From da8dc75f0c4663a568a0ed4e744c6d55d428d8b6 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 4 Mar 2011 18:56:41 +0800 Subject: [PATCH] KVM: MMU: fix kvm_mmu_slot_remove_write_access dropping intermediate W bits Only remove write access in the last sptes. Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index b6a9963400a7..b9bf016d7f0f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3540,12 +3540,17 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) pt = sp->spt; for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - if (sp->role.level != PT_PAGE_TABLE_LEVEL - && is_large_pte(pt[i])) { + if (!is_shadow_present_pte(pt[i]) || + !is_last_spte(pt[i], sp->role.level)) + continue; + + if (is_large_pte(pt[i])) { drop_spte(kvm, &pt[i], shadow_trap_nonpresent_pte); --kvm->stat.lpages; + continue; } + /* avoid RMW */ if (is_writable_pte(pt[i])) update_spte(&pt[i], pt[i] & ~PT_WRITABLE_MASK);