Messages in this thread | | | Date | Wed, 27 Jul 2011 12:15:29 +0300 | From | Avi Kivity <> | Subject | Re: [PATCH 10/11] KVM: MMU: fix detecting misaligned accessed |
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On 07/26/2011 02:31 PM, Xiao Guangrong wrote: > Sometimes, we only modify the last one byte of a pte to update status bit, > for example, clear_bit is used to clear r/w bit in linux kernel and 'andb' > instruction is used in this function, in this case, kvm_mmu_pte_write will > treat it as misaligned access, and the shadow page table is zapped > > @@ -3597,6 +3597,14 @@ static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, > > offset = offset_in_page(gpa); > pte_size = sp->role.cr4_pae ? 8 : 4; > + > + /* > + * Sometimes, the OS only writes the last one bytes to update status > + * bits, for example, in linux, andb instruction is used in clear_bit(). > + */ > + if (sp->role.level == 1&& !(offset& (pte_size - 1))&& bytes == 1) > + return false; > +
Could be true for level > 1, no?
-- error compiling committee.c: too many arguments to function
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