Re: re-writing on powerpc

[Hollis Blanchard <hollis_blanchard@mentor.com>]

On 12/13/2010 12:35 AM, Avi Kivity wrote:
> On 12/13/2010 06:45 AM, Yoder Stuart-B08248 wrote:
>> Avi/Hollis,
>>
>> Exchanged some emails with Alex on the topic of rewriting on
>> powerpc KVM-- the current approach taken by Alex's PV patch is
>> to have a guest Linux paravirt  itself, by re-writing certain
>> instructions.
>>
>> The downside to this approach (guest side patching) is that every OS
>> to be run on KVM has to be modified or dynamically patched.
>>
>> What were the reasons for not going down the path of doing the
>> re-writing in the hypervisor?  (Alex couldn't remember the
>> specifics).    What about doing it from Qemu?
>>
>
> Rewriting is dangerous if the guest is unaware of it.  As soon as it 
> is made aware of it, it might as well actually do it in the best way 
> that suits it.
Can you list some examples of dangerous scenarios?

Hollis Blanchard
Mentor Graphics, Embedded Systems Division