Changing the current vm, and writing that change to the file
system, all before a new qemu starts, is risky; it's hard to
roll back if starting the new qemu fails for some reason.
Instead of abusing vm->current_snapshot and making the command
line generator decide whether the current snapshot warrants
using -loadvm, it is better to just directly pass a snapshot all
the way through the call chain if it is to be loaded.

This frees up the last use of snapshot->def->active for qemu's
use, so the next patch can repurpose that field for tracking
which snapshot is current.

* src/qemu/qemu_command.c (qemuBuildCommandLine): Don't use active
field of snapshot.
* src/qemu/qemu_process.c (qemuProcessStart): Add a parameter.
* src/qemu/qemu_process.h (qemuProcessStart): Update prototype.
* src/qemu/qemu_migration.c (qemuMigrationPrepareAny): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainCreate)
(qemuDomainSaveImageStartVM, qemuDomainObjStart)
(qemuDomainRevertToSnapshot): Likewise.
(qemuDomainSnapshotSetCurrentActive)
(qemuDomainSnapshotSetCurrentInactive): Delete unused functions.

https://bugzilla.redhat.com/show_bug.cgi?id=727709
mentions that if qemu fails to create the snapshot (such as what
happens on Fedora 15 qemu, which has qmp but where savevm is only
in hmp, and where libvirt is old enough to not try the hmp fallback),
then 'virsh snapshot-list dom' will show a garbage snapshot entry,
and the libvirt internal directory for storing snapshot metadata
will have a bogus file.

This fixes the fallout bug of polluting the snapshot-list with
garbage on failure (the root cause of the F15 bug of not having
fallback to hmp has already been fixed in newer libvirt releases).

* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Allocate
memory before making snapshot, and cleanup on failure.  Don't
dereference NULL if transient domain exited during snapshot creation.

* src/qemu/qemu_migration.c: avoid dead 'ret' assignment and silence
  clang warning.

Detected by ccc-analyzer:

  CC     libvirt_driver_qemu_la-qemu_migration.lo
qemu/qemu_migration.c:2046:5: warning: Value stored to 'ret' is never read
    ret = qemuMigrationConfirm(driver, sconn, vm,
    ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: NSteve Hodgson <shodgson@solarflare.com>

pciDeviceListSteal(pcidevs, dev) removes dev from pcidevs reducing
the length of pcidevs, so moving onto what was the next dev is wrong.

Instead callers should pop entry 0 repeatedly until pcidevs is empty.
Signed-off-by: NSteve Hodgson <shodgson@solarflare.com>
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

* src/qemu/qemu_monitor_json.c: Handle error "CommandNotFound" and
  report the error.

* src/qemu/qemu_monitor_text.c: If a sub info command is not found,
  it prints the output of "help info", for other commands,
  "unknown command" is printed.

Without this patch, libvirt always report:

  An error occurred, but the cause is unknown

This patch was adapted from a patch by Osier Yang <jyang@redhat.com> to
break out detection of unrecognized text monitor commands into a separate
function.
Signed-off-by: NAdam Litke <agl@us.ibm.com>

* src/qemu/qemu_driver.c (qemuDomainSaveInternal): Fix typo.
* src/conf/domain_event.c (virDomainEventDispatchMatchCallback):
Likewise.
* daemon/libvirtd.c (daemonRunStateInit): Likewise.
* src/lxc/lxc_container.c (lxcContainerChildMountSort): Likewise.
* src/util/virterror.c (virCopyError, virRaiseErrorFull): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxprSound): Likewise.

* src/qemu/qemu_command.c: s/VIR_ERR_NO_SUPPORT/VIR_ERR_CONFIG_UNSUPPORTED/

* src/qemu/qemu_driver.c: s/VIR_ERR_NO_SUPPORT/VIR_ERR_OPERATION_INVALID/

* src/qemu/qemu_process.c: s/VIR_ERR_NO_SUPPORT/VIR_ERR_OPERATION_INVALID/

* src/qemu/qemu_monitor_text.c: Error like "this function is not
supported by the connection driver" is confused obviously.

Repetitive patterns should be factored.  The sign of a good
factorization is a change that kills 5x more lines than it adds :)

* src/conf/domain_conf.c (virDomainDeviceDefParse)
(virDomainSnapshotDefParseString): Use new convenience macros.
* src/conf/storage_conf.c (virStoragePoolDefParseSourceString):
Likewise.
* src/cpu/cpu.c (cpuCompareXML, cpuBaselineXML): Likewise.
* src/esx/esx_vi.c (esxVI_Context_Execute): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationCookieXMLParseStr):
Likewise.
* src/security/virt-aa-helper.c (caps_mockup): Likewise.
* src/test/test_driver.c (testOpenFromFile): Likewise.
* tests/cputest.c (cpuTestLoadXML, cpuTestLoadMultiXML):
Likewise.
* tools/virsh.c (cmdFreecell, makeCloneXML, cmdVNCDisplay)
(cmdTTYConsole, cmdDetachInterface, cmdDetachDisk)
(cmdSnapshotCreate, cmdSnapshotCreateAs, cmdSnapshotCurrent)
(cmdSnapshotList, cmdSnapshotParent): Likewise.

