Re: obsd as domU?

2010-05-20 Thread Kenneth R Westerback
On Wed, Jan 13, 2010 at 10:10:16AM -0700, Diana Eichert wrote:
 Chuckle, try to troubleshoot a network issue when it is in a
 virtual network.  Lots of fun, not.
 
 diana

Better yet, get told by management NOT to troubleshoot but let the
outsourcers do it. While your whole hospital is down for 7 hours.

Not that that would really happen.

 Ken



Re: obsd as domU?

2010-01-18 Thread SJP Lists
2010/1/13 Ciprian Dorin, Craciun ciprian.crac...@gmail.com:

 3.) Many of the benefits you gain by running a stable and secure
 operating system like OpenBSD are lost when you run it as a guest on
 top of some other insecure host operating system.

This is only true if either:
* there is a security bug in the virtualization software (highly
 improbable, and maybe easibly fixed);

http://taviso.decsystem.org/virtsec.pdf

No virtual machine tested was robust enough to withstand the testing
procedure used, and multiple exploitable flaws were presented that
could allow an attacker restricted to a virtualised environment to
reliably escape onto the host system.


http://www.vmware.com/security/advisories/VMSA-2009-0006.html

A critical vulnerability in the virtual machine display function
might allow a guest operating system to run code on the host.


http://www.vmware.com/security/advisories/VMSA-2008-0019.html

A memory corruption condition may occur in the virtual machine
hardware. A malicious request sent from the guest operating system to
the virtual hardware may cause the virtual hardware to write to
uncontrolled physical memory.


Shane



Re: obsd as domU?

2010-01-13 Thread bofh
On Wed, Jan 13, 2010 at 2:08 AM, Eric Furman ericfur...@fastmail.net wrote:
 On Wed, 13 Jan 2010 08:31 +0200, Ciprian Dorin, Craciun
 ciprian.crac...@gmail.com wrote:

 Sorry, but you guys from OpenBSD have proved that you can trust
 the skills of **some** developers to write an __supposed__ perfectly
 secure operating system, so why not trust other developers to write
 a __supposed__ secure software emulation with the help of hardware.
 (Let me say it more simply: we have trust in you, but why don't you
 have the disposition to trust in others?)

How did you guys... have proved that you can trust the skills turn
into we can trust virtualization developers.  Since when have the
virtualization developers demonstrated that tust?

  2.) If systems and application software runs fine on real hardware, but
  fails to run on emulated/virtualized hardware, then the problem is in
  the virtualization software. --In other words, take questions and
  complaints to the vendor of your virtualization software.

 Agree. This is the same as with software: if software runs
 perfectly on one version of OpenBSD, but not on another it does not
 mean that its the fault of the new version. (But Xen is not all about
 emulation, it cooperates with the guest kernel, so in this case the
 blame could be on both sides.)

 Wrong. If it works on real hardware and fails in virtualization
 the virtualization software is *always* to blame.

I think he's thinking of para virtualization, which open bsd doesn't do,
iirc.

  3.) Many of the benefits you gain by running a stable and secure
  operating system like OpenBSD are lost when you run it as a guest on
  top of some other insecure host operating system.

 This is only true if either:
 * there is a security bug in the virtualization software (highly
 improbable, and maybe easibly fixed);

 BWHAHHAHAHAHAHH. Have you ever actually worked with any
 virtualization software?
 There have been many documented security bugs in every virtualization
 software.
 Try Securityfocus or your favorite search engine.

I just finished sans 560 pen testing class.  We had some discussions
about day 0 exploits of guest-host bugs.  Highly improbably should
be changed to it's out there


--
http://www.glumbert.com/media/shift
http://www.youtube.com/watch?v=tGvHNNOLnCk
This officer's men seem to follow him merely out of idle curiosity.
-- Sandhurst officer cadet evaluation.
Securing an environment of Windows platforms from abuse - external or
internal - is akin to trying to install sprinklers in a fireworks
factory where smoking on the job is permitted.  -- Gene Spafford
learn french:  http://www.youtube.com/watch?v=30v_g83VHK4



Re: obsd as domU?

