Messages in this thread | | | Date | Wed, 03 Aug 2011 14:02:31 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v2 02/12] KVM: x86: tag the instructions which are used to write page table |
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On 08/02/2011 08:20 PM, Avi Kivity wrote: > On 08/02/2011 02:07 PM, 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 > > We already have a mechanism for this, the decode tables. Why not add a new flag, PageTable, and set it on all relevant instructions? >
OK, will do it in the next version.
> Note we don't need to actually emulate, just decode, since page_fault can tell us whether a write failed due to page tables or mmio. >
This is a interesting feature. If it happens, i will just drop the shadow pages and retry these instructions directly.
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