This one is a relatively easy move.  We don't ever convert the
enum to or from strings (it is inferred from other elements in
the xml, rather than directly represented).

* src/conf/domain_conf.h (virDomainDiskSecretType): Move...
* src/util/virstoragefile.h (virStorageSecreteType): ...and
rename.
* src/conf/domain_conf.c (virDomainDiskSecretType): Drop unused
enum conversion.
(virDomainDiskAuthClear, virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Adjust clients.
* src/qemu/qemu_command.c (qemuGetSecretString): Likewise.
* src/qemu/qemu_conf.c (qemuTranslateDiskSourcePoolAuth):
Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Another enum moved to util/, this time the fallout from renaming
is not quite as large.

* src/conf/domain_conf.h (virDomainDiskProtocol): Move...
* src/util/virstoragefile.h (virStorageNetProtocol): ...and
rename.
* src/conf/domain_conf.c: Update clients.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/storage/storage_backend.c: Likewise.
* src/storage/storage_backend_gluster.c: Likewise.
* src/libvirt_private.syms (domain_conf.h): Move symbols...
(virstoragefile.h): ...as appropriate.
Signed-off-by: NEric Blake <eblake@redhat.com>

A continuation of the migration of disk details to virstoragefile.
This patch moves a single enum, but converting the name has quite
a bit of fallout.

* src/conf/domain_conf.h (virDomainDiskType): Move...
* src/util/virstoragefile.h (virStorageType): ...and rename.
* src/bhyve/bhyve_command.c (bhyveBuildDiskArgStr)
(virBhyveProcessBuildLoadCmd): Update clients.
* src/conf/domain_conf.c (virDomainDiskSourceDefParse)
(virDomainDiskDefParseXML, virDomainDiskSourceDefFormatInternal)
(virDomainDiskDefFormat, virDomainDiskGetActualType)
(virDomainDiskDefForeachPath, virDomainDiskSourceIsBlockType):
Likewise.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Likewise.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotAlignDisks, virDomainSnapshotDiskDefFormat):
Likewise.
* src/esx/esx_driver.c (esxAutodetectSCSIControllerModel)
(esxDomainDefineXML): Likewise.
* src/locking/domain_lock.c (virDomainLockManagerAddDisk):
Likewise.
* src/lxc/lxc_controller.c
(virLXCControllerSetupLoopDeviceDisk)
(virLXCControllerSetupNBDDeviceDisk)
(virLXCControllerSetupLoopDevices, virLXCControllerSetupDisk):
Likewise.
* src/parallels/parallels_driver.c (parallelsGetHddInfo):
Likewise.
* src/phyp/phyp_driver.c (phypDiskType): Likewise.
* src/qemu/qemu_command.c (qemuGetDriveSourceString)
(qemuDomainDiskGetSourceString, qemuBuildDriveStr)
(qemuBuildCommandLine, qemuParseCommandLineDisk)
(qemuParseCommandLine): Likewise.
* src/qemu/qemu_conf.c (qemuCheckSharedDevice)
(qemuTranslateDiskSourcePool)
(qemuTranslateSnapshotDiskSourcePool): Likewise.
* src/qemu/qemu_domain.c (qemuDomainDeviceDefPostParse)
(qemuDomainDetermineDiskChain): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo)
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskExternalBackingActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeEjectableMedia):
Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/security/security_apparmor.c
(AppArmorRestoreSecurityImageLabel)
(AppArmorSetSecurityImageLabel): Likewise.
* src/security/security_dac.c (virSecurityDACSetSecurityImageLabel)
(virSecurityDACRestoreSecurityImageLabelInt)
(virSecurityDACSetSecurityAllLabel): Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxRestoreSecurityImageLabelInt)
(virSecuritySELinuxSetSecurityImageLabel)
(virSecuritySELinuxSetSecurityAllLabel): Likewise.
* src/storage/storage_backend.c (virStorageFileBackendForType):
Likewise.
* src/storage/storage_backend_fs.c (virStorageFileBackendFile)
(virStorageFileBackendBlock): Likewise.
* src/storage/storage_backend_gluster.c
(virStorageFileBackendGluster): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc, vboxAttachDrives)
(vboxDomainAttachDeviceImpl, vboxDomainDetachDevice): Likewise.
* src/vmware/vmware_conf.c (vmwareVmxPath): Likewise.
* src/vmx/vmx.c (virVMXParseDisk, virVMXFormatDisk)
(virVMXFormatFloppy): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxprDisks, xenParseSxpr)
(xenFormatSxprDisk): Likewise.
* src/xenxs/xen_xm.c (xenParseXM, xenFormatXMDisk): Likewise.
* tests/securityselinuxlabeltest.c (testSELinuxLoadDef):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Move symbols...
(virstoragefile.h): ...as appropriate.
Signed-off-by: NEric Blake <eblake@redhat.com>

Continuing the refactoring of host-side storage descriptions out
of conf/domain_conf and into util/virstoragefile, this patch
focuses on details about a host name/port/transport as used by
a network storage volume.

* src/conf/domain_conf.h (virDomainDiskProtocolTransport)
(virDomainDiskHostDef, virDomainDiskHostDefClear)
(virDomainDiskHostDefFree, virDomainDiskHostDefCopy): Move...
* src/util/virstoragefile.h (virStorageNetHostTransport)
(virStorageNetHostDef, virStorageNetHostDefClear)
(virStorageNetHostDefFree, virStorageNetHostDefCopy): ...here,
with better names.
* src/util/virstoragefile.c (virStorageNetHostDefClear)
(virStorageNetHostDefFree, virStorageNetHostDefCopy): Moved from...
* src/conf/domain_conf.c (virDomainDiskHostDefClear)
(virDomainDiskHostDefFree, virDomainDiskHostDefCopy): ...here.
(virDomainDiskSourceDefClear, virDomainDiskSourceDefParse)
(virDomainDiskSourceDefFormatInternal): Adjust callers.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Likewise.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefClear):
Likewise.
* src/qemu/qemu_command.c (qemuAddRBDHost)
(qemuParseDriveURIString, qemuParseNBDString)
(qemuBuildNetworkDriveURI, qemuParseCommandLineDisk)
(qemuParseCommandLine, qemuGetDriveSourceString): Likewise.
* src/qemu/qemu_command.h: Likewise.
* src/qemu/qemu_conf.c (qemuAddISCSIPoolSourceHost)
(qemuTranslateDiskSourcePool): Likewise.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive): Likewise.
* src/storage/storage_backend_gluster.c
(virStorageFileBackendGlusterInit): Likewise.
* src/storage/storage_driver.c (virStorageFileFree)
(virStorageFileInitInternal): Likewise.
* src/storage/storage_driver.h (_virStorageFile): Likewise.
* src/libvirt_private.syms (domain_conf.h): Move symbols...
(virstoragefile.h): ...as appropriate.
Signed-off-by: NEric Blake <eblake@redhat.com>

Currently, <cputune><shares>0</shares></cputune> is treated
as if it were not specified.

Treat is as a valid value if it was explicitly specified
and write it to the cgroups.

It's finally time to start tracking disk backing chains in
<domain> XML.  The first step is to start refactoring code
so that we have an object more convenient for representing
each host source resource in the context of a single guest
<disk>.  Ultimately, I plan to move the new type into src/util
where it can be reused by virStorageFile, but to make the
transition easier to review, this patch just creates the
new type then fixes everything until it compiles again.

