f105627992
The only use for the 'current' member of virDomainSnapshotDef was with the PARSE/FORMAT_INTERNAL flag for controlling an internal-use <active> element marking whether a particular snapshot definition was current, and even then, only by the qemu driver on output, and by qemu and test driver on input. But this duplicates vm->snapshot_current, and gets in the way of potential simplifications to have qemu store a single file for all snapshots rather than one file per snapshot. Get rid of the member by adding a bool* parameter during parse (ignored if the PARSE_INTERNAL flag is not set), and by adding a new flag during format (if FORMAT_INTERNAL is set, the value printed in <active> depends on the new FORMAT_CURRENT). Then update the qemu driver accordingly, which involves hoisting assignments to vm->current_snapshot to occur prior to any point where a snapshot XML file is written (although qemu kept vm->current_snapshot and snapshot->def_current in sync by the end of the function, they were not always identical in the middle of functions, so the shuffling gets a bit interesting). Later patches will clean up some of that confusing churn to vm->current_snapshot. Note: even if later patches refactor qemu to no longer use FORMAT_INTERNAL for output (by storing bulk snapshot XML instead), we will always need PARSE_INTERNAL for input (because on upgrade, a new libvirt still has to parse XML left from a previous libvirt). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Ferlan <jferlan@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General
Public License, version 2.1 (or later). Some parts of the code that are
not part of the C library may have the more restrictive GNU General
Public License, version 2.1 (or later). See the files COPYING.LESSER
and COPYING for full license terms & conditions.
Installation
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure script and a summary printed
which lists any missing (optional) dependencies.
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: