Coverity complains that return from virHookCall is not checked in
one place in qemuProcessStop.  Since the comment notes that we cannot
stop the operation even it if fails, just added the ignore_value.

So while working on my previous patches, I've noticed that
virDomainRestore implementation in qemu and test drivers has the
same problem as I am fixing.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far we have the following pattern occurring over and over
again:

  if (!vm->persistent)
      qemuDomainRemoveInactive(driver, vm);

It's safe to put the check into the function and save some LoC.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=871452

So, you want to create a domain from XML. The domain already
exists in libvirt's database of domains. It's okay, because name
and UUID matches. However, on domain startup, internal
representation of the domain is overwritten with your XML even
though we claim that the XML you've provided is a transient one.
The bug is to be found across nearly all the drivers.
Le sigh.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=871452

Okay, so we allow users to 'virsh create' an already existing
domain, providing completely different XML than the one stored in
Libvirt. Well, as long as name and UUID matches. However, in some
drivers the code that handles errors unconditionally removes the
domain that failed to start even though the domain might have
been persistent. Fortunately, the domain is removed just from the
internal list of domains and the config file is kept around.

Steps to reproduce:

1) virsh dumpxml $dom > /tmp/dom.xml
2) change XML so that it is still parse-able but won't boot, e.g.
change guest agent path to /foo/bar
3) virsh create /tmp/dom.xml
4) virsh dumpxml $dom
5) Observe "No such domain" error
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

I initially added this in order to keep the code more error-prone to
following additions, but it seems it's still frowned upon.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Now that virQEMUDriverCreateXMLConf is never called with NULL
(after 086f37e9) we can safely drop useless check in
qemuDomainDeviceDefPostParse as we are guaranteed to be always
called with the driver initialized. Therefore checking if driver
is NULL makes no sense. Moreover, if we mix it with direct driver
dereference. And after that, we are sure that nor @cfg will be
NULL, therefore we can drop checks for that too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Qemu unfortunately doesn't update internal state right after migration
and so the actual balloon size as returned by 'query-balloon' are
invalid for a while after the CPUs are started after migration. If we'd
refresh our internal state at this point we would report invalid current
memory size until the next balloon event would arrive.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1242940

My original implementation was based on a qemu version that still did
not have all the checks in place. Using sizes that would align to odd
megabyte increments will produce the following error:

qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: backend memory size must be multiple of 0x200000
qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: Device 'pc-dimm' could not be initialized

Introduce an alignment retrieval function for memory devices and use it
to align the devices separately and modify a test case to verify it.

This reverts commit 69b850fe.

This change broke the ability to "clear" or reset unfiltered back
to filtered.

For some machine types ppc64 machines now require that memory sizes are
aligned to 256MiB increments (due to the dynamically reconfigurable
memory). As now we treat existing configs reasonably in regards to
migration, we can round all the sizes unconditionally. The only drawback
will be that the memory size of a VM can potentially increase by
(256MiB - 1byte) * number_of_NUMA_nodes.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1249006

When we are starting a qemu process for an incomming migration or
snapshot reloading we should not modify the memory sizes in the domain
since we could potentially change the guest ABI that was tediously
checked before. Additionally the function now updates the initial memory
size according to the NUMA node size, which should not happen if we are
restoring state.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1252685

When implementing memory hotplug I've opted to recalculate the initial
memory size (contents of the <memory> element) as a sum of the sizes of
NUMA nodes when NUMA was enabled. This was based on an assumption that
qemu did not allow starting when the NUMA node size total didn't equal
to the initial memory size. Unfortunately the check was introduced to
qemu just lately.

This patch uses the new XML parser flag to decide whether it's safe to
update the memory size total from the NUMA cell sizes or not.

As an additional improvement we now report an error in case when the
size of hotplug memory would exceed the total memory size.

The rest of the changes assures that the function is called with correct
flags.

Add 'initial_memory' member to struct virDomainMemtune so that the
memory size can be pre-calculated once instead of inferring it always
again and again.

Separating of the fields will also allow finer granularity of decisions
in later patches where it will allow to keep the old initial memory
value in cases where we are handling incomming migration from older
versions that did not always update the size from NUMA as the code did
previously.

The change also requires modification of the qemu memory alignment
function since at the point where we are modifying the size of NUMA
nodes the total size needs to be recalculated too.

The refactoring done in this patch also fixes a crash in the hyperv
driver that did not properly initialize def->numa and thus
virDomainNumaGetMemorySize(def->numa) crashed.

In summary this patch should have no functional impact at this point.

The name of the variable was misleading. Rename it and it's setting
accessor before other fixes.

Add a new parser flag that will mark code paths that parse XML files
wich will not be used with existing VM state so that post parse
callbacks can possibly do ABI incompatible changes if needed.

Extract the size determination into a separate function and reuse it
across the memory device alignment functions. Since later we will need
to decide the alignment size according to architecture let's pass def to
the functions.

