KVM: nVMX: support descriptor table exits

These are never used by the host, but they can still be reflected to
the guest.

Tested-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7eb72f7..dcb840e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2796,6 +2796,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
 	vmx->nested.nested_vmx_secondary_ctls_high &=
 		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
 		SECONDARY_EXEC_RDTSCP |
+		SECONDARY_EXEC_DESC |
 		SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
 		SECONDARY_EXEC_ENABLE_VPID |
 		SECONDARY_EXEC_APIC_REGISTER_VIRT |
@@ -7961,6 +7962,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 		return nested_cpu_has(vmcs12, CPU_BASED_MOV_DR_EXITING);
 	case EXIT_REASON_IO_INSTRUCTION:
 		return nested_vmx_exit_handled_io(vcpu, vmcs12);
+	case EXIT_REASON_GDTR_IDTR: case EXIT_REASON_LDTR_TR:
+		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_DESC);
 	case EXIT_REASON_MSR_READ:
 	case EXIT_REASON_MSR_WRITE:
 		return nested_vmx_exit_handled_msr(vcpu, vmcs12, exit_reason);