[PATCH v2 02/24] target/arm: Adjust definition of CONTEXTIDR_EL2

[Richard Henderson]

This register is present for either VHE or Debugv8p2, and is
RES0 from EL3 when EL2 is not present.  Move the definition
out of vhe_reginfo and provide a fallback for missing EL2.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 7d14650615..210c139818 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -7443,11 +7443,20 @@ static const ARMCPRegInfo jazelle_regs[] = {
     REGINFO_SENTINEL
 };
 
+static const ARMCPRegInfo contextidr_el2 = {
+    .name = "CONTEXTIDR_EL2", .state = ARM_CP_STATE_AA64,
+    .opc0 = 3, .opc1 = 4, .crn = 13, .crm = 0, .opc2 = 1,
+    .access = PL2_RW,
+    .fieldoffset = offsetof(CPUARMState, cp15.contextidr_el[2])
+};
+
+static const ARMCPRegInfo contextidr_no_el2 = {
+    .name = "CONTEXTIDR_EL2", .state = ARM_CP_STATE_AA64,
+    .opc0 = 3, .opc1 = 4, .crn = 13, .crm = 0, .opc2 = 1,
+    .access = PL2_RW, .type = ARM_CP_CONST, .resetvalue = 0
+};
+
 static const ARMCPRegInfo vhe_reginfo[] = {
-    { .name = "CONTEXTIDR_EL2", .state = ARM_CP_STATE_AA64,
-      .opc0 = 3, .opc1 = 4, .crn = 13, .crm = 0, .opc2 = 1,
-      .access = PL2_RW,
-      .fieldoffset = offsetof(CPUARMState, cp15.contextidr_el[2]) },
     { .name = "TTBR1_EL2", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 0, .opc2 = 1,
       .access = PL2_RW, .writefn = vmsa_tcr_ttbr_el2_write,
@@ -8443,6 +8452,14 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         define_one_arm_cp_reg(cpu, &ssbs_reginfo);
     }
 
+    if (cpu_isar_feature(aa64_vh, cpu) ||
+        cpu_isar_feature(aa64_debugv8p2, cpu)) {
+        if (arm_feature(env, ARM_FEATURE_EL2)) {
+            define_one_arm_cp_reg(cpu, &contextidr_el2);
+        } else {
+            define_one_arm_cp_reg(cpu, &contextidr_no_el2);
+        }
+    }
     if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {
         define_arm_cp_regs(cpu, vhe_reginfo);
     }
-- 
2.25.1