Add a simple helper so that the code doesn't have to rewrite the same
condition multiple times.

Since test suite now correctly creates capabilities cache, the hack is not
needed any more.
Signed-off-by: NPavel Fedin <p.fedin@samsung.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

The main purpose of this patch is to introduce test mode to
virQEMUCapsCacheLookup(). This is done by adding a global variable, which
effectively overrides binary name. This variable is supposed to be set by
test suite.

The second addition is qemuTestCapsCacheInsert() function which allows the
test suite to actually populate the cache.
Signed-off-by: NPavel Fedin <p.fedin@samsung.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1159219Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far this function was not kept in sync with changing
virDomainDiskDef. Fill in all the missing checks and reorganize
their order so it's easier to track which items are not being
checked for.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

I always felt like this function is qemu specific rather than
libvirt-wide. Other drivers may act differently on virDomainDef
change and in fact may require talking to underlying hypervisor
even if something else's than disk->src has changed.  I know that
the function is still incomplete, but lets break that into two
commits that are easier to review. This one is pure code
movement.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Firstly, our coding guidelines suggest using 'cleanup' label
instead of 'end'. Then, @ret should be set to value representing
success as the last statement before the 'cleanup' label.
And while I am at this function, lets enumerate all the possible
enum items (virDomainDiskDevice) and avoid using 'default' in
switch(). Pooh. Also, nothing bad happens if we look up the disk
to change in the domain upfront. In fact, it's going to be
helpful later when we want to keep some old values for performing
a rollback.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This new private API should return true iff sources of two disks
differs in sense that qemu should be instructed to change the
disk backend. For instance, ejecting a CDROM is such case, or
pointing disk into a different ISO location, and so on.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

While we currently only allow changing a media in a disk, this is
going to change in a while, so the function name would be
invalid. Moreover, the old name does not match the pattern laid
out by other update functions.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1159219

So, in 11e058ca I've tried to make UpdateDevice update
startupPolicy too. And it worked well until somebody came around
and pushed d0dc6c03 which accidentally removed my
contribution. Redo my commit.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

When persistently migrating a domain to a destination host where the
same domain already exists (i.e., it is persistent and shutdown at the
destination), we would happily throw away the original persistent
definition without properly freeing it. And when updating the definition
fails for some reason we don't properly revert to the original state
leaving the domain broken.

In addition to fixing these issues, the patch also makes sure the domain
definition parsed from a migration cookie is either used or freed.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

For quite a long time we don't need to postpone queueing events until
the end of the function since we no longer have the big driver lock.
Let's make the code of qemuMigrationFinish simpler by queuing events at
the time we generate them.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Every single call to qemuDomainEventQueue() uses the following pattern:

    if (event)
        qemuDomainEventQueue(driver, event);

Let's move the check for valid event to qemuDomainEventQueue and
simplify all callers.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Finish is the final state in v2 of our migration protocol. If something
fails, we have no option to abort the migration and resume the original
domain. Non fatal errors (such as failure to start guest CPUs or make
the domain persistent) has to be treated as success. Keeping the domain
running while reporting the failure was just asking for trouble.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Whenever something fails during incoming migration in Finish phase
before we started guest CPUs, we need to kill the domain in addition to
reporting the failure.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When we save status XML at the point during migration where we have
already started the domain on destination, we can't really go back and
abort migration. Thus the only thing we can do is to log a warning and
report success.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Offline migration is quite special because we don't really need to do
anything but make the domain persistent. Let's do it separately from
normal migration to avoid cluttering the code with
!(flags & VIR_MIGRATE_OFFLINE).
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Separate code which makes incoming domain persistent into
qemuMigrationPersist.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Commit id 'f1f68ca3' added code to remove the directory paths for
auto-generated sockets, but that code could be called before the
paths were created resulting in generating error messages from
virFileDeleteTree indicating that the file doesn't exist.

Rather than "enforce" all callers to make the non-NULL and existence
checks, modify the virFileDeleteTree API to silently ignore NULL on
input and non-existent directory trees.

When looking for a QEMU binary suitable for running ppc64le guests
we have to take into account the fact that we use the QEMU target
as key for the hash, so direct comparison is not good enough.

Factor out the logic from virQEMUCapsFindBinaryForArch() to a new
virQEMUCapsFindTarget() function and use that both when looking
for QEMU binaries available on the system and when looking up
QEMU capabilities later.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1260753

Fixes the following error when attempting to add a disk with bus='virtio'
to a machine which actually supports virtio-mmio (caught with ARM virt):

virtio disk cannot have an address of type 'virtio-mmio'

The problem has been likely introduced by
e8d55172. Before that
qemuAssignDevicePCISlots() was never called for ARM "virt" machine.
Signed-off-by: NPavel Fedin <p.fedin@samsung.com>

We may want to do some decisions in drivers based on fact if we
are running as privileged user or not. Propagate this info there.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

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