* src/conf/domain_conf.h (_virDomainDiskDef): Split...
(_virDomainDiskSourceDef): ...to new struct.
(virDomainDiskAuthClear): Use new type.
* src/conf/domain_conf.c (virDomainDiskDefFree): Split...
(virDomainDiskSourceDefClear): ...to new function.
(virDomainDiskGetType, virDomainDiskSetType)
(virDomainDiskGetSource, virDomainDiskSetSource)
(virDomainDiskGetDriver, virDomainDiskSetDriver)
(virDomainDiskGetFormat, virDomainDiskSetFormat)
(virDomainDiskAuthClear, virDomainDiskGetActualType)
(virDomainDiskDefParseXML, virDomainDiskSourceDefFormat)
(virDomainDiskDefFormat, virDomainDiskDefForeachPath)
(virDomainDiskDefGetSecurityLabelDef)
(virDomainDiskSourceIsBlockType): Adjust all users.
* src/lxc/lxc_controller.c (virLXCControllerSetupDisk):
Likewise.
* src/lxc/lxc_driver.c (lxcDomainAttachDeviceMknodHelper):
Likewise.
* src/qemu/qemu_command.c (qemuAddRBDHost, qemuParseRBDString)
(qemuParseDriveURIString, qemuParseGlusterString)
(qemuParseISCSIString, qemuParseNBDString)
(qemuDomainDiskGetSourceString, qemuBuildDriveStr)
(qemuBuildCommandLine, qemuParseCommandLineDisk)
(qemuParseCommandLine): Likewise.
* src/qemu/qemu_conf.c (qemuCheckSharedDevice)
(qemuAddISCSIPoolSourceHost, qemuTranslateDiskSourcePool):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainUpdateDeviceConfig)
(qemuDomainPrepareDiskChainElement)
(qemuDomainSnapshotCreateInactiveExternal)
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive)
(qemuDomainBlockPivot, qemuDomainBlockJobImpl)
(qemuDomainBlockCopy, qemuDomainBlockCommit): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/qemu/qemu_process.c (qemuProcessGetVolumeQcowPassphrase)
(qemuProcessInitPasswords): Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityFileLabel): Likewise.
* src/storage/storage_driver.c (virStorageFileInitFromDiskDef):
Likewise.
* tests/securityselinuxlabeltest.c (testSELinuxLoadDef):
Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

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

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch is not trying to fix every switch, just the ones I worked
with last time, because some of these were especially unreadable.
Covers enums virDomainGraphicsType and virDomainChrType (where
applicable).

Also sort its cases by their value.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='.  One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Just skip the vhost command line generation, since this won't work if
attempting to run manually.

-S causes qemu to start in the paused state. Since XML2Native is intended
to generate something that users can run directly, this will trip them up.

Add VIR_DOMAIN_HOSTDEV_PCI_BACKEND_XEN. For legacy xen, it will use "pciback" as
stub driver.

The qemu_bridge_filter.c file had some helpers for calling
the ebtablesXXX functions todo bridge filtering. The only
thing these helpers did was to overwrite the original error
message from the ebtables code. For added fun, the callers
of these helpers overwrote the errors yet again. For even
more fun, one of the helpers called another helper and
overwrite its errors too.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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

When domain is started with setting that cannot be done, i.e. those
that require cgroups, there is no error reported and it succeeds
without any message whatsoever.

When setting with API, virsh, an error is reported, but only due to
the fact that no cgroups are mounted (priv->cgroup == NULL).

Given the above it seems reasonable to reject such unsupported
settings.

This patch effectively changes the error message from:

$ virsh -c qemu:///session schedinfo dummy
Scheduler      : Unknown
error: Requested operation is not valid: cgroup CPU controller is not mounted

to:

$ virsh -c qemu:///session schedinfo dummy
Scheduler      : Unknown
error: Operation not supported: CPU tuning is not available in session mode

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1023366Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

As I did previously in 4f588a1b, libvirt needs to set virtio vectors.
Previously, we were advised to use vectors=N, where

N = 2 * (number of queues) + 1

However, just recently this advisory has changed on the Multiquue wiki
page [1] to:

N = 2 * (number of queues) + 2

1: http://www.linux-kvm.org/page/Multiqueue#Enable_MQ_featureSigned-off-by: NMichal Privoznik <mprivozn@redhat.com>

Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations.  Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit.  Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big.  And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.

So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.

* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Format qemu command line for USB keyboard
and add test cases for it.
Signed-off-by: NLi Zhang <zhlcindy@linux.vnet.ibm.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

There might be some use cases, where user wants to prepare the host or
its environment prior to starting a network and do some cleanup after
the network has been shut down. Consider all the functionality that
libvirt doesn't currently have as an example what a hook script can
possibly do.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Add support for gluster backed images as sources for snapshots in the
qemu driver. This will also simplify adding further network backed
volumes as sources for snapshot in case qemu will support them.

