Commit Graph

185 Commits

Author SHA1 Message Date
Daniel P. Berrangé
305cdc37f0 api: introduce virConnectSetIdentity for passing uid, gid, selinux info
When using the fine grained access control mechanism for APIs, when a
client connects to libvirtd, the latter will fetch the uid, gid, selinux
info of the remote client on the UNIX domain socket. This is then used
as the identity when checking ACLs.

With the new split daemons things are a bit more complicated. The user
can connect to virtproxyd, which in turn connects to virtqemud. When
virtqemud requests the identity over the UNIX domain socket, it will
get the identity that virtproxyd is running as, not the identity of
the real end user/application.

virproxyd knows what the real identity is, and needs to be able to
forward this information to virtqemud. The virConnectSetIdentity API
provides a mechanism for doing this. Obviously virtqemud should not
accept such identity overrides from any client, it must only honour it
from a trusted client, aka one running as the same uid/gid as itself.

The typed parameters exposed in the API are the same as those currently
supported by the internal virIdentity class, with a few small name
changes.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:01 +01:00
Jonathon Jongsma
96880b87d0 lib: add virDomainGetGuestInfo()
This API is intended to aggregate several guest agent information
queries and is ispired by stats API virDomainListGetStats(). It is
anticipated that this information will be provided by a guest agent
running within the domain.

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-08-26 17:27:40 +02:00
Eric Blake
0d44788fc3 backup: Introduce virDomainCheckpoint APIs
Introduce a bunch of new public APIs related to backup checkpoints.
Checkpoints are modeled heavily after virDomainSnapshotPtr (both
represent a point in time of the guest), although a snapshot exists
with the intent of rolling back to that state, while a checkpoint
exists to make it possible to create an incremental backup at a later
time.  We may have a future hypervisor that can completely manage
checkpoints without libvirt metadata, but the first two planned
hypervisors (qemu and test) both always use libvirt for tracking
metadata relations between checkpoints, so for now, I've deferred
the counterpart of virDomainSnapshotHasMetadata for a separate
API addition at a later date if there is ever a need for it.

Note that until we allow snapshots and checkpoints to exist
simultaneously on the same domain (although the actual prevention of
this will be in a separate patch for the sake of an easier revert down
the road), that it is not possible to branch out to create more than
one checkpoint child to a given parent, although it may become
possible later when we revert to a snapshot that coincides with a
checkpoint.  This also means that for now, the decision of which
checkpoint becomes the parent of a newly created one is the only
checkpoint with no child (so while there are APIs for dealing with a
current snapshot, we do not need those for checkpoints).  We may end
up exposing a notion of a current checkpoint later, but it's easier to
add stuff when proven needed than to blindly support it now and wish
we hadn't exposed it.

The following map shows the API relations to snapshots, with new APIs
on the right:

Operate on a domain object to create/redefine a child:
virDomainSnapshotCreateXML          virDomainCheckpointCreateXML

Operate on a child object for lifetime management:
virDomainSnapshotDelete             virDomainCheckpointDelete
virDomainSnapshotFree               virDomainCheckpointFree
virDomainSnapshotRef                virDomainCheckpointRef

Operate on a child object to learn more about it:
virDomainSnapshotGetXMLDesc         virDomainCheckpointGetXMLDesc
virDomainSnapshotGetConnect         virDomainCheckpointGetConnect
virDomainSnapshotGetDomain          virDomainCheckpointGetDomain
virDomainSnapshotGetName            virDomainCheckpiontGetName
virDomainSnapshotGetParent          virDomainCheckpiontGetParent
virDomainSnapshotHasMetadata        (deferred for later)
virDomainSnapshotIsCurrent          (no counterpart, see note above)

Operate on a domain object to list all children:
virDomainSnapshotNum                (no counterparts, these are the old
virDomainSnapshotListNames           racy interfaces)
virDomainSnapshotListAllSnapshots   virDomainListAllCheckpoints

Operate on a child object to list descendents:
virDomainSnapshotNumChildren        (no counterparts, these are the old
virDomainSnapshotListChildrenNames   racy interfaces)
virDomainSnapshotListAllChildren    virDomainCheckpointListAllChildren

Operate on a domain to locate a particular child:
virDomainSnapshotLookupByName       virDomainCheckpointLookupByName
virDomainSnapshotCurrent            (no counterpart, see note above)
virDomainHasCurrentSnapshot         (no counterpart, old racy interface)

