Xen only supports a single type of PCI hostdev assignment, so it is superfluous to have <driver name='xen'/> peppered throughout the config. It *is* necessary to have the driver type explicitly set in the hostdev object before calling into the hypervisor-agnostic "hostdev manager" though (otherwise the hostdev manager doesn't know whether it should do Xen-specific setup, or VFIO-specific setup). Historically, the Xen driver has checked for "default" driver name (i.e. not set in the XML), and set it to "xen', during the XML postparse, thus guaranteeing that it will be set by the time the object is sent to the hostdev manager at runtime, but also setting it so early that a simple round-trip of parse-format results in the XML always containing an explicit <driver name='xen'/>, even if that wasn't specified in the original XML. The QEMU driver *doesn't* set driver.name during postparse though; instead, it waits until domain startup time (or device attach time for hotplug), and sets the driver.name then. The result is that a parse-format round trip of the XML in the QEMU driver *doesn't* add in the <driver name='vfio'/>. This patch modifies the Xen driver to behave similarly to the QEMU driver - the PostParse just checks for a driver.name that isn't supported by the Xen driver, and any explicit setting to "xen" is deferred until domain runtime rather than during the postparse, thus Xen domain XML also doesn't get extraneous <driver name='xen'/>. This delayed setting of driver.name of course results in slightly different xml2xml parse-format results, so the unit test data is modified accordingly. Signed-off-by: Laine Stump <laine@redhat.com> Reviewed-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 2.0 (or later). See the files COPYING.LESSER
and COPYING
for full license terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
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:
- users@lists.libvirt.org (for user discussions)
- devel@lists.libvirt.org (for development only)
Further details on contacting the project are available on the website: