On 03/29/2012 11:25 AM, Xiao Guangrong wrote: > Using PTE_LIST_WRITE_PROTECT bit in rmap store the write-protect status to > avoid unnecessary shadow page walking > > Also if no shadow page is indirect, the page is write-free > > > @@ -2262,6 +2291,9 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, > } > if (need_unsync) > kvm_unsync_pages(vcpu, gfn); > + > + *rmap &= ~PTE_LIST_WRITE_PROTECT; > + > So what are the rules for PTE_LIST_WRITE_PROTECT? Is is a cache for the mmu_need_write_protect? I'd like to understand it, I guess it can be set while write protection is unneeded, and cleared on the next check? Maybe split into two functions, one the normal mmu_need_write_protect (but renamed) and a new mmu_need_write_protect(), with locked and unlocked variants, calling the old one. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
