Xen 4.2 Release Notes
Xen 4.2 contains many new features and improvements to existing functionality. Changes include improvements to Security, Scalability, Performance, RAS, Documentation and to the toolstack.
For a list of new features and changes see Xen 4.2 Feature List.
The previous Xend toolstack is now formally deprecated and should be expected to be removed in the 4.3 timescale. Therefore it is strongly recommended that users evaluate Xen 4.2 with XL for their use case and report any omissions or blockers such that they can be addressed for 4.3.
The requirements for building Xen are documented in the README file in the Xen source tree.
Some additional build dependencies have been added since Xen 4.1:
- markdown (optional)
In addition Xen will now prefer to use the system wide libaio if it is available. If libaio is not installed then an intree version will be used. Users are strongly encouraged to install their distribution's version of libaio.
An additional step has also been added to the build process. It is now necessary to run:
before building the tools (e.g. make tools, make world, make dist etc).
As a consequence of this change Xen now defaults to installing libraries into /usr/lib by default. Users on systems which use /usr/lib64 for 64-bit libraries should use the --libdir option. e.g:
$ ./configure --libdir=/usr/lib64
On systems running a 32-bit hypervisor xl info will report incorrectly report large values for sharing_used_memory and sharing_freed_memory. Memory sharing is not supported on the 32-bit hypervisor and these should read zero.