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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.
c329db7180
When support for was added for PCI multifunction cards (in commit 9f8baf, first included in libvirt 0.9.3), it was done by always turning on the multifunction bit for all PCI devices. Since that time it has been realized that this is not an ideal solution, and that the multifunction bit must be selectively turned on. For example, see https://bugzilla.redhat.com/show_bug.cgi?id=728174 and the discussion before and after https://www.redhat.com/archives/libvir-list/2011-September/msg01036.html This patch modifies multifunction support so that the multifunction=on option is only added to the qemu commandline for a device if its PCI <address> definition has the attribute "multifunction='on'", e.g.: <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='on'/> In practice, the multifunction bit should only be turned on if function='0' AND other functions will be used in the same slot - it usually isn't needed for functions 1-7 (although there are apparently some exceptions, e.g. the Intel X53 according to the QEMU source code), and should never be set if only function 0 will be used in the slot. The test cases have been changed accordingly to illustrate. With this patch in place, if a user attempts to assign multiple functions in a slot without setting the multifunction bit for function 0, libvirt will issue an error when the domain is defined, and the define operation will fail. In the future, we may decide to detect this situation and automatically add multifunction=on to avoid the error; even then it will still be useful to have a manual method of turning on multifunction since, as stated above, there are some devices that excpect it to be turned on for all functions in a slot. A side effect of this patch is that attempts to use the same PCI address for two different devices will now log an error (previously this would cause the domain define operation to fail, but there would be no log message generated). Because the function doing this log was almost completely rewritten, I didn't think it worthwhile to make a separate patch for that fix (the entire patch would immediately be obsoleted). |
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| daemon | ||
| docs | ||
| examples | ||
| gnulib | ||
| include | ||
| m4 | ||
| po | ||
| python | ||
| src | ||
| tests | ||
| tools | ||
| .dir-locals.el | ||
| .gitignore | ||
| .gitmodules | ||
| .mailmap | ||
| AUTHORS | ||
| autobuild.sh | ||
| autogen.sh | ||
| bootstrap | ||
| bootstrap.conf | ||
| cfg.mk | ||
| ChangeLog-old | ||
| configure.ac | ||
| COPYING.LIB | ||
| HACKING | ||
| libvirt.pc.in | ||
| libvirt.spec.in | ||
| Makefile.am | ||
| Makefile.nonreentrant | ||
| mingw32-libvirt.spec.in | ||
| README | ||
| README-hacking | ||
| TODO | ||
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>