xen discuss - Aug 2006 - Linux domU weirdness

Hi There,

Something weird happens when I boot a Linux domU [1] on Solaris dom0 
[2]. The domU kernel instance sees itself as a dom0...? A manifestation 
of this is the creation, in the domU, of the 8 veth* and vif* network 
interfaces. Is there a known explanation to this?

David:
FYI, I do see too the already reported "Received packet is 16 bytes 
before head"  error message!

Thanks
   - Patrick

[1] The linux domU is a 2.6.15-1.2054_FC5xenU
[2] The solaris dom0 is a SunOS 5.11 matrix-build-2006-07-14

On 2 Aug 2006, at 4:12pm, Patrick Petit wrote:
> Something weird happens when I boot a Linux domU [1] on Solaris  
> dom0 [2]. The domU kernel instance sees itself as a dom0...? A  
> manifestation of this is the creation, in the domU, of the 8 veth*  
> and vif* network interfaces. Is there a known explanation to this?
None that I''m aware of.  Is that the only problem you see?
> David:
> FYI, I do see too the already reported "Received packet is 16 bytes  
> before head"  error message!
I''m testing a fix for this.  If you are building your own Solaris  
kernel from source I could send out a patch...

dme.
-- 
David Edmondson, Solaris Engineering, http://www.dme.org

David Edmondson wrote:
>
> On 2 Aug 2006, at 4:12pm, Patrick Petit wrote:
>
>> Something weird happens when I boot a Linux domU [1] on Solaris  dom0 
>> [2]. The domU kernel instance sees itself as a dom0...? A  
>> manifestation of this is the creation, in the domU, of the 8 veth*  
>> and vif* network interfaces. Is there a known explanation to this?
>
>
> None that I''m aware of.  Is that the only problem you see?
This the most apparent problem. As far as I can tell for now, the system 
seems to operate ok but I haven''t really tested things yet. Note that I
went a little too quickly yesterday. In fact, the problem shows up when 
I boot using the pre-built tarball installation of Xen from Xensource 
for Linux. As we know they provide only one
''vmlinuz-2.6.16-xen'' binary
for both dom0 and domU instances as opposed to other distributions (like 
FC5) which provide differentiated kernel binaries. You also have to 
create your initrd which is not provided. So, it appears that when the 
vmlinuz-2.6.16-xen is booted from Solaris dom0 it sees itself as dom0 
like if it were booted on bare-metal machine. I am wondering whether the 
internal artifacts indicating a domain''s role (host or guest) at boot 
time wouldn''t be honored or exposed differently on Solaris dom0 than on
Linux dom0...? Thoughts are welcome.
>
>> David:
>> FYI, I do see too the already reported "Received packet is 16
bytes
>> before head"  error message!
>
>
> I''m testing a fix for this.  If you are building your own Solaris
> kernel from source I could send out a patch...
I can wait for the next build, this doesn''t seem to be a showstopper.
Thanks
  - Patrick
>
> dme.


-- 
Patrick Petit                   Sun Microsystems Inc.
Labs, CTO - G2 Systems Exp.     ICNC Grenoble (http://icncweb.france)  
Phone: (+33)476 188 232 x38232  180, Avenue de l''Europe
Fax: (+33)476 188 282           38334 Saint-Ismier Cedex, France