[PATCH v3 4/7] target/arm: Honor the HCR_EL2.TACR bit

[Richard Henderson]

This bit traps EL1 access to the auxiliary control registers.

Signed-off-by: Richard Henderson <address@hidden>
---
 target/arm/helper.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index dc99ee5d18..52b6e68659 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -553,6 +553,16 @@ static CPAccessResult access_tsw(CPUARMState *env, const 
ARMCPRegInfo *ri,
     return CP_ACCESS_OK;
 }
 
+/* Check for traps from EL1 due to HCR_EL2.TACR.  */
+static CPAccessResult access_tacr(CPUARMState *env, const ARMCPRegInfo *ri,
+                                  bool isread)
+{
+    if (arm_current_el(env) == 1 && (arm_hcr_el2_eff(env) & HCR_TACR)) {
+        return CP_ACCESS_TRAP_EL2;
+    }
+    return CP_ACCESS_OK;
+}
+
 static void dacr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t 
value)
 {
     ARMCPU *cpu = env_archcpu(env);
@@ -6911,8 +6921,8 @@ static const ARMCPRegInfo ats1cp_reginfo[] = {
 static const ARMCPRegInfo actlr2_hactlr2_reginfo[] = {
     { .name = "ACTLR2", .state = ARM_CP_STATE_AA32,
       .cp = 15, .opc1 = 0, .crn = 1, .crm = 0, .opc2 = 3,
-      .access = PL1_RW, .type = ARM_CP_CONST,
-      .resetvalue = 0 },
+      .access = PL1_RW, .accessfn = access_tacr,
+      .type = ARM_CP_CONST, .resetvalue = 0 },
     { .name = "HACTLR2", .state = ARM_CP_STATE_AA32,
       .cp = 15, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 3,
       .access = PL2_RW, .type = ARM_CP_CONST,
@@ -7668,8 +7678,8 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         ARMCPRegInfo auxcr_reginfo[] = {
             { .name = "ACTLR_EL1", .state = ARM_CP_STATE_BOTH,
               .opc0 = 3, .opc1 = 0, .crn = 1, .crm = 0, .opc2 = 1,
-              .access = PL1_RW, .type = ARM_CP_CONST,
-              .resetvalue = cpu->reset_auxcr },
+              .access = PL1_RW, .accessfn = access_tacr,
+              .type = ARM_CP_CONST, .resetvalue = cpu->reset_auxcr },
             { .name = "ACTLR_EL2", .state = ARM_CP_STATE_BOTH,
               .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 1,
               .access = PL2_RW, .type = ARM_CP_CONST,
-- 
2.20.1