KVM: nVMX: Write ENCLS-exiting bitmap once per vmcs02

KVM doesn't yet support SGX virtualization, i.e. writes a constant value
to ENCLS_EXITING_BITMAP so that it can intercept ENCLS and inject a #UD.

Fixes: 0b665d30 ("KVM: vmx: Inject #UD for SGX ENCLS instruction in guest")
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -1943,6 +1943,9 @@ static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx)
 	if (enable_pml)
 		vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
 
+	if (cpu_has_vmx_encls_vmexit())
+		vmcs_write64(ENCLS_EXITING_BITMAP, -1ull);
+
 	/*
 	 * Set the MSR load/store lists to match L0's settings.  Only the
 	 * addresses are constant (for vmcs02), the counts can change based
@@ -2065,9 +2068,6 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 		if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)
 			vmcs_write64(APIC_ACCESS_ADDR, -1ull);
 
-		if (exec_control & SECONDARY_EXEC_ENCLS_EXITING)
-			vmcs_write64(ENCLS_EXITING_BITMAP, -1ull);
-
 		vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
 	}