Currently, virCgroupGetPercpuStats is only used by the LXC driver,
filling out the CPUTIME stats. qemuDomainGetPercpuStats does this
and also filles out VCPUTIME stats.

Extend virCgroupGetPercpuStats to also report VCPUTIME stats if
nvcpupids is non-zero. In the LXC driver, we don't have cpupids.
In the QEMU driver, there is at least one cpupid for a running domain,
so the behavior shouldn't change for QEMU either.

Also rename getSumVcpuPercpuStats to virCgroupGetPercpuVcpuSum.

All we need is the virCgroupPtr and number of vcpupids.
This will allow the function to be moved to util/vircgroup.c.

Refactor the function to avoid multiple wrappers splitting identical
fields from the now common metadata struct.

The refactor is done by folding in the wrapper used for disk sources
which allows us to lookup secrets via the secret driver. This may allow
using stored secrets for snapshot disk images too in the future.

Now that we store all metadata about a storage image in a
virStorageSource struct let's use it also to store information needed by
the storage driver to access and do operations on the files.

Now that storage source metadata is stored in a single struct we don't
need two initialization functions for different structs.

Now that the storage source definition is uniform convert the helpers to
retrieve the actual storage type to a single one.

Right now, virStorageFileMetadata tracks bool backingStoreIsFile
for whether the backing string specified in metadata can be
resolved as a file (covering both block and regular file
resources) or is treated as a network protocol.  But when
merging this struct with virStorageSource, it will be easier
to just actually track which type of resource it is, as well
as have a reserved value for the case where the resource type
is unknown (or had an error during probing).

* src/util/virstoragefile.h (virStorageType): Add a placeholder
value, swap order to match similar public enum.
* src/util/virstoragefile.c (virStorage): Update string mapping.
* src/conf/domain_conf.c (virDomainDiskSourceParse)
(virDomainDiskDefParseXML, virDomainDiskDefFormat)
(virDomainDiskSourceFormat): Adjust clients.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML):
Likewise.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/qemu/qemu_command.c (qemuGetDriveSourceString): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Every caller checked the return value and logged an error
- one if no device with the specified MAC was found,
other if there were multiple devices matching the MAC address
(except for qemuDomainUpdateDeviceConfig which logged the same
 message in both cases).

Move the error reporting into virDomainNetFindIdx, since in both cases,
we couldn't find one single match - it's just the error messages that
differ.

Now that we have a common struct, it's time to start using it!
Since external snapshots make a longer backing chain, it is
only natural to use the same struct for the file created by
the snapshot as what we use for <domain> disks.

* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Use common
struct instead of open-coded duplicate fields.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefClear)
(virDomainSnapshotDiskDefParseXML, virDomainSnapshotAlignDisks)
(virDomainSnapshotDiskDefFormat)
(virDomainSnapshotDiskGetActualType): Adjust clients.
* src/qemu/qemu_conf.c (qemuTranslateSnapshotDiskSourcePool):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskGetSourceString)
(qemuDomainSnapshotCreateInactiveExternal)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/storage/storage_driver.c
(virStorageFileInitFromSnapshotDef): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The code in virstoragefile.c is getting more complex as I
consolidate backing chain handling code.  But for the setuid
virt-login-shell, we don't need to crawl backing chains.  It's
easier to audit things for setuid security if there are fewer
files involved, so this patch moves the one function that
virFileOpen() was actually relying on to also live in virfile.c.

* src/util/virstoragefile.c (virStorageFileIsSharedFS)
(virStorageFileIsSharedFSType): Move...
* src/util/virfile.c (virFileIsSharedFS, virFileIsSharedFSType):
...to here, and rename.
(virFileOpenAs): Update caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetFileconHelper)
(virSecuritySELinuxSetSecurityAllLabel)
(virSecuritySELinuxRestoreSecurityImageLabelInt): Likewise.
* src/security/security_dac.c
(virSecurityDACRestoreSecurityImageLabelInt): Likewise.
* src/qemu/qemu_driver.c (qemuOpenFileAs): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/util/virstoragefile.h: Adjust declarations.
* src/util/virfile.h: Likewise.
* src/libvirt_private.syms (virfile.h, virstoragefile.h): Move
symbols as appropriate.
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>

In all other drivers we are doing so. Moreover, we don't want to parse
runtime information in attach (even if the attach is meant as live)
because we are generating the runtime info ourselves. We can't trust
users they supply sane values anyway.

