Re: [PATCH v2 05/12] KVM: x86: fast emulate repeat string write instructions

Avi Kivity
2011-08-03T08:10:53Z

On 08/02/2011 02:09 PM, Xiao Guangrong wrote:
> We usually use repeat string instructions to clear the page, for example,
> we call memset to clear a page table, stosb is used in this function, and
> repeated for 1024 times, that means we should occupy mmu lock for 1024 times
> and walking shadow page cache for 1024 times, it is terrible
>
> In fact, if it is the repeat string instructions emulated and it is not a
> IO/MMIO access, we can zap all the corresponding shadow pages and return to the
> guest, then the mapping can became writable and we can directly write the page
>

This isn't needed if we zap before emulating, right?

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error compiling committee.c: too many arguments to function