Operate on a snapshot to roll back to earlier state:
virDomainSnapshotRevert             (no counterpart, instead checkpoints
                                     are used in incremental backups via
				     XML to virDomainBackupBegin)

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-07-26 16:48:58 -05:00
Eric Blake
7fddf33f18 maint: Add missing 'global:' tag in libvirt_public.syms
Fixes: c08fc8d1

Signed-off-by: Eric Blake <eblake@redhat.com>
2019-06-21 14:26:39 -05:00
Daniel P. Berrangé
7c570f06bd network: add virNetworkPortRef API
Normal practice is to provide a Ref API for all objects, but this was
forgotten for the virNetworkPortPtr object.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-06-19 11:21:38 +01:00
Daniel P. Berrangé
c08fc8d199 network: add public APIs for network port object
Introduce a new virNetworPort object that will present an attachment to
a virtual network from a VM.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-06-17 15:19:54 +01:00
John Ferlan
6696155ae6 libvirt: Introduce virConnectGetStoragePoolCapabilities
Introduce the API to expose the storage pool capabilities along
with all the remote munglement required to hook up the client.

Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by: Michal Privoznik <mprivozn@redhat.com>
2019-03-06 11:12:48 -05:00
John Ferlan
ae69bda5c2 lib: Introduce virDomainSetIOThreadParams
Create a new API that will allow an adjustment of IOThread
polling parameters for the specified IOThread. These parameters
will not be saved in the guest XML. Currently the only parameters
supported will allow the hypervisor to adjust the parameters used
to limit and alter the scope of the polling interval. The polling
interval allows the IOThread to spend more or less time processing
in the guest.

Based on code originally posted by Pavel Hrdina <phrdina@redhat.com>
to add virDomainAddIOThreadParams and virDomainModIOThreadParams.
Modification of those changes to use virDomainSetIOThreadParams
instead and remove concepts related to saving the data in guest
XML as well as the way to specifically enable the polling parameters.

Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by: Michal Privoznik <mprivozn@redhat.com>
2018-11-19 07:26:40 -05:00
Daniel P. Berrangé
b57a9aecaf nwfilter: export port binding concept in the public API
When the daemons are split there will need to be a way for the virt
drivers and/or network driver to create and delete bindings between
network ports and network filters. This defines a set of public APIs
that are suitable for managing this facility.

Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-06-26 11:22:07 +01:00
Brijesh Singh
077c9a2504 libvirt: Introduce virDomainGetLaunchSecurityInfo public API
The API can be used outside the libvirt to get the launch security
information. When SEV is enabled, the API can be used to get the
measurement of the launch process.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
2018-06-12 10:00:49 +02:00
Brijesh Singh
45422935c3 libvirt: Introduce virNodeGetSEVInfo public API
The API can be used by application to retrieve the Platform Diffie-Hellman
Key and Platform Certificate chain.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
2018-06-12 09:52:00 +02:00
ramyelkest
50e96bb2a1 util: virerror: Introduce virGetLastError{Code,Domain} public APIs
Many places in the code call virGetLastError() just to check the
raised error code, or domain. However virGetLastError() can return
NULL, so the code has to check for that first. This patch therefore
introduces virGetLasError{Code,Domain} functions which always return a
valid error code or domain respectively, thus dropping the need to
perform any checks on the error object.

Signed-off-by: Ramy Elkest <ramyelkest@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
2018-06-05 18:44:05 +02:00
Jiri Denemark
7d0a1efcd6 Introduce virConnectBaselineHypervisorCPU public API
The new API computes the most feature-rich CPU which is compatible with
all given CPUs and can be provided by the specified hypervisor. It is a
more useful version of virConnectBaselineCPU, which doesn't consider any
hypervisor capabilities when computing the best CPU.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Collin Walling <walling@linux.ibm.com>
2018-05-28 15:58:05 +02:00
Jiri Denemark
24a41aa643 Introduce virConnectCompareHypervisorCPU public API
This new API compares the given CPU description with the CPU the
specified hypervisor is able to provide on the host. It is a more useful
version of virConnectCompareCPU, which compares the CPU definition with
the host CPU without considering any specific hypervisor and its
abilities.

https://bugzilla.redhat.com/show_bug.cgi?id=1559832
https://bugzilla.redhat.com/show_bug.cgi?id=1559835

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Collin Walling <walling@linux.ibm.com>
2018-05-28 15:55:17 +02:00
Michal Privoznik
007f500a23 Introduce virDomainDetachDeviceAlias API
When detaching a device it can be uniquely identified by its
alias. Instead of misusing virDomainDetachDeviceFlags which has
the same signature introduce new function.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2018-05-28 13:08:38 +02:00
Daniel P. Berrangé
7aa0e8c0cb storage: export virStoragePoolLookupByTargetPath as a public API
The storagePoolLookupByTargetPath() method in the storage driver is used
by the QEMU driver during block migration. If there's a valid use case
for this in the QEMU driver, then external apps likely have similar
needs. Exposing it in the public API removes the direct dependancy from
the QEMU driver to the storage driver.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-02-09 11:05:10 +00:00
Pavel Hrdina
1a2f34e363 lib: introduce virDomainSetLifecycleAction() API
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2017-10-19 11:52:26 +02:00
Kothapally Madhu Pavan
1558f2584f lib: Add API to edit domain's managed save state xml configuration
Similar to domainSaveImageDefineXML this commit adds domainManagedSaveDefineXML
API which allows to edit domain's managed save state xml configuration.

Signed-off-by: Kothapally Madhu Pavan <kmp@linux.vnet.ibm.com>
2017-08-29 13:40:13 +02:00
Kothapally Madhu Pavan
a67e3872a6 lib: Add API to dump xml configuration of managed save state domain
Similar to domainSaveImageGetXMLDesc this commit adds domainManagedSaveGetXMLDesc
API which allows to get the xml of managed save state domain.

Signed-off-by: Kothapally Madhu Pavan <kmp@linux.vnet.ibm.com>
2017-08-29 13:40:13 +02:00
Scott Garfinkle
4601a546b7 Add virDomainMigrateGetMaxDowntime public API
Add virDomainMigrateGetMaxDowntime to support querying maximum allowable
downtime during live migration.
2017-08-26 07:55:17 -04:00
Michal Privoznik
a524951091 Introduce virStreamSparseSendAll
This is just a wrapper over new function that have been just
introduced: virStreamSendHole() . It's very similar to
virStreamSendAll() except it handles sparse streams well.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Michal Privoznik
3a1e2e920e Introduce virStreamSparseRecvAll
This is just a wrapper over new functions that have been just
introduced: virStreamRecvFlags(), virStreamRecvHole(). It's very
similar to virStreamRecvAll() except it handles sparse streams
well.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Michal Privoznik
b6aedd2f05 Introduce virStreamRecvHole
This function is basically a counterpart for virStreamSendHole().
If one side of a stream called virStreamSendHole() the other
should call virStreamRecvHole() to get the size of the hole.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Michal Privoznik
69a573d010 Introduce virStreamSendHole
This API is used to tell the other side of the stream to skip
some bytes in the stream. This can be used to create a sparse
file on the receiving side of a stream.

It takes @length argument, which says how big the hole is. This
skipping is done from the current point of stream. Since our
streams are not rewindable like regular files, we don't need
@whence argument like seek(2) has.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Michal Privoznik
a35e2836b3 Introduce virStreamRecvFlags
This patch is adding the virStreamRecvFlags as a variant to the
virStreamRecv function in order to allow for future expansion of
functionality for processing sparse streams using a @flags
argument.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-05-18 07:42:13 +02:00
Peter Krempa
bb09798fbe lib: Add API for setting the threshold size for VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD
The new API can be used to configure the threshold when
VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD should be fired.
2017-03-27 10:09:49 +02:00
Peter Krempa
8f657259bb lib: Add API for specific vCPU hot(un)plug
Similarly to domainSetGuestVcpus this commit adds API which allows to
modify state of individual vcpus rather than just setting the count.

This allows to enable CPUs in specific guest NUMA nodes to achieve any
necessary configuration.
2017-02-21 15:06:59 +01:00
Daniel P. Berrange
34fd3caabf Introduce secret lifecycle event APIs
Add public APIs to allow applications to watch for define and
undefine of secret objects.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-09 15:53:48 +00:00
John Ferlan
0c234889c4 storage: Introduce virStorageVolInfoFlags
https://bugzilla.redhat.com/show_bug.cgi?id=1332019

This function will essentially be a wrapper to virStorageVolInfo in order
to provide a mechanism to have the "physical" size of the volume returned
instead of the "allocation" size. This will provide similar capabilities to
the virDomainBlockInfo which can return both allocation and physical of a
domain storage volume.

NB: Since we're reusing the _virStorageVolInfo and not creating a new
_virStorageVolInfoFlags structure, we'll need to generate the rpc APIs
remoteStorageVolGetInfoFlags and remoteDispatchStorageVolGetInfoFlags
(although both were originally created from gendispatch.pl and then
just copied into daemon/remote.c and src/remote/remote_driver.c).

The new API will allow the usage of a VIR_STORAGE_VOL_GET_PHYSICAL flag
and will make the decision to return the physical or allocation value
into the allocation field.

In order to get that physical value, virStorageBackendUpdateVolTargetInfoFD
adds logic to fill in physical value matching logic in qemuStorageLimitsRefresh
used by virDomainBlockInfo when the domain is inactive.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2016-12-20 13:52:39 -05:00
Jovanka Gulicoska
fcabc1ca53 Introduce node device lifecycle event APIs
Node device lifecycle event API entry points for registering and
deregistering node deivce events, as well as types of events
associated with node device.
These entry points will be used for implementing asynchronous
lifecycle events.

Node device API:
virConnectNodeDeviceEventRegisterAny
virConnectNodeDeviceEventDeregisterAny
virNodeDeviceEventLifecycleType which has events CREATED and DELETED
2016-08-02 09:52:00 -04:00
Peter Krempa
3ebf7ca07e lib: Add API to set individual vcpu usage in the guest via guest agent
To allow finer-grained control of vcpu state using guest agent this API
can be used to individually set the state of the vCPU.

This will allow to better control NUMA enabled guests and/or test
various vCPU configurations.
2016-06-22 09:25:47 +02:00
Peter Krempa
800244faf3 lib: Add API to query guest vcpu info using guest agent
Add a rather universal API implemented via typed params that will allow
to query the guest agent for the state and possibly other aspects of
guest vcpus.
2016-06-22 08:16:31 +02:00
Jovanka Gulicoska
1328f98224 Introduce storage lifecycle event APIs
Storage pool lifecycle event API entry points for registering and deregistering
storage pool events, as well as types of events associated with storage pools.
These entry points will be used for implementing asynchronous lifecycle events.

Storage pool API:
virConnectStoragePoolEventRegisterAny
virConnectStoragePoolEventDeregisterAny
virStoragePoolEventLifecycleType which has events STARTED, STOPPED, DEFINED,
UNDEFINED, and REFRESHED
2016-06-16 12:22:11 -04:00
Qiaowei Ren
c803b0072b perf: add new public APIs for perf event
API agreed on in
https://www.redhat.com/archives/libvir-list/2015-October/msg00872.html

* include/libvirt/libvirt-domain.h (virDomainGetPerfEvents,
virDomainSetPerfEvents): New declarations.
* src/libvirt_public.syms: Export new symbols.
* src/driver-hypervisor.h (virDrvDomainGetPerfEvents,
virDrvDomainSetPerfEvents): New typedefs.
* src/libvirt-domain.c: Implement virDomainGetPerfEvents and
virDomainSetPerfEvents.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Message-id: 1459171833-26416-2-git-send-email-qiaowei.ren@intel.com
2016-03-29 13:13:05 +01:00
Cristian Klein
1a1246ec7d Add public APIs for post-copy migration
To use post-copy one has to start the migration with
VIR_MIGRATE_POSTCOPY flag and, while migration is in progress, call
virDomainMigrateStartPostCopy() to switch from pre-copy to post-copy.

Signed-off-by: Cristian Klein <cristiklein@gmail.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2016-03-21 15:15:46 +01:00
Tomas Meszaros
9f7a559a6d Introduce virDomainRename API
Also, among with this new API new ACL that restricts rename
capability is invented too.

Signed-off-by: Tomas Meszaros <exo@tty.sk>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2015-08-14 10:50:20 +02:00
Martin Kletzander
f7d8aa44b0 Revert "Change livbirt version to 1.3.0 for the next release"
This reverts commit 9a8d916e89.

Also some changes that were introduced after that commit are fixed to
use 1.2.17 instead of 1.3.0
2015-06-28 11:34:30 +08:00
Pavel Boldin
5eb03b6ea0 util: add virTypedParamsAddStringList
The `virTypedParamsAddStringList' function provides interface to add a
NULL-terminated array of string values as a multi-value to the params.

Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2015-06-18 16:46:09 +02:00
Ján Tomko
e8982c88bd Introduce virDomainSetUserPassword API
For setting passwords of users inside the domain.

With the VIR_DOMAIN_PASSWORD_ENCRYPTED flag set, the password
is assumed to be already encrypted by the method required
by the guest OS.

https://bugzilla.redhat.com/show_bug.cgi?id=1174177
2015-05-21 16:04:01 +02:00
John Ferlan
130a0ed281 Implement virDomainAddIOThread and virDomainDelIOThread
Add libvirt API's to manage adding and deleting IOThreads to/from the
domain
2015-04-27 12:36:36 -04:00
Ján Tomko
a96b68e7a4 Rename DomainGetIOThreadsInfo to DomainGetIOThreadInfo
While it returns info about multiple threads, the version
without the plural is easier to read.
2015-03-26 16:11:10 +01:00
Ján Tomko
cf8b828a72 Rename virDomainIOThreadsInfoFree to virDomainIOThreadInfoFree
This function only frees the info for one thread.
2015-03-26 16:11:10 +01:00
Nehal J Wani
5b5242a7cb domifaddr: Implement the public APIs
Define helper function virDomainInterfaceFree, which allows
the upper layer application to free the domain interface object
conveniently.

The API is going to provide multiple methods by flags, e.g.
  * Query guest agent
  * Parse DHCP lease file

include/libvirt/libvirt-domain.h
  * Define virDomainInterfaceAddresses, virDomainInterfaceFree
  * Define structs virDomainInterface, virDomainIPAddress

src/driver-hypervisor.h:
  * Define domainInterfaceAddresses

src/libvirt-domain.c:
  * Implement virDomainInterfaceAddresses
  * Implement virDomainInterfaceFree

src/libvirt_public.syms:
  * Export the new symbols

Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>
2015-03-17 15:15:38 +00:00
John Ferlan
71b234ce68 Implement public API for virDomainPinIOThread
Add virDomainPinIOThread to allow setting the CPU affinity for a specific
IOThread based on the output generated from virDomainGetIOThreadsInfo

The API supports updating both the --live domain and the --config data
2015-03-11 12:23:33 -04:00
John Ferlan
11a5a0956f Implement public API for virDomainGetIOThreadsInfo
Add virDomainGetIOThreadInfo in order to return a list of
virDomainIOThreadInfoPtr structures which list the IOThread ID
and the CPU Affinity map for each IOThread for the domain.

For an active domain, the live data will be returned, while for
an inactive domain, the config data will be returned.

The API supports either the --live or --config flag, but not both.

Also added virDomainIOThreadsInfoFree in order to free the cpumap
and the IOThreadInfo structure.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2015-03-06 06:49:32 -05:00
Daniel P. Berrange
2a5ee95441 Add new virDomainDefineXMLFlags public API
The virDomainDefineXML method is one of the few that still lacks
an 'unsigned int flags' parameter. This will be needed for adding
XML validation to this API. virDomainCreateXML fortunately already
has flags.
2015-01-13 10:35:09 +00:00
Tomoki Sekiyama
612e037b4c Implement public API for virDomainGetFSInfo
virDomainGetFSInfo returns a list of filesystems information mounted in the
guest, which contains mountpoints, device names, filesystem types, and
device aliases named by libvirt. This will be useful, for example, to
specify mountpoints to fsfreeze when taking snapshot of a part of disks.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
2014-11-24 10:02:08 -05:00
Michal Privoznik
fa5c5580d6 Introduce virNodeAllocPages
A long time ago in a galaxy far, far away it has been decided
that libvirt will manage not only domains but host as well. And
with my latest work on qemu driver supporting huge pages, we miss
the cherry on top: an API to allocate huge pages on the run.
Currently users are forced to log into the host and adjust the
huge pages pool themselves.  However, with this API the problem
is gone - they can both size up and size down the pool.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-09-25 10:24:44 +02:00
Eric Blake
993fa528a6 blockcopy: virDomainBlockCopy with XML destination, typed params
This commit (finally) adds the virDomainBlockCopy API, with the
intent that it will provide more power to the existing 'virsh
blockcopy' command.

'virsh blockcopy' was first added in Apr 2012 (v0.9.12), which
corresponds to the upstream qemu 1.2 timeframe.  It was done as
a hack on top of the existing virDomainBlockRebase() API call,
for two reasons: 1) it was targetting a feature that landed first
in downstream RHEL qemu, but had not stabilized in upstream qemu
at the time (and indeed, 'drive-mirror' only landed upstream in
qemu 1.3 with slight differences to the first RHEL attempt,
and later gained further parameters like granularity and buf-size
that are also worth exposing), and 2) extending an existing API
allowed it to be backported without worrying about bumping .so
versions.  A virDomainBlockCopy() API was proposed at that time
[1], but we decided not to accept it into libvirt until after
upstream qemu stabilized, and it ended up getting scrapped.
Whether or not RHEL should have attempted adding a new feature
without getting it upstream first is a debate that can be held
another day; but enough time has now elapsed that we are ready to
do the interface cleanly.

[1] https://www.redhat.com/archives/libvir-list/2012-April/msg00768.html

Delaying the creation of a clean API until now has also had a
benefit: we've only recently learned of a few shortcomings in the
original design: 1) it is unable to target a network destination
(such as a gluster volume) because it hard-coded the assumption
that the destination is a local file name.  Because of all the
refactoring we've done to add virStorageSourcePtr, we are in a
better position to declare an API that parses XML describing a
host storage source as the copy destination, which was not
possible had we implemented virDomainBlockCopy as it had been
originally envisioned (although a network target will have to wait
until a later libvirt release compared to the API addition to
actually be implemented).  2) the design of using MiB/sec as the
bandwidth throttle is rather coarse; qemu is actually tuned to
bytes/second, and libvirt is preventing access to that level of
detail.  A later patch will add flags to existing block job API
that can request bytes/second instead of back-compat MiB/s, but as
this is a new API, we can get it right to begin with.

At least I had the foresight to create 'virsh blockcopy' as a
separate command at the UI level (commit 1f06c00) rather than
leaking the underlying API overload of virDomainBlockRebase onto
shell users.

A further note on the bandwidth option: virTypedParameters
intentionally lacks unsigned long (since variable-width
interaction between mixed 32- vs. 64-bit client/server setups is
nasty), but we have to deal with the fact that we are interacting
with existing older code that mistakenly chose unsigned long
bandwidth at a point before we decided to prohibit it in all new
API.  The typed parameter is therefore unsigned long long, but
the implementation (in a later patch) will have to do overflow
detection on 32-bit platforms, as well as capping the value to
match the LLONG_MAX>>20 cap of the existing MiB/s interfaces.

* include/libvirt/libvirt.h.in (virDomainBlockCopy): New API.
(virDomainBlockJobType, virConnectDomainEventBlockJobStatus):
Update related documentation.
* src/libvirt.c (virDomainBlockCopy): Implement it.
* src/libvirt_public.syms (LIBVIRT_1.2.8): Export it.
* src/driver.h (_virDriver): New driver callback.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-08-26 15:42:35 -06:00
Peter Krempa
76a5bc4eef lib: Introduce API for retrieving bulk domain stats
The motivation for this API is that management layers that use libvirt
usually poll for statistics using various split up APIs we currently
provide. To get all the necessary stuff, the app needs to issue a lot of
calls and aggregate the results.

The APIs I'm introducing here:
1) Returns data in a format that we can expand in the future and is
(pseudo) hierarchical. The data is returned as typed parameters where
the fields are constructed as dot-separated strings containing names and
other stuff in a list of typed params.

2) Stats for multiple (all) domains can be queried at once and are
returned in one call. This will decrease the overhead necessary to issue
multiple calls per domain multiplied by the count of domains.

3) Selectable (bit mask) fields in the returned format. This will allow
to retrieve only specific stats according to the app's need.

The stats groups will be enabled using a bit field @stats passed as the
function argument. A few sample stats groups that this API will support:

VIR_DOMAIN_STATS_STATE
VIR_DOMAIN_STATS_CPU
VIR_DOMAIN_STATS_BLOCK
VIR_DOMAIN_STATS_INTERFACE

(Note that this is only an example, the initial implementation supports
 only VIR_DOMAIN_STATS_STATE while others will be added later.)

the returned typed params will use the following scheme

state.state = VIR_DOMAIN_RUNNING
state.reason = VIR_DOMAIN_RUNNING_BOOTED (the actual values according to
                                          the enum)
cpu.count = 8
cpu.0.state = running
cpu.0.time = 1234
2014-08-26 22:46:12 +02:00