2010-01-13 Thread William Boshuck
On Wed, Jan 13, 2010 at 08:31:14AM +0200, Ciprian Dorin, Craciun wrote:

  Sorry, but you guys from OpenBSD have proved that you can trust
 the skills of **some** developers

viz., precisely those developers that are telling you to not trust
the virtualization hype/crap.  So, why not trust those developers?

 .. we have trust in you, but why don't you  have the disposition
  to trust in others?)

These developers have _earned_ (through careful hard work and
meticulously accurate documentation) the trust accorded them.
With respect to the others, this remains to be seen (and current
indications are not promising).



Re: obsd as domU?

2010-01-13 Thread Marco Peereboom
On Wed, Jan 13, 2010 at 08:55:33AM +0200, Ciprian Dorin, Craciun wrote:
 On Wed, Jan 13, 2010 at 8:43 AM, Bret S. Lambert bret.lamb...@gmail.com 
 wrote:
  How did lazy internet denizen gets told he's lazy turn into
  anything worth spending this much time on?
 
 I would like to personally apologize for criticizing you, Bret, of
 lmgtfy the other guy (which I didn't knew he also posted another
 question about OpenBSD and dom0, and he was also responded).
 
 But I wouldn't say that the discussion has turned into something
 not-worth discussing. I myself have learned a lot about the position
 of the OpenBSD developers regarding the possibility of ever using
 OpenBSD ontop of virtualization (not emulation) platforms (like Xen).
 (I had my hopes, but not any more... :) )

Virtualization is a toy sold as an enterprise solution.  The argument
goes like this: you need a domain controller and sequel server so you
need 2 machines.  So instead of paying for 2 machines you virtualize
them! OMGZOMG1ONe

What Mr. dingle berry insultant forgets to point out is that both tasks
will run like ass in a virtualized environment AND can be easily
combined on the same box.  Usually lost in the same conversation is
that you need both machines to be up at the same time too to be useful.

I have seen people virtualize a file server and domain controller on a
single machine.  Which is awesome because now you get free 30% loss of
IO performance. You know it keeps bandwidth use lower and latency
higher.  Exactly what lusers like.

Virtualization is great to develop kernel code and get an idea if it'd
work before moving on to real hardware (and fixing real bugs on real
hardware because virtualization failed to run right).

I like to play with old OS' as well so its neat for that but usually
doesn't work.  This really is in the toy section though.

 Thanks again for all the time and effort spent,
 Ciprian.
 
 P.S.: Maybe an entry in the FAQ about this topic will cut down all
 these questions about virtualization?

What's next?  Pokemon on OpenBSD FAQ entry?



Re: obsd as domU?

2010-01-13 Thread Peter N. M. Hansteen
Marco Peereboom sl...@peereboom.us writes:

 I have seen people virtualize a file server and domain controller on a
 single machine.  Which is awesome because now you get free 30% loss of
 IO performance. You know it keeps bandwidth use lower and latency
 higher.  Exactly what lusers like.

Oh, try what a medium sized educational institution not too far from
here did: put several file servers on the same physical rig (sharing
one gigabit ethernet interface), then start whining when backups to
$elsewhere don't complete overhight.

-- 
Peter N. M. Hansteen, member of the first RFC 1149 implementation team
http://bsdly.blogspot.com/ http://www.bsdly.net/ http://www.nuug.no/
Remember to set the evil bit on all malicious network traffic
delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds.



Re: obsd as domU?

2010-01-13 Thread bofh
Of course it didn't!  What they should have done was put the backup
server on the same VM!!!  Problem solved!

On 1/13/10, Peter N. M. Hansteen pe...@bsdly.net wrote:
 Marco Peereboom sl...@peereboom.us writes:

 I have seen people virtualize a file server and domain controller on a
 single machine.  Which is awesome because now you get free 30% loss of
 IO performance. You know it keeps bandwidth use lower and latency
 higher.  Exactly what lusers like.

