KVM: MMU: Introduce kvm_pdptr_read_mmu

This function is implemented to load the pdptr pointers of
the currently running guest (l1 or l2 guest). Therefore it
takes care about the current paging mode and can read pdptrs
out of l2 guest physical memory.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

3 files changed, 9 insertions, 2 deletions

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index a37abe2ec39a..975bb45329a1 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -45,6 +45,13 @@ static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
         return vcpu->arch.walk_mmu->pdptrs[index];
 }
 
+static inline u64 kvm_pdptr_read_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, int index)
+{
+        load_pdptrs(vcpu, mmu, mmu->get_cr3(vcpu));
+
+        return mmu->pdptrs[index];
+}
+
 static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
 {
         ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a26f13bd34e0..a25173a0d8b9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2398,7 +2398,7 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
 
                 ASSERT(!VALID_PAGE(root));
                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
-                        pdptr = kvm_pdptr_read(vcpu, i);
+                        pdptr = kvm_pdptr_read_mmu(vcpu, &vcpu->arch.mmu, i);
                         if (!is_present_gpte(pdptr)) {
                                 vcpu->arch.mmu.pae_root[i] = 0;
                                 continue;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index f4e09d341e28..a28f09bb76c6 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -137,7 +137,7 @@ walk:
 
 #if PTTYPE == 64
         if (walker->level == PT32E_ROOT_LEVEL) {
-                pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
+                pte = kvm_pdptr_read_mmu(vcpu, mmu, (addr >> 30) & 3);
                 trace_kvm_mmu_paging_element(pte, walker->level);
                 if (!is_present_gpte(pte)) {
                         present = false;