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.
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Laine Stump 0702f48ef4 qemu: auto-add pcie-root-port/dmi-to-pci-bridge controllers as needed
Previously libvirt would only add pci-bridge devices automatically
when an address was requested for a device that required a legacy PCI
slot and none was available. This patch expands that support to
dmi-to-pci-bridge (which is needed in order to add a pci-bridge on a
machine with a pcie-root), and pcie-root-port (which is needed to add
a hotpluggable PCIe device). It does *not* automatically add
pcie-switch-upstream-ports or pcie-switch-downstream-ports (and
currently there are no plans for that).

Given the existing code to auto-add pci-bridge devices, automatically
adding pcie-root-ports is fairly straightforward. The
dmi-to-pci-bridge support is a bit tricky though, for a few reasons:

1) Although the only reason to add a dmi-to-pci-bridge is so that
   there is a reasonable place to plug in a pci-bridge controller,
   most of the time it's not the presence of a pci-bridge *in the
   config* that triggers the requirement to add a dmi-to-pci-bridge.
   Rather, it is the presence of a legacy-PCI device in the config,
   which triggers auto-add of a pci-bridge, which triggers auto-add of
   a dmi-to-pci-bridge (this is handled in
   virDomainPCIAddressSetGrow() - if there's a request to add a
   pci-bridge we'll check if there is a suitable bus to plug it into;
   if not, we first add a dmi-to-pci-bridge).

2) Once there is already a single dmi-to-pci-bridge on the system,
   there won't be a need for any more, even if it's full, as long as
   there is a pci-bridge with an open slot - you can also plug
   pci-bridges into existing pci-bridges. So we have to make sure we
   don't add a dmi-to-pci-bridge unless there aren't any
   dmi-to-pci-bridges *or* any pci-bridges.

3) Although it is strongly discouraged, it is legal for a pci-bridge
   to be directly plugged into pcie-root, and we don't want to
   auto-add a dmi-to-pci-bridge if there is already a pci-bridge
   that's been forced directly into pcie-root.

Although libvirt will now automatically create a dmi-to-pci-bridge
when it's needed, the code still remains for now that forces a
dmi-to-pci-bridge on all domains with pcie-root (in
qemuDomainDefAddDefaultDevices()). That will be removed in a future
patch.

For now, the pcie-root-ports are added one to a slot, which is a bit
wasteful and means it will fail after 31 total PCIe devices (30 if
there are also some PCI devices), but helps keep the changeset down
for this patch. A future patch will have 8 pcie-root-ports sharing the
functions on a single slot.
2016-11-14 14:19:36 -05:00
.gnulib@5ddd9d713d build: update to latest gnulib 2016-11-12 14:51:52 -06:00
build-aux prohibit-duplicate-header: print file name and line 2016-06-23 12:48:40 +02:00
daemon daemon: Fix crash during daemon cleanup 2016-10-27 15:58:47 -04:00
docs storage.html.in: Kill useless spaces in <pre/> 2016-11-14 11:03:34 +01:00
examples examples: Distribute all systemtap scripts. 2016-10-10 15:02:38 +08:00
gnulib build: drop hack for old mingw ssize_t 2016-07-12 08:57:13 -06:00
include/libvirt qemu: Add length for bps/iops throttling parameters to driver 2016-10-25 17:20:13 -04:00
m4 wireshark: Use ${exec_prefix} instead of ${prefix} 2016-11-07 10:16:06 +01:00
po datatypes: Introduce some admin-related close callback handling helpers 2016-11-14 10:18:56 +01:00
src qemu: auto-add pcie-root-port/dmi-to-pci-bridge controllers as needed 2016-11-14 14:19:36 -05:00
tests qemu: auto-add pcie-root-port/dmi-to-pci-bridge controllers as needed 2016-11-14 14:19:36 -05:00
tools tools: Replace vshPrint with vshPrintExtra on places we forgot about 2016-11-14 12:14:11 +01:00
.ctags maint: Make ctags work out of the box 2013-07-18 08:47:21 +02:00
.dir-locals.el build: avoid tabs that failed syntax-check 2012-09-06 09:43:46 -06:00
.gitignore tests: Self test virt-admin 2016-09-14 13:18:07 +02:00
.gitmodules
.mailmap maint: update .mailmap for recent contributions 2015-03-20 06:17:55 -06:00
AUTHORS.in Change maintainers list 2016-02-12 13:10:05 +03:00
autobuild.sh maint: Switch to xz compressed PAX release archives 2016-06-15 18:53:34 +02:00
autogen.sh maint: improve usage of autogen's --no-git 2015-02-06 11:35:29 -07:00
bootstrap build: update to latest gnulib 2016-11-12 14:51:52 -06:00
bootstrap.conf hvsupport: use a regex instead of XML::XPath 2016-07-19 18:42:44 +02:00
cfg.mk docs: rewrite content on front page to be more useful 2016-11-11 12:15:05 +00:00
ChangeLog-old Fix typos in src/* 2014-04-21 16:49:08 -06:00
config-post.h config-post.h:fix a typo 2016-09-21 09:35:51 +02:00
configure.ac configure: remove fallback check for parted 2016-11-10 16:00:02 +00:00
COPYING maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
COPYING.LESSER maint: Remove control characters from LGPL license file 2015-09-25 09:16:24 +02:00
HACKING docs: remove outdated suggestion to make patches with "diff -urp"/"git diff" 2016-07-01 12:41:10 -04:00
libvirt-admin.pc.in Add libvirt-admin library 2015-06-16 13:46:20 +02:00
libvirt-lxc.pc.in Add pkg-config files for libvirt-qemu & libvirt-lxc 2014-06-23 16:17:27 +01:00
libvirt-qemu.pc.in Add pkg-config files for libvirt-qemu & libvirt-lxc 2014-06-23 16:17:27 +01:00
libvirt.pc.in Add pkg-config files for libvirt-qemu & libvirt-lxc 2014-06-23 16:17:27 +01:00
libvirt.spec.in docs: redo style of front page 2016-11-11 12:15:03 +00:00
Makefile.am dist: Speed up distribution compression 2016-06-30 16:05:24 +02:00
Makefile.nonreentrant cfg.mk: use a single regex for all non-reentrant functions 2016-06-15 15:00:56 +02:00
mingw-libvirt.spec.in docs: redo style of front page 2016-11-11 12:15:03 +00:00
README
README-hacking docs: update README-hacking 2014-05-06 16:20:24 -06:00
run.in Add PKG_CONFIG_PATH to run.in script. 2014-06-26 14:32:35 +01:00
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>