[Qemu-devel] [PULL 11/23] target-arm: Handle SMC/HVC undef-if-no-ELx in pre_* helpers

[Peter Maydell <peter.maydell@linaro.org>]

SMC must UNDEF if EL3 is not implemented; similarly HVC UNDEFs
if EL2 is not implemented. Move the handling of this from
translate-a64.c into the pre_smc and pre_hvc helper functions.
This is necessary because use of these instructions for PSCI
takes precedence over this UNDEF case, and we can't tell if
this is a PSCI call until runtime.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-5-git-send-email-peter.maydell@linaro.org
---
 target-arm/op_helper.c     | 17 ++++++++++-------
 target-arm/translate-a64.c |  4 ++--
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index 03ac92a..5652096 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -392,10 +392,11 @@ void HELPER(pre_hvc)(CPUARMState *env)
     bool secure = false;
     bool undef;
 
-    /* We've already checked that EL2 exists at translation time.
-     * EL3.HCE has priority over EL2.HCD.
-     */
-    if (arm_feature(env, ARM_FEATURE_EL3)) {
+    if (!arm_feature(env, ARM_FEATURE_EL2)) {
+        /* If EL2 doesn't exist, HVC always UNDEFs */
+        undef = true;
+    } else if (arm_feature(env, ARM_FEATURE_EL3)) {
+        /* EL3.HCE has priority over EL2.HCD. */
         undef = !(env->cp15.scr_el3 & SCR_HCE);
     } else {
         undef = env->cp15.hcr_el2 & HCR_HCD;
@@ -429,13 +430,15 @@ void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)
      */
     bool undef = is_a64(env) ? smd : (!secure && smd);
 
-    /* In NS EL1, HCR controlled routing to EL2 has priority over SMD.  */
-    if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
+    if (!arm_feature(env, ARM_FEATURE_EL3)) {
+        /* If we have no EL3 then SMC always UNDEFs */
+        undef = true;
+    } else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) {
+        /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. */
         env->exception.syndrome = syndrome;
         raise_exception(env, EXCP_HYP_TRAP);
     }
 
-    /* We've already checked that EL3 exists at translation time.  */
     if (undef) {
         env->exception.syndrome = syn_uncategorized();
         raise_exception(env, EXCP_UDEF);
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 35ae3ea..b