https://bugzilla.redhat.com/show_bug.cgi?id=1183869

Soo. you've successfully started yourself a domain. And since you want
to use it on your host exclusively you are confident enough to
passthrough the host CPU model, like this:

  <cpu mode='host-passthrough'/>

Then, after a while, you want to save the domain into a file (e.g.
virsh save dom dom.save). And here comes the trouble. The file consist
of two parts: Libvirt header (containing domain XML among other
things), and qemu migration data. Now, the domain XML in the header is
formatted using special flags (VIR_DOMAIN_XML_SECURE |
VIR_DOMAIN_XML_UPDATE_CPU | VIR_DOMAIN_XML_INACTIVE |
VIR_DOMAIN_XML_MIGRATABLE).

Then, on your way back from the bar, you think of changing something
in the XML in the saved file (we have a command for it after all), say
listen address for graphics console. So you successfully type in the
command:

  virsh save-image-edit dom.save

Change all the bits, and exit the editor. But instead of success
you're left with sad error message:

  error: unsupported configuration: Target CPU model <null> does not
  match source Pentium Pro

Sigh. Digging into the code you see lines, where we check for ABI
stability. The new XML you've produced is compared with the old one
from the saved file to see if qemu ABI will break or not. Wait, what?
We are using different flags to parse the XML you've provided so we
were just lucky it worked in some cases? Yep, that's right.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Well, not that we are not formatting invalid XML, rather than not as
beautiful as we can:

  <cpu mode='host-passthrough'>
  </cpu>

If there are no children, let's use the singleton element.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Well, so far there are no variables to free, no cleanup work needed on
an error, so bare 'return -1;' after each error is just okay. But this
will change in a while.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This API joins the following two lines:

char *s = virBufferContentAndReset(buf1);
virBufferAdd(buf2, s, -1);

into one:

virBufferAddBuffer(buf2, buf1);

With one exception: there's no re-indentation applied to @buf1.
The idea is, that in general both can have different indentation
(like the test I'm adding proves)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

In commit cc41c648 I've re-factored qemuMonitorFindBalloonObjectPath, but
missed that there is a memory leak. The "nextpath" variable is
overwritten while looping in for cycle and we have to free it before next
cycle.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1151942

While the restriction doesn't have origin in any RFC, it matters
to us while constructing the dnsmasq config file (or command line
previously). For better picture, this is how the corresponding
part of network XML look like:

  <dns>
    <forwarder addr='8.8.4.4'/>
    <txt name='example' value='example value'/>
  </dns>

And this is how the config file looks like then:

  server=8.8.4.4
  txt-record=example,example value

Now we can see why there can't be any commas in the TXT name.
They are used by dnsmasq to separate @name and @value.

Funny, we have it in the documentation, but the code (which was
pushed back in 2011) didn't reflect that.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Making use of the ARCH_IS_S390 macro introduced with
e8083575Signed-off-by: NStefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

Since s390 does not support usb the default creation of a usb controller
for a domain should not occur.

Also adjust s390 test cases by removing usb device instances since
usb devices are no longer created by default for s390 the s390
test cases need to be adjusted.
Signed-off-by: NStefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

The description of the virsh command 'cpu-models' was written in the
wrong context (i.e. beside the domain states).
This patch moves the command description just to the cpu related
commands like 'cpu-baseline' and 'cpu-compare'.
Signed-off-by: NDaniel Hansel <daniel.hansel@linux.vnet.ibm.com>

Add configuration file for use with https://fedora.zanata.org
translation system

Well, imagine domains were running, and as the host went down, they
were managesaved. Later, after some time, the host went up again and
domains got restored. But without correct time. And depending on how
long was the host shut off, it may take some time for ntp to sync the
time too. But hey, wait a minute. We have an API just for that! So:

1) Introduce SYNC_TIME variable in libvirt-guests.sysconf to allow
users control over the new functionality
2) Call 'virsh domtime --sync $dom' in the libvirt-guests script.

Unfortunately, this is all-or-nothing approach (just like anything
else with the script). Domains are required to have configured and
running qemu-ga inside.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The AAVMF and OVMF names were swapped. Reorder the one usage where it
matters so behavior doesn't change.

This implement handling of <backenddomain name=''/>  parameter introduced
in previous patch.

Works on Xen >= 4.3, because only there libxl supports setting backend
domain by name.  Specifying backend domain by ID or UUID is currently not
supported.
Signed-off-by: NMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

At least Xen supports backend drivers in another domain (aka "driver
domain"). This patch introduces an XML config option for specifying the
backend domain name for <disk> and <interface> devices.  E.g.