 Oh, try what a medium sized educational institution not too far from
 here did: put several file servers on the same physical rig (sharing
 one gigabit ethernet interface), then start whining when backups to
 $elsewhere don't complete overhight.

 --
 Peter N. M. Hansteen, member of the first RFC 1149 implementation team
 http://bsdly.blogspot.com/ http://www.bsdly.net/ http://www.nuug.no/
 Remember to set the evil bit on all malicious network traffic
 delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds.



-- 
Sent from my mobile device

http://www.glumbert.com/media/shift
http://www.youtube.com/watch?v=tGvHNNOLnCk
This officer's men seem to follow him merely out of idle curiosity.
-- Sandhurst officer cadet evaluation.
Securing an environment of Windows platforms from abuse - external or
internal - is akin to trying to install sprinklers in a fireworks
factory where smoking on the job is permitted.  -- Gene Spafford
learn french:  http://www.youtube.com/watch?v=30v_g83VHK4



Re: obsd as domU?

2010-01-13 Thread Chris Dukes
On Tue, Jan 12, 2010 at 10:41:15AM +0200, Ciprian Dorin, Craciun wrote:
 * any other options??? (anyone???)

If you are looking at OpenBSD in a production environment as
a firewall, ssl accelerator, or for protection from OS privilege
escalation when someone else finds and uses an exploit in your apps,
run it on bare metal.

If you are looking at virtualization to maximize hardware utilization,
look at the operating systems officially supported by the virtualization
software you choose.

If you are looking at Xen for virtualization because paravirtualization
might give a lower impact on performance, I would suggest checking
the performance impact between paravirtualization and VT extension
assisted virtualization on real workloads.

But look on the bright side... odds are whatever you are trying to
do is probably so full of holes at the application layer even with
all of OpenBSD's protections you'll still get sufficiently maliciously
pwned through several application exploits.
-- 
Chris Dukes



Re: obsd as domU?

2010-01-13 Thread Chris Dukes
On Wed, Jan 13, 2010 at 07:54:46AM -0600, Marco Peereboom wrote:
 
 Virtualization is a toy sold as an enterprise solution.  The argument
 goes like this: you need a domain controller and sequel server so you
 need 2 machines.  So instead of paying for 2 machines you virtualize
 them! OMGZOMG1ONe
 
 What Mr. dingle berry insultant forgets to point out is that both tasks
 will run like ass in a virtualized environment AND can be easily
 combined on the same box.  Usually lost in the same conversation is
 that you need both machines to be up at the same time too to be useful.

Ah, but the dingle berry insultant was probably brought in because
management finally listened when they were told
1) The machines with the most compute power and memory are 
nearly completely idle file and backup servers.
2) The key compute heavy apps are running on 7 year old hardware
for which replacement parts are becoming nearly non-existant.
So the insultant picks the virtualization topology best suited
to bring a second insulting contract for performance detuning...
 
 I have seen people virtualize a file server and domain controller on a
 single machine.  Which is awesome because now you get free 30% loss of
 IO performance. You know it keeps bandwidth use lower and latency
 higher.  Exactly what lusers like.

We intentionally did this for an environment for application developers 
so they would find the performance issues with their applications sooner.

 
 Virtualization is great to develop kernel code and get an idea if it'd
 work before moving on to real hardware (and fixing real bugs on real
 hardware because virtualization failed to run right).

It also works rather well testlabs for software applications.
Faster reinstall turnarounds.  Smaller budget required for chairs and 
displays and KVM switches and work surfaces.  Higher homicide rates as
5 app developers pile into a cube that isn't large enough for one
person all looking at one tiny display for a problem involving 6 different
virtual machines and start accusing each other loudly (Previously
they had enough space to run and scatter).
 
 I like to play with old OS' as well so its neat for that but usually
 doesn't work.  This really is in the toy section though.

I find that it's useful to validating procedures before applied to production
and for working out a load balanced configuration.
-- 
Chris Dukes



Re: obsd as domU?

2010-01-13 Thread Diana Eichert

Chuckle, try to troubleshoot a network issue when it is in a
virtual network.  Lots of fun, not.

diana



Re: obsd as domU?

2010-01-13 Thread Ted Unangst
On Wed, Jan 13, 2010 at 1:31 AM, Ciprian Dorin, Craciun
ciprian.crac...@gmail.com wrote:
Sorry, but you guys from OpenBSD have proved that you can trust
 the skills of **some** developers to write an __supposed__ perfectly
 secure operating system, so why not trust other developers to write
 a __supposed__ secure software emulation with the help of hardware.
 (Let me say it more simply: we have trust in you, but why don't you
 have the disposition to trust in others?)

A lot of OpenBSD's security comes from a model of bad things can and
will happen and trying to mitigate the damage, ala privilege
separation.  We don't assume the code is perfect, we assume it's NOT.
Combining virtual servers onto a single physical machine is the exact
opposite of that philosophy.



obsd as domU?

2010-01-12 Thread Vadkan Jozsef
Can I run obsd as a xen guest?



Re: obsd as domU?

2010-01-12 Thread Bret Lambert
On Tue, Jan 12, 2010 at 8:59 AM, Vadkan Jozsef jozsi.avad...@gmail.com wrote:
 Can I run obsd as a xen guest?



http://lmgtfy.com/?q=Can+I+run+obsd+as+a+xen+guest

The internet: you're doing it wrong.



Re: obsd as domU?

2010-01-12 Thread Ciprian Dorin, Craciun
On Tue, Jan 12, 2010 at 10:10 AM, Bret Lambert bret.lamb...@gmail.com wrote:
 On Tue, Jan 12, 2010 at 8:59 AM, Vadkan Jozsef jozsi.avad...@gmail.com 
 wrote:
 Can I run obsd as a xen guest?



 http://lmgtfy.com/?q=Can+I+run+obsd+as+a+xen+guest

 The internet: you're doing it wrong.


Hello all! (I'm a very new OpenBSD user (tested only on Qemu, but
would like to put OpenBSD in production).)

And I just want to say that I had the same question a couple a
days ago: Is it really possible (as in tried in a quasi-production
environment) to run OpenBSD as a Xen domU? And if so are there some
guidelines, documentation, etc.? If not is there any disponibility to
implement such a feature?

I've searched a little on the net and I've reached to the
following two possibilities:
* Yes but under Xen with HVM support, with the drawback of
(greater) CPU overhead and with some networking problems;
* And also yes as direct DomU, but based on the work of
Christoph Egger but which is not available on the net anymore;
* any other options??? (anyone???)

   So I bet that the initial poster expected an (authoritative) answer
that should have came in the form of an advice based on experience or
at least something useful... (Not lmgtfy, which I'm sure he already
did, but did not found a good enough answer (as in authoritative)...)

Sorry,
Ciprian.



Re: obsd as domU?

2010-01-12 Thread Bret Lambert
On Tue, Jan 12, 2010 at 9:41 AM, Ciprian Dorin, Craciun
ciprian.crac...@gmail.com wrote:

[snipz0rz]

   So I bet that the initial poster expected an (authoritative) answer
 that should have came in the form of an advice based on experience or
 at least something useful... (Not lmgtfy, which I'm sure he already
 did, but did not found a good enough answer (as in authoritative)...)

When both of his questions were, verbatim:

OpenBSD as Dom0: Is it possible?

and

Can I run obsd as a xen guest?

it's unclear to me, since he's unwilling to document what he's
found in order to help others to help him, whether or not he's willing
to do the work required in finding those answers to begin with.



Re: obsd as domU?

2010-01-12 Thread Michiel van Baak
On 08:59, Tue 12 Jan 10, Vadkan Jozsef wrote:
 Can I run obsd as a xen guest?

under 'full' virtualisation, yes.
under para-virtualisation, no.

-- 

Michiel van Baak
mich...@vanbaak.eu
http://michiel.vanbaak.eu
GnuPG key: http://pgp.mit.edu:11371/pks/lookup?op=getsearch=0x71C946BD

Why is it drug addicts and computer aficionados are both called users?



Re: obsd as domU?

