How to detect if a machine is a Virtual machine ??

How to detect if a machine is a Virtual machine ??

[Sachin Goel]

Hi,

Just curious to know, if there is any way that given a terminal to a 
box, we can determine is it a physical machine or a virtual machine ?

Thanks,
Sachin.

Re: How to detect if a machine is a Virtual machine ??

[Konrad Rzeszutek Wilk]

> Just curious to know, if there is any way that given a terminal to a  
> box, we can determine is it a physical machine or a virtual machine ?

./tools/misc/xen-detect.c

Re: How to detect if a machine is a Virtual machine ??

[Sachin Goel]

Hi,

Where is the tools directory located ?

I am not able to find it on a xen virtual machine..:(

Thanks,
Sachin.

----- Original Message -----
From: konrad.wilk@oracle.com
To: sachin.goel@oracle.com
Cc: xen-devel@lists.xensource.com
Sent: Monday, December 21, 2009 10:34:20 PM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
Subject: Re: [Xen-devel] How to detect if a machine is a Virtual machine ??

> Just curious to know, if there is any way that given a terminal to a  
> box, we can determine is it a physical machine or a virtual machine ?

./tools/misc/xen-detect.c

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Re: How to detect if a machine is a Virtual machine ??

[Michal Novotny]

Hi Sachin,
the tool is not in the virtual machine. This is the tool that's in dom0. 
Since there is a source code for this one you could scp it to the guest, 
compile and run inside the guest environment. There is no need to 
provide a guest with this tool by default and in fact this is really 
impossible so it's better to scp it to the guest and compile there.

Michal

On 12/21/2009 07:00 PM, Sachin Goel wrote:
> Hi,
>
> Where is the tools directory located ?
>
> I am not able to find it on a xen virtual machine..:(
>
> Thanks,
> Sachin.
>
> ----- Original Message -----
> From: konrad.wilk@oracle.com
> To: sachin.goel@oracle.com
> Cc: xen-devel@lists.xensource.com
> Sent: Monday, December 21, 2009 10:34:20 PM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
> Subject: Re: [Xen-devel] How to detect if a machine is a Virtual machine ??
>
>    
>> Just curious to know, if there is any way that given a terminal to a
>> box, we can determine is it a physical machine or a virtual machine ?
>>      
> ./tools/misc/xen-detect.c
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>    

Re: How to detect if a machine is a Virtual machine ??

[John Haxby]

On 22/12/09 10:37, Michal Novotny wrote:
> Hi Sachin,
> the tool is not in the virtual machine. This is the tool that's in 
> dom0. Since there is a source code for this one you could scp it to 
> the guest, compile and run inside the guest environment. There is no 
> need to provide a guest with this tool by default and in fact this is 
> really impossible so it's better to scp it to the guest and compile 
> there.

It's also worth pointing out that the underlying test for xen in this 
program executes a particular instruction to find the information about 
its environment.   What that means is that it's possible to write a 
version of ./tools/misc/xen-detect.c that will work in any guest machine OS.

jch

Re: How to detect if a machine is a Virtual machine ??

[Michal Novotny]

On 12/23/2009 10:16 AM, John Haxby wrote:
> On 22/12/09 10:37, Michal Novotny wrote:
>> Hi Sachin,
>> the tool is not in the virtual machine. This is the tool that's in 
>> dom0. Since there is a source code for this one you could scp it to 
>> the guest, compile and run inside the guest environment. There is no 
>> need to provide a guest with this tool by default and in fact this is 
>> really impossible so it's better to scp it to the guest and compile 
>> there.
>
> It's also worth pointing out that the underlying test for xen in this 
> program executes a particular instruction to find the information 
> about its environment.   What that means is that it's possible to 
> write a version of ./tools/misc/xen-detect.c that will work in any 
> guest machine OS.
>
I am not saying this does not work in any guest machine but just that 
the tools is provided in dom0 only and installed to guest machines by 
default. In fact it's trapping some instruction and according to my 
testing it's OK to scp it to the guest and XEN_PV return value will be 
set for PV guest or XEN_FV (or something similar) for fully virtualized 
environment...

Michal

Re: How to detect if a machine is a Virtual machine ??

[Michal Novotny]

On 12/23/2009 10:16 AM, John Haxby wrote:
> On 22/12/09 10:37, Michal Novotny wrote:
>> Hi Sachin,
>> the tool is not in the virtual machine. This is the tool that's in 
>> dom0. Since there is a source code for this one you could scp it to 
>> the guest, compile and run inside the guest environment. There is no 
>> need to provide a guest with this tool by default and in fact this is 
>> really impossible so it's better to scp it to the guest and compile 
>> there.
>
> It's also worth pointing out that the underlying test for xen in this 
> program executes a particular instruction to find the information 
> about its environment.   What that means is that it's possible to 
> write a version of ./tools/misc/xen-detect.c that will work in any 
> guest machine OS.
But one more point, if you want to know whether XEN_PV is returned for 
dom0 PV guest or domU (since it's the same for both) you can try to look 
for /proc/xen/privcmd. This one is available only in dom0 because 
privileged commands are for privileged domain (domain-0) only...

Michal

Re: How to detect if a machine is a Virtual machine ??

[Michal Novotny]

On 12/23/2009 10:34 AM, Michal Novotny wrote:
> On 12/23/2009 10:16 AM, John Haxby wrote:
>> On 22/12/09 10:37, Michal Novotny wrote:
>>> Hi Sachin,
>>> the tool is not in the virtual machine. This is the tool that's in 
>>> dom0. Since there is a source code for this one you could scp it to 
>>> the guest, compile and run inside the guest environment. There is no 
>>> need to provide a guest with this tool by default and in fact this 
>>> is really impossible so it's better to scp it to the guest and 
>>> compile there.
>>
>> It's also worth pointing out that the underlying test for xen in this 
>> program executes a particular instruction to find the information 
>> about its environment.   What that means is that it's possible to 
>> write a version of ./tools/misc/xen-detect.c that will work in any 
>> guest machine OS.
> But one more point, if you want to know whether XEN_PV is returned for 
> dom0 PV guest or domU (since it's the same for both) you can try to 
> look for /proc/xen/privcmd. This one is available only in dom0 because 
> privileged commands are for privileged domain (domain-0) only...
Oh, sorry, I did mean for domU PV guest or dom0, of course...

Michal

Re: How to detect if a machine is a Virtual machine ??

[Sachin Goel]

Thanks Michal for clarifying..

For a moment I got confused :)

- Sachin.

----- Original Message -----
From: minovotn@redhat.com
To: xen-devel@lists.xensource.com
Sent: Thursday, December 24, 2009 1:20:34 AM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
Subject: Re: [Xen-devel] How to detect if a machine is a Virtual machine ??

On 12/23/2009 10:34 AM, Michal Novotny wrote:
> On 12/23/2009 10:16 AM, John Haxby wrote:
>> On 22/12/09 10:37, Michal Novotny wrote:
>>> Hi Sachin,
>>> the tool is not in the virtual machine. This is the tool that's in 
>>> dom0. Since there is a source code for this one you could scp it to 
>>> the guest, compile and run inside the guest environment. There is no 
>>> need to provide a guest with this tool by default and in fact this 
>>> is really impossible so it's better to scp it to the guest and 
>>> compile there.
>>
>> It's also worth pointing out that the underlying test for xen in this 
>> program executes a particular instruction to find the information 
>> about its environment.   What that means is that it's possible to 
>> write a version of ./tools/misc/xen-detect.c that will work in any 
>> guest machine OS.
> But one more point, if you want to know whether XEN_PV is returned for 
> dom0 PV guest or domU (since it's the same for both) you can try to 
> look for /proc/xen/privcmd. This one is available only in dom0 because 
> privileged commands are for privileged domain (domain-0) only...
Oh, sorry, I did mean for domU PV guest or dom0, of course...

Michal

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Re: How to detect if a machine is a Virtual machine ??

[Michal Novotny]

Yeah, sorry about that. Hope you're not confused anymore ;)

Michal

On 12/23/2009 09:39 PM, Sachin Goel wrote:
> Thanks Michal for clarifying..
>
> For a moment I got confused :)
>
> - Sachin.
>
> ----- Original Message -----
> From: minovotn@redhat.com
> To: xen-devel@lists.xensource.com
> Sent: Thursday, December 24, 2009 1:20:34 AM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
> Subject: Re: [Xen-devel] How to detect if a machine is a Virtual machine ??
>
> On 12/23/2009 10:34 AM, Michal Novotny wrote:
>    
>> On 12/23/2009 10:16 AM, John Haxby wrote:
>>      
>>> On 22/12/09 10:37, Michal Novotny wrote:
>>>        
>>>> Hi Sachin,
>>>> the tool is not in the virtual machine. This is the tool that's in
>>>> dom0. Since there is a source code for this one you could scp it to
>>>> the guest, compile and run inside the guest environment. There is no
>>>> need to provide a guest with this tool by default and in fact this
>>>> is really impossible so it's better to scp it to the guest and
>>>> compile there.
>>>>          
>>> It's also worth pointing out that the underlying test for xen in this
>>> program executes a particular instruction to find the information
>>> about its environment.   What that means is that it's possible to
>>> write a version of ./tools/misc/xen-detect.c that will work in any
>>> guest machine OS.
>>>        
>> But one more point, if you want to know whether XEN_PV is returned for
>> dom0 PV guest or domU (since it's the same for both) you can try to
>> look for /proc/xen/privcmd. This one is available only in dom0 because
>> privileged commands are for privileged domain (domain-0) only...
>>      
> Oh, sorry, I did mean for domU PV guest or dom0, of course...
>
> Michal
>
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> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>