Uncategorized
I’ve started to work on the Xen on ARM project by trying to get Xen running on the nice little Samsung Chromebook which run an ARM processor with the virtualization extensions. The Chromebook uses Exynos 5250 dual core platform with 2GB of RAM, which could be perfect for a
Announcements
We proudly announce that the Xen 4.3 RC-cycle has just started, with the tagging of 4.3.0-rc1 in our repository. Read the official announcement from George on xen-devel here. A tarball has been made available for ease and speed-up testing: Xen 4.3.0 RC1 Tarball (andÂ
Uncategorized
The following has been posted on the xen-devel and xen-users mailing lists. Executive summary The number of event channels available for dom0 is currently one of the biggest limitations on scaling up the number of VMs which can be created on a single system. There are two alternative implementations we
Uncategorized
Background and Motivation This blog already hosted a couple of stories about what is going on, in the Xen development community, regarding improving Xen NUMA support. Therefore, if you really are interested in some background and motivation, feel free to check them out: * NUMA and Xen: Part I, Introduction * NUMA
Uncategorized
As machines are getting more and more powerful today, people want more from the powerful hardware. From a cloud user’s perspective, it is better to run more virtual machines on a single host. Xen currently supports running hundreds of guests on a single physical machine, but we plan to
policy
We do some automatic testing of the Xen hypervisor and tools branches. These tests form the “push gate” between the “staging” branch of xen-unstable (and the stable releases) and the non-staging branches. Changes are committed to non-staging, and if the tests pass, the test system pushes them through to staging.
Uncategorized
What is Valgrind? Valgrind is a framework for building dynamic analysis tools. Several useful tools are included in the Valgrind distribution including tools to check dynamic memory usage (memcheck), a cache profiler (cachegrind), heap profiler (massif) and thread debugger (helgrind) among others. Valgrind also provides a framework which can be
Uncategorized
The blkback/blkfront drivers developed by the original Xen team was lightweight and fast zero-copy protocol that has served well for many years. However, as the number of physical cores and the number of guests have increased on systems, we have begun to identify some bottlenecks to scalability. This prompted
Uncategorized
The Xen community achieved a major milestone last summer when all the necessary components for Xen dom0 support made it into the upstream kernel for the 3.0 release. However, during that process developers were focused on functionality, and not on performance. As a result a handful of performance regressions
Uncategorized
The Xen Security team recently disclosed a vulnerability, Xen Security Advisory 7 (CVE-2012-0217), which would allow guest administrators to escalate to hypervisor-level privileges. The impact is much wider than Xen; many other operating systems seem to have the same vulnerability, including NetBSD, FreeBSD, some versions of Microsoft Windows (including Windows
Uncategorized
This post written collaboratively by Attilio Rao and George Dunlap Operating systems are generally written assuming that they are in direct control of the hardware. So when we run operating systems in virtual machines, where they share the hardware with other operating systems, this can sometimes cause problems. One of
Uncategorized
If you are upgrading domain 0 Linux kernel from a non-pvops (classic, 2.6.18/2.6.32/etc.) kernel to a pvops one (3.0 or later), you may find that the amount of free memory inside dom0 has decreased significantly. This is because of changes in the