2010-01-12 Thread J.C. Roberts
On Tue, 12 Jan 2010 10:41:15 +0200 Ciprian Dorin, Craciun
ciprian.crac...@gmail.com wrote:

So I bet that the initial poster expected an (authoritative) answer
 that should have came in the form of an advice based on experience or
 at least something useful... (Not lmgtfy, which I'm sure he already
 did, but did not found a good enough answer (as in authoritative)...)

You are missing the point. Virtualization has been discussed to death
for *YEARS* and all of it is in the misc@ list archives.

Here's the short version of those years of discussion:

1.) Since you can't trust the skill of most developers to write a
perfectly secure operating systems, trusting them to write a perfectly
secure software emulation of hardware is insane.

2.) If systems and application software runs fine on real hardware, but
fails to run on emulated/virtualized hardware, then the problem is in
the virtualization software. --In other words, take questions and
complaints to the vendor of your virtualization software.

3.) Many of the benefits you gain by running a stable and secure
operating system like OpenBSD are lost when you run it as a guest on
top of some other insecure host operating system.

4.) Most Virtualization Software fails to emulate hardware perfectly.

5.) Most Virtualization Software expects the host operating system to
have specific features, and hence, it's not easily portable, or it is
not portable at all.

6.) Most Virtualization Software wants to use fancy hardware features
and/or have direct access to hardware. If your vitualization software
is by-passing the restrictions enforced by the host operating system,
then the host operating systems is not able to do it's job.


Virtualization can be very useful in certain situations, yet you not
only need to fully understand and accept the implications and risks of
virtualization, but *you* also need to test it in *your* environment to
determine if it meets *your* requirements. Anything less is irrelevant!

If you're too lazy to do the weeks or months of research work on your
own, then you really should not use virtualization. Unfortunately, most
people just believe the constant bullshit from the virtualization
vendors, or ask irrelevant questions on various mailing lists.


Lastly, Bret Lambert is one of the OpenBSD developers, so you can
consider his lmgtfy reply as authoritative --He's humorously telling
you to do your own work. There is no other way.


-- 
J.C. Roberts



Re: obsd as domU?

2010-01-12 Thread Ciprian Dorin, Craciun
On Wed, Jan 13, 2010 at 7:43 AM, J.C. Roberts list-...@designtools.org
wrote:
 On Tue, 12 Jan 2010 10:41:15 +0200 Ciprian Dorin, Craciun
 ciprian.crac...@gmail.com wrote:

 B  B So I bet that the initial poster expected an (authoritative) answer
 that should have came in the form of an advice based on experience or
 at least something useful... (Not lmgtfy, which I'm sure he already
 did, but did not found a good enough answer (as in authoritative)...)

 You are missing the point. Virtualization has been discussed to death
 for *YEARS* and all of it is in the misc@ list archives.

Sorry didn't knew... (I should have checked the mailing list...)


 Here's the short version of those years of discussion:

 1.) Since you can't trust the skill of most developers to write a
 perfectly secure operating systems, trusting them to write a perfectly
 secure software emulation of hardware is insane.

Sorry, but you guys from OpenBSD have proved that you can trust
the skills of **some** developers to write an __supposed__ perfectly
secure operating system, so why not trust other developers to write
a __supposed__ secure software emulation with the help of hardware.
(Let me say it more simply: we have trust in you, but why don't you
have the disposition to trust in others?)


 2.) If systems and application software runs fine on real hardware, but
 fails to run on emulated/virtualized hardware, then the problem is in
 the virtualization software. --In other words, take questions and
 complaints to the vendor of your virtualization software.

Agree. This is the same as with software: if software runs
perfectly on one version of OpenBSD, but not on another it does not
mean that its the fault of the new version. (But Xen is not all about
emulation, it cooperates with the guest kernel, so in this case the
blame could be on both sides.)


 3.) Many of the benefits you gain by running a stable and secure
 operating system like OpenBSD are lost when you run it as a guest on
 top of some other insecure host operating system.

This is only true if either:
* there is a security bug in the virtualization software (highly
improbable, and maybe easibly fixed);
* you let the host operating system front the Internet; (but you
could just filter out all the traffic from the exterior to the host,
and use one of the guests (OpenBSD) as a gateway);


 4.) Most Virtualization Software fails to emulate hardware perfectly.

(Again we are not speaking of emulation, we are speaking of
cooperation between the hypervisor and the guest kernel.)


 5.) Most Virtualization Software expects the host operating system to
 have specific features, and hence, it's not easily portable, or it is
 not portable at all.

 6.) Most Virtualization Software wants to use fancy hardware features
 and/or have direct access to hardware. If your vitualization software
 is by-passing the restrictions enforced by the host operating system,
 then the host operating systems is not able to do it's job.

No, (in general) the requirement of virtualization is not to
bypass the restrictions imposed by OS to hardware.


 Virtualization can be very useful in certain situations, yet you not
 only need to fully understand and accept the implications and risks of
 virtualization, but *you* also need to test it in *your* environment to
 determine if it meets *your* requirements. Anything less is irrelevant!

One important use of virtualization software (like Xen for
example), is to allow experimentation. For example I don't have 4
pieces of hardware to be able to also host a Linux server (for
personal stuff), experiment with OpenBSD or Plan9, and also give one
of my friends a small VPN and download host. So I use Xen and turn one
computer into many. (As you see it's not the security aspect I'm
interested but the consolidation aspect...) (Yes very lame I know, but
sometimes money does beat security...)


 If you're too lazy to do the weeks or months of research work on your
 own, then you really should not use virtualization. Unfortunately, most
 people just believe the constant bullshit from the virtualization
 vendors, or ask irrelevant questions on various mailing lists.

(I hope I've touched this subject above.)


 Lastly, Bret Lambert is one of the OpenBSD developers, so you can
 consider his lmgtfy reply as authoritative --He's humorously telling
 you to do your own work. There is no other way.
 --
 J.C. Roberts


Thanks for the time and the responses,
Ciprian.



Re: obsd as domU?

2010-01-12 Thread Bret S. Lambert
How did lazy internet denizen gets told he's lazy turn into
anything worth spending this much time on?



Re: obsd as domU?

2010-01-12 Thread Ciprian Dorin, Craciun
On Wed, Jan 13, 2010 at 8:43 AM, Bret S. Lambert bret.lamb...@gmail.com wrote:
 How did lazy internet denizen gets told he's lazy turn into
 anything worth spending this much time on?

I would like to personally apologize for criticizing you, Bret, of
lmgtfy the other guy (which I didn't knew he also posted another
question about OpenBSD and dom0, and he was also responded).

But I wouldn't say that the discussion has turned into something
not-worth discussing. I myself have learned a lot about the position
of the OpenBSD developers regarding the possibility of ever using
OpenBSD ontop of virtualization (not emulation) platforms (like Xen).
(I had my hopes, but not any more... :) )

Thanks again for all the time and effort spent,
Ciprian.

P.S.: Maybe an entry in the FAQ about this topic will cut down all
these questions about virtualization?



Re: obsd as domU?

2010-01-12 Thread Henning Brauer
* Ciprian Dorin, Craciun ciprian.crac...@gmail.com [2010-01-13 07:37]:
 This is only true if either:
 * there is a security bug in the virtualization software (highly
 improbable, and maybe easibly fixed);

i owuld pee my pants (or maybe bob's instead) laughing if it wasn't so
sad. it is this mindset that gets this industry in shit every other
day.

-- 
Henning Brauer, h...@bsws.de, henn...@openbsd.org
BS Web Services, http://bsws.de
Full-Service ISP - Secure Hosting, Mail and DNS Services
Dedicated Servers, Rootservers, Application Hosting



Re: obsd as domU?

2010-01-12 Thread Eric Furman
On Wed, 13 Jan 2010 08:31 +0200, Ciprian Dorin, Craciun
ciprian.crac...@gmail.com wrote:
 On Wed, Jan 13, 2010 at 7:43 AM, J.C. Roberts list-...@designtools.org
 wrote:
  On Tue, 12 Jan 2010 10:41:15 +0200 Ciprian Dorin, Craciun
  ciprian.crac...@gmail.com wrote:
 
  B  B So I bet that the initial poster expected an (authoritative) answer
  that should have came in the form of an advice based on experience or
  at least something useful... (Not lmgtfy, which I'm sure he already
  did, but did not found a good enough answer (as in authoritative)...)
 
  You are missing the point. Virtualization has been discussed to death
  for *YEARS* and all of it is in the misc@ list archives.
 
 Sorry didn't knew... (I should have checked the mailing list...)
 
 
  Here's the short version of those years of discussion:
 
  1.) Since you can't trust the skill of most developers to write a
  perfectly secure operating systems, trusting them to write a perfectly
  secure software emulation of hardware is insane.
 
 Sorry, but you guys from OpenBSD have proved that you can trust
 the skills of **some** developers to write an __supposed__ perfectly
 secure operating system, so why not trust other developers to write
 a __supposed__ secure software emulation with the help of hardware.
 (Let me say it more simply: we have trust in you, but why don't you
 have the disposition to trust in others?)

Very few have demonstrated that they can be trusted.
BTW, *any* virtualization software written for i386 is always going
to have the potential for compromise because of the inherent flaws
in that architecture. It was *not* designed with virtualization in mind.

 
 
  2.) If systems and application software runs fine on real hardware, but
  fails to run on emulated/virtualized hardware, then the problem is in
  the virtualization software. --In other words, take questions and
  complaints to the vendor of your virtualization software.
 
 Agree. This is the same as with software: if software runs
 perfectly on one version of OpenBSD, but not on another it does not
 mean that its the fault of the new version. (But Xen is not all about
 emulation, it cooperates with the guest kernel, so in this case the
 blame could be on both sides.)

Wrong. If it works on real hardware and fails in virtualization
the virtualization software is *always* to blame.

 
 
  3.) Many of the benefits you gain by running a stable and secure
  operating system like OpenBSD are lost when you run it as a guest on
  top of some other insecure host operating system.
 
 This is only true if either:
 * there is a security bug in the virtualization software (highly
 improbable, and maybe easibly fixed);

BWHAHHAHAHAHAHH. Have you ever actually worked with any
virtualization software?
There have been many documented security bugs in every virtualization
software.
Try Securityfocus or your favorite search engine.

 * you let the host operating system front the Internet; (but you
 could just filter out all the traffic from the exterior to the host,
 and use one of the guests (OpenBSD) as a gateway);
 
 
  4.) Most Virtualization Software fails to emulate hardware perfectly.
 
 (Again we are not speaking of emulation, we are speaking of
 cooperation between the hypervisor and the guest kernel.)
 
 
  5.) Most Virtualization Software expects the host operating system to
  have specific features, and hence, it's not easily portable, or it is
  not portable at all.
 
  6.) Most Virtualization Software wants to use fancy hardware features
  and/or have direct access to hardware. If your vitualization software
  is by-passing the restrictions enforced by the host operating system,
  then the host operating systems is not able to do it's job.
 
 No, (in general) the requirement of virtualization is not to
 bypass the restrictions imposed by OS to hardware.

BWAAAHAHAHAHAHAH! It *should* be a requirement, but rarely *is*.

 
 
  Virtualization can be very useful in certain situations, yet you not
  only need to fully understand and accept the implications and risks of
  virtualization, but *you* also need to test it in *your* environment to
  determine if it meets *your* requirements. Anything less is irrelevant!
 
 One important use of virtualization software (like Xen for
 example), is to allow experimentation. For example I don't have 4
 pieces of hardware to be able to also host a Linux server (for
 personal stuff), experiment with OpenBSD or Plan9, and also give one
 of my friends a small VPN and download host. So I use Xen and turn one
 computer into many. (As you see it's not the security aspect I'm
 interested but the consolidation aspect...) (Yes very lame I know, but
 sometimes money does beat security...)

This is actually very true. But you need to be very aware of where
it does and where it doesn't.