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KVM: MMU: fix kvm_mmu_slot_remove_write_access dropping intermediate W bits

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Only remove write access in the last sptes.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Xiao Guangrong
2011-03-04 18:56:41 +08:00
committed by Marcelo Tosatti
parent 38a778aa18
commit da8dc75f0c
1 changed files with 7 additions and 2 deletions
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9
arch/x86/kvm/mmu.c
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@@ -3540,12 +3540,17 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
pt = sp->spt; pt = sp->spt;
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
if (sp->role.level != PT_PAGE_TABLE_LEVEL if (!is_shadow_present_pte(pt[i]) ||
&& is_large_pte(pt[i])) { !is_last_spte(pt[i], sp->role.level))
continue;
if (is_large_pte(pt[i])) {
drop_spte(kvm, &pt[i], drop_spte(kvm, &pt[i],
shadow_trap_nonpresent_pte); shadow_trap_nonpresent_pte);
--kvm->stat.lpages; --kvm->stat.lpages;
continue;
} }
/* avoid RMW */ /* avoid RMW */
if (is_writable_pte(pt[i])) if (is_writable_pte(pt[i]))
update_spte(&pt[i], pt[i] & ~PT_WRITABLE_MASK); update_spte(&pt[i], pt[i] & ~PT_WRITABLE_MASK);