KVM: MMU: Introduce init_kvm_nested_mmu()

This patch introduces the init_kvm_nested_mmu() function
which is used to re-initialize the nested mmu when the l2
guest changes its paging mode.

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

1 files changed, 17 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 46843ed36dc1..e4c76bf86081 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3489,6 +3489,22 @@ static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
         return gpa;
 }
 
+static gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
+{
+        gpa_t t_gpa;
+        u32 error;
+
+        BUG_ON(!mmu_is_nested(vcpu));
+
+        /* NPT walks are always user-walks */
+        access |= PFERR_USER_MASK;
+        t_gpa  = vcpu->arch.mmu.gva_to_gpa(vcpu, gpa, access, &error);
+        if (t_gpa == UNMAPPED_GVA)
+                vcpu->arch.fault.error_code |= PFERR_NESTED_MASK;
+
+        return t_gpa;
+}
+
 gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva, u32 *error)
 {
         u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
@@ -5704,6 +5720,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
         vcpu->arch.walk_mmu = &vcpu->arch.mmu;
         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
         vcpu->arch.mmu.translate_gpa = translate_gpa;
+        vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa;
         if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_bsp(vcpu))
                 vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
         else