Re: [Qemu-devel] On x86 MMU modes

[Sandhya Kumar]

Well, I think we can also achieve this like adding a flag in the structure of CPUTLBEntry. 

Am I missing something?

On Wed, Jun 3, 2015 at 4:22 PM, Paolo Bonzini <address@hidden> wrote:

On 03/06/2015 10:07, Sandhya Kumar wrote:
> Thanks again. One more question.
>
> On versions prior to the mentioned commit, is there any specific reason
> (in x86 source code of QEMU) to choose separate modes for address
> translations (of kernel and user mode)? Or was that done just for
> performance improvement?

It's because pages can be accessible only from kernel space, so the
protection bits for the pages can be different in the two TLBs.

Paolo