Re: [PATCH v2 3/10] KVM: MMU: fix direct sp's access corruptted

Xiao Guangrong
2010-06-28T10:02:26Z

Avi Kivity wrote:

>
> Instead of adding a new bit, can you encode the protection in the direct
> sp's access bits? So we'll have one sp for read-only or
> writeable-but-not-dirty small pages, and another sp for
> writeable-and-dirty small pages.
>

It looks like it can't solve all problems, it fix the access corrupted,
but will cause D bit losed:

mapping A and mapping B both are writable-and-dirty, when mapping A write
#PF occurs, the mapping is writable, then we can't set B's D bit anymore.

Anyway, i think we should re-intall the mapping when the state is changed. :-(