Messages in this thread | | | Date | Tue, 12 Jun 2012 23:01:03 -0300 | From | Marcelo Tosatti <> | Subject | Re: [PATCH v6 5/9] KVM: MMU: introduce SPTE_MMU_WRITEABLE bit |
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On Tue, Jun 12, 2012 at 10:23:47AM +0800, Xiao Guangrong wrote: > On 06/12/2012 07:32 AM, Marcelo Tosatti wrote: > > > On Tue, May 29, 2012 at 02:49:14PM +0800, Xiao Guangrong wrote: > >> This bit indicates whether the spte can be writable on MMU, that means > >> the corresponding gpte is writable and the corresponding gfn is not > >> protected by shadow page protection > > > > Why is this still necessary, now that only sptes of direct shadow pages > > are updated locklessly? > > > > > Yes, but it is still needed, for nested npt/ept, we need protect > the nested page tables.
Sure, but shadowed L1 nested pagetables are not direct shadow pages.
They are shadows of L1 nested pagetables.
Checking sp->direct should be enough (instead of the flags).
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