I have now updated xen on Fedora 20 to version 4.3.0. I have built it with
the XSM/FLASK security subsystem available if you add a xenpolicy file as
a module in the grub configuration. Note that the xen-hypervisor package
on i686 is currently empty because it was dropped in this version, but a
32-bit dom0 should work on a 64-bit hypervisor if your hardware supports
I was posting a couple weeks back here, asking questions about getting
DomUs working in Xen when installing Xen from source.
Well, I have managed to get things working. Currently my setup is like this
Xen 4.2.2, installed from source,
Fedora 18 Dom0 x86_64, Debian 6 PV DomU x86_64, and Ubuntu 12.04 HVM DomU
My processor has Intel VT-X enabled.
I used xl/xm to create DomUs. I was unable to get virt-manager working to
I faced a similar problem with Xen 4.1 and Fedora 17 earlier.
As the next step in my project, I want to log some system call information.
Basically, every time a system call is made in my PV DomU, I just want to
print a line like "System call made from DomU, systemcall id = xx". That is
all I need for now.
I have some questions regarding the same.
1. This might be a stupid question, but here goes.
After I modify source code, should I do the whole compilation/install
process to see my changes.
ie. should i do "make and install xen, tools and stubdom" or will "make and
install xen" suffice ?
2. How is the system call flow happening in Xen?
Where in the code is the system call being intercepted by the hypervisor
for a PV DomU. ?
I found some information from this paper,
but still am not clear about the whole picture.
Is there documentation available explaining for how system calls are
handled in Xen ?
The Xen code is quite large, and I am sorry to say I get lost reading it
without some kind of knowledge.
3. How to log data?
I see printk statements in the code. Are printk statements tied to a
certain logging level ? Should I add "loglvl=all guest_loglvl=all" to my
Dom0 grub to see the output from printk statements ?
Also, which output file should I be seeing for my scenario?
I apologize for the long email.
Please take some time out and kindly reply.
Go get it! :-)
-------- Forwarded Message --------
From: George Dunlap
To: xen-devel@, xen-users@
Date: Tue, 9 Jul 2013 14:01:17 +0100
The Xen Project team is pleased to announce the release of Xen 4.3.
The result of nearly 10 of development, new features include:
* Early support for ARM 32- and 64-bit architectures
* qemu-upstream is now the default for VMs not using stub domains.
* openvswitch hot-plug script support.
* NUMA affinity for the scheduler
* xl can now accept several USB devices, rather than only one.
* XSM improvements. XSM can now override all IS_PRIV checks in the hypervisor.
* As always, a number of stability, performance, and security
enhancements "under the hood".
Detailed release notes, including a more extensive feature list:
To download tarballs:
Or the git source repository (tag 'RELEASE-4.3.0'):
And the announcement on the Xen blog:
Thanks to the many people who have contributed to this release!
The Xen Project Team
<<This happens because I choose it to happen!>> (Raistlin Majere)
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)