[RFC PATCH v8 01/23] target/arm: Handle HCR_EL2 accesses for bits introduced with FEAT_NMI

[Jinjie Ruan via <qemu-devel@nongnu.org>]

FEAT_NMI defines another three new bits in HCRX_EL2: TALLINT, HCRX_VINMI and
HCRX_VFNMI. When the feature is enabled, allow these bits to be written in
HCRX_EL2.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v4:
- Update the comment for FEAT_NMI in hcrx_write().
- Update the commit message, s/thress/three/g.
v3:
- Add Reviewed-by.
- Add HCRX_VINMI and HCRX_VFNMI support in HCRX_EL2.
- Upate the commit messsage.
---
 target/arm/cpu-features.h | 5 +++++
 target/arm/helper.c       | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/target/arm/cpu-features.h b/target/arm/cpu-features.h
index e5758d9fbc..b300d0446d 100644
--- a/target/arm/cpu-features.h
+++ b/target/arm/cpu-features.h
@@ -681,6 +681,11 @@ static inline bool isar_feature_aa64_sme(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, SME) != 0;
 }
 
+static inline bool isar_feature_aa64_nmi(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, NMI) != 0;
+}
+
 static inline bool isar_feature_aa64_tgran4_lpa2(const ARMISARegisters *id)
 {
     return FIELD_SEX64(id->id_aa64mmfr0, ID_AA64MMFR0, TGRAN4) >= 1;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 3f3a5b55d4..b19a0178ce 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6190,6 +6190,11 @@ static void hcrx_write(CPUARMState *env, const ARMCPRegInfo *ri,
         valid_mask |= HCRX_MSCEN | HCRX_MCE2;
     }
 
+    /* FEAT_NMI adds TALLINT, VINMI and VFNMI */
+    if (cpu_isar_feature(aa64_nmi, env_archcpu(env))) {
+        valid_mask |= HCRX_TALLINT | HCRX_VINMI | HCRX_VFNMI;
+    }
+
     /* Clear RES0 bits.  */
     env->cp15.hcrx_el2 = value & valid_mask;
 }
-- 
2.34.1