KVM: MMU: add kvm_mmu_get_spte_hierarchy helper

Required by EPT misconfiguration handler.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e18f65bf2de7..12974de88aa5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3038,6 +3038,24 @@ out:
         return r;
 }
 
+int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
+{
+        struct kvm_shadow_walk_iterator iterator;
+        int nr_sptes = 0;
+
+        spin_lock(&vcpu->kvm->mmu_lock);
+        for_each_shadow_entry(vcpu, addr, iterator) {
+                sptes[iterator.level-1] = *iterator.sptep;
+                nr_sptes++;
+                if (!is_shadow_present_pte(*iterator.sptep))
+                        break;
+        }
+        spin_unlock(&vcpu->kvm->mmu_lock);
+
+        return nr_sptes;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
+
 #ifdef AUDIT
 
 static const char *audit_msg;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 016bf7183e9f..61a1b3884b49 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -37,6 +37,8 @@
 #define PT32_ROOT_LEVEL 2
 #define PT32E_ROOT_LEVEL 3
 
+int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
+
 static inline void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
 {
         if (unlikely(vcpu->kvm->arch.n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES))