Re: Minix as an HVM guest crashes

["Jonathan M. McCune" <jonmccune@cmu.edu>]

During boot, Minix prints "Executing in 32-bit protected mode."

-Jon


Petersson, Mats wrote:

>Jon, 
>
>Is Minix a 16-bit or 32-bit OS? If it's 16-bit, it's most likely the
>cause of problems. There are a lot of places in Xen where it's assumed
>that the base of a segment is zero unless in real-mode... 
>
>Just a thought... 
>
>--
>Mats
>
>  
>
>>-----Original Message-----
>>From: xen-devel-bounces@lists.xensource.com 
>>[mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of 
>>Petersson, Mats
>>Sent: 16 May 2006 21:35
>>To: Jonathan M. McCune; xen-devel@lists.xensource.com
>>Subject: RE: [Xen-devel] Minix as an HVM guest crashes
>>
>> 
>>
>>    
>>
>>>-----Original Message-----
>>>From: xen-devel-bounces@lists.xensource.com
>>>[mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of 
>>>      
>>>
>>Jonathan 
>>    
>>
>>>M. McCune
>>>Sent: 16 May 2006 21:09
>>>To: xen-devel@lists.xensource.com
>>>Subject: [Xen-devel] Minix as an HVM guest crashes
>>>
>>>Hello Xen community,
>>>
>>>I have tried to boot Minix 3.1.2 as an HVM guest on Xen 3.0.2 on a 
>>>system with AMD SVM extensions, but it crashes.  I have 
>>>      
>>>
>>successfully 
>>    
>>
>>>booted Linux and Windows XP as HVM guests on this system.  I have 
>>>included here the output of `xm dmesg` after attempting to boot the 
>>>Minix domain.  Here is my minix.xm file:
>>>
>>>kernel = "/usr/lib/xen/boot/hvmloader"
>>>builder='hvm'
>>>memory = 512
>>>name = "Minix"
>>>disk = [ 'file:/minix/disk.img,ioemu:hda,w' ] vif = [ 'type=ioemu, 
>>>bridge=xenbr0' ] device_model = '/usr/lib/xen/bin/qemu-dm'
>>>memmap = '/usr/lib/xen/boot/mem-map.sxp'
>>>cdrom='/minix/IDE-3.1.2.iso'
>>>boot='d'
>>>sdl=1
>>>vnc=0
>>>
>>>
>>>The command I executed in dom0 to boot the minix.xm domain 
>>>was `xm create -f minix.xm`.  The HVM guest window opens, and 
>>>minix boots to the point where it asks whether I want to 
>>>configure for "Large" or "Small" 
>>>memory.  Regardless of my choice, the HVM guest window 
>>>"blinks out of existence" shortly thereafter, and 
>>>automatically restarts itself once, before crashing again in 
>>>exactly the same way.  I chose Large both times.  This 
>>>auto-restart behavior is why there are two guests in the `xm 
>>>dmesg` output below:
>>>
>>>Does anybody know why it crashes?  Is this a Minix bug? Xen bug?  
>>>Admittedly, I haven't tried the latest xen-unstable yet, so 
>>>perhaps the issue is already solved.
>>>
>>>Thanks,
>>>-Jon
>>>
>>>
>>>      
>>>
>>This is a typical dump of a unimplemented opcode in hvm/platform.c. 
>>
>>I'm not quite sure which opcode it's trying to execute, but I'm sure
>>this is why it's failing. I'm also confused as to the base address of
>>the instruction, because the 31A7 instruction is a "add $10, %esp",
>>which shouldn't be page-faulting. One possibility is that the base of
>>the CS register isn't zero, in which case the dump of the instruction
>>bytes is bogus... 
>>
>>I doubt that the Latest Xen will fix anything.
>>
>>--
>>Mats
>>
>>
>>_______________________________________________
>>Xen-devel mailing list
>>Xen-devel@lists.xensource.com
>>http://lists.xensource.com/xen-devel
>>
>>
>>    
>>
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>  
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