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Konrad Rzeszutek Wilk
414979ba85
The code that populates E820 is unconditionally triggered by the guest configuration having "pci=['<BDF>,..']", being a PV guest, and if b_info->u.pv.e820_host is set. The code do_domain_create calls the libxl__e820_alloc when it notices that the guest is PV, has at least one PCI devices, and has the e820_host flag set. libxl__e820_alloc calls the xc_get_machine_memory_map to retrieve the systems E820. Then the E820 is sanitized to weed out E820 entries below 16MB, and as well remove any E820_RAM or E820_UNUSED regions as the guest does not need to know about them. The guest only needs the E820_ACPI, E820_NVS, E820_RESERVED to get an idea of where the PCI I/O space is. Mostly.. The Linux kernel assumes that any gap in the E820 is considered PCI I/O space which means that if we pass in the guest 2GB, and the E820_ACPI, and its friend start at 3GB, the gap between 2GB and 3GB will be considered as PCI I/O space. To guard against that we also create an E820_UNUSABLE between the region of 'target_kb' (called ram_end in the code) up to the first E820_[ACPI,NVS,RESERVED] region. Lastly, the xc_domain_set_memory_map is called to install the new E820. When tested with another PV guest (NetBSD 5.1) the modified E820 gave it no trouble. The code has also been tested with older "classic" Xen Linux and with the newer "pvops" with success (SLES11, RHEL5, Ubuntu Lucid, Debian Squeeze, 2.6.37, 2.6.38, 2.6.39). Memory that is slack or for balloon (so 'maxmem' in guest configuration) is put behind the machine E820. Which in most cases is after the 4GB. The reason for doing the fetching of the E820 using the hypercall in the toolstack (instead of the guest doing it) is that when a guest would do a hypercall to 'XENMEM_machine_memory_map' it would retrieve an E820 with I/O range caps added in. Meaning that the region after 4GB up to end of possible memory would be marked as unusable and the kernel would not have any space to allocate a balloon region. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Committed-by: Ian Jackson <ian.jackson.citrix.com>
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http://www.xen.org/
What is Xen?
============
Xen is a Virtual Machine Monitor (VMM) originally developed by the
Systems Research Group of the University of Cambridge Computer
Laboratory, as part of the UK-EPSRC funded XenoServers project. Xen
is freely-distributable Open Source software, released under the GNU
GPL. Since its initial public release, Xen has grown a large
development community, spearheaded by xen.org (http://www.xen.org).
The 4.2 release offers excellent performance, hardware support and
enterprise-grade features such as x86_32-PAE, x86_64, SMP guests and
live relocation of VMs. Ports to Linux, NetBSD, FreeBSD and Solaris
are available from the community.
This file contains some quick-start instructions to install Xen on
your system. For full documentation, see the Xen User Manual. If this
is a pre-built release then you can find the manual at:
dist/install/usr/share/doc/xen/pdf/user.pdf
If you have a source release, then 'make -C docs' will build the
manual at docs/pdf/user.pdf.
Quick-Start Guide
=================
First, there are a number of prerequisites for building a Xen source
release. Make sure you have all the following installed, either by
visiting the project webpage or installing a pre-built package
provided by your OS distributor:
* GCC v3.4 or later
* GNU Make
* GNU Binutils
* Development install of zlib (e.g., zlib-dev)
* Development install of Python v2.3 or later (e.g., python-dev)
* Development install of curses (e.g., libncurses-dev)
* Development install of openssl (e.g., openssl-dev)
* Development install of x11 (e.g. xorg-x11-dev)
* Development install of uuid (e.g. uuid-dev)
* bridge-utils package (/sbin/brctl)
* iproute package (/sbin/ip)
* hotplug or udev
* GNU bison and GNU flex
* GNU gettext
* 16-bit x86 assembler, loader and compiler (dev86 rpm or bin86 & bcc debs)
* ACPI ASL compiler (iasl)
Second, you need to acquire a suitable kernel for use in domain 0. If
possible you should use a kernel provided by your OS distributor. If
no suitable kernel is available from your OS distributor then refer to
http://wiki.xen.org/xenwiki/XenDom0Kernels for suggestions for
suitable kernels to use.
If you are looking to compile a Dom0 kernel from source, please refer to
http://wiki.xensource.com/xenwiki/XenParavirtOps.
[NB. Unless noted otherwise, all the following steps should be
performed with root privileges.]
1. Download and untar the source tarball file. This will be a
file named xen-unstable-src.tgz, or xen-$version-src.tgz.
You can also pull the current version from the mercurial
repository at http://xenbits.xen.org/
# tar xzf xen-unstable-src.tgz
Assuming you are using the unstable tree, this will
untar into xen-unstable. The rest of the instructions
use the unstable tree as an example, substitute the
version for unstable.
2. cd to xen-unstable (or whatever you sensibly rename it to).
3. For the very first build, or if you want to destroy build trees,
perform the following steps:
# make world
# make install
This will create and install onto the local machine. It will build
the xen binary (xen.gz), the tools and the documentation.
You can override the destination for make install by setting DESTDIR
to some value.
4. To rebuild an existing tree without modifying the config:
# make dist
This will build and install xen, tools, and docs into the local dist/
directory.
You can override the destination for make install by setting DISTDIR
to some value.
make install and make dist differ in that make install does the
right things for your local machine (installing the appropriate
version of hotplug or udev scripts, for example), but make dist
includes all versions of those scripts, so that you can copy the dist
directory to another machine and install from that distribution.
Python Runtime Libraries
========================
Xend (the Xen daemon) has the following runtime dependencies:
* Python 2.3 or later.
In some distros, the XML-aspects to the standard library
(xml.dom.minidom etc) are broken out into a separate python-xml package.
This is also required.
In more recent versions of Debian and Ubuntu the XML-aspects are included
in the base python package however (python-xml has been removed
from Debian in squeeze and from Ubuntu in intrepid).
URL: http://www.python.org/
Debian: python
* For optional SSL support, pyOpenSSL:
URL: http://pyopenssl.sourceforge.net/
Debian: python-pyopenssl
* For optional PAM support, PyPAM:
URL: http://www.pangalactic.org/PyPAM/
Debian: python-pam
* For optional XenAPI support in XM, PyXML:
URL: http://codespeak.net/lxml/
Debian: python-lxml
YUM: python-lxml
Intel(R) Trusted Execution Technology Support
=============================================
Intel's technology for safer computing, Intel(R) Trusted Execution Technology
(Intel(R) TXT), defines platform-level enhancements that provide the building
blocks for creating trusted platforms. For more information, see
http://www.intel.com/technology/security/.
Intel(R) TXT support is provided by the Trusted Boot (tboot) module in
conjunction with minimal logic in the Xen hypervisor.
Tboot is an open source, pre- kernel/VMM module that uses Intel(R) TXT to
perform a measured and verified launch of an OS kernel/VMM.
The Trusted Boot module is available from
http://sourceforge.net/projects/tboot. This project hosts the code in a
mercurial repo at http://tboot.sourceforge.net/hg/tboot.hg and contains
tarballs of the source. Instructions in the tboot README describe how
to modify grub.conf to use tboot to launch Xen.
There are optional targets as part of Xen's top-level makefile that will
download and build tboot: install-tboot, build-tboot, dist-tboot, clean-tboot.
These will download the latest tar file from the SourceForge site using wget,
then build/install/dist according to Xen's settings.