<htmlxmlns="http://www.w3.org/1999/xhtml"><head><metahttp-equiv="Content-Type"content="text/html; charset=ISO-8859-1"/><linkrel="stylesheet"type="text/css"href="libvirt.css"/><linkrel="SHORTCUT ICON"href="/32favicon.png"/><title>libvirt architecture</title></head><body><divid="container"><divid="intro"><divid="adjustments"></div><divid="pageHeader"></div><divid="content2"><h1class="style1">libvirt architecture</h1><p>Currently libvirt supports 2 kind of virtualization, and its
internal structure is based on a driver model which simplifies adding new
connect to initialize the library. It will then fork a libvirt_proxy
program running as root and providing read_only access to the API, this is
then only useful for reporting and monitoring.</p><h3><aname="QEmu"id="QEmu">Libvirt QEmu and KVM support</a></h3><p>The model for QEmu and KVM is completely similar, basically KVM is based
on QEmu for the process controlling a new domain, only small details differs
between the two. In both case the libvirt API is provided by a controlling
process forked by libvirt in the background and which launch and control the
QEmu or KVM process. That program called libvirt_qemud talks though a specific
protocol to the library, and connects to the console of the QEmu process in
order to control and report on its status. Libvirt tries to expose all the
emulations models of QEmu, the selection is done when creating the new
domain, by specifying the architecture and machine type targetted.</p><p>The code controlling the QEmu process is available in the
<code>qemud/</code> directory.</p><h3><aname="drivers"id="drivers">the driver based architecture</a></h3><p>As the previous section explains, libvirt can communicate using different
channels with the current hypervisor, and should also be able to use
different kind of hypervisor. To simplify the internal design, code, ease
unsupported functions are initialized to NULL.</p><p></p></div></div><divclass="linkList2"><divclass="llinks2"><h3class="links2"><span>main menu</span></h3><ul><li><ahref="index.html">Home</a></li><li><ahref="news.html">Releases</a></li><li><ahref="intro.html">Introduction</a></li><li><ahref="architecture.html">libvirt architecture</a></li><li><ahref="downloads.html">Downloads</a></li><li><ahref="format.html">XML Format</a></li><li><ahref="python.html">Bindings for other languages</a></li><li><ahref="errors.html">Handling of errors</a></li><li><ahref="FAQ.html">FAQ</a></li><li><ahref="bugs.html">Reporting bugs and getting help</a></li><li><ahref="remote.html">Remote support</a></li><li><ahref="uri.html">Connection URIs</a></li><li><ahref="hvsupport.html">Hypervisor support</a></li><li><ahref="html/index.html">API Menu</a></li><li><ahref="examples/index.html">C code examples</a></li><li><ahref="ChangeLog.html">Recent Changes</a></li></ul></div><divclass="llinks2"><h3class="links2"><span>related links</span></h3><ul><li><ahref="https://www.redhat.com/archives/libvir-list/">Mail archive</a></li><li><ahref="https://bugzilla.redhat.com/bugzilla/buglist.cgi?product=Fedora+Core&component=libvirt&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_status=MODIFIED&short_desc_type=allwordssubstr&short_desc=&long_desc_type=allwordssubstr">Open bugs</a></li><li><ahref="http://virt-manager.et.redhat.com/">virt-manager</a></li><li><ahref="http://search.cpan.org/~danberr/Sys-Virt-0.1.0/">Perl bindings</a></li><li><ahref="http://libvirt.org/ocaml/">OCaml bindings</a></li><li><ahref="http://libvirt.org/ruby/">Ruby bindings</a></li><li><ahref="http://www.cl.cam.ac.uk/Research/SRG/netos/xen/index.html">Xen project</a></li><li><formaction="search.php"enctype="application/x-www-form-urlencoded"method="get"><inputname="query"type="text"size="12"value="Search..."/><inputname="submit"type="submit"value="Go"/></form></li><li><ahref="http://xmlsoft.org/"><imgsrc="Libxml2-Logo-90x34.gif"alt="Made with Libxml2 Logo"/></a></li></ul><pclass="credits">Graphics and design by <ahref="mail:dfong@redhat.com">Diana Fong</a></p></div></div><divid="bottom"><pclass="p1"></p></div></div></body></html>