489a937eb4
When using a VF from an SRIOV-capable network card in a guest (either in macvtap passthrough mode, or via VFIO PCI device assignment), The associated PF netdev must be online in order for the VF to be usable by the guest. The guest, however, is not able to change the state of the PF. And libvirt *could* set the PF online as needed, but that could lead to the host receiving unexpected IPv6 traffic (since the default for an unconfigured interface is to participate in IPv6 autoconf). For this reason, before assigning a VF to a guest, libvirt verifies that the related PF netdev is online - if it isn't, then we log an error and don't allow the guest startup to continue. Until now, this check was done during virNetDevSetNetConfig(). This works nicely because the same function is called both for macvtap passthrough and for VFIO device assignment. But in the case of VFIO, the VF has already been unbound from its netdev driver by the time we get to virNetDevSetNetConfig(), and in the case of dual port Mellanox NICs that have their VFs setup in single port mode, the *only* way to determine the proper PF netdev to query for online status is via the "phys_port_id" file that is in the VF netdev's sysfs directory. *BUT* if we've unbound the VF from the netdev driver, then it doesn't *have* a netdev sysfs directory. So, in order to check the correct PF netdev for online status, this patch moved the check earlier in the setup, into virNetDevSaveNetConfig(), which is called *before* unbinding the VF from its netdev driver. (Note that this implies that if you are using VFIO device assignment for the VFs of a Mellanox NIC that has the VFs programmed in single port mode, you must let the VFs be bound to their net driver and use "managed='yes'" in the device definition. To be more specific, this is only true if the VFs in single port mode are using port *2* of the PF - if the VFs are using only port 1, then the correct PF netdev will be arrived at by default/chance)) This resolves: https://bugzilla.redhat.com/267191
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: