Xen users - Apr 2007 - Unable to boot a full virtualized guest with two or more processors on a Xeon-VT platform

On my VT platform (4 dual-core Xeon-VT processors with 16 GB RAM), I am 
unable to boot a full virtualized guest domain with two or more 
processors. This problem is independent of the guest type, in example I 
have this problem with Linux Knoppix, Linux Mandriva, Windows 2003, 
Windows XP, etc... In all cases, the guest OS recognizes only one processor.


I''ve seen that VMware has already related this problem on its
comparison
between VMware ESX and Xen 3.0.3. An extract of the document "A 
Performance Comparison of Hypervisors" found found on the WMware web site:

  " The tests for both virtual SMP configuration as well as virtual 
machine scalability could not be run due to issues with the Xen 
virtualization hypervisor. A two virtual CPU Windows guest could not be 
booted using the Xen hypervisor.
  The virtual machine scalability tests could not be run because more 
than two uniprocessor Windows guests could not be booted using the Xen 
hypervisor. At this time, it is not known when this issue will be fixed 
and the tests can be tried again.
  While Xen claims to support virtual SMP and virtual machine 
scalability, the results from these experiments demonstrate that 
enterprise customers should run their own tests to make sure such 
configurations actually work."


I confirm that SMP doesn''t work on Xen 3.0.3 on Xeon-VT platform while 
XenSource has denigrate this fact.

When trying to boot a multiprocessors Linux guest, I''ve the following 
messages on the guest log:
 ...
CPU0: Intel(R) Xeon(TM) CPU 2.60Ghz stepping 08
SMP alternatives: switching to SMP code
Booting processor 1/1 eip 3000
Not responding.
Inquiring remote APIC #1...
... APIC #1 ID: failed
... APIC #1 VERSION: failed
... APIC #1 SPIV: failed
CPU#1 not responding - cannot use it.
Total of 1 processors activated (5225.61 BogoMIPS).
...


I''am using the Xen version (3.0.3) of Red Hat, RHEL-5 official version.
Anyone has an idea of what is the problem ?
Thanks.


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> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com 
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
> Philippe Berthault
> Sent: 05 April 2007 09:35
> To: xen-users@lists.xensource.com
> Subject: [Xen-users] Unable to boot a full virtualized guest 
> with two or more processors on a Xeon-VT platform
> 
> On my VT platform (4 dual-core Xeon-VT processors with 16 GB 
> RAM), I am 
> unable to boot a full virtualized guest domain with two or more 
> processors. This problem is independent of the guest type, in 
> example I 
> have this problem with Linux Knoppix, Linux Mandriva, Windows 2003, 
> Windows XP, etc... In all cases, the guest OS recognizes only 
> one processor.
I believe this problem is fixed in 3.0.4 - for certain it''s fixed in
unstable which is what I use right now. Unstable will become 3.0.5 in
the next couple of weeks or so. 

The main problem is that the BIOS supplied for 3.0.3 doesn''t build the
correct MP-tables when you give it multiple processors. You can
manipulate the BIOS image (from memory, there is a setting for number of
processors in the makefile used to generate the BIOS image), but of
course whatever number you choose will be THE number of processors that
the guest gets [unless you build multiple versions of the BIOS and
hvmloader (hvmloader contains a copy of the BIOS which it copies into
the BIOS location in memory, and then jumps to that location). A lot of
work compared to upgrading to a newer Xen-version... 

I don''t know if there were other problems that needed fixing too (there
may have been), but the BIOS not building the correct information is
definitely a hindrance.
--
Mats



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I believe this support is supposed to be completed in 3.0.4 and above. 
I''ve
heard that RedHat may be releasing a service pack incorporating an updated 
version of Xen at some point in the future.

In the meantime, I''m afraid your best solution is probably to either
build Xen
from source or find some RPMs of 3.0.4 that will work on RHEL...  This might 
not suit RedHat''s support people, but AFAIK they don''t support
anything other
than RHEL-on-RHEL at the moment anyhow.

Hope that helps clarify things somewhat.

Cheers,
Mark

On Thursday 05 April 2007 09:35, Philippe Berthault
wrote:
> On my VT platform (4 dual-core Xeon-VT processors with 16 GB RAM), I am
> unable to boot a full virtualized guest domain with two or more
> processors. This problem is independent of the guest type, in example I
> have this problem with Linux Knoppix, Linux Mandriva, Windows 2003,
> Windows XP, etc... In all cases, the guest OS recognizes only one
> processor.
>
>
> I''ve seen that VMware has already related this problem on its
comparison
> between VMware ESX and Xen 3.0.3. An extract of the document "A
> Performance Comparison of Hypervisors" found found on the WMware web
site:
>
>   " The tests for both virtual SMP configuration as well as virtual
> machine scalability could not be run due to issues with the Xen
> virtualization hypervisor. A two virtual CPU Windows guest could not be
> booted using the Xen hypervisor.
>   The virtual machine scalability tests could not be run because more
> than two uniprocessor Windows guests could not be booted using the Xen
> hypervisor. At this time, it is not known when this issue will be fixed
> and the tests can be tried again.
>   While Xen claims to support virtual SMP and virtual machine
> scalability, the results from these experiments demonstrate that
> enterprise customers should run their own tests to make sure such
> configurations actually work."
>
>
> I confirm that SMP doesn''t work on Xen 3.0.3 on Xeon-VT platform
while
> XenSource has denigrate this fact.
>
> When trying to boot a multiprocessors Linux guest, I''ve the
following
> messages on the guest log:
>  ...
> CPU0: Intel(R) Xeon(TM) CPU 2.60Ghz stepping 08
> SMP alternatives: switching to SMP code
> Booting processor 1/1 eip 3000
> Not responding.
> Inquiring remote APIC #1...
> ... APIC #1 ID: failed
> ... APIC #1 VERSION: failed
> ... APIC #1 SPIV: failed
> CPU#1 not responding - cannot use it.
> Total of 1 processors activated (5225.61 BogoMIPS).
> ...
>
>
> I''am using the Xen version (3.0.3) of Red Hat, RHEL-5 official
version.
> Anyone has an idea of what is the problem ?
> Thanks.
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
-- 
Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

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