* src/qemu/qemu_monitor_text.c: BALLOON_PREFIX was defined as
"balloon: actual=", which cause "actual=" is stripped early before
the real parsing. This patch changes BALLOON_PREFIX into "balloon: ",
and modifies related functions, also renames
"qemuMonitorParseExtraBalloonInfo" to "qemuMonitorParseBalloonInfo",
as after the changing, it parses all the info returned by "info balloon".

A virsh command like:

migrate --live --copy-storage-all Guest qemu+ssh://user@host/system
--persistent --verbose

shows

Migration: [  0 %]

during the storage copy and does not start counting
until the ram transfer starts

Fix this by scraping optional disk transfer status, and adding it
into the progress meter.

Otherwise the device will still be bound to pci-stub driver even
it's set as "managed=yes" when do detaching. Of course, it won't
triger any driver reprobing too.

In some versions of qemu, both virtio-blk-pci and virtio-net-pci
devices can have an event_idx setting that determines some details of
event processing. When it is enabled, it "reduces the number of
interrupts and exits for the guest". qemu will automatically enable
this feature when it is available, but there may be cases where this
new feature could actually make performance worse (NB: no such case
has been found so far).

As a safety switch in case such a situation is encountered in the
field, this patch adds a new attribute "event_idx" to the <driver>
element of both disk and interface devices. event_idx can be set to
"on" (to force event_idx on in case qemu has it disabled by default)
or "off" (for force event_idx off). In the case that event_idx support
isn't present in qemu, the attribute is ignored (this on the advice of
the qemu developer).

docs/formatdomain.html.in: document the new flag (marking it as
   "don't mess with this!"
docs/schemas/domain.rng: add event_idx in appropriate places
src/conf/domain_conf.[ch]: add event_idx to parser and formatter
src/libvirt_private.syms: export
   virDomainVirtioEventIdx(From|To)String
src/qemu/qemu_capabilities.[ch]: detect and report event_idx in
   disk/net
src/qemu/qemu_command.c: add event_idx parameter to qemu commandline
    when appropriate.
tests/qemuxml2argvdata/qemuxml2argv-event_idx.args,
tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml,
tests/qemuxml2argvtest.c,
tests/qemuxml2xmltest.c: test cases for event_idx.

Fix pointer for error message uri if domain migration fails.

BZ# 730244

By opening a connection to remote qemu process ourselves and passing the
socket to qemu we get much better errors than just "migration failed"
when the connection is opened by qemu.

The core of these two functions is very similar and most of it is even
exactly the same. Factor out the core functionality into a separate
function to remove code duplication and make further changes easier.

The functions for manipulating pidfiles are in util/util.{c,h}.
We will shortly be adding some further pidfile related functions.
To avoid further growing util.c, this moves the pidfile related
functions into a dedicated virpidfile.{c,h}. The functions are
also all renamed to have 'virPidFile' as their name prefix

* util/util.h, util/util.c: Remove all pidfile code
* util/virpidfile.c, util/virpidfile.h: Add new APIs for pidfile
  handling.
* lxc/lxc_controller.c, lxc/lxc_driver.c, network/bridge_driver.c,
  qemu/qemu_process.c: Add virpidfile.h include and adapt for API
  renames

Our logic throws off analyzer tools:

ptr var = NULL;
if (flags == 0) flags = live ? _LIVE : _CONFIG;
if (flags & _LIVE) do stuff
if (flags & _CONFIG) var = non-null;
if (flags & _LIVE) do more stuff
else if (flags & _CONFIG) use var

the tools keep thinking that var can still be NULL in the last
if clause, adding the hint shuts them up.

* src/qemu/qemu_driver.c (qemuDomainSetBlkioParameters): Add a
static analysis hint.

The following XML:

    <serial type='udp'>
      <source mode='connect' service='9999'/>
    </serial>

is accepted by domain_conf.c but maps to the qemu command line:

-chardev udp,host=127.0.0.1,port=2222,localaddr=(null),localport=(null)

qemu can cope with everything omitting except the connection port, which
seems to also be the intent of domain_conf validation, so let's not
generate bogus command lines for that case.
The defaults are empty strings for addresses and 0 for the localport

Additionally, tweak the qemu cli parsing to handle omitted host
parameters
for -serial udp

Transient domains reject attempts to set autostart, and using
virDomainCreate to restart a domain only works on persistent
domains.  Therefore, managed save makes no sense on transient
domains, and should be rejected up front rather than creating
an otherwise unrecoverable managed save file.

