Messages in this thread | | | Date | Tue, 29 Jun 2010 17:13:44 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v2 3/10] KVM: MMU: fix direct sp's access corruptted |
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Avi Kivity wrote: > On 06/29/2010 12:04 PM, Xiao Guangrong wrote: >> >>> Simply replace (*spte& SPTE_NO_DIRTY) with a condition that checks >>> whether sp->access is consistent with gw->pt(e)_access. >>> >>> >> If the guest mapping is writable and it !dirty, we mark SPTE_NO_DIRTY >> flag in >> the spte, when the next #PF occurs, we just need check this flag and >> see whether >> gpte's D bit is set, if it's true, we zap this spte and map to the >> correct sp. >> > > My point is, SPTE_NO_DIRTY is equivalent to an sp->role.access check > (the access check is a bit slower, but that shouldn't matter). >
I see.
> >>> Can you write a test case for qemu-kvm.git/kvm/test that demonstrates >>> the problem and the fix? It will help ensure we don't regress in this >>> area. >>> >>> >> OK, but allow me do it later :-) >> >> > > Sure, but please do it soon.
Sure, i will do it as soon as possible.
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