Support ALLINT msr access as follow:
	mrs <xt>, ALLINT	// read allint
	msr ALLINT, <xt>	// write allint with imm

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
v3:
- Remove EL0 check in aa64_allint_access() which alreay checks in .access
  PL1_RW.
- Use arm_hcrx_el2_eff() in aa64_allint_access() instead of env->cp15.hcrx_el2.
- Make ALLINT msr access function controlled by aa64_nmi.
---
 target/arm/helper.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index b7e4c7ddbc..b01f23b939 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -4618,6 +4618,37 @@ static void aa64_daif_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->daif = value & PSTATE_DAIF;
 }
 
+static void aa64_allint_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint64_t value)
+{
+    env->allint = value & PSTATE_ALLINT;
+}
+
+static uint64_t aa64_allint_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    return env->allint & PSTATE_ALLINT;
+}
+
+static CPAccessResult aa64_allint_access(CPUARMState *env,
+                                         const ARMCPRegInfo *ri, bool isread)
+{
+    if (arm_current_el(env) == 1 && arm_is_el2_enabled(env) &&
+        (arm_hcrx_el2_eff(env) & HCRX_TALLINT)) {
+        return CP_ACCESS_TRAP_EL2;
+    }
+    return CP_ACCESS_OK;
+}
+
+static const ARMCPRegInfo nmi_reginfo[] = {
+    { .name = "ALLINT", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 0, .opc2 = 0, .crn = 4, .crm = 3,
+      .type = ARM_CP_NO_RAW,
+      .access = PL1_RW, .accessfn = aa64_allint_access,
+      .fieldoffset = offsetof(CPUARMState, allint),
+      .writefn = aa64_allint_write, .readfn = aa64_allint_read,
+      .resetfn = arm_cp_reset_ignore },
+};
+
 static uint64_t aa64_pan_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
     return env->pstate & PSTATE_PAN;
@@ -9724,6 +9755,10 @@ void register_cp_regs_for_features(ARMCPU *cpu)
     if (cpu_isar_feature(aa64_nv2, cpu)) {
         define_arm_cp_regs(cpu, nv2_reginfo);
     }
+
+    if (cpu_isar_feature(aa64_nmi, cpu)) {
+        define_arm_cp_regs(cpu, nmi_reginfo);
+    }
 #endif
 
     if (cpu_isar_feature(any_predinv, cpu)) {
-- 
2.34.1

On 2/23/24 00:32, Jinjie Ruan via wrote:
> +static CPAccessResult aa64_allint_access(CPUARMState *env,
> +                                         const ARMCPRegInfo *ri, bool isread)
> +{
> +    if (arm_current_el(env) == 1 && arm_is_el2_enabled(env) &&
> +        (arm_hcrx_el2_eff(env) & HCRX_TALLINT)) {

No need to test arm_is_el2_enabled explicitly, as that is done by arm_hcrx_el2_eff.
The bit test with TALLINT will fail if el2 is disabled.


r~