Besides, transient domains imply that a lot more management is
being done by the upper layer; this includes the assumption
that the upper layer is okay managing the saved state file
created by virDomainSave, and does not need to use managed save.

* src/libvirt.c: Document that transient domains are incompatible
with managed save.
* src/qemu/qemu_driver.c (qemuDomainManagedSave): Enforce it.
* src/libxl/libxl_driver.c (libxlDomainManagedSave): Likewise.

I noticed some inconsistent use of 'else'.

* src/qemu/qemu_driver.c (qemuCPUCompare)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDiscard): Match coding conventions.

If a snapshot with the name already exists, virDomainSnapshotAssignDef()
just returns NULL, in which case the snapshot definition is leaked.
Currently this leak is not a big problem, since qemuDomainSnapshotLoad()
is only called once during initial startup of libvirtd.
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

Detected by ccc-analyzer, reported by Alex Jia.

qemuProcessStart always calls qemuProcessWaitForMonitor with a
non-negative position, but qemuProcessAttach always calls with -1.
In the latter case, there is no log file we can scrape, so we
also should not be trying to scrape the logs if the qemu process
died at the very end.

* src/qemu/qemu_process.c (qemuProcessWaitForMonitor): Don't try
to read from log in qemuProcessAttach case.

Value stored to 'ret' is never read, so remove this dead assignment.

* src/qemu/qemu_monitor_text.c: kill dead assignment.
Signed-off-by: NAlex Jia <ajia@redhat.com>

Value stored to 'ret' is never read, in fact, 'cleanup' section will
directly return -1 when function is fail, so remove this dead assignment.

* src/qemu/qemu_process.c: kill dead assignment.
Signed-off-by: NAlex Jia <ajia@redhat.com>

Coverity gets confused by our logic.  Add some hints to silence
false positives.

* src/qemu/qemu_driver.c (qemudDomainGetVcpuPinInfo): Add hint.
(qemuDomainGetMemoryParameters): Likewise.

Quite a few leaks detected by coverity.  For chr, the leaks were
close enough to the allocations to plug in place; for disk, the
leaks were separated from the allocation by enough other lines with
intermediate failure cases that I refactored the cleanup instead.

* src/qemu/qemu_command.c (qemuParseCommandLine): Plug leaks.

Detected by Coverity.  Leak introduced by typo in commit 58e668d2.

* src/qemu/qemu_driver.c (doCoreDump): Use correct function.

Warning detected by Coverity.  No need for the NULL check, and
removing it silences the warning without any semantic change.

* src/qemu/qemu_migration.c (qemuMigrationFinish): All entries to
endjob had non-NULL vm.

Coverity detected that 5 of 6 callers of virJSONValueArrayGet checked
for a NULL return; and that by not checking we risk a null deref
during an error.  The error is unlikely since the prior call to
virJSONValueArraySize would probably have already caught any botched
JSON array parse, but better safe than sorry.

* src/qemu/qemu_monitor_json.c (qemuMonitorJSONGetBlockJobInfo):
Check for NULL.
(qemuMonitorJSONExtractPtyPaths): Fix typo.

Revert 6a1f5f56.  Now that libvirt_iohelper takes fds by
inheritance rather than by open() (commit 1eb66479), there is
no longer a race where the parent can unlink() a file prior to
the iohelper open()ing the same file.  From there, it makes
more sense to have the callers both create and unlink, rather
than the caller create and the stream unlink, since the latter
was only needed when iohelper had to do the unlink.

* src/fdstream.h (virFDStreamOpenFile, virFDStreamCreateFile):
Callers are responsible for deletion.
* src/fdstream.c (virFDStreamOpenFileInternal): Don't leak created
file on failure.
(virFDStreamOpenFile, virFDStreamCreateFile): Drop parameter.
* src/lxc/lxc_driver.c (lxcDomainOpenConsole): Update callers.
* src/qemu/qemu_driver.c (qemuDomainScreenshot)
(qemuDomainOpenConsole): Likewise.
* src/storage/storage_driver.c (storageVolumeDownload)
(storageVolumeUpload): Likewise.
* src/uml/uml_driver.c (umlDomainOpenConsole): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainScreenshot): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainOpenConsole): Likewise.

