Re: AMD-Intel guest migration and CPUs without NX

[Tomasz Chmielewski <mangoo@wpkg.org>]

Avi Kivity schrieb:

>> So the above says I may have some problems.
> 
> Right, it's not safe in general.  It may work if the guest doesn't use 
> NX.  It may also work if the guest does not rely on NX working properly.

Although I think my guests don't use it, you never know.
Is it possible to disable NX for chosen guests?


>> On the other hand, FAQ below seems to indicate that migration on 64 
>> bit hosts should be fine (even when they don't support NX?), only 32 
>> bit hosts may have problems:
>>
>> http://www.linux-kvm.org/page/FAQ
>>
>>   Yes. There may be issues on 32-bit Intel hosts which don't support NX
>>   (or XD), but for 64-bit hosts back and forth migration should work
>>   well. Migration of 32-bit guests should work between 32-bit hosts and
>>   64-bit hosts.
> 
> Looks like that paragraph assumes that all 64-bit hosts have NX.  Your 
> /proc/cpuinfo proves otherwise.

-- 
Tomasz Chmielewski
http://wpkg.org