Monthly Archives: May 2017

Automotive, Security and the Future of the Xen Project at The Xen Project Developer and Design Summit

The Xen Developer and Design Summit schedule is now live! This conference combines the formats of the Xen Project Developer Summits with the Xen Project Hackathons. If you are part of the Xen Project’s community of developers and power users, come join us in Budapest, Hungary, July 11 – 13 for this must-attend event!

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The conference will cover many different topic areas including community, embedded/automotive, performance, tooling, hardware, security and more. The format will include traditional panels and presentation, as well as design and problem solving sessions.

Design and problem solving session proposals will be accepted until July 7. This is a great way to meet other developers face-to-face to:

  • Discuss and advance the design and architecture of future functionality
  • Coordinate and plan upcoming features
  • Discuss and share best practices and ideas on how to improve community collaboration
  • Hear interactive sessions covering lessons learned from contributors, users and vendor

Submit your design and problem solving ideas here.

Keynotes this year are coming from Lars Kurth, Xen Project Chairperson and Director of Open Source Solutions at Citrix; Oleksandr Andrushchenko, Lead Software Engineer at EPAM Systems; Stefano Stabellini, Virtualization Architect at Aporeto; and Wei Liu, Senior Software Engineer at Citrix.

Here’s a small sampling of other speaking sessions during the conference:

Automotive

  • Dedicated Secure Domain as an Approach for Certification of Automotive Sector Solutions from Iurii Mykhalskyi of GlobalLogic
  • Harmony of CPU Scheduling Between RT Guest OS and Rich Guest OS in Automotive Virtualization from Sangyun Lee of LG Electronics

Security

  • Hypervisor-Based Security: Bringing Virtualized Exceptions Into the Game from Mihai Dontu of Bitdefender
  • Uniprof: Transparent Unikernel Performance Profiling and Debugging from Florian Schmidt of NEC

Future of Xen

  • Intel GVT-g: From Production to Upstream from Zhi Wang of Intel
  • Recent and Ongoing Xen Related Work in the Linux Kernel from Jürgen Groß of SUSE

General Hypervisor

  • Bring up PCI Passthrough on ARM from Julien Grall of ARM
  • EFI Secure Boot, Shim and Xen: Current Status of Developments from Daniel Kiper of Oracle

You can view the entire schedule here. Early bird specials for tickets (price is $250) are available until May 31st.

A special thank you to our Diamond Sponsor Citrix and Gold sponsors ARM, Intel and Superfluidity. We look forward to seeing you at the event in July, and please stay informed on Xen Project updates by following us on social (Twitter and Facebook) and registering to our xen-announce mailing list.

 

Announcing the Windows PV Console Driver

It has long been the case that all HVM guests under Xen are provided with a PV console. You can attach to this console in the same way that you attach to the console of a PV guest, by typing in the control domain:

xl console name_of_guest

Until recently there has been no Windows PV driver interaction with this console. Starting with this commit support for logging via the PV console was added to the XENBUS driver.

I’m happy to announce that the three commits to XENBUS starting with this one added the necessary infrastructure to support a brand new XENCONS PV driver which exposes the PV console to Windows user-space as a character device.

The XENCONS driver source is hosted alongside the other PV driver sources on xenbits.xen.org and development builds are available for download here.

The XENCONS package also contains a Windows service to monitor the presence of the PV console device and invoke a command shell login process with redirected stdin/stdout. This means that, once the driver package has been installed, if you attach to the PV console and hit ENTER you’ll see a prompt something like this:

DESKTOP-KVEHAKT login:

From this prompt you can log in as any local user and you’ll then be presented with the command shell:

DESKTOP-KVEHAKT login: User
Password:
Microsoft Windows [Version 10.0.15063]
(c) 2017 Microsoft Corporation. All rights reserved.

C:\Users\User>

Be aware that this shell is running in session 0 so does not have access to the interactive session, but you can still use it for many administrative tasks. For instance, you can run netsh to display aspects of your network configuration:


C:\Users\User>netsh
netsh>interface ipv4 show global
Querying active state...

General Global Parameters
---------------------------------------------
Default Hop Limit : 128 hops
Neighbor Cache Limit : 256 entries per interface
Route Cache Limit : 4096 entries per compartment
Reassembly Limit : 33420160 bytes
ICMP Redirects : enabled
Source Routing Behavior : dontforward
Task Offload : enabled
Dhcp Media Sense : enabled
Media Sense Logging : disabled
MLD Level : all
MLD Version : version3
Multicast Forwarding : disabled
Group Forwarded Fragments : disabled
Randomize Identifiers : enabled
Address Mask Reply : disabled
Minimum Mtu : 576
Locality Address Selection : disabled
Flow Label : disabled

Current Global Statistics
---------------------------------------------
Number of Compartments : 1
Number of NL clients : 7
Number of FL providers : 4

Over the coming weeks I intend to add to the functionality that the driver provides. One obvious extension would be some form of hotkey support to link into the XENBUS_DEBUG interface to enable PV drivers to register a callback to be triggered by a particuler key.

If you are interested in this then please try the XENCONS package and send feedback to the mailing list.

Updates on XSA-213, XSA-214 and XSA-215

Today we released three patches for the following vulnerabilities: XSA-213, XSA-214 and XSA-215. Xen Project follows industry-accepted best practices regarding software security. This includes observing an embargo period, during which time the Xen Project security team will assess, respond, and prepare patches fixing the vulnerability, and distribute them privately to software and cloud providers before the public disclosure occurs.

When issuing a Xen Project Security Advisory (XSA), during the embargo this advisory is pre-disclosed to only members on the Xen Project Pre-Disclosure List. Vendors and open source projects who are on the Xen Project pre-disclosure list will not be affected by this security vulnerability and have updated their systems. The Xen Project security team has created fixes for these vulnerabilities, which can be publicly downloaded here: http://xenbits.xen.org/xsa/

Public cloud providers on the Xen Project predisclosure list were notified of these vulnerabilities two weeks ago; if your public cloud provider is on the list it is likely that your VMs are not vulnerable. Distributions and other software providers were also notified; they should have updated packages available soon (if they are not available already).

All three vulnerabilities have the potential to enable a guest virtual machine to break out of the hypervisor isolation. However, in order to exploit this vulnerability, an attacker would need to be running code in kernel mode of one or more VMs on the system. Any system that allows untrusted users to run arbitrary kernels will be particularly vulnerable.

Systems which only allow trusted users (such as IT professionals employed by the company) to run arbitrary kernels are less vulnerable, because an attacker would first need to find one or more exploit in the software running on one of the VMs before being able to then exploit this vulnerability. However, all users are encouraged to update as soon as possible.

Any 64-bit PV guest can exploit the vulnerability with XSA-213. The other two are more constrained. XSA-214 requires an attacker to control two different kinds of guests (either a PV one and an HVM one or a 32-bit PV one and 64-bit PV one). XSA-215 only affects you if your host has a very large amount of memory (either 3.5 TiB or 5 TiB depending on configuration).

Again, even with these constraints, we encourage you to update as soon as possible.

We take security very seriously and have developed security process best practices that are aimed for cloud environments that maximize fairness and transparency. We also have a very strict standard of review when it comes to new code being added to the Xen Project. We run Coverity static analyzer regularly to prevent certain classes of programming errors from being introduced. Additionally, we regularly run a generational fuzzing tool on our instruction emulator.

The Xen Project community developed Live Patching and introduced it into Xen Project 4.7. Now security fixes can be deployed without having to reboot VMs or have significant spare compute capacity to avoid reboots via VM migration.

These vulnerabilities were discovered by Jann Horn, from Google Project Zero.