All the data for getting the actual type is present in the domain
config. There is no need to have this function private to the qemu
driver and it will be re-used later in other parts of libvirt

Add a new backend for any character device.  This backend uses channel
in spice connection.  This channel is similar to spicevmc, but
all-purpose in contrast to spicevmc.

Apart from spicevmc, spiceport-backed chardev will not be formatted
into the command-line if there is no spice to use (with test for that
as well).  For this I moved the def->graphics counting to the start
of the function so its results can be used in rest of the code even in
the future.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

This patch is here just to ease the code review and make related
changes look more sensible.  Apart from removing the condition this is
merely a whitespace (indentation) change.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Limiting ourselves to qemu without QEMU_CAPS_DEVICE capability, we
used '-serial none' only if there was no serial device defined in the
domain XML.  This means that if we want to have a possibility of the
device being defined in XML, but not used in the command-line
(e.g. when it's pointless), we'll fail to attach '-serial none' to the
command-line (when skipping the device's command-line building and the
device being the only one).

Since there is no such device, this patch doesn't actually do
anything, but enables easier future additions in this manner.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Add a new <timer> for the HyperV reference time counter enlightenment
and the iTSC reference page for Windows guests.

This feature provides a paravirtual approach to track timer events for
the guest (similar to kvmclock) with the option to use real hardware
clock on systems with a iTSC with compensation across various hosts.

According to the documentation various timer options are only supported
by certain timer types. Add a post parse check to verify that the user
didn't specify invalid options.

Also fix the qemu command line parsing function to set correct default
values for the kvmclock timer so that it passes the new check.

https://bugzilla.redhat.com/show_bug.cgi?id=1046192

Commit b8bf79aa, which adds clock='variable', forgets to check
localtime basis in qemuBuildClockArgStr(). So that localtime
basis could not be used.
Reported-by: NJincheng Miao <jmiao@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We support only one spicevmc channel name anyway and the code is
prepared to use the default one, there's only one check missing.  It
is also mentioned in the documentation already and helps defining
domains with spice vdagent for people using virsh.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

To support passing the path of the test data to the utils, one
more argument is added to virSCSIDeviceGetSgName,
virSCSIDeviceGetDevName, and virSCSIDeviceNew, and the related
code is changed accordingly.

Later tests for the scsi utils will be based on this patch.
Signed-off-by: NOsier Yang <jyang@redhat.com>

spice-server offers an API to disable file transfer messages
on the agent channel between the client and the guest.
This is supported in qemu through the disable-agent-file-xfer option.

This patch exposes this option to libvirt.
Adds a new element 'filetransfer', with one property,
'enable', which accepts a boolean.
Default is enabled, for backward compatibility.

Depends on the capability exported in the first patch of the series.
Signed-off-by: NFrancesco Romani <fromani@redhat.com>

Yet another advice appeared on the Multiqueue wiki page:

http://www.linux-kvm.org/page/Multiqueue#Enable_MQ_feature

We should add vectors=N onto the qemu command line, where
N = 2 * (number of queues) + 1.

AArch64 qemu has similar behavior as armv7l, like use of mmio etc.
This patch adds similar bypass checks what we have for armv7l to aarch64.
E.g. we are enabling mmio transport for Nicdev.
Making addDefaultUSB and addDefaultMemballoon to false etc.

V3:
- Adding missing domain rng schema for aarcg64 and test case in
  testutilsqemu.c which was causing test suite failure
  while running make check.

V2:
- Added testcase to qemuxml2argvtest as suggested
  during review comments of V1.

V1:
- Initial patch.
Signed-off-by: NAnup Patel <anup.patel@linaro.org>
Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org>

Do not leave the PCI address of the primary video card set
to the legacy default (0000:00:02.0) if we're doing two-pass
allocation.

Since QEMU 1.6 (QEMU_CAPS_VIDEO_PRIMARY) we allow the primary
video card to be on other slots than 0000:00:02.0 (as we use
-device instead of -vga).