==1140== 9 bytes in 1 blocks are definitely lost in loss record 72 of 1,151
==1140==    at 0x4A06C2B: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==1140==    by 0x623C758: xmlStrndup (in /usr/lib64/libxml2.so.2.9.1)
==1140==    by 0x50FD763: virXMLPropString (virxml.c:483)
==1140==    by 0x510F8B7: virDomainDeviceInfoParseXML (domain_conf.c:3685)
==1140==    by 0x511ACFD: virDomainChrDefParseXML (domain_conf.c:7535)
==1140==    by 0x5121D13: virDomainDeviceDefParse (domain_conf.c:9918)
==1140==    by 0x13AE6313: qemuDomainAttachDeviceFlags (qemu_driver.c:6926)
==1140==    by 0x13AE65FA: qemuDomainAttachDevice (qemu_driver.c:7005)
==1140==    by 0x51C77DA: virDomainAttachDevice (libvirt.c:10231)
==1140==    by 0x127FDD: remoteDispatchDomainAttachDevice (remote_dispatch.h:2404)
==1140==    by 0x127EC5: remoteDispatchDomainAttachDeviceHelper (remote_dispatch.h:2382)
==1140==    by 0x5241F81: virNetServerProgramDispatchCall (virnetserverprogram.c:437)

When doing live attach, we are passing the inactive definition anyway
since we are passing the result of virDomainDeviceDefCopy() which does
inactive copy by default.

Moreover, we are doing the same mistake in qemuhotplugtest.

Just a side note - it makes perfect sense to parse the runtime info
like alias in qemuDomainDetachDevice and qemuDomainUpdateDeviceFlags()
as in some cases the only difference to distinguish two devices can be
just their alias.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Currently, the Linux kernel treats values of '0' and '1' as
the minimum of 2. Values larger than the maximum are changed
to the maximum.

Re-reading the shares value after setting it reflects this in
the live domain XML.

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.

qemuDomainSetSchedulerParametersFlags() calls virQEMUDriverGetConfig() twice
and makes the reference counter leak. This removes redundant call.

Problem introduced in commit 45ad1adbSigned-off-by: NEric Blake <eblake@redhat.com>

This patch makes qemu driver support virDomainCoreDumpWithFormat API.
Signed-off-by: NQiao Nuohan <qiaonuohan@cn.fujitsu.com>

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>

Part of a series of cleanups to use new accessor methods.

* src/qemu/qemu_conf.c (qemuCheckSharedDevice)
(qemuAddSharedDevice, qemuRemoveSharedDevice, qemuSetUnprivSGIO):
Use accessors.
* src/qemu/qemu_domain.c (qemuDomainDeviceDefPostParse)
(qemuDomainObjCheckDiskTaint, qemuDomainSnapshotForEachQcow2Raw)
(qemuDomainCheckRemoveOptionalDisk, qemuDomainCheckDiskPresence)
(qemuDiskChainCheckBroken, qemuDomainDetermineDiskChain):
Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeEjectableMedia)
(qemuDomainCheckEjectableMedia)
(qemuDomainAttachVirtioDiskDevice, qemuDomainAttachSCSIDisk)
(qemuDomainAttachUSBMassstorageDevice)
(qemuDomainAttachDeviceDiskLive, qemuDomainRemoveDiskDevice)
(qemuDomainDetachVirtioDiskDevice, qemuDomainDetachDiskDevice):
Likewise.
* src/qemu/qemu_migration.c (qemuMigrationStartNBDServer)
(qemuMigrationDriveMirror, qemuMigrationCancelDriveMirror)
(qemuMigrationIsSafe): Likewise.
* src/qemu/qemu_process.c (qemuProcessGetVolumeQcowPassphrase)
(qemuProcessHandleIOError, qemuProcessHandleBlockJob)
(qemuProcessInitPasswords): Likewise.
* src/qemu/qemu_driver.c (qemuDomainChangeDiskMediaLive)
(qemuDomainGetBlockInfo, qemuDiskPathToAlias): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

When checking compatibility of a device with a domain definition, we
should know what we're going to do with the device. Because we may need
to check for different things when we're attaching a new device versus
detaching an existing device.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

A device needs to be checked for compatibility with the domain
definition it corresponds to. Specifically, for VIR_DOMAIN_AFFECT_CONFIG
case we should check against persistent def rather than active def.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Wire up all the pieces to send arbitrary qemu events to a
client using libvirt-qemu.so.  If the extra bookkeeping of
generating event objects even when no one is listening turns
out to be noticeable, we can try to further optimize things
by adding a counter for how many connections are using events,
and only dump events when the counter is non-zero; but for
now, I didn't think it was worth the code complexity.

