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.
Go to file
Daniel P. Berrange e1de552150 lxc: re-arrange startup synchronization sequence with controller
Currently the lxc controller process itself is responsible for
daemonizing itself into the background and writing out its pid
file. The lxc driver would fork the controller and then attempt
to connect to the lxc monitor. This connection would only
succeed after the controller has backgrounded itself, setup
cgroups and written its pid file, so startup was race free.

The problem is that we need to delay create of the cgroups to
much later, such that we can tell systemd the container init
pid when we create the cgroups. If we delay cgroup creation
though the current synchronization won't work.

A second problem is that the controller needs the XML config
of the guest. Currently we write out the plain virDomainDefPtr
XML before starting the controller, and then later replace it
with the full virDomainObjPtr status XML. This is kind of gross
and also means that the controller doesn't get a record of the
live XML config right away. This means it doesn't have a record
of the veth device names either and so can't give that info
to systemd when creating the cgroups.

To address this we change the startup sequencing. The goal
is that we want to get the PID as soon as possible, before
the LXC controller even starts. So we stop letting the LXC
controller daemonize itself, and instead use virCommand's
built-in capabilities. This daemonizes and writes the PID
before LXC controller is exec'd. So the driver can read
the PID as soon as virCommandRun returns. It is no longer
safe to connect to the monitor or detect the cgroups though.

Fortunately the LXC controller already has a second point
of synchronization. Immediately before its  event loop
starts running, it performs a handshake with the driver.
So we move the opening of the monitor connection and cgroup
detection after this synchronization point.
2015-01-27 13:57:02 +00:00
.gnulib@c27f1a356f maint: update to latest gnulib 2015-01-05 16:38:50 -07:00
build-aux bracket-spacing: Add syntax-check for unnecessary curly brackets 2014-11-14 17:13:36 +01:00
daemon Fix shadowed variable warning 2015-01-27 13:43:23 +01:00
docs Release of libvirt-1.2.12 2015-01-27 16:01:12 +08:00
examples Grant access to helpers 2015-01-23 11:12:44 +01:00
gnulib maint: fix date in local gnulib patch 2015-01-05 16:44:10 +00:00
include storage: add a flag to clone files on btrfs 2015-01-27 13:41:14 +01:00
m4 Conditionalize use of -Wno-suggest-attribute=format pragma 2015-01-16 17:12:27 +00:00
po Release of libvirt-1.2.12 2015-01-27 16:01:12 +08:00
src lxc: re-arrange startup synchronization sequence with controller 2015-01-27 13:57:02 +00:00
tests qemu: report TAP device indexes to systemd 2015-01-27 13:57:02 +00:00
tools virsh: add support for domain XML validation 2015-01-16 11:07:59 +00:00
.ctags maint: Make ctags work out of the box 2013-07-18 08:47:21 +02:00
.dir-locals.el
.gitignore Revert "src/xenconfig: Xen-xl parser" 2015-01-12 10:15:13 -07:00
.gitmodules
.mailmap maint: update .mailmap 2014-12-21 00:21:34 +01:00
AUTHORS.in Update my email address in AUTHORS.in 2014-12-19 22:30:31 +01:00
autobuild.sh Disable libvirtd by default when building on Win32 2014-04-29 11:30:32 +01:00
autogen.sh maint: detect VPATH builds when checking for gnulib update 2014-06-04 16:06:55 -06:00
bootstrap maint: update to latest gnulib 2015-01-05 16:05:12 +00:00
bootstrap.conf Revert "bootstrap.conf: add check for flex" 2015-01-12 10:14:30 -07:00
cfg.mk Fix virCgroupGetPercpuStats with non-continuous present CPUs 2015-01-22 17:01:11 +01:00
ChangeLog-old Fix typos in src/* 2014-04-21 16:49:08 -06:00
config-post.h build: fix build of virt-login-shell on systems with older gnutls 2013-10-22 09:41:50 -06:00
configure.ac storage: introduce btrfsCloneFile() for COW copy 2015-01-27 13:24:10 +01:00
COPYING maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
COPYING.LESSER maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
HACKING docs: Fix missing curly braces 2014-12-10 11:21:31 +01:00
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 Release of libvirt-1.2.12 2015-01-27 16:01:12 +08:00
Makefile.am examples: Introduce domtop 2014-07-18 16:39:54 +02:00
Makefile.nonreentrant
mingw-libvirt.spec.in Move virConnect related APIs out of libvirt.h.in 2014-10-24 17:23:51 +01:00
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>