a1dec315c9
The qemuMigrationParamsApply internal API was designed to apply all
migration parameters and capabilities before we start to migrate a
domain. While migration parameters are only passed to QEMU when we
explicitly want to set a specific value, capabilities are always either
enabled or disabled.
Thus when this API is called outside migration job, e.g., via a call to
qemuDomainMigrateSetMaxSpeed with VIR_DOMAIN_MIGRATE_MAX_SPEED_POSTCOPY
flag, we would call migrate-set-capabilities and disable all
capabilities. However, changing capabilities while migration is already
running does not make sense and our code should never be trying to do
so. In fact QEMU even reports an error if migrate-set-capabilities is
called during migration and qemuDomainMigrateSetMaxSpeed would fail
with:
internal error: unable to execute QEMU command
migrate-set-capabilities: There's a migration process in progress
With this patch qemuMigrationParamsApply never tries to call
migrate-set-capabilities outside of migration job. When the capabilities
bitmap is all zeros (which is its initial value after
qemuMigrationParamsNew), we just skip the command. But when any
capability bit is set to 1 by a non-migration job, we report an error to
highlight a bug in our code.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Acked-by: Peter Krempa <pkrempa@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: