While debugging a failure of 'virsh qemu-attach', I noticed that
we were leaking the count of active domains on failure.  This
means that a libvirtd session that is supposed to quit after
active domains disappear will hang around forever.

* src/qemu/qemu_process.c (qemuProcessAttach): Undo count of
active domains on failure.
Signed-off-by: NEric Blake <eblake@redhat.com>

QEMU ARM boards don't give us any way to explicitly wire in
a -chardev, so use the old style -serial options.

Unfortunately this isn't as simple as just turning off the CHARDEV flag
for qemu-system-arm, as upcoming virtio support _will_ use device/chardev.

When using a <interface type="network"> that points to a network with
hostdev forwarding mode a hostdev alias is created for the network. This
allias is inserted into the hostdev list, but is backed with a part of
the network object that it is connected to.

When a VM is being stopped qemuProcessStop() calls
networkReleaseActualDevice() which eventually frees the memory for the
hostdev object. Afterwards when the domain definition is being freed by
virDomainDefFree() an invalid pointer is accessed by
virDomainHostdevDefFree() and may cause a crash of the daemon.

This patch removes the entry in the hostdev list before freeing the
depending memory to avoid this issue.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1000973

We will have to pass a mock-up of the driver when testing monitor
events.

https://bugzilla.redhat.com/show_bug.cgi?id=822052

When doing a live migration, if the destination fails for any
reason after the point in which files should be labeled, then
the cleanup of the destination would restore the labels to their
defaults, even though the source is still trying to continue
running with the image open.  Bug 822052 mentioned one source
of live migration failure - a mismatch in SELinux virt_use_nfs
settings (on for source, off for destination); but I found other
situations that would also trigger it (for example, having a
graphics device tied to port 5999 on the source, and a different
domain on the destination already using that port, so that the
destination cannot reuse the port).

In short, just as cleanup of the source on a successful migration
must not relabel files (because the destination would be crippled
by the relabel), cleanup of the destination on a failed migration
must not relabel files (because the source would be crippled).

* src/qemu/qemu_process.c (qemuProcessStart): Set flag to avoid
label restoration when cleaning up on failed migration.
Signed-off-by: NEric Blake <eblake@redhat.com>

This restores the error message when QMP probing is not used.

https://bugzilla.redhat.com/show_bug.cgi?id=991334

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

The VIR_DOMAIN_PAUSED_GUEST_PANICKED constant is badly named,
leaking the QEMU event name. Elsewhere in the API we use
'CRASHED' rather than 'PANICKED', and the addition of 'GUEST'
is redundant since all events are guest related.

Thus rename it to VIR_DOMAIN_PAUSED_CRASHED, which matches
with VIR_DOMAIN_RUNNING_CRASHED and VIR_DOMAIN_EVENT_CRASHED.

It was added in commit 14e7e0ae
which post-dates v1.1.0, so is safe to rename before 1.1.1
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the QEMU driver creates the VM's cgroup prior to
forking, and then uses a virCommand hook to move the child
into the cgroup. This won't work with systemd whose APIs
do the creation of cgroups + attachment of processes atomically.

Fortunately we have a handshake taking place between the
QEMU driver and the child process prior to QEMU being exec()d,
which was introduced to allow setup of disk locking. By good
fortune this synchronization point can be used to enable the
QEMU driver to do atomic setup of cgroups removing the use
of the hook script.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Use the new virCgroupNewDetect function to determine cgroup
placement of existing running VMs. This will allow the legacy
cgroups creation APIs to be removed entirely
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The translation must be done before both of cgroup and security
setting, otherwise since the disk source is not translated yet,
it might be skipped on cgroup and security setting.

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.

A future patch wants the DAC security manager to be able to safely
get the supplemental group list for a given uid, but at the time
of a fork rather than during initialization so as to pick up on
live changes to the system's group database.  This patch adds the
framework, including the possibility of a pre-fork callback
failing.

For now, any driver that implements a prefork callback must be
robust against the possibility of being part of a security stack
where a later element in the chain fails prefork.  This means
that drivers cannot do any action that requires a call to postfork
for proper cleanup (no grabbing a mutex, for example).  If this
is too prohibitive in the future, we would have to switch to a
transactioning sequence, where each driver has (up to) 3 callbacks:
PreForkPrepare, PreForkCommit, and PreForkAbort, to either clean
up or commit changes made during prepare.

* src/security/security_driver.h (virSecurityDriverPreFork): New
callback.
* src/security/security_manager.h (virSecurityManagerPreFork):
Change signature.
* src/security/security_manager.c (virSecurityManagerPreFork):
Optionally call into driver, and allow returning failure.
* src/security/security_stack.c (virSecurityDriverStack):
Wrap the handler for the stack driver.
* src/qemu/qemu_process.c (qemuProcessStart): Adjust caller.
Signed-off-by: NEric Blake <eblake@redhat.com>

When virAsprintf was changed from a function to a macro
reporting OOM error in dc6f2dad, it was documented as returning
0 on success. This is incorrect, it returns the number of bytes
written as asprintf does.

Some of the functions were converted to use virAsprintf's return
value directly, changing the return value on success from 0 to >= 0.

For most of these, this is not a problem, but the change in
virPCIDriverDir breaks PCI passthrough.

The return value check in virhashtest pre-dates virAsprintf OOM
conversion.

vmwareMakePath seems to be unused.

At vm startup and attach attempt to set the balloon driver statistics
collection period based on the value found in the domain xml file. This
is not done at reconnect since it's possible that a collection period
was set on the live guest and making the set period call would reset to
whatever value is stored in the config file.

Setting the stats collection period has a side effect of searching through
the qom-list output for the virtio balloon driver and making sure that it
has the right properties in order to allow setting of a collection period
and eventually fetching of statistics.