* src/qemu/qemu_driver.c
(qemuConnectDomainQemuMonitorEventRegister)
(qemuConnectDomainQemuMonitorEventDeregister): New functions.
* src/qemu/qemu_monitor.h (qemuMonitorEmitEvent): New prototype.
(qemuMonitorDomainEventCallback): New typedef.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONIOProcessEvent):
Report events.
* src/qemu/qemu_monitor.c (qemuMonitorEmitEvent): New function, to
pass events through.
* src/qemu/qemu_process.c (qemuProcessHandleEvent): 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>

We allow translation from no_bandwidth to has_bandwidth for a vnic.
However, going in the opposite direction is not implemented. It's not
limitation of the API rather than internal implementation. The problem
is, we correctly detect that user hasn't specified any outbound (say
he wants to clear out outbound). However, this gets overwritten by
current vnic outbound settings. Then, virNetDevBandwidthSet doesn't
change anything. We need to stop overwriting the outbound if users
don't want us to. Same applies for inbound.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Eliminate all the code re-use which checks for priv->agentError or
priv->agent.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Coverity found an issue in lxc_driver and uml_driver that we don't
check the return value of register functions.

I've also updated all other places and unify the way we check the
return value.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Right now we are parsing the XML as though it's live, which for example
will choke on hardcoded XML like:

  <seclabel type='dynamic' model='selinux' relabel='yes'/>

Erroring with:

  $ sudo virsh domxml-to-native qemu-argv f
  error: XML error: security label is missing

All drivers are fixed, but only qemu was tested.

-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.

Change any method names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

While investigating https://bugzilla.redhat.com/show_bug.cgi?id=1061827
I noticed that we pass user input unscathed for block-pull, but
always pass a canonical absolute name through for block-commit.
[Note that we probably _ought_ to validate that the user's request
for block-pull actually matches the backing chain, the way we already
do for block-commit - but that's a separate issue.  Further note that
the ability to pass user input through unscathed allows backdoors
such as specifying a backing image that is a network URI such as
a gluster disk, instead of forcing things to the local file system;
which is an area still under active investigation on whether libvirt
needs to behave differently for network disks.]

Since qemu may write the name that the user passed in as the backing
file, a user may have a reason to want a relative file name passed
through to qemu, and always munging things to absolute prevents that.

Put another way, if you have the backing chain:

[A] <- [B(back=./A)] <- [C(back=./B)]

and commit B into A (virsh blockcommit $dom vda --base A --top B),
the metadata of C will have to be re-written. But should it be
rewritten as [C(back=./A)] or as [C(back=/path/to/A)]?  Still up in
the air is whether qemu's decision should be based on whether B
and/or C had relative paths, or on whether the --base and/or
--top arguments to the command were relative paths; but if we always
pass a canonical name, we've prevented the spelling of the command
arguments from being part of the hueristics that qemu uses.

I also audited the code, and verified that we never call
qemuMonitorBlockCommit() with a NULL base, either before or after
the change to qemu_driver.c.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Preserve user's
spelling, since absolute vs. relative matters to qemu.
* src/qemu/qemu_monitor.h (qemuMonitorBlockCommit): Base is never
null.
* src/qemu/qemu_monitor.c (qemuMonitorBlockCommit): Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockCommit):
Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockCommit):
Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

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>

Extracting capabilities from QEMU takes a notable amount of time
when all QEMU binaries are installed. Each system emulator
needs about 200-300ms multiplied by 26 binaries == ~5-8 seconds.

This change causes the QEMU driver to save an XML file containing
the content of the virQEMUCaps object instance in the cache
dir eg /var/cache/libvirt/qemu/capabilities/$SHA256(binarypath).xml
or $HOME/.cache/libvirt/qemu/cache/capabilities/$SHA256(binarypath).xml

We attempt to load this and only if it fails, do we fallback to
probing the QEMU binary. The ctime of the QEMU binary and libvirtd
are stored in the cached file and its data discarded if either
of them change.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>