Muli Ben-Yehuda's Journal|
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Below are the 20 most recent journal entries recorded in
Muli Ben-Yehuda's LiveJournal:
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|Thursday, February 3rd, 2011|
|Tuesday, October 5th, 2010|
You know it's a good day when you get to use angry turtle in a presentation. Angry turtle is angry!
|Monday, October 4th, 2010|
I was hurrying down the Newark airport terminal, wondering whether I
was going to make the connecting flight to Seattle, en-route to
Vancouver for the 9th USENIX
Symposium on Operating Systems Design and
. Suddenly, my cell phone rang. It
, a long-time co-worker and mentor. "Have you seen the
email?" "No, I just landed in Newark and am on the way to catch a
connection to Seattle. Which email?" "Here, let me read you the
Your paper has been selected as one of two
winners of the OSDI Jay
Lepreau Best Paper award."
Receiving this award is a unique experience and a great honor. It is
doubly sweet because of all the research projects I've worked on, the
Turtles nested virtualization project is perhaps the one I am most
proud of. When Orit, Ben, and I started working on it in 2008, we set
out to do the impossible. Many colleagues claimed that efficient
nested x86 virtualization on the Intel platform could not be
done. Eventually, working long and hard, and with help from friends,
we showed that not only could it be done, it even performs well. I've
learned a lot in the process, about x86 virtualization, about leading
a team, and about the art and craft doing research, but the most
important lesson was to never lose hope, to always believe that
eventually, it will work. And guess what? It did!
If you want to know how we did it, and what we learned in the process,
check out The Turtles
Project: Design and Implementation of Nested Virtualization.
In classical machine virtualization, a hypervisor runs multiple
operating systems simultaneously, each on its own virtual machine. In
nested virtualization a hypervisor can run multiple other
hypervisors with their associated virtual machines. As operating
systems gain hypervisor functionality---Microsoft Windows 7 already
runs Windows XP in a virtual machine---nested virtualization will
become necessary in hypervisors that wish to host them. We present the
design, implementation, analysis, and evaluation of high-performance
nested virtualization on Intel x86-based systems. The Turtles project,
which is part of the Linux/KVM hypervisor, runs multiple
unmodified hypervisors (e.g., KVM and VMware) and operating
systems (e.g., Linux and Windows). Despite the lack of architectural
support for nested virtualization in the x86 architecture, it can
achieve performance that is within 6-8\% of single-level (non-nested)
virtualization for common workloads, through multi-dimensional
paging for MMU virtualization and multi-level device
assignment for I/O virtualization.
The scientist gave a superior smile before replying, ``What
is the tortoise standing on?'' ``You're very clever, young man, very
clever'', said the old lady. ``But it's turtles
all the way down!''
|Monday, September 6th, 2010|
|Tuesday, November 17th, 2009|
|interesting call for papers
I have been remiss in updating this thing recently. In penance, I
offer you these interesting call for papers from conferences that you
should, without a doubt, submit your best papers to:
Workshop on I/O Virtualization, which I will be co-chairing, will
be co-located with ASPLOS 2010 and VEE 2010 in
Pittsburgh, Pennsylvania, in March 2010. Once again we will be looking for
and thought-provoking papers in I/O virtualization,
although if your paper is only ground-breaking or only thought
provoking, that's fine too.
International Conference on Supercomputing (ICS'10) will be held
in Japan (Japan!) in June 2010. We are soliciting papers on all
aspects of research, development, and application of high-performance
experimental and commercial systems. This will be my first time on the
ICS PC, and I am looking forward to the experience.
Last but certainly not least, SYSTOR
2010---The 3rd Annual Haifa Experimental Systems Conference, will
be held once again in Haifa in May, 2010, and you should all come
Current Mood: tired
|Tuesday, April 7th, 2009|
|SYSTOR 2009 Call for Participation
CALL FOR PARTICIPATION
SYSTOR 2009---The Israeli Experimental Systems Conference
4-6 May 2009
Registration deadline: May 2nd
SYSTOR 2009, the Israeli Experimental Systems Conference, will be held
at IBM Haifa Labs, in Haifa, Israel. The conference program will run
over three days, combining the forefront of academic systems research
with real-world systems developed in industry. The goal of the
conference is to promote systems research and to foster stronger ties
between the Israeli and worldwide systems research communities and
industry. Conference proceedings will be published by ACM in the ACM
There is a limited number of seats available on a
first-come-first-served basis upon registration at
(registration is free of charge). Lunch and refreshments will be
served on all three days courtesy of IBM Haifa Labs.