However we fail to assign it an address if:
* another device explicitly uses 0000:00:02.0 and
* the primary video device has no address specified

On the first pass, we have set the address to default, then checked
if it's available, leaving it set even if it wasn't. This address
got picked up by the second pass, resulting in a conflict:

XML error: Attempted double use of PCI slot 0000:00:02.0
(may need "multifunction='on'" for device on function 0)

Also fix the test that was supposed to catch this.

On a system that is enforcing FIPS, most libraries honor the
current mode by default.  Qemu, on the other hand, refused to
honor FIPS mode unless you add the '-enable-fips' command
line option; worse, this option is not discoverable via QMP,
and is only present on binaries built for Linux.  So, if we
detect FIPS mode, then we unconditionally ask for FIPS; either
qemu is new enough to have the option and then correctly
cripple insecure VNC passwords, or it is so old that we are
correctly avoiding a FIPS violation by preventing qemu from
starting.  Meanwhile, if we don't detect FIPS mode, then
omitting the argument is safe whether the qemu has the option
(but it would do nothing because FIPS is disabled) or whether
qemu lacks the option (including in the case where we are not
running on Linux).

The testsuite was a bit interesting: we don't want our test
to depend on whether it is being run in FIPS mode, so I had
to tweak things to set the capability bit outside of our
normal interaction with capability parsing.

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1035474

* src/qemu/qemu_capabilities.h (QEMU_CAPS_ENABLE_FIPS): New bit.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Conditionally
set capability according to detection of FIPS mode.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Use it.
* tests/qemucapabilitiestest.c (testQemuCaps): Conditionally set
capability to test expected output.
* tests/qemucapabilitiesdata/caps_1.2.2-1.caps: Update list.
* tests/qemucapabilitiesdata/caps_1.6.0-1.caps: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Map the new <panic> device in XML to the '-device pvpanic' command
line of qemu.  Clients can then couple the <panic> device and the
<on_crash> directive to control behavior when the guest reports
a panic to qemu.
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch fixes memory leaks reported by valgrind on running
qemuxml2argvtest; introduced in commit 0df53f04.

Most of them are of the form:

==24777== 15 bytes in 1 blocks are definitely lost in loss record 39 of 129
==24777==    at 0x4A0887C: malloc (vg_replace_malloc.c:270)
==24777==    by 0x341F485E21: strdup (strdup.c:42)
==24777==    by 0x4CADE5F: virStrdup (virstring.c:554)
==24777==    by 0x4362B6: qemuBuildDriveStr (qemu_command.c:3848)
==24777==    by 0x43EF73: qemuBuildCommandLine (qemu_command.c:8500)
==24777==    by 0x426670: testCompareXMLToArgvHelper (qemuxml2argvtest.c:350)
==24777==    by 0x427C01: virtTestRun (testutils.c:138)
==24777==    by 0x41DDB5: mymain (qemuxml2argvtest.c:658)
==24777==    by 0x4282A2: virtTestMain (testutils.c:593)
==24777==    by 0x341F421A04: (below main) (libc-start.c:225)
==24777==
Signed-off-by: NEric Blake <eblake@redhat.com>

This resolves:

  https://bugzilla.redhat.com/show_bug.cgi?id=888635

(which was already closed as CANTFIX because the qemu "-boot strict"
commandline option wasn't available at the time).

Problem: you couldn't have a domain that used PXE to boot, but also
had an un-bootable disk device *even if that disk wasn't listed in the
boot order*, because if PXE timed out (e.g. due to the bridge
forwarding delay), the BIOS would move on to the next target, which
would be the unbootable disk device (again - even though it wasn't
given a boot order), and get stuck at a "BOOT DISK FAILURE, PRESS ANY
KEY" message until a user intervened.

The solution available since sometime around QEMU 1.5, is to add
"-boot strict=on" to *every* qemu command. When this is done, if any
devices have a boot order specified, then QEMU will *only* attempt to
boot from those devices that have an explicit boot order, ignoring the
rest.

This patch adds function qemuGetDriveSourceString to produce
qemu-compatible disk source strings that will enable to reuse the code
and refactors building of the qemu commandline of disks to use this new
helper.