By using this we are able to easily switch the sysfs path being
used (fake it).  This will not only help tests in the future but can
be also used from files where the code is duplicated currently.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The functionality these tests partially relied on (scanning the cpu
directory for cpu[0-9]+ subdirectories) is going to be removed, so we
need additional files that are present on all non-medieval systems.
Removing all these tests would be an option but we would lose the
ability to test the topologies.  Even though we just extract number of
sockets/cores/threads from all these directory trees.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

These helpers are doing just a read and covert the value, but they
properly size the read limit, handle additional whitespace characters,
and unify error reporting.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

We are not using them at all and the directories are missing bunch of
files already.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

There is particular function for this, there is no need to build whole
nodeinfo for it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Commits eaf18f4c and 86dd9fac separated util/host{cpu,mem}
stuff from nodeinfo, but did not adjust the syms file.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

It is everywhere else.  I even remember one of our scripts failing if
the newline is missing, but it doesn't happen currently.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Don't leak guest if adding it to virCapabilities fails.  Also return
NULL and not pointer to free'd object with zero references in such
case.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Guests are handled in callers, but if something goes wrong (when it
cannot be added to virCapabilities, for example), there's no way for
them to free it properly.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Both QEMU and bhyve are using the same function for setting up the CPU
in virCapabilities, so de-duplicate it, save code and time, and help
other drivers adopt it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

STREQ_NULLABLE returns true if both parameters are NULL.  And that's
not what we want here.  We just want to skop comparing source nodes
that don't have that info set.  The function wouldn't make much sense
with nodeName == NULL, so we don't need to check that.  Moreover, the
function's declaration uses ATTRIBUDE_NONNULL for nodeName, which not
only means that function expects the parameter not to be NULL, but
actually tells the compiler that it can optimize out the NULL checks.
That way it could end up calling strcmp on NULL (either nodeformat or
nodebacking).  GCC figures this out if libvirt is compiled with
lv_cv_static_analysis=yes, unfortunately not everyone uses that.

Caused by cbc6d535.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Management tools may want to check whether the threshold is still set if
they missed an event. Add the data to the bulk stats API where they can
also query the current backing size at the same time.

To allow updating stats based on the node name, add a helper function
that will fetch the required data from 'query-named-block-nodes' and
return it in hash table for easy lookup.

Move the helper that frees JSON entries put into hash tables into the
JSON module so that it does not have to be reimplemented.

Detect the node names when setting block threshold and when reconnecting
or when they are cleared when a block job finishes. This operation will
become a no-op once we fully support node names.

To allow matching the node names gathered via 'query-named-block-nodes'
we need to query and then use the top level nodes from 'query-block'.
Add the data to the structure returned by qemuMonitorGetBlockInfo.

oVirt uses relative names with directories in them. Test such
configuration. Also tests a snapshot done with _REUSE_EXTERNAL and a
relative backing file pre-specified in the qcow2 metadata.

Since we have to match the images by filename a common backing image
will break the detection process. Add a test case to see that the code
correctly did not continue the detection process.

The code is rather magic so a test case will help making sure that
everything works well. The first case is a simple backing chain.

qemu for some time already sets node names automatically for the block
nodes. This patch adds code that attempts a best-effort detection of the
node names for the backing chain from the output of
'query-named-block-nodes'. The only drawback is that the data provided
by qemu needs to be matched by the filename as seen by qemu and thus
if two disks share a single backing store file the detection won't work.

This will allow us to use qemu commands such as
'block-set-write-threshold' which only accepts node names.

In this patch only the detection code is added, it will be used later.

Add monitor tooling for calling query-named-block-nodes. The monitor
returns the data as the raw JSON array that is returned from the
monitor.

Unfortunately the logic to extract the node names for a complete backing
chain will be so complex that I won't be able to extract any meaningful
subset of the data in the monitor code.

Add code to call the appropriate monitor command and code to lookup the
given disk backing chain member.

Add a simple wrapper which will allow to set the threshold for
delivering the event.

The new API can be used to configure the threshold when
VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD should be fired.

Bind it to qemu's BLOCK_WRITE_THRESHOLD event. Look up the disk by
nodename and construct the string to return.

The code is currently simple, but if we later add node names, it will be
necessary to generate the names based on the node name. Add a helper so
that there's a central point to fix once we add self-generated node
names.

Looks up a disk and its corresponding backing chain element by node
name.

The event is fired when a given block backend node (identified by the
node name) experiences a write beyond the bound set via
block-set-write-threshold QMP command. This wires up the monitor code to
extract the data and allow us receiving the events and the capability.

When using thin provisioning, management tools need to resize the disk
in certain cases. To avoid having them to poll disk usage introduce an
event which will be fired when a given offset of the storage is written
by the hypervisor. Together with the API which will be added later, it
will allow registering thresholds for given storage backing volumes and
this event will then notify management if the threshold is exceeded.

'nodeformat' should be used for strings which describe the storage
format object, and 'nodebacking' for the actual storage object itself.

The function has very specific semantics. Split out the part that parses
the backing store specification string into a separate helper so that it
can be reused later while keeping the wrapper with existing semantics.

Note that virStorageFileParseChainIndex is pretty well covered by the
test suite.

It will be useful to set indentation level to 0 after formatting a
nested structure rather than having to track the depth.