diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 87b446535185..4a4a98a4b1bd 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -35,6 +35,8 @@
 #define ARM64_HYP_OFFSET_LOW			14
 #define ARM64_MISMATCHED_CACHE_LINE_SIZE	15
 
-#define ARM64_NCAPS				16
+#define ARM64_UNMAP_KERNEL_AT_EL0		23
+
+#define ARM64_NCAPS				24
 
 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 478e6bc6b4e8..78b79dfc2905 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -35,7 +35,8 @@ typedef struct {
 
 static inline bool arm64_kernel_unmapped_at_el0(void)
 {
-	return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0);
+	return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0) &&
+	       cpus_have_cap(ARM64_UNMAP_KERNEL_AT_EL0);
 }
 
 extern void paging_init(void);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0127e1bb5a7c..bfbd9e90fa04 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -748,6 +748,40 @@ static bool hyp_offset_low(const struct arm64_cpu_capabilities *entry,
 	return idmap_addr > GENMASK(VA_BITS - 2, 0) && !is_kernel_in_hyp_mode();
 }
 
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
+
+static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
+				int __unused)
+{
+	/* Forced on command line? */
+	if (__kpti_forced) {
+		pr_info_once("kernel page table isolation forced %s by command line option\n",
+			     __kpti_forced > 0 ? "ON" : "OFF");
+		return __kpti_forced > 0;
+	}
+
+	/* Useful for KASLR robustness */
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
+		return true;
+
+	return false;
+}
+
+static int __init parse_kpti(char *str)
+{
+	bool enabled;
+	int ret = strtobool(str, &enabled);
+
+	if (ret)
+		return ret;
+
+	__kpti_forced = enabled ? 1 : -1;
+	return 0;
+}
+__setup("kpti=", parse_kpti);
+#endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
+
 static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "GIC system register CPU interface",
@@ -831,6 +865,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.def_scope = SCOPE_SYSTEM,
 		.matches = hyp_offset_low,
 	},
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+	{
+		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
+		.def_scope = SCOPE_SYSTEM,
+		.matches = unmap_kernel_at_el0,
+	},
+#endif
 	{},
 };
 
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 79ea90b33682..6e9ce0fb147b 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -74,6 +74,7 @@
 	.macro kernel_ventry, el, label, regsize = 64
 	.align 7
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+alternative_if ARM64_UNMAP_KERNEL_AT_EL0
 	.if	\el == 0
 	.if	\regsize == 64
 	mrs	x30, tpidrro_el0
@@ -82,6 +83,7 @@
 	mov	x30, xzr
 	.endif
 	.endif
+alternative_else_nop_endif
 #endif
 
 	sub	sp, sp, #S_FRAME_SIZE
@@ -270,10 +272,9 @@ alternative_else_nop_endif
 	ldr	lr, [sp, #S_LR]
 	add	sp, sp, #S_FRAME_SIZE		// restore sp
 
-#ifndef CONFIG_UNMAP_KERNEL_AT_EL0
-	eret
-#else
 	.if	\el == 0
+alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 	bne	4f
 	msr	far_el1, x30
 	tramp_alias	x30, tramp_exit_native
@@ -281,10 +282,10 @@ alternative_else_nop_endif
 4:
 	tramp_alias	x30, tramp_exit_compat
 	br	x30
+#endif
 	.else
 	eret
 	.endif
-#endif
 	.endm
 
 	.macro	irq_stack_entry