The previous qemu patch could end up calling unlink(tmp) before
tmp was the name of a valid file (unlinking a fileXXXXXX template
instead), or calling unlink(tmp) twice on success (once here,
and once at the end of the stream).  Meanwhile, vbox also suffered
from the same leaked tmp file bug.

* src/qemu/qemu_driver.c (qemuDomainScreenshot): Don't unlink on
success, or on invalid name.
* src/vbox/vbox_tmpl.c (vboxDomainScreenshot): Don't leak temp file.

Although virFDStreamOpenFile will unlink it once opened, when we hit
error path, we must unlink it by hand.

Currently, we attempt to run sync job and async job at the same time. It
means that the monitor commands for two jobs can be run in any order.

In the function qemuDomainObjEnterMonitorInternal():
    if (priv->job.active == QEMU_JOB_NONE && priv->job.asyncJob) {
        if (qemuDomainObjBeginNestedJob(driver, obj) < 0)
We check whether the caller is an async job by priv->job.active and
priv->job.asynJob. But when an async job is running, and a sync job is
also running at the time of the check, then priv->job.active is not
QEMU_JOB_NONE. So we cannot check whether the caller is an async job
in the function qemuDomainObjEnterMonitorInternal(), and must instead
put the burden on the caller to tell us when an async command wants
to do a nested job.

Once the burden is on the caller, then only async monitor enters need
to worry about whether the VM is still running; for sync monitor enter,
the internal return is always 0, so lots of ignore_value can be dropped.

* src/qemu/THREADS.txt: Reflect new rules.
* src/qemu/qemu_domain.h (qemuDomainObjEnterMonitorAsync): New
prototype.
* src/qemu/qemu_process.h (qemuProcessStartCPUs)
(qemuProcessStopCPUs): Add parameter.
* src/qemu/qemu_migration.h (qemuMigrationToFile): Likewise.
(qemuMigrationWaitForCompletion): Make static.
* src/qemu/qemu_domain.c (qemuDomainObjEnterMonitorInternal): Add
parameter.
(qemuDomainObjEnterMonitorAsync): New function.
(qemuDomainObjEnterMonitor, qemuDomainObjEnterMonitorWithDriver):
Update callers.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemudDomainCoreDump, doCoreDump, processWatchdogEvent)
(qemudDomainSuspend, qemudDomainResume, qemuDomainSaveImageStartVM)
(qemuDomainSnapshotCreateActive, qemuDomainRevertToSnapshot):
Likewise.
* src/qemu/qemu_process.c (qemuProcessStopCPUs)
(qemuProcessFakeReboot, qemuProcessRecoverMigration)
(qemuProcessRecoverJob, qemuProcessStart): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationToFile)
(qemuMigrationWaitForCompletion, qemuMigrationUpdateJobStatus)
(qemuMigrationJobStart, qemuDomainMigrateGraphicsRelocate)
(doNativeMigrate, doTunnelMigrate, qemuMigrationPerformJob)
(qemuMigrationPerformPhase, qemuMigrationFinish)
(qemuMigrationConfirm): Likewise.
* src/qemu/qemu_hotplug.c: Drop unneeded ignore_value.

whether or not previous return value is -1, the following codes will be
executed for a inactive guest in src/qemu/qemu_driver.c:
ret = virDomainSaveConfig(driver->configDir, persistentDef);
and if everything is okay, 'ret' is assigned to 0, the previous 'ret'
will be overwritten, this patch will fix this issue.

* src/qemu/qemu_driver.c: avoid return value is overwritten when give a argument
  in out of blkio weight range for a inactive guest.

* how to reproduce?
  % virsh blkiotune ${guestname} --weight 10
  % echo $?

  Note: guest must be inactive, argument 10 in out of blkio weight range,
  and can get a error information by checking libvirtd.log, however,
  virsh hasn't raised any error information, and return value is 0.

  https://bugzilla.redhat.com/show_bug.cgi?id=726304Signed-off-by: NAlex Jia <ajia@redhat.com>

whether or not previous return value is -1, the following codes will be
executed for a inactive guest in qemuDomainSetMemoryParameters:
ret = virDomainSaveConfig(driver->configDir, persistentDef);
and if everything is okay, 'ret' is assigned to 0, the previous 'ret'
will be overwritten, this patch will fix this issue.

* src/qemu/qemu_driver.c: avoid return value is overwritten when set
  min_guarante value to a inactive guest.

* how to reproduce?
  % virsh memtune ${guestname} --min_guarante 1024
  % echo $?

  Note: guest must be inactive, in fact, 'min_guarante' hasn't been implemented
  in memory tunable, and I can get the error when check actual libvirtd.log,
  however, virsh hasn't raised any error information, and return value is 0.
Signed-off-by: NAlex Jia <ajia@redhat.com>