and
vlan data from the NetDef (unless there was also a portgroup involved
- see networkAllocateActualDevice()).

However, virDomainNetGetActual(Bandwidth|Vlan)() were coded to make it
appear as if it might be possible to have a valid bandwidth/vlan in
the NetDef, but a NULL in the ActualNetDef. Believing this un-truth
could lead to writing unnecessarily defensive code when dealing with
the virDomainGetActual*() functions, so this patch makes it more
obvious:

   If there is an ActualNetDef, it will always have a copy of the
   various appropriate bits from its parent NetDef, and the
   virDomainGetActual* function will *always* return the data from the
   ActualNetDef, not from the NetDef.

The reason for this effective-NOP patch is that a subsequent patch to
change virDomainNetDefFormat will rely on the above rule.
conf: handle null pointer in virNetDevVlanFormat

Other *Format() functions (e.g. virNetDevBandwidthFormat()) return
with no action when called with a NULL *Def pointer. This makes
virNetDevVlanFormat() consistent with that behavior.
conf: make virDomainNetDefFormat a public function

We will need to call virDomainNetDefFormat() from the network hook (in
the network driver).
conf: re-situate <bandwidth> element in <interface>

This moves the call to virNetDevBandwidthFormat() in
virDomainNetDefFormat() to be called right after the call to
virNetDevVPortProfileFormat(), so that a single chunk of that function
can be placed inside an if that conditionally calls
virDomainActualNetDefContentsFormat() instead (next patch). The
re-ordering necessitates modifying a couple of test data files.
conf: new function virDomainActualNetDefContentsFormat

This function is currently only called from one place, but in a
subsequent patch will be called from a 2nd place.

The new function exactly replicates the original behavior of the part
of virDomainActualNetDefFormat() that it replaces, but takes a
virDomainNetDefPtr instead of virDomainActualNetDefPtr, and uses the
virDomainNetGetActual*() functions whenever possible, rather than
reaching into def->data.network.actual - this is to be sure that we
are reporting exactly what is being used internally, just in case
there are any discrepancies (there shouldn't be).
conf: output actual netdev status in <interface> XML

Until now, the "live" XML status of an <interface type='network'>
device would always show the network information, rather than the
exact hardware device that was used. It would also show the name of
any portgroup the interface belonged to, rather than providing the
configuration that was derived from that portgroup. As an example,
given the following network definition:

[A]
  <network>
    <name>testnet</name>
    <forward type='bridge' dev='p4p1_0'>
      <interface dev='p4p1_0'/>
      <interface dev='p4p1_1'/>
      <interface dev='p4p1_2'/>
      <interface dev='p4p1_3'/>
    </forward>
    <portgroup name='admin'>
      <bandwidth>
          <inbound average='1000' peak='5000' burst='1024'/>
          <outbound average='128' peak='256' burst='256'/>
      </bandwidth>
    </portgroup>
  </network>

and the following domain <interface>:

[B]
  <interface type='network'>
    <source network='testnet' portgroup='admin'/>
  </interface>

the output of "virsh dumpxml $domain" while the domain was running
would yield something like this:

[C]
  <interface type='network'>
    <source network='testnet' portgroup='admin'/>
    <target dev='macvtap0'/>
    <alias name='net0'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
  </interface>

In order to learn the exact bandwidth information of the interface, a
management application would need to retrieve the XML for testnet,
then search for the portgroup named "admin". Even worse, there was no
simple and standard way to learn which host physdev the macvtap0
device is attached to.

Internally, libvirt has always kept this information in the
virDomainDef that is held in memory, as well as storing it in the
(libvirt-internal-only) domain status XML (in
/var/run/libvirt/qemu/$domain.xml). In order to not confuse the runtime
"actual state" with the config of the device, it's internally stored
like this:

[D]
  <interface type='network'>
    <source network='testnet' portgroup='admin'/>
    <actual type='direct'>
      <source dev='p4p1_0' mode='bridge'/>
      <bandwidth>
          <inbound average='1000' peak='5000' burst='1024'/>
          <outbound average='128' peak='256' burst='256'/>
      </bandwidth>
    </actual>
    <target dev='macvtap0'/>
    <alias name='net0'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
  </interface>

This was never exposed outside of libvirt though, because I thought it
would be too awkward for a management application to need to look in
two places for the same information, but I also wasn't sure that it
would be okay to overwrite the config info (in this case "<source
network='testnet' portgroup='admin'/>") with the actual runtime info
(everything inside <actual> above).

Now we have a need for this information to be made available to
management applications (in particular, so that a network "plugged"
hook will have full information about the device that is being plugged
in), so it's time to take the leap and decide that it is acceptable
for the config info to be replaced with actual runtime state (but
*only* when reporting domain live status, *not* when saving state in
/var/run/libvirt/qemu/$domain.xml - that remains the same so that
there is no loss of information). That is what this patch does - once
applied, the output of "virsh dumpxml $domain" when the domain is
running will contain something like this:

[E]
  <interface type='direct'>
    <source dev='p4p1_0' mode='bridge'/>
    <bandwidth>
        <inbound average='1000' peak='5000' burst='1024'/>
        <outbound average='128' peak='256' burst='256'/>
    </bandwidth>
    <target dev='macvtap0'/>
    <alias name='net0'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
  </interface>

In effect, everything that is internally stored within <actual> is
moved up a level to where a management application will expect
it. This means that the management application will only look in a
single place to learn - the type of interface in use, the name of the
physdev (if relevant), the <bandwidth>, <vlan>, and <virtualport>
settings in use.

The potential downside is that a management app looking at this output
will not see that the physdev 'p4p1_0' was actually allocated from the
network named 'testnet', or that the bandwidth numbers were taken from
the portgroup 'admin'. However, if they are interested in that info,
they can always get the "inactive" XML for the domain.

An example of where this could cause problems is in virt-manager's
network device display, which shows the status of the device, but
allows you to edit that status info and save it as the new
config. Previously virt-manager would always display the information
in example [C] above, and allow editing that. With this patch, it will
instead display what is in [E] and allow editing it directly, which
could lead to some confusion. I would suggest that virt-manager have
an "edit" button which would change the display from the "live" xml to
the "inactive" xml, so that editing would be done on that; such a
change would both handle the new situation, and also be compatible
with older releases.
network: include plugged interface XML in "plugged" network hook

The network hook script gets called whenever an interface is plugged
into or unplugged from a network, but even though the full XML of both
the network and the domain is included, there is no reasonable way to
determine what exact resources the plugged interface is using:

1) Prior to a recent patch which modified the status XML of interfaces
to include the information about actual hardware resources used, it
would be possible to scan through the domain XML output sent to the
hook, and from there find the correct interface, but that interface
definition would not include any runtime info (e.g. bandwidth or vlan
taken from a portgroup, or which physdev was used in case of a macvtap
network).

2) After the patch modifying the status XML of interfaces, the network
name would no longer be included in the domain XML, so it would be
completely impossible to determine which interface was the one being
plugged.

To solve that problem, this patch includes a single <interface>
element at the beginning of the XML sent to the network hook for
"plugged" and "unplugged" (just inside <hookData>) that is the status
XML of the interface being plugged. This XML will include all info
gathered from the chosen network and portgroup.

NB: due to hardcoded spaces in all of the device *Format() functions,
the <interface> element inside the <hookData> will be indented by 6
spaces rather than 2. I had intended to fix this, but it turns out
that to make virDomainNetDefFormat() indentation relative, I would
have to do the same to virDomainDeviceInfoFormat(), and that function
is called from 19 places - making that a prerequisite of this patch
would cause too many merge difficulties if we needed to backport
network hooks, so I chose to ignore the problem here and fix the
problem for *all* devices in a followup later.
libxl: queue domain event earlier in shutdown handler

The shutdown handler may restart a domain when handling a reboot
event or when <on_*> is set to 'restart'.  Restarting consists of
calling libxlVmCleanup followed by libxlVmStart.  libxlVmStart will
emit a VIR_DOMAIN_EVENT_STARTED event, but the SHUTDOWN event is
not emitted until exiting the shutdown handler, after the STARTED
event.

This patch changes the logic a bit to queue the event at the start
of the shutdown action, ensuring it is queued before any subsequent
events that may be generated while executing the shutdown action.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
build: fix cgroups on non-Linux

Running ./autobuild.sh detected a mingw failure:

  CCLD     libvirt.la
Cannot export virCgroupGetPercpuStats: symbol not defined
Cannot export virCgroupSetOwner: symbol not defined

* src/util/vircgroup.c (virCgroupGetPercpuStats)
(virCgroupSetOwner): Implement stubs.

