https://bugzilla.redhat.com/show_bug.cgi?id=994364

Whenever we check for ABI stability, we have new xml (e.g. provided by
user, or obtained from snapshot, whatever) which we compare to old xml
and see if ABI won't break. However, if the new xml was produced via
virDomainGetXMLDesc(..., VIR_DOMAIN_XML_MIGRATABLE) it lacks some
devices, e.g. 'pci-root' controller. Hence, the ABI stability check
fails even though it is stable. Moreover, we can't simply fix
virDomainDefCheckABIStability because removing the correct devices is
task for the driver. For instance, qemu driver wants to remove the usb
controller too, while LXC driver doesn't. That's why we need special
qemu wrapper over virDomainDefCheckABIStability which removes the
correct devices from domain XML, produces MIGRATABLE xml and calls the
check ABI stability function.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

If qemuParseCommandLine finds an arg it does not understand
it adds it to the QEMU passthrough custom arg list. If the
qemuParseCommandLine method hits an error for any reason
though, it just does 'VIR_FREE(cmd)' on the custom arg list.
This means all actual args / env vars are leaked. Introduce
a qemuDomainCmdlineDefFree method to be used for cleanup.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The VIR_FREE() macro will cast away any const-ness. This masked a
number of places where we passed a 'const char *' string to
VIR_FREE. Fortunately in all of these cases, the variable was not
in fact const data, but a heap allocated string. Fix all the
variable declarations to reflect this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Similar to the chardev bit, ARM boards depend on the old style '-net nic'
for actually instantiating net devices. But we can't block out
-netdev altogether since it's needed for upcoming virtio support.

And add tests for working ARM XML with console, disk, and networking.

And add test cases for a basic working ARM guest.

This should be a no-op change for now.

This function is to guess the correct limit for maximal memory
usage by qemu for given domain. This can never be guessed
correctly, not to mention all the pains and sleepless nights this
code has caused. Once somebody discovers algorithm to solve the
Halting Problem, we can compute the limit algorithmically. But
till then, this code should never see the light of the release
again.

Go through disks of guest, if one disk doesn't exist or its backing
chain is broken, with 'optional' startupPolicy, for CDROM and Floppy
we only discard its source path definition in xml, for disks we drop
it from disk list and free it.

This patch adds in special handling for a few devices that need to be
treated differently for q35 domains:

usb - there is no implicit/default usb controller for the q35
machinetype. This is done because normally the default usb controller
is added to a domain by just adding "-usb" to the qemu commandline,
and it's assumed that this will add a single piix3 usb1 controller at
slot 1 function 2. That's not what happens when the machinetype is
q35, though. Instead, adding -usb to the commandline adds 3 usb
(version 2) controllers to the domain at slot 0x1D.{1,2,7}. Rather
than having

  <controller type='usb' index='0'/>

translate into 3 separate devices on the PCI bus, it's cleaner to not
automatically add a default usb device; one can always be added
explicitly if desired. Or we may decide that on q35 machines, 3 usb
controllers will be automatically added when none is given. But for
this initial commit, at least we aren't locking ourselves into
something we later won't want.

video - qemu always initializes the primary video device immediately
after any integrated devices for the machinetype. Unless instructed
otherwise (by using "-device vga..." instead of "-vga" which libvirt
uses in many cases to work around deficiencies and bugs in various
qemu versions) qemu will always pick the first unused slot. In the
case of the "pc" machinetype and its derivatives, this is always slot
2, but on q35 machinetypes, the first free slot is slot 1 (since the
q35's integrated peripheral devices are placed in other slots,
e.g. slot 0x1f). In order to make the PCI address of the video device
predictable, that slot (1 or 2, depending on machinetype) is reserved
even when no video device has been specified.

sata - a q35 machine always has a sata controller implicitly added at
slot 0x1F, function 2. There is no way to avoid this controller, so we
always add it. Note that the xml2xml tests for the pcie-root and q35
cases were changed to use DO_TEST_DIFFERENT() so that we can check for
the sata controller being automatically added. This is especially
important because we can't check for it in the xml2argv output (it has
no effect on that output since it's an implicit device).

ide - q35 has no ide controllers.

isa and smbus controllers - these two are always present in a q35 (at
slot 0x1F functions 0 and 3) but we have no way of modelling them in
our config. We do need to reserve those functions so that the user
doesn't attempt to put anything else there though. (note that the "pc"
machine type also has an ISA controller, which we also ignore).

