Offline migration transfers inactive definition of a domain (which may
or may not be active). After successful completion, the domain remains
in its current state on source host and is defined but inactive on
destination host. It's a bit more clever than virDomainGetXMLDesc() on
source host followed by virDomainDefineXML() on destination host, as
offline migration will run pre-migration hook to update the domain XML
on destination host. Currently, copying non-shared storage is not
supported during offline migration.

Offline migration can be requested with a new migration flag called
VIR_MIGRATE_OFFLINE (which has to be combined with
VIR_MIGRATE_PERSIST_DEST flag).

Add VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA flag to virStorageVolCreateXML
and virStorageVolCreateXMLFrom. This flag requests metadata
preallocation when creating/cloning qcow2 images, resulting in creating
a sparse file with qcow2 metadata. It has only slightly larger disk usage
compared to new image with no allocation, but offers higher performance.

Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Fix the "if ... else" coding style, and indentions problem.

Commit a21f5112 fixed one API, but missed two others that also
failed to log their 'flags' argument.

* src/libvirt.c (virNodeSuspendForDuration, virDomainGetHostname):
Log flags parameter.

Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The fact that only the guest agent, or ACPI flag can be used
when requesting reboot/shutdown is merely a limitation of the
QEMU driver impl at this time. Thus it should not be in
libvirt.c code
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virStateInitialize method and several cgroups methods were
using an 'int privileged' parameter or similar for dual-state
values. These are better represented with the bool type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To allow actions to be performed in libvirtd when the host
shuts down, or user session exits, introduce a 'stop'
method to virDriverState. This will do things like saving
the VM state to a file.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add an API for sending signals to arbitrary processes in the
guest OS. This is primarily useful for container based virt,
but can be used for machine virt too, if there is a suitable
guest agent,

* include/libvirt/libvirt.h.in: Add virDomainSendProcessSignal
  and virDomainProcessSignal enum
* src/driver.h: Driver entry point
* src/libvirt.c, src/libvirt_public.syms: Impl for new API
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The documentation to this API has some defects from
grammar and wording POV. These were raised after I've
pushed the patches, so they are in a separate commit.

It makes no sense to fail the whole getting command if there is
a parameter unsupported by the kernel. This patch fixes it by
omitting the unsupported parameter for getMemoryParameters.

And for setMemoryParameters, this checks if there is an unsupported
parameter up front of the setting, and just returns failure if not
all parameters are supported.

Throughout the code, we've always used VIR_DOMAIN_SHUTDOWN* flags
even for virDomainReboot() API and its implementation. Fortunately,
the appropriate macros has the same value. But if we want to keep
things consistent, we should be using the correct macros. This
patch doesn't break anything, luckily.

This will call FITRIM within guest. The API has 4 arguments,
however, only 2 will be used for now (@dom and @minumum).
The rest two are there if in future qemu guest agent learns them.

As we enable more modes of snapshot creation, it becomes more important
to be able to quickly filter based on snapshot properties.  This patch
introduces new filter flags; subsequent patches will introduce virsh
back-compat filtering, as well as actual libvirt filtering.

* include/libvirt/libvirt.h.in (virDomainSnapshotListFlags): Add
five new flags in two new groups.
* src/libvirt.c (virDomainSnapshotNum, virDomainSnapshotListNames)
(virDomainListAllSnapshots, virDomainSnapshotNumChildren)
(virDomainSnapshotListChildrenNames)
(virDomainSnapshotListAllChildren): Document them.
* src/conf/snapshot_conf.h (VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS)
(VIR_DOMAIN_SNAPSHOT_FILTERS_LOCATION): Add new convenience filter
collection macros.
* tools/virsh-snapshot.c (cmdSnapshotList): Add 5 new flags.
* tools/virsh.pod (snapshot-list): Document them.

This API was never synchronous and probably doesn't even need to be.

The default behavior while creating external checkpoints is to pause the
guest while the memory state is captured. We want the users to sacrifice
space saving for creating the memory save image while the guest is live
to minimize downtime.

This patch adds a flag that causes the guest not to be paused before
taking the snapshot.
 *include/libvirt/libvirt.h.in:
    - add new paused reason: VIR_DOMAIN_PAUSED_SNAPSHOT
    - add new flag for taking snapshot: VIR_DOMAIN_SNAPSHOT_CREATE_LIVE
 *tools/virsh-domain-monitor.c:
    - add string representation for VIR_DOMAIN_PAUSED_SNAPSHOT
 *tools/virsh-snapshot.c:
    - add support for VIR_DOMAIN_SNAPSHOT_CREATE_LIVE
 *tools/virsh.pod:
    - add docs for --live option added to use
    VIR_DOMAIN_SNAPSHOT_CREATE_LIVE flag

The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

I noticed this while answering a list question about Java bindings
of volume creation.  All other functions that take xml logged xmlDesc.

* src/libvirt.c (virStorageVolCreateXML)
(virStorageVolCreateXMLFrom): Use consistent spelling of xmlDesc,
and log the argument.

Handle the new type of block copy event and info.  Of course,
this patch does nothing until a later patch actually allows the
creation/abort of a block copy job.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_BLOCK_JOB_READY): New
block job status.
* src/libvirt.c (virDomainBlockRebase): Document the event.
* src/qemu/qemu_monitor_json.c (eventHandlers): New event.
(qemuMonitorJSONHandleBlockJobReady): New function.
(qemuMonitorJSONGetBlockJobInfoOne): Translate new job type.
(qemuMonitorJSONHandleBlockJobImpl): Handle new event and job type.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Recognize
the event to minimize snooping.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Snoop a successful
info query to save effort on a pivot request.

Adding a new API to obtain information about the
host node's present, online and offline CPUs.

int virNodeGetCPUMap(virConnectPtr conn,
                     unsigned char **cpumap,
                     unsigned int *online,
                     unsigned int flags);

The function will return the number of CPUs present on the host
or -1 on failure;
If cpumap is non-NULL virNodeGetCPUMap will allocate an array
containing a bit map representation of the online CPUs. It's
the callers responsibility to deallocate cpumap using free().
If online is non-NULL, the variable pointed to will contain
the number of online host node CPUs.
The variable flags has been added to support future extensions
and must be set to 0.

Extend the driver structure by nodeGetCPUMap entry in support of the
new API virNodeGetCPUMap.
Added implementation of virNodeGetCPUMap to libvirt.c
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

In v2 migration protocol, XML is obtained by calling domainGetXMLDesc.
This includes the default USB controller in XML, which breaks migration
to older libvirt (before 0.9.2).

Commit 409b5f54
    qemu: Emit compatible XML when migrating a domain
only fixed this for v3 migration.

This patch uses the new VIR_DOMAIN_XML_MIGRATABLE flag (detected by
VIR_DRV_FEATURE_XML_MIGRATABLE) to obtain XML without the default controller,
enabling backward v2 migration.

Now that we can crawl the chain of backing files, we can do
argument validation and implement the 'shallow' flag.  In
testing this, I discovered that it can be handy to pass the
shallow flag and an explicit base, as a means of validating
that the base is indeed the file we expected.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Crawl through
chain to implement shallow flag.
* src/libvirt.c (virDomainBlockCommit): Relax API.

Currently there is a restriction that multi-threaded applications
must manually call virInitialize, before threads start using
libvirt, because it is not thread-safe. By switching it to use
a virOnceControl initializer we gain thread safety, and thus
applications no longer need to manually call it. They can rely
on virConnectOpen invoking it for them.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

curl_global_init is not thread-safe. curl_easy_init might call
curl_global_init when it was no called before. But curl_easy_init
can be called from different threads by the ESX driver. Therefore,
call curl_global_init from virInitialize to stop curl_easy_init from
calling it.

Reported by Benjamin Wang.

Jim Fehlig reported a compilation error with older gcc 4.3.4:

libvirt.c: In function 'virDomainGetEmulatorPinInfo':
libvirt.c:9111: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]

It looks like someone programmed via too much copy-and-paste.

* src/libvirt.c (virDomainGetEmulatorPinInfo): Multiplying by 1 is
a no-op, and thus will never overflow.

To declare that it's not recommended to use the tuning API while
the outside tuning program (such as ksmtuned under Linux) is running.

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

This patch adds a new public API virNetworkUpdate that will permit
updating an existing network configuration without requiring that the
network be destroyed/restarted for the changes to take effect.

A block commit moves data in the opposite direction of block pull.
Block pull reduces the chain length by dropping backing files after
data has been pulled into the top overlay, and is always safe; block
commit reduces the chain length by dropping overlays after data has
been committed into the backing file, and any files that depended
on base but not on top are invalidated at any point where they have
unallocated data that is now pointing to changed contents in base.
Both directions are useful, however: a qcow2 layer that is more than
50% allocated will typically be faster with a pull operation, while
a qcow2 layer with less than 50% allocation will be faster as a
commit operation.  Committing across multiple layers can be more
efficient than repeatedly committing one layer at a time, but
requires extra support from the hypervisor.

This API matches Jeff Cody's proposed qemu command 'block-commit':
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02226.html

Jeff's command is still in the works for qemu 1.3, and may gain
further enhancements, such as the ability to control on-error
handling (it will be comparable to the error handling Paolo is
adding to 'drive-mirror', so a similar solution will be needed
when I finally propose virDomainBlockCopy with more functionality
than the basics supported by virDomainBlockRebase).  However, even
without qemu support, this API will be useful for _offline_ block
commits, by wrapping qemu-img calls and turning them into a block
job, so this API is worth committing now.

For some examples of how this will be implemented, all starting
with the chain: base <- snap1 <- snap2 <- active

+ These are equivalent:
 virDomainBlockCommit(dom, disk, NULL, NULL, 0, 0)
 virDomainBlockCommit(dom, disk, NULL, "active", 0, 0)
 virDomainBlockCommit(dom, disk, "base", NULL, 0, 0)
 virDomainBlockCommit(dom, disk, "base", "active", 0, 0)
but cannot be implemented for online qemu with round 1 of
Jeff's patches; and for offline images, it would require
three back-to-back qemu-img invocations unless qemu-img
is patched to allow more efficient multi-layer commits;
the end result would be 'base' as the active disk with
contents from all three other files, where 'snap1' and
'snap2' are invalid right away, and 'active' is invalid
once any further changes to 'base' are made.

+ These are equivalent:
 virDomainBlockCommit(dom, disk, "snap2", NULL, 0, 0)
 virDomainBlockCommit(dom, disk, NULL, NULL, 0, _SHALLOW)
they cannot be implemented for online qemu, but for offline,
it is a matter of 'qemu-img commit active', so that 'snap2'
is now the active disk with contents formerly in 'active'.

+ Similarly:
 virDomainBlockCommit(dom, disk, "snap2", NULL, 0, _DELETE)
for an offline domain will merge 'active' into 'snap2', then
delete 'active' to avoid leaving a potentially invalid file
around.

+ This version:
 virDomainBlockCommit(dom, disk, NULL, "snap2", 0, _SHALLOW)
can be implemented online with 'block-commit' passing a base of
snap1 and a top of snap2; and can be implemented offline by
'qemu-img commit snap2' followed by 'qemu-img rebase -u
-b snap1 active'

* include/libvirt/libvirt.h.in (virDomainBlockCommit): New API.
* src/libvirt.c (virDomainBlockCommit): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.10.2): Export it.
* src/driver.h (virDrvDomainBlockCommit): New driver callback.
* docs/apibuild.py (CParser.parseSignature): Add exception.

* include/libvirt/libvirt.h.in: (Add macros for the param fields,
  declare the APIs).
* src/driver.h: (New methods for the driver struct)
* src/libvirt.c: (Implement the public APIs)
* src/libvirt_public.syms: (Export the public symbols)

This is to list the secret objects. Supports to filter the secrets
by its storage location, and whether it's private or not.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllSecretFlags
                              and virConnectListAllSecrets.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllSecrets)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public

This is to list the network filter objects. No flags are supported

include/libvirt/libvirt.h.in: Declare enum virConnectListAllNWFilterFlags
                              and virConnectListAllNWFilters.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNWFilters)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public

This is to list the node device objects, supports to filter the results
by capability types.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllNodeDeviceFlags
                              and virConnectListAllNodeDevices.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNodeDevices)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public

Assume not only domain object will use it.

This is to list the interface objects, supported filtering flags
are: active|inactive.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllInterfaceFlags
                              and virConnectListAllInterfaces.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllInterfaces)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public

All public API functions must call virResetLastError to clear
out any previous error. The virConnectOpen* functions forgot
to do this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This is to list the network objects, supported filtering flags
are: active|inactive, persistent|transient, autostart|no-autostart.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllNetworkFlags
                              and virConnectListAllNetworks.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNetworks)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public