diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index ea6995920b7a..e6eaee8509ce 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -256,6 +256,22 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
 	testl	$X2APIC_ENABLE, %eax
 	jnz	.Lread_apicid_msr
 
+#ifdef CONFIG_X86_X2APIC
+	/*
+	 * If system is in X2APIC mode then MMIO base might not be
+	 * mapped causing the MMIO read below to fault. Faults can't
+	 * be handled at that point.
+	 */
+	cmpl	$0, x2apic_mode(%rip)
+	jz	.Lread_apicid_mmio
+
+	/* Force the AP into X2APIC mode. */
+	orl	$X2APIC_ENABLE, %eax
+	wrmsr
+	jmp	.Lread_apicid_msr
+#endif
+
+.Lread_apicid_mmio:
 	/* Read the APIC ID from the fix-mapped MMIO space. */
 	movq	apic_mmio_base(%rip), %rcx
 	addq	$APIC_ID, %rcx