This PCI controller, named "dmi-to-pci-bridge" in the libvirt config,
and implemented with qemu's "i82801b11-bridge" device, connects to a
PCI Express slot (e.g. one of the slots provided by the pcie-root
controller, aka "pcie.0" on the qemu commandline), and provides 31
*non-hot-pluggable* PCI (*not* PCIe) slots, numbered 1-31.

Any time a machine is defined which has a pcie-root controller
(i.e. any q35-based machinetype), libvirt will automatically add a
dmi-to-pci-bridge controller if one doesn't exist, and also add a
pci-bridge controller. The reasoning here is that any useful domain
will have either an immediate (startup time) or eventual (subsequent
hot-plug) need for a standard PCI slot; since the pcie-root controller
only provides PCIe slots, we need to connect a dmi-to-pci-bridge
controller to it in order to get a non-hot-plug PCI slot that we can
then use to connect a pci-bridge - the slots provided by the
pci-bridge will be both standard PCI and hot-pluggable.

Since pci-bridge devices themselves can not be hot-plugged into a
running system (although you can hot-plug other devices into a
pci-bridge's slots), any new pci-bridge controller that is added can
(and will) be plugged into the dmi-to-pci-bridge as long as it has
empty slots available.

This patch is also changing the qemuxml2xml-pcie test from a "DO_TEST"
to a "DO_DIFFERENT_TEST". This is so that the "before" xml can omit
the automatically added dmi-to-pci-bridge and pci-bridge devices, and
the "after" xml can include it - this way we are testing if libvirt is
properly adding these devices.

This controller is implicit on q35 machinetypes. It provides 31 PCIe
(*not* PCI) slots as controller 0.

Currently there are no devices that can connect to pcie-root, and no
implicit pci controller on a q35 machine, so q35 is still
unusable. For a usable q35 system, we need to add a
"dmi-to-pci-bridge" pci controller, which can connect to pcie-root,
and provides standard pci slots that can be used to connect other
devices.

The parser shouldn't be doing arch-specific things like adding in
implicit controllers to the config. This should instead be done in the
hypervisor's post-parse callback.

This patch removes the auto-add of a usb controller from the domain
parser, and puts it into the qemu driver's post-parse callback (just
as is already done with the auto-add of the pci-root controller). In
the future, any machine/arch that shouldn't have a default usb
controller added should just set addDefaultUSB = false in this
function.

We've recently seen that q35 and ARMV7L domains shouldn't get a default USB
controller, so I've set addDefaultUSB to false for both of those.

For disk with startupPolicy support, such as cdrom and floppy
when its chain is broken, the startup policy will apply,
otherwise, report an error.

*src/util/virstoragefile.c: Add a helper function to get
the first name of missing backing files, if the name is NULL,
it means the diskchain is not broken.
*src/qemu/qemu_domain.c: qemuDiskChainCheckBroken(disk) to
check if its chain is broken

Refactor this function to make it focus on disk presence checking,
including diskchain checking, and not only for CDROM and Floppy.
This change is good for the following patches.

In case libvirtd is asked to unplug a device but the device is actually
unplugged later when libvirtd is not running, we need to detect that and
remove such device when libvirtd starts again and reconnects to running
domains.

For low-memory domains (roughly under 400MB) our automatic memory limit
computation comes up with a limit that's too low. This is because the
0.5 multiplication does not add enough for such small values. Let's
increase the constant part of the computation to fix this.

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Convert input XML to migratable before using it in
qemuDomainSaveImageOpen.

XML in the save image is migratable, i.e. doesn't contain implicit
controllers. If these controllers were in a non-default order in the
input XML, the ABI check would fail. Removing and re-adding these
controllers fixes it.

https://bugzilla.redhat.com/show_bug.cgi?id=834196

Follows on the heels of other bool cleanups, such as commit 93002b98.

* src/qemu/qemu_monitor.h (qemuMonitorOpen, qemuMonitorOpenFD):
Update json parameter type.
* src/qemu/qemu_monitor.c (qemuMonitorOpen, qemuMonitorOpenFD):
Likewise.
(_qemuMonitor): Adjust field type.
* src/qemu/qemu_domain.h (_qemuDomainObjPrivate): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjPrivateXMLParse): Adjust
client.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* tests/qemumonitortestutils.c (qemuMonitorTestNew): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Use virBufferAddLit or virBufferAddChar instead.

