Re: [PATCH 02/11] KVM: x86: tag the instructions which are used to write page table

Marcelo Tosatti
2011-08-22T14:32:52Z

On Tue, Aug 16, 2011 at 02:41:27PM +0800, Xiao Guangrong wrote:
> The idea is from Avi:
> | tag instructions that are typically used to modify the page tables, and
> | drop shadow if any other instruction is used.
> | The list would include, I'd guess, and, or, bts, btc, mov, xchg, cmpxchg,
> | and cmpxchg8b.
>
> This patch is used to tag the instructions and in the later path, shadow page
> is dropped if it is written by other instructions

What is the advantage of doing this again? What is the point of
dropping shadow if the instruction is emulated?