diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index 8a20dce..0e7656f 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -207,6 +207,7 @@
 MSR_i_TCO       1101 0101 0000 0 011 0100 .... 100 11111 @msr_i
 MSR_i_DAIFSET   1101 0101 0000 0 011 0100 .... 110 11111 @msr_i
 MSR_i_DAIFCLEAR 1101 0101 0000 0 011 0100 .... 111 11111 @msr_i
+MSR_i_ALLINT    1101 0101 0000 0 001 0100 000 imm:1 000 11111
 MSR_i_SVCR      1101 0101 0000 0 011 0100 0 mask:2 imm:1 011 11111
 
 # MRS, MSR (register), SYS, SYSL. These are all essentially the
diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c
index 29f3ef2..0ea8668 100644
--- a/target/arm/tcg/helper-a64.c
+++ b/target/arm/tcg/helper-a64.c
@@ -66,6 +66,18 @@
     update_spsel(env, imm);
 }
 
+void HELPER(msr_set_allint_el1)(CPUARMState *env)
+{
+    /* ALLINT update to PSTATE. */
+    if (arm_hcrx_el2_eff(env) & HCRX_TALLINT) {
+        raise_exception_ra(env, EXCP_UDEF,
+                           syn_aa64_sysregtrap(0, 1, 0, 4, 1, 0x1f, 0), 2,
+                           GETPC());
+    }
+
+    env->pstate |= PSTATE_ALLINT;
+}
+
 static void daif_check(CPUARMState *env, uint32_t op,
                        uint32_t imm, uintptr_t ra)
 {
diff --git a/target/arm/tcg/helper-a64.h b/target/arm/tcg/helper-a64.h
index 575a5da..0518165 100644
--- a/target/arm/tcg/helper-a64.h
+++ b/target/arm/tcg/helper-a64.h
@@ -22,6 +22,7 @@
 DEF_HELPER_2(msr_i_spsel, void, env, i32)
 DEF_HELPER_2(msr_i_daifset, void, env, i32)
 DEF_HELPER_2(msr_i_daifclear, void, env, i32)
+DEF_HELPER_1(msr_set_allint_el1, void, env)
 DEF_HELPER_3(vfp_cmph_a64, i64, f16, f16, ptr)
 DEF_HELPER_3(vfp_cmpeh_a64, i64, f16, f16, ptr)
 DEF_HELPER_3(vfp_cmps_a64, i64, f32, f32, ptr)
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 2666d52..976094a 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -2036,6 +2036,25 @@
     return true;
 }
 
+static bool trans_MSR_i_ALLINT(DisasContext *s, arg_i *a)
+{
+    if (!dc_isar_feature(aa64_nmi, s) || s->current_el == 0) {
+        return false;
+    }
+
+    if (a->imm == 0) {
+        clear_pstate_bits(PSTATE_ALLINT);
+    } else if (s->current_el > 1) {
+        set_pstate_bits(PSTATE_ALLINT);
+    } else {
+        gen_helper_msr_set_allint_el1(tcg_env);
+    }
+
+    /* Exit the cpu loop to re-evaluate pending IRQs. */
+    s->base.is_jmp = DISAS_UPDATE_EXIT;
+    return true;
+}
+
 static bool trans_MSR_i_SVCR(DisasContext *s, arg_MSR_i_SVCR *a)
 {
     if (!dc_isar_feature(aa64_sme, s) || a->mask == 0) {