Signed-off-by: Eric Blake <eblake@redhat.com>
build: avoid ld_preload tests on mingw

Running ./autobuild.sh complained during the mingw cross-compile:

  CC       libvirportallocatormock_la-virportallocatortest.lo
../../tests/virportallocatortest.c:32:20: fatal error: dlfcn.h: No such file or directory
 # include <dlfcn.h>
                    ^
compilation terminated.  With that fixed, the next failure was:

  CCLD     qemuxml2argvmock.la
libtool: link: libtool library `qemuxml2argvmock.la' must begin with `lib'
libtool: link: Try `libtool --help --mode=link' for more information.

While we don't need to limit all LD_PRELOAD tests to just Linux, we
do need to limit them to platforms that actually support loading;
we also need to avoid building qemu tests when qemu is not enabled.

* tests/virportallocatortest.c: Make conditional on <dlfcn.h>.
* tests/Makefile.am (test_libraries): Only build qemu mock library
when building qemu tests.

Signed-off-by: Eric Blake <eblake@redhat.com>
virNetDevVethCreate: Serialize callers

Consider dozen of LXC domains, each of them having this type of interface:

    <interface type='network'>
      <mac address='52:54:00:a7:05:4b'/>
      <source network='default'/>
    </interface>

When starting these domain in parallel, all workers may meet in
virNetDevVethCreate() where a race starts. Race over allocating veth
pairs because allocation requires two steps:

  1) find first nonexistent '/sys/class/net/vnet%d/'
  2) run 'ip link add ...' command

Now consider two threads. Both of them find N as the first unused veth
index but only one of them succeeds allocating it. The other one fails.
For such cases, we are running the allocation in a loop with 10 rounds.
However this is very flaky synchronization. It should be rather used
when libvirt is competing with other process than when libvirt threads
fight each other. Therefore, internally we should use mutex to serialize
callers, and do the allocation in loop (just in case we are competing
with a different process). By the way we have something similar already
since 1cf97c87.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Fix memory leak in virSCSIDeviceListDel()

While running virscsitest, it was found that valgrind pointed out the following
memory leak:

==320== 5 bytes in 1 blocks are definitely lost in loss record 4 of 37
==320==    at 0x4A069EE: malloc (vg_replace_malloc.c:270)
==320==    by 0x3E6CE81171: strdup (strdup.c:43)
==320==    by 0x4CB28DF: virStrdup (virstring.c:554)
==320==    by 0x4CAC987: virSCSIDeviceSetUsedBy (virscsi.c:289)
==320==    by 0x402321: test2 (virscsitest.c:100)
==320==    by 0x403231: virtTestRun (testutils.c:199)
==320==    by 0x402121: mymain (virscsitest.c:180)
==320==    by 0x4039AD: virtTestMain (testutils.c:782)
==320==    by 0x3E6CE1ED1C: (below main) (libc-start.c:226)
==320==

Introduced by commit fd243fc.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
network: don't even call networkRunHook if there is no network

networkAllocateActualDevice() is called for *all* interfaces, not just
those with type='network'. In that case, it will jump down to its
validate: label immediately, without allocating anything. After
validation is done, two counters are potentially updated (one for the
network, and one for any particular physical device that is chosen),
and then networkRunHook() is called.

This patch refactors that code a slight bit so that networkRunHook()
doesn't get called if netdef is NULL (i.e. type != network) and to
place the conditional increment of dev->connections inside the "if
(netdef)" as well - dev can never be non-null if netdef is null
(because "dev" is the pointer to a device in a network's pool of
devices), so this doesn't have any functional effect, it just makes
the code clearer.
network: unplug bandwidth and call networkRunHook only when appropriate

According to commit b4e0299d if networkAllocateActualDevice() was
successful, it will *always* allocate an iface->data.network.actual,
so we can use this during networkReleaseActualDevice() to know if
there is really anything to undo. We were properly using this
information to only decrement the network connections counter if it
had previously been incremented, but we were unconditionally
unplugging bandwidth and calling the "unplugged" network hook for
*all* interfaces (during qemuProcessStop()) whether they had been
previously plugged or not. This caused problems if a domain failed to
start at some time prior to all interfaces being allocated. (I
encountered this when an interface had a bandwidth floor set but no
inbound QoS).

This patch changes both the call to networkUnplugBandwidth() and the
call to networkRunHook() to only be called if there was a previous
call to "plug" for the same interface.
spec: Use correct versions of libgfapi in RHEL builds

RHEL still uses the 3.4.0 package of libgfapi and the package is built
only for x86_64.
build: use --with-systemd-daemon as configure option

Commit 68954fb added a configure option --with-systemd_daemon,
which violates the conventions of configure files preferring
dash in all option names.  This fixes it, before we hit a
release where the tarball is baked with an awkward name.

* m4/virt-lib.m4 (LIBVIRT_CHECK_LIB, LIBVIRT_CHECK_LIB_ALT)
(LIBVIRT_CHECK_PKG): Favor - over _ in configure option names.

Signed-off-by: Eric Blake <eblake@redhat.com>
spec: explicitly avoid bhyve on Linux

Generally, we try to make the spec file tweakable via user
variables, so that they can select a different subset of sub-rpms
to build.  We also try to explicitly list all driver config
options, rather than leaving the chance that the rpm build may be
non-deterministic based on what the user had installed locally.
But in the case of the recent bhyve hypervisor driver, there is
no port of bhyve to Linux, so it is easier to just blindly
disable it for now.  If someone ever does try to port bhyve to
Fedora, we can make the spec file conditional at that point.

* libvirt.spec.in (%configure): Don't try to build bhyve.

Signed-off-by: Eric Blake <eblake@redhat.com>
spec: require device-mapper-devel for storage-disk

On Fedora 20, with the following in my ~/.rpmmacros:

%_without_udev 1
%_without_storage_mpath 1

and with device-mapper-devel uninstalled, 'make rpm' fails with:

checking for libdevmapper.h... no
configure: error: You must install device-mapper-devel/libdevmapper >= 1.0.0 to compile libvirt
error: Bad exit status from /var/tmp/rpm-tmp.Wo9pOG (%build)

This is a rather late point to be issuing an error; better is
to flag missing packages up front.  The fix is to match the logic
in configure.ac on when devmapper is required (for both mpath and
storage).  While at it, rbd storage is not dependent on mpath.
With this patch applied, I now get:

$ rpmbuild -ta libvirt-1.2.2.tar.gz
error: Failed build dependencies:
       device-mapper-devel is needed by libvirt-1.2.2-1.fc20.x86_64

until either installing the package or further modifying
~/.rpmmacros to add "%_without_storage_disk 1".

* libvirt.spec.in (BuildRequires): Fix build when mpath is
disabled.

Signed-off-by: Eric Blake <eblake@redhat.com>
spec: make systemd_daemon usage configurable

On Fedora 20, I added this to my '~/.rpmmacros':

%_without_udev 1
%_without_storage_mpath 1
%_without_storage_disk 1

and uninstalled systemd-devel (which also removed device-mapper-devel).
Then I ran 'make rpm', and inspected the results:

$ ldd ~/rpmbuild/BUILD/libvirt-1.2.2/daemon/.libs/libvirtd | grep syst
$

Then I reinstalled systemd-devel, where I now see:

$ ldd ~/rpmbuild/BUILD/libvirt-1.2.2/daemon/.libs/libvirtd | grep syst
  libsystemd-daemon.so.0 => /lib64/libsystemd-daemon.so.0 (0x00007ffb858ba000)
$

Oops - the build is non-deterministic, where the final binary
depends on my build environment.  The fix is to require
systemd-devel in all situations where the code base uses it.
Now ~/.rpmmacros can contain "%define _without_systemd_daemon 1"
to explicitly disable use of the library, but the library is now
a strict build requirement for normal builds; if systemd-devel
is not installed, the user now gets an up-front warning:

$ rpmbuild -ta libvirt-1.2.2.tar.gz
error: Failed build dependencies:
       systemd-devel is needed by libvirt-1.2.2-1.fc20.x86_64

* libvirt.spec.in (with_systemd_daemon): New variable.
(BuildRequires): Require systemd-devel for more than just udev.
(%configure): Make choice of systemd_daemon explicit.

Signed-off-by: Eric Blake <eblake@redhat.com>
virsh: Honour -q in domblklist, vcpupin and emulatorpin

If user wants to grep some info from domain, e.g. disk paths:

    # virsh -q domblklist win7 | awk '{print $2}'
    Source

    /var/lib/libvirt/images/windows.qcow2
    /home/zippy/work/tmp/en_windows_7_professional_x64_dvd_X15-65805.iso

while with my change:

    # virsh -q domblklist win7 | awk '{print $2}'
    /var/lib/libvirt/images/windows.qcow2
    /home/zippy/work/tmp/en_windows_7_professional_x64_dvd_X15-65805.iso

We don't print table header in other commands, like list.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>