So far the decision whether /dev/* entry is created in the qemu
namespace is really simple: does the path starts with "/dev/"?
This can be easily fooled by providing path like the following
(for any considered device like disk, rng, chardev, ..):

  /dev/../var/lib/libvirt/images/disk.qcow2

Therefore, before making the decision the path should be
canonicalized.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far the namespaces were turned on by default unconditionally.
For all non-Linux platforms we provided stub functions that just
ignored whatever namespaces setting there was in qemu.conf and
returned 0 to indicate success. Moreover, we didn't really check
if namespaces are available on the host kernel.

This is suboptimal as we might have ignored user setting.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This is a simple wrapper over mount(). However, not every system
out there is capable of moving a mount point. Therefore, instead
of having to deal with this fact in all the places of our code we
can have a simple wrapper and deal with this fact at just one
place.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Due to a copy-paste error, the debug message reads:

  Setting up disks

It should have been:

  Setting up inputs.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Surprisingly there was a virDomainPCIAddressReleaseAddr() function
already, but it was completely unused. Since we don't reserve entire
slots at once any more, there is no need to release entire slots
either, so we just replace the single call to
virDomainPCIAddressReleaseSlot() with a call to
virDomainPCIAddressReleaseAddr() and remove the now unused function.

The keen observer may be concerned that ...Addr() doesn't call
virDomainPCIAddressValidate(), as ...Slot() did. But really the
validation was pointless anyway - if the device hadn't been suitable
to be connected at that address, it would have failed validation
before every being reserved in the first place, so by definition it
will pass validation when it is being unplugged. (And anyway, even if
something "bad" happened and we managed to have a device incorrectly
at the given address, we would still want to be able to free it up for
use by a device that *did* validate properly).

This function doesn't actually reserve an entire slot any more, it
reserves a single PCI address, so this name is more appropriate.

This function is only called in two places, and the function itself is
just adding a single argument and calling
virDomainPCIAddressReserveNextAddr(), so we can remove it and instead
call virDomainPCIAddressReserveNextAddr() directly. (The main
motivation for doing this is to free up the name so that
qemuDomainPCIAddressReserveNextSlot() can be renamed in the next
patch, as its current name is now inaccurate and misleading).

This function doesn't actually reserve an entire slot any more, it
reserves a single PCI address, so this name is more appropriate.

All occurences of the former use fromConfig=true, and that's exactly
how virDomainPCIAddressReserveSlot() calls
virDomainPCIaddressReserveAddr(), so just use *Slot() so that *Addr()
can be made static to conf/domain_addr.c (both functions will be
renamed in upcoming patches).

fromConfig should be true if the caller wants
virDomainPCIAddressValidate() to loosen restrictions on its
interpretation of the pciConnectFlags. In particular, either
PCI_DEVICE or PCIE_DEVICE will be counted as equivalent to both, and
HOTPLUG will be ignored. In a few cases where libvirt was manually
overriding automatic address assignment, it was setting fromConfig to
false when validating the hardcoded manual override. This patch
changes those to fromConfig=true as a preemptive strike against any
future bugs that might otherwise surface.

Although setting virDomainPCIAddressReserveAddr()'s fromConfig=true is
correct when a PCI addres is coming from a domain's config, the *true*
purpose of the fromConfig argument is to lower restrictions on what
kind of device can plug into what kind of controller - if fromConfig
is true, then a PCIE_DEVICE can plug into a slot that is marked as
only compatible with PCI_DEVICE (and vice versa), and the HOTPLUG flag
is ignored.

For a long time there have been several calls to
virDomainPCIAddressReserveAddr() that have fromConfig incorrectly set
to false - it's correct that the addresses aren't coming from user
config, but they are coming from hardcoded exceptions in libvirt that
should, if anything, pay *even less* attention to following the
pciConnectFlags (under the assumption that the libvirt programmer knew
what they were doing).

See commit b87703cf for an example of an actual bug caused by the
incorrect setting of the "fromConfig" argument to
virDomainPCIAddressReserveAddr(). Although they haven't resulted in
any reported bugs, this patch corrects all the other incorrect
settings of fromConfig in calls to virDomainPCIAddressReserveAddr().

If a PCI device has VIR_PCI_CONNECT_AGGREGATE_SLOT set in its
pciConnectFlags, then during address assignment we allow multiple
instances of this type of device to be auto-assigned to multiple
functions on the same device. A slot is used for aggregating multiple
devices only if the first device assigned to that slot had
VIR_PCI_CONNECT_AGGREGATE_SLOT set. but any device types that have
AGGREGATE_SLOT set might be mix/matched on the same slot.

(NB: libvirt should never set the AGGREGATE_SLOT flag for a device
type that might need to be hotplugged. Currently it is only planned
for pcie-root-port and possibly other PCI controller types, and none
of those are hotpluggable anyway)

There aren't yet any devices that use this flag. That will be in a
later patch.

If there are multiple devices assigned to the different functions of a
single PCI slot, they will not work properly if the device at function
0 doesn't have its "multi" attribute turned on, so it makes sense for
libvirt to turn it on during PCI address assignment. Setting multi
then assures that the new setting is stored in the config (so it will
be used next time the domain is started), preventing any potential
problems in the case that a future change in the configuration
eliminates the devices on all non-0 functions (multi will still be set
for function 0 even though it is the only function in use on the slot,
which has no useful purpose, but also doesn't cause any problems).

(NB: If we were to instead just decide on the setting for
multifunction at runtime, a later removal of the non-0 functions of a
slot would result in a silent change in the guest ABI for the
remaining device on function 0 (although it may seem like an
inconsequential guest ABI change, it *is* a guest ABI change to turn
off the multi bit).)

setting reserveEntireSlot really accomplishes nothing - instead of
going to the trouble of computing the value for reserveEntireSlot and
then possibly setting *all* functions of the slot as in-use, we can
just set the in-use bit only for the specific function being used by a
device.  Later we will know from the context (the PCI connect flags,
and whether we are reserving a specific address or asking for "the
next available") whether or not it is okay to allocate other functions
on the same slot.

Although it's not used yet, we allow specifying "-1" for the function
number when looking for the "next available slot" - this is going to
end up meaning "return the lowest available function in the slot, but
since we currently only provide a function from an otherwise unused
slot, "-1" ends up meaning "0".

When keeping track of which functions of which slots are allocated, we
will need to have more information than just the current bitmap with a
bit for each function that is currently stored for each slot in a
virDomainPCIAddressBus. To prepare for adding more per-slot info, this
patch changes "uint8_t slots" into "virDomainPCIAddressSlot slot", which
currently has a single member named "functions" that serves the same
purpose previously served directly by "slots".

This function is used only from code compiled on Linux. Therefore
on non-Linux platforms it triggers compilation error:

../../src/qemu/qemu_domain.c:209:1: error: unused function 'qemuDomainGetPreservedMounts' [-Werror,-Wunused-function]
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

For the blockjobs, where libvirt is able to track the state internally
we can fix locking of images we can remove the appropriate locks.

Also when doing a pivoting operation we should not acquire the lock on
any of those images since both are actually locked already.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1302168

Images that became the backing chain of the current image due to the
snapshot need to be unlocked in the lock manager. Also if qemu was
paused during the snapshot the current top level images need to be
released until qemu is resumed so that they can be acquired properly.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1191901

The code at first changed the definition and then rolled it back in case
of failure. This was ridiculous. Refactor the code so that the image in
the definition is changed only when the snapshot is successful.

The refactor will also simplify further fix of image locking when doing
snapshots.

Libvirt is able to properly model what happens to the backing chain
after a snapshot so there's no real need to redetect the data.
Additionally with the _REUSE_EXT flag this might end up in redetecting
wrong data if the user puts wrong backing chain reference into the
snapshot image.

After previous commits, this function is no longer needed.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Again, there is no need to create /var/lib/libvirt/$domain.*
directories in CreateNamespace(). It is sufficient to create them
as soon as we need them which is in BuildNamespace. This way we
don't leave them around for the whole lifetime of domain.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The c1140eb9 got me thinking. We don't want to special case /dev
in qemuDomainGetPreservedMounts(), but in all other places in the
code we special case it anyway. I mean,
/var/run/libvirt/$domain.dev path is constructed separately just
so that it is not constructed here. It makes only a little sense
(if any at all).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

If something goes wrong in this function we try a rollback. That
is unlink all the directories we created earlier. For some weird
reason unlink() was called instead of rmdir().
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far if qemu is spawned under separate mount namespace in order
to relabel everything it needs an access to the security driver
to run in that namespace too. This has a very nasty down side -
it is being run in a separate process, so any internal state
transition is NOT reflected in the daemon. This can lead to many
sleepless nights. Therefore, use the transaction APIs so that
libvirt developers can sleep tight again.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The code at the very bottom of the DAC secdriver that calls
chown() should be fine with read-only data. If something needs to
be prepared it should have been done beforehand.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

virtio-pci is the way forward for aarch64 guests: it's faster
and less alien to people coming from other architectures.
Now that guest support is finally getting there (Fedora 24,
CentOS 7.3, Ubuntu 16.04 and Debian testing all support
virtio-pci out of the box), we'd like to start using it by
default instead of virtio-mmio.