POSIX says pthread_t is opaque.  We can't guarantee if it is scaler
or a pointer, nor what size it is; and BSD differs from Linux.
We've also had reports of gcc complaining on attempts to cast it,
if we use a cast to the wrong type (for example, pointers have to be
cast to void* or intptr_t before being narrowed; while casting a
function return of scalar pthread_t to void* triggers a different
warning).

Give up on casts, and use unions to get at decent bits instead.  And
rather than futz around with figuring which 32 bits of a potentially
64-bit pointer are most likely to be unique, convert the rest of
the code base to use 64-bit values when using a debug id.

Based on a report by Guido Günther against kFreeBSD, but with a
fix that doesn't regress commit 4d970fd2 for FreeBSD.

* src/util/virthreadpthread.c (virThreadSelfID, virThreadID): Use
union to get at a decent bit representation of thread_t bits.
* src/util/virthread.h (virThreadSelfID, virThreadID): Alter
signature.
* src/util/virthreadwin32.c (virThreadSelfID, virThreadID):
Likewise.
* src/qemu/qemu_domain.h (qemuDomainJobObj): Alter type of owner.
* src/qemu/qemu_domain.c (qemuDomainObjTransferJob)
(qemuDomainObjSetJobPhase, qemuDomainObjReleaseAsyncJob)
(qemuDomainObjBeginNestedJob, qemuDomainObjBeginJobInternal): Fix
clients.
* src/util/virlog.c (virLogFormatString): Likewise.
* src/util/vireventpoll.c (virEventPollInterruptLocked):
Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

It's not desired to force users imagine path for a socket they
are not even supposed to connect to. On the other hand, we
already have a release where the qemu agent socket path is
exposed to XML, so we cannot silently drop it from there.
The new path is generated in form:

$LOCALSTATEDIR/lib/libvirt/qemu/channel/target/$domain.$name

for qemu system mode, and

$XDG_CONFIG_HOME/qemu/lib/channel/target/$domain.$name

for qemu session mode.

For s390 we don't want to have a default USB device generated even
if QEMU is silently tolerating -usb on the command line. This may change
in the future.
Another reason to avoid the USB controller is that it implies a PCI
bus which might cause a regression at some later point in time.
The following change will set the USB controller model to 'none'
unless a model or address has been specified, which can be the case
if a legacy definition is loaded or the XML writer knows what
she/he's doing.
Requiring the user to explicitly disable USB on systems not supporting
it seems cumbersome.
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

Jim Fehlig reported on IRC that older gcc/glibc triggers this warning:

cc1: warnings being treated as errors
qemu/qemu_domain.c: In function 'qemuDomainDefFormatBuf':
qemu/qemu_domain.c:1297: error: declaration of 'remove' shadows a global declaration [-Wshadow]
/usr/include/stdio.h:157: error: shadowed declaration is here [-Wshadow]
make[3]: *** [libvirt_driver_qemu_impl_la-qemu_domain.lo] Error 1

Fix it like we have done in the past (such as commit 2e6322a7).

* src/qemu/qemu_domain.c (qemuDomainDefFormatBuf): Avoid shadowing
a function name.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit b33eb0dc missed this machine type.

<controller type='pci' index='0' model='pci-root'/>
is auto-added to pc* machine types.
Without this controller PCI bus 0 is not available and
no PCI addresses are assigned by default.

Since older libvirt supported PCI bus 0 even without
this controller, it is removed from the XML when migrating.

Instead of calling virCgroupForDomain every time we need
the virCgrouPtr instance, just do it once at Vm startup
and cache a reference to the object in qemuDomainObjPrivatePtr
until shutdown of the VM. Removing the virCgroupPtr from
the QEMU driver state also means we don't have stale mount
info, if someone mounts the cgroups filesystem after libvirtd
has been started
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit a68d6726 breaks networking on s390 as it
changes the default network card model.

This adds a new helper qemuTranslateDiskSourcePool which uses the
storage pool/vol APIs to translate the disk source before building
the drive string. Network volume is not supported yet. Disk chain
for volume type disk may be supported later, but before I'm confident
it doesn't break anything, it's just disabled now.

This patch refactors various places to allow removing of the
defaultConsoleTargetType callback from the virCaps structure.

A new console character device target type is introduced -
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_NONE - to mark that no type was
specified in the XML. This type is at the end converted to the standard
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL. Other types that are
different from this default have to be processed separately in the
device post parse callback.

Use the qemu specific callback to fill this data in the qemu driver as
it's the only place where it was used and fix tests as the qemu test
capability object didn't configure the defaults for the tests.