The walk through the qom-list is expensive and thus the balloonpath will
be saved in the monitor private structure as well as a flag indicating
that the initialization has already been attempted (in the event that a
path is not found, no sense to keep checking).

This processing model conforms to the qom object model model which
requires setting object properties after device startup. That is, it's
not possible to pass the period along via the startup code as it won't
be recognized.

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>

Whenever virPortAllocatorRelease is called with port == 0, it complains
that the port is not in an allowed range, which is expectable as the
port was never allocated. Let's make virPortAllocatorRelease ignore 0
ports in a similar way free() ignores NULL pointers.

Commit 23e8b5d8 forgot to check the
return value for all calls to qemuDomainChangeGraphicsPasswords().

Add monitor callback API domainGuestPanic, that implements
'destroy', 'restart' and 'preserve' events of the 'on_crash'
in the XML when domain crashed.

Later code will need this outside of qemu_process.c

Split the code to make the driver workpool more generalized

Implement check whether (maximum) vCPUs doesn't exceed machine
type's cpu-max settings.

On older versions of QEMU the check is disabled.
Signed-off-by: NMichal Novotny <minovotn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=971485

As of d7f9d827 we copy the listen
address from the qemu.conf config file in case none has been provided
via XML. But later, when migrating, we should not include such listen
address in the migratable XML as it is something autogenerated, not
requested by user. Moreover, the binding to the listen address will
likely fail, unless the address is '0.0.0.0' or its IPv6 equivalent.
This patch introduces a new boolean attribute to virDomainGraphicsListenDef
to distinguish autofilled listen addresses. However, we must keep the
attribute over libvirtd restarts, so it must be kept within status XML.

https://bugzilla.redhat.com/show_bug.cgi?id=964177

Though both libvirt and QEMU's document say RTC_CHANGE returns
the offset from the host UTC, qemu actually returns the offset
from the specified date instead when specific date is provided
(-rtc base=$date).

It's not safe for qemu to fix it in code, it worked like that
for 3 years, changing it now may break other QEMU use cases.
What qemu tries to do is to fix the document:

http://lists.gnu.org/archive/html/qemu-devel/2013-05/msg04782.html

And in libvirt side, instead of replying on the value from qemu,
this converts the offset returned from qemu to the offset from
host UTC, by:

  /*
   * a: the offset from qemu RTC_CHANGE event
   * b: The specified date (-rtc base=$date)
   * c: the host date when libvirt gets the RTC_CHANGE event
   * offset: What libvirt will report
   */

  offset = a + (b - c);

The specified date (-rtc base=$date) is recorded in clock's def as
an internal only member (may be useful to exposed outside?).

Internal only XML tag "basetime" is introduced to not lose the
guest's basetime after libvirt restarting/reloading:

<clock offset='variable' adjustment='304' basis='utc' basetime='1370423588'/>

Found with 'git grep "= 1"'.

Currently qemuDomainReboot() does reboot in two phases:
qemuMonitorSystemPowerdown() and qemuProcessFakeReboot().

qemuMonitorSystemPowerdown() shutdowns the domain and saves domain
state/reason as VIR_DOMAIN_SHUTDOWN_UNKNOWN.

qemuProcessFakeReboot() sets domain state/reason to
VIR_DOMAIN_RESUMED_UNPAUSED but does not save domain state changes.

Subsequent restart of libvirtd leads to restoring domain state/reason to
saved that is VIR_DOMAIN_SHUTDOWN_UNKNOWN and to automatic shutdown of
the domain. This commit adds virDomainSaveStatus() into
qemuProcessFakeReboot() to avoid unexpected shutdowns.

Since 0d70656a, it starts to access the sysfs files to build
the qemu command line (by virSCSIDeviceGetSgName, which is to find
out the scsi generic device name by adpater:bus:target:unit), there
is no way to work around, qemu wants to see the scsi generic device
like "/dev/sg6" anyway.

And there might be other places which need to access sysfs files
when building qemu command line in future.

Instead of increasing the arguments of qemuBuildCommandLine, this
introduces a new callback for qemuBuildCommandLine, and thus tests
can register their own callbacks for sysfs test input files accessing.

* src/qemu/qemu_command.h: (New callback struct
                            qemuBuildCommandLineCallbacks;
                            extern buildCommandLineCallbacks)
* src/qemu/qemu_command.c: (wire up the callback struct)
* src/qemu/qemu_driver.c: (Use the new syntax of qemuBuildCommandLine)
* src/qemu/qemu_hotplug.c: Likewise
* src/qemu/qemu_process.c: Likewise
* tests/testutilsqemu.[ch]: (Helper testSCSIDeviceGetSgName;
                             callback struct testCallbacks;)
* tests/qemuxml2argvtest.c: (Use testCallbacks)
* src/tests/qemuxmlnstest.c: (Like above)

Resolves:https://bugzilla.redhat.com/show_bug.cgi?id=927620

 #kill -STOP `pidof qemu-kvm`
 #virsh destroy $guest --graceful
 error: Failed to destroy domain testVM
 error: An error occurred, but the cause is unknown

With --graceful, SIGTERM always is emitted to kill driver
process, but it won't success till burning out waiting time
in case of process being stopped.
But domain destroy without --graceful can work, SIGKILL will
be emitted to the stopped process after 10 secs which always
kills a process even one that is currently stopped.
So report an error after burning out waiting time in this case.

Just like what previous patches do, it refactors qemuSetUnprivSGIO
to take the virDomainDeviceDefPtr as argument instead.

unpriv_sgio setting is tight with the shared device helpers, let's
put them together in qemu_conf.c

SCSI host device will also support "sgio", and perhaps we could
use "sgio" in other places too in future, renaming the enum to
reuse.