The first day of the conference will feature sessions on distributed
systems, concurrency, and power management. Marc Snir, University of
Illinois at Urbana Champaign, will give a keynote talk, and in the
afternoon a student poster session with sweet refreshments will be
The second day will begin with the keynote "Towards Invisible Storage"
by Alain Azagury, Director, XIV Business Executive, IBM, and an
invited talk on "The Next Generation Data Center" by Michael Kagan,
Mellanox CTO. After the morning talks, there will be paper sessions
focusing on data de-duplication and storage issues. The day will end
with an optional social event in Caesarea.
The third day will conclude the conference with paper sessions on
virtualization and system optimizations, and a panel of well-known
systems researchers who will debate "What is Systems Research about
and is it Relevant?" The full program for all three days is available
on the conference website.
We look forward to seeing you at SYSTOR 2009!
SYSTOR Advisory Committee
* Marc Auslander, IBM
* Ken Birman, Cornell
* Danny Dolev, HUJI
* Julian Satran, IBM
* Marc Snir, UIUC
* Willy Zwaenepoel, EPFL
* Michael Factor, IBM
* Dror Feitelson, HUJI
* Miriam Allalouf, IBM
* Muli Ben Yehuda, IBM
* Gregory Chockler, IBM
|Sunday, April 5th, 2009|
I want to update this thing more often, but there's so much going on, the days filled with action and counter-action, that before I know it it's past midnight, and I have to wake up at 5 AM for a workout, and updating the blog is left on the TODO list for yet another day. Like, today.
I've been a manager for a month and change now, managing the virtualization and systems architecture group at the lab
. It's an interesting challenge (which is why I agreed to do it), often frustrating, occasionally exhilarating. To my surprise, the part I like most is dealing with human beings in their myriad forms. To my non-surprise, the part I like least is the bureaucracy, but I figured I'd wait a couple more months before I start tilting at wind-mills. I still write code (well, debug code, mostly) and conduct research, but it's no longer the most important part of my day.
On the research front, we had two papers accepted to ICAC 2009
(one full paper and one short paper/poster), both in the general area of treating virtual machines as black boxes and inferring useful things about them---performance bottlenecks and boot-time--via statistical analysis of their inputs and outputs. Another paper, on the DMA mapping problem in direct assignment, was not accepted to USENIX ATC to my disappointment, and we are now revising it while looking for a new home.
I am continuing to work out twice a week with a private trainer who is seriously kicking my butt. It's rare when I don't finish a workout on the brink of exhaustion, drenched in sweat. I *love* it. Twice a week is no longer enough---I crave the endorphin rushes and sore muscles---so I've also re-started going for long walks, and hitting the punching bag in the back-yard like I really mean it. The kilograms are coming off, too, an added bonus.
Last but not least, SYSTOR 2009
is coming up next month, with a great program
combining academic research and real-world systems. See y'all there!
|Wednesday, January 28th, 2009|
It's 5:40 AM. I am is sitting in an empty room full of half-assembled furniture, waiting for the personal trainer to arrive and whip my ass into shape.
|Tuesday, December 23rd, 2008|
There will be a half-day workshop at the Technion's EE department on Thursday afternoon on "Technology Transfer - from Academy to Industry"
which looks mildly interesting. I am on nominally on vacation this week and flying to Italy that night, but perhaps I'll go anyway. Anyone else planning to go?
|Wednesday, December 10th, 2008|
|Scalable I/O paper online
Our new paper is online: "Scalable I/O---A
Well-Architected Way to Do Scalable, Secure and Virtualized I/O"
by Julian Satran, Leah Shalev, Muli Ben-Yehuda, and Zorik
Machulsky. This is an overview paper showcasing the main ideas
underlying a system we've been working on on and off since 2004. It's
not as detailed as I would've liked due to the space constraints, but
hopefully it will be followed by more detailed papers. The
I'll be presenting later today at WIOV '08
are also available
and go into a bit more details in areas.