  <disk>
    <backenddomain name='diskvm'/>
    ...
  </disk>
  <interface type='bridge'>
    <backenddomain name='netvm'/>
    ...
  </interface>

In the future, same option will be needed for USB devices (hostdev
objects), but for now libxl doesn't have support for PVUSB.
Signed-off-by: NMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

The function that parses the <forward> subelement of a network used to
fail/log an error if the network definition contained both a <pf>
element as well as at least one <interface> or <address> element. That
check was present because the configuration of a network should have
either one <pf>, one or more <interface>, or one or more <address>,
but never combinations of multiple kinds.

This caused a problem when libvirtd was restarted with a network
already active - when a network with a <pf> element is started, the
referenced PF (Physical Function of an SRIOV-capable network card) is
checked for VFs (Virtual Functions), and the <forward> is filled in
with a list of all VFs for that PF either in the form of their PCI
addresses (a list of <address>) or their netdev names (a list of
<interface>); the <pf> element is not removed though. When libvirtd is
restarted, it parses the network status and finds both the original
<pf> from the config, as well as the list of either <address> or
<interface>, fails the parse, and the network is not added to the
active list. This failure is often obscured because the network is
marked as autostart so libvirt immediately restarts it.

It seems odd to me that <interface> and <address> are stored in the
same array rather than keeping two separate arrays, and having
separate arrays would have made the check much simpler. However,
changing to use two separate arrays would have required changes in
more places, potentially creating more conflicts and (more
importantly) more possible regressions in the event of a backport, so
I chose to keep the existing data structure in order to localize the
change.

It appears that this problem has been in the code ever since support
for <pf> was added (0.9.10), but until commit
34cc3b2f (first in libvirt 1.2.4)
networks with interface pools were not properly marked as active on
restart anyway, so there is no point in backporting this patch any
further than that.

The pc-dimm device represents a RAM memory module.

Later patches will need to access the full definition to do check the
memory size and thus the checking needs to be done after the whole
definition including devices is known.

Add helper to compare initial sizes of indivitual NUMA nodes and the map
of belonging vCPUs. Other configuration is not ABI.

The backing of the vm's memory isn't influencing the guest ABI thus
shouldn't be checked.

For historical reasons data regarding NUMA configuration were split
between the CPU definition and numatune. We cannot do anything about the
XML still being split, but we certainly can at least store the relevant
data in one place.

This patch moves the NUMA stuff to the right place.

Add the helpers and refactor places where the value is accessed without
them.

Add virDomainNumaGetNodeCpumask() and refactor a few places that would
get the cpu mask without the helper.

Add an accessor so that a later refactor is simpler.

The function uses the cell count in 6 places. Add a temp variable to
hold the count as it will greatly simplify the refactor.

virDomainNumatuneParseXML now doesn't allocate the def->numa object any
longer so we don't need to pass a double pointer.

As virDomainNumatuneSet now doesn't allocate the virDomainNuma object
any longer it's not necessary to pass the pointer to a pointer to store
the object as it will not change any longer.

While touching the parameter definitions I've also changed the name of
the parameter to "numa".

Since our formatter now handles well if the config is allocated and not
filled we can safely always-allocate the NUMA config and remove the
ad-hoc allocation code.

This will help in later patches as the parser will be refactored to just
fill the data.

Use the virDomainDefNew() helper to allocate the definition instead of
doing it via VIR_ALLOC.

Move the existing virDomainDefNew to virDomainDefNewFull as it's setting
a few things in the conf and re-introduce virDomainDefNew as a function
without parameters for common use.

Do a content-aware check if formatting of the <numatune> element is
necessary. Later on the def->numa structure will be always present so we
cannot decide only on the basis whether it's allocated.

Shuffling around the logic will allow to simplify the code quite a bit.
As an additional bonus the change in the logic now reports an error if
automatic placement is selected and individual placement is configured.

Collapse few of the conditions so that the program flow is more clear.

Currently the code would exit without reporting an error as
virBitmapParse reports one only if it fails to parse the bitmap, whereas
the code was jumping to the error label even in case 0 cpus were
correctly parsed in the map.

It's easier to recalculate the number in the one place it's used as
having a separate variable to track it. It will also help with moving
the NUMA code to the separate module.

Name it virNumaMemAccess and add it to conf/numa_conf.[ch]

Note that to avoid a circular dependency the type of the NUMA cell
memAccess variable was changed to int. It will be turned back later
after the circular dependency will not exist.

The structure will gradually become the only place for NUMA related
config, thus rename it appropriately.

Move the code that formats the /domain/cpu/numa element to numa_conf as
it belongs there.

The mask was stored both as a bitmap and as a string. The string is used
for XML output only. Remove the string, as it can be reconstructed from
the bitmap.

The test change is necessary as the bitmap formatter doesn't "optimize"
using the '^' operator.

Rewrite the function to save a few local variables and reorder the code
to make more sense.

Additionally the ncells_max member of the virCPUDef structure is used
only for tracking allocation when parsing the numa definition, which can
be avoided by switching to VIR_ALLOC_N as the array is not resized
after initial allocation.