Re: [Qemu-devel] cpuid problem in upstream qemu with kvm

[Alexander Graf]

On 21.12.2009, at 12:38, Michael S. Tsirkin wrote:

> On Mon, Dec 21, 2009 at 12:22:53PM +0100, Alexander Graf wrote:
>> 
>> On 21.12.2009, at 12:18, Michael S. Tsirkin wrote:
>> 
>>> On Mon, Dec 21, 2009 at 01:12:26PM +0200, Avi Kivity wrote:
>>>> On 12/20/2009 07:18 PM, Michael S. Tsirkin wrote:
>>>>> 
>>>>>>> Hmm, then, shouldn't either kvm or qemu mask features that we do not
>>>>>>> emulate well enough to make windows not crash?
>>>>>>> 
>>>>>> -cpu host does that already, no?
>>>>>> 
>>>>>> Alex
>>>>>> 
>>>>> I expected so, but Avi here seems to say windows will crash if you
>>>>> use a new CPU with it ...
>>>>> 
>>>> 
>>>> No, Windows tries to detect changes in your hardware and assumes that if  
>>>> too many things change, you might be a pirate and requires you to phone  
>>>> their offices to re-authenticate.
>>> 
>>> How often does a casual user upgrade his host CPU?
>> 
>> I tend to have my VM images on an NFS share and expect them to work properly 
>> on all PCs I work on.
>> So I guess the answer is "often"?
>> 
>> Alex
> 
> Yes but you are not a casual user, are you?  

Well, we have two groups:

1) Casual user w/o management app
2) Enterprise user w/ management app

So I clearly belong to the first group.

> Consider a 64 bit guest to
> see why moving a VM across machines needs some planning.

-ENOPARSE

We're still talking about bootup on different machines, not migration / loadvm.

Alex