[Qemu-devel] Add Intel VT support to QEMU?

[Qemu-devel] Add Intel VT support to QEMU?

[Jason Martens]

Hello Everyone
   I'm a part of a school group, and we are looking at adding Intel VT
support to QEMU for a class project.  We would be implementing support
for VT guests, so that other VMMs that rely on VT could be run/debugged
using QEMU.  We are not familiar with QEMU code (yet!), so we are
looking for some feedback from all of you experts.

1. Has this been attempted before, or is there any existing code for
this?  I saw some posts about a year ago that perhaps someone started on
it, but nothing after that.

2. What would be required to implement this?  Any suggestions on where
to start looking would be appreciated.  Obviously, the Intel VT docs are
going to be necessary.  Are there other things that you recommend we
look at before we start?

Thanks,

Jason Martens

Re: [Qemu-devel] Add Intel VT support to QEMU?

[Jamie Lokier]

Jason Martens wrote:
> 1. Has this been attempted before, or is there any existing code for
> this?  I saw some posts about a year ago that perhaps someone started on
> it, but nothing after that.

AMD SVM guest support was added recently, although the change note
suggests it needs to run on an SVM host.

Intel VT would be a great addition alongside it, and might be able to
share some of the code.

-- Jamie

Re: [Qemu-devel] Add Intel VT support to QEMU?

[Alexey Eremenko]

On Mon, Jan 19, 2009 at 12:22 AM, Jamie Lokier <jamie@shareable.org> wrote:
> Jason Martens wrote:
>> 1. Has this been attempted before, or is there any existing code for
>> this?  I saw some posts about a year ago that perhaps someone started on
>> it, but nothing after that.
>
> AMD SVM guest support was added recently, although the change note
> suggests it needs to run on an SVM host.
>
> Intel VT would be a great addition alongside it, and might be able to
> share some of the code.
>
> -- Jamie

People I don't really understand it -- but maybe it is easier for you
to make KVM more portable (i.e. port it to Windows) and better
integrate with Qemu ?
instead of writing from scratch

-- 
-Alexey Eromenko "Technologov"

Re: [Qemu-devel] Add Intel VT support to QEMU?

[Alexander Graf]

On 18.01.2009, at 19:33, Jason Martens wrote:

> Hello Everyone
>  I'm a part of a school group, and we are looking at adding Intel VT
> support to QEMU for a class project.  We would be implementing support
> for VT guests, so that other VMMs that rely on VT could be run/ 
> debugged
> using QEMU.  We are not familiar with QEMU code (yet!), so we are
> looking for some feedback from all of you experts.

Now that's good news :-). I would really love to see this implemented.

> 1. Has this been attempted before, or is there any existing code for
> this?  I saw some posts about a year ago that perhaps someone  
> started on
> it, but nothing after that.

Well - yes and no. I implemented SVM emulation support quite some time  
ago, so you can base on that. It should be possible to reuse some of  
that logic and the basic approach is the same anyways.

> 2. What would be required to implement this?  Any suggestions on where
> to start looking would be appreciated.  Obviously, the Intel VT docs  
> are
> going to be necessary.  Are there other things that you recommend we
> look at before we start?

If I were you I'd start with the instructions themselves. Look through  
the docs and see what each instruction does. Implement the easy ones  
first (VMXON and the CR4 bit), then go forward to VMENTER and  
implement the world switch. As soon as you are running code fine in  
the guest (check using -d in_asm,cpu) you can try and go for intercepts.

By the time you have these working, you should be pretty much done.

Good luck!

Alex

Re: [Qemu-devel] Add Intel VT support to QEMU?

[Kevin Wolf]

Jason Martens schrieb:
> Hello Everyone
>   I'm a part of a school group, and we are looking at adding Intel VT
> support to QEMU for a class project.  We would be implementing support
> for VT guests, so that other VMMs that rely on VT could be run/debugged
> using QEMU.  We are not familiar with QEMU code (yet!), so we are
> looking for some feedback from all of you experts.
> 
> 1. Has this been attempted before, or is there any existing code for
> this?  I saw some posts about a year ago that perhaps someone started on
> it, but nothing after that.

I've started to implement it once, but haven't come very far. The very
basic instructions are implemented, but that's it. IIRC you could load
the KVM modules but it wouldn't run anything.

If you like I can try to rebase my code on the current SVN version and
send you a patch series.

> 2. What would be required to implement this?  Any suggestions on where
> to start looking would be appreciated.  Obviously, the Intel VT docs are
> going to be necessary.  Are there other things that you recommend we
> look at before we start?

What I used was only the Intel docs and partly the KVM sources.

Kevin

Re: [Qemu-devel] Add Intel VT support to QEMU?

[Jason Martens]

Kevin Wolf wrote:
> Jason Martens schrieb:
>   
>> Hello Everyone
>>   I'm a part of a school group, and we are looking at adding Intel VT
>> support to QEMU for a class project.  We would be implementing support
>> for VT guests, so that other VMMs that rely on VT could be run/debugged
>> using QEMU.  We are not familiar with QEMU code (yet!), so we are
>> looking for some feedback from all of you experts.
>>
>> 1. Has this been attempted before, or is there any existing code for
>> this?  I saw some posts about a year ago that perhaps someone started on
>> it, but nothing after that.
>>     
>
> I've started to implement it once, but haven't come very far. The very
> basic instructions are implemented, but that's it. IIRC you could load
> the KVM modules but it wouldn't run anything.
>
> If you like I can try to rebase my code on the current SVN version and
> send you a patch series.
>   
Sure, that would be great. Or, if you don't have any time just send me 
what you have and we can use it for reference/starting point.

Thanks,
Jason Martens