Users and applications can already opt-in by explicitly using

  <address type='pci'/>

inside the relevant elements, but that's kind of cumbersome and
requires all users and management applications to adapt, which
we'd really like to avoid.

What we can do instead is use virtio-mmio only if the guest
already has at least one virtio-mmio device, and use virtio-pci
in all other situations.

That means existing virtio-mmio guests will keep using the old
addressing scheme, and new guests will automatically be created
using virtio-pci instead. Users can still override the default
in either direction.

Existing tests such as aarch64-aavmf-virtio-mmio and
aarch64-virtio-pci-default already cover all possible
scenarios, so no additions to the test suites are necessary.

When coldplugging vcpus to a VM that already has a few hotpluggable
vcpus the code might generate invalid configuration as
non-hotpluggable cpus need to be clustered starting from vcpu 0.

This fix forces the added vcpus to be hotpluggable in such case.

Fixes a corner case described in:
https://bugzilla.redhat.com/show_bug.cgi?id=1370357

This patch adds support and documentation for
a generalized hardware cache event called cache_l1d
perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

When changing the metadata via virDomainSetMetadata, we now
emit an event to notify the app of changes. This is useful
when co-ordinating different applications read/write of
custom metadata.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Separate out the "policy=discard" into it's own specific
qemu command line.

We'll rename "kvm-pit-device" test case to be "kvm-pit-discard"
since it has the syntax we'd be using.
Signed-off-by: NMaxim Nestratov <mnestratov@virtuozzo.com>

By a mistake, for the VIR_DOMAIN_TIMER_TICKPOLICY_DELAY qemu
command line creation, 'discard' was used instead of 'delay'
in commit id '1569fa14'.

Test "kvm-pit-delay" is fixed accordingly to show the correct
option being generated.

Remove the (now) redundant kvm-pit-device tests. As it turns
out there is no need to specify both QEMU_CAPS_NO_KVM_PIT and
QEMU_CAPS_KVM_PIT_TICK_POLICY since they are mutually exclusive
and "kvm-pit-device" becomes just the same as "kvm-pit-delay".
Signed-off-by: NMaxim Nestratov <mnestratov@virtuozzo.com>

Qemu has abandoned the +/-feature syntax in favor of key=value. Some
architectures (s390) do not support +/-feature. So we update libvirt to handle
both formats.

If we detect a sufficiently new Qemu (indicated by support for qmp
query-cpu-model-expansion) we use key=value else we fall back to +/-feature.
Signed-off-by: NCollin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>

When qmp query-cpu-model-expansion is available probe Qemu for its view of the
host model. In kvm environments this can provide a more complete view of the
host model because features supported by Qemu and Kvm can be considered.
Signed-off-by: NCollin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>

query-cpu-model-expansion is used to get a list of features for a given cpu
model name or to get the model and features of the host hardware/environment
as seen by Qemu/kvm.
Signed-off-by: NCollin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>

Just so it doesn't bite us in the future, even though it's unlikely.

And fix the comment above it as well.  Commit e08ee7cd took the
info from the function it's calling, but that was lie itself in the
first place.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

With my namespace patches, we are spawning qemu in its own
namespace so that we can manage /dev entries ourselves. However,
some filesystems mounted under /dev needs to be preserved in
order to be shared with the parent namespace (e.g. /dev/pts).
Currently, the list of mount points to preserve is hardcoded
which ain't right - on some systems there might be less or more
items under real /dev that on our list. The solution is to parse
/proc/mounts and fetch the list from there.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

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

If we restart libvirtd while VM was doing external memory snapshot, VM's
state be updated to paused as a result of running a migration-to-file
operation, and then VM will be left as paused state. In this case we must
restart the VM's CPUs to resume it.
Signed-off-by: NWang King <king.wang@huawei.com>

Commit 4b951d1e missed the fact that the
VM needs to be resumed after a live external checkpoint (memory
snapshot) where the cpus would be paused by the migration rather than
libvirt.