Today in both virtualized and non-virtualized systems the entire I/O
functionality is based on device drivers. They are central to any
system structure; both anecdotal and informed evidence indicates
device drivers as a major source of trouble in the classical OS and a
source of scaling and performance issues in virtual I/O, due to
"trusted intermediary" required for the shared I/O. We propose an
architecture which virtualizes the entire I/O subsystem rather than
each I/O device, and provides device-independent I/O at higher level
of abstraction than the traditional I/O interfaces. In our suggested
architecture the system robustness is increased by isolating drivers;
efficient and scalable virtualization becomes possible by a complete
separation of the I/O and compute function and introducing a
protection model that does not require a trusted intermediary for
|Monday, November 24th, 2008|
|new IOMMU paper available
New online for your perusing pleasure: "Direct
Device Assignment for Untrusted Fully-Virtualized Virtual
, by Ben-Ami Yassour, Muli Ben-Yehuda and Orit Wasserman,
IBM Research Report H-0263.
This is a short paper describing and evaluating our work earlier this
year on direct device assignment in KVM, using Intel's VT-d IOMMU. Not
much new here if you've read our other IOMMU papers, but it does make
two contributions. First, it's the best (and only) available
description (IMHO) of KVM's direct device assignment code, and second
it's yet another data point on the relative performance of device
emulation vs. virtual I/O drivers vs. direct device assignment. As
always, comments appreciated. The abstract follows.
The I/O interfaces between a host platform and a guest virtual machine
take one of three forms: either the hypervisor provides the guest with
emulation of hardware devices, or the hypervisor provides virtual I/O
drivers, or the hypervisor assigns a selected subset of the host's
real I/O devices directly to the guest. Each method has advantages and
disadvantages, but letting VMs access devices directly has a number of
particularly interesting benefits, such as not requiring any guest VM
changes and in theory providing near-native performance.
In an effort to quantify the benefits of direct device access, we have
implemented direct device assignment for untrusted, fully-virtualized
virtual machines in the Linux/KVM environment using Intel's VT-d
IOMMU. Our implementation required no guest OS changes and---unlike
alternative I/O virtualization approaches---provided near native I/O
performance. In particular, a quantitative comparison of network
performance on a 1GbE network shows that with large-enough messages
direct device access throughput is statistically indistinguishable
from native, albeit with CPU utilization that is slightly higher.
|Wednesday, October 22nd, 2008|
|notes for Sunday Oct 20 through Tuesday Oct 22nd
This is not serious, I'm supposed to remember what I was doing three days ago? I can barely remember what I had for breakfast this morning.
I started walking again in the mornings. Today I was up before the crack of dawn for a brisk walk on the sea shore, and when I got back home, I even had enough energy left for a few rounds with the boxing bag. Finished reading Haruki Murakami, and now re-reading Living the Martial Way
. It's a funny little book, so earnest it's hard to take it seriously, but with nuggets of wisdom nonetheless.
|Sunday, October 19th, 2008|
|notes for Thursday Oct 16 through Saturday Oct 18
Thursday: just another day at work . In the afternoon, went to meet an amazing carpenter (US: cabinet maker). Spent three hours going over the plans in minute detail, making lots of changes, and then he told us how much it was going to cost. Staggered to Noga's cauldron for a late dinner.
Friday: BBQ with old friends at Ira's
. Once upon a time it would've been all Linux hacking, all the time, but now business and what the kids are doing is that much more interesting. Progress, of a sort.
Saturday: a day of rest and recuperation. In the evening off to Mika's 1-year old birthday party. I still remember the sense of accomplishment we felt at Yael's 1-year old birthday party, that we actually managed to raise her and she is fine. Resumed reading Haruki Murakmi's What I Talk About When I Talk About Running
|Thursday, October 16th, 2008|
|notes for Wednesday Oct 15
A day of odds and ends. The WIOV
schedule should be going up today or tomorrow. Continued looking into the feasibility of a new project which will require coordination with an inordinate amount of people. Worked on a bunch of new patent disclosures. Hacked a bit on a new idea for IOTLB design until the serial port server stopped giving me love, and then went into paper reading mode
|Wednesday, October 15th, 2008|
|notes for Tuesday Oct 14
Lunch with the Tel-Aviv, business oriented, brunch of the family in their nice new house. In the evening didn't feel like doing much of anything; ended up de-cluttering my publications
|Tuesday, October 14th, 2008|
|notes for Monday Oct 13
More work on the nap and vnic papers in the morning, making progress toward their respective deadlines. In the evening BBQ---fillet mignon and a good wine---with my folks in our garden.
|Sunday, October 12th, 2008|
|notes for Sunday Oct 12
Woke up bleary eyed, but settled into a productive day at the office debugging by proxy and reviewing a couple of draft papers (vnic and nap). In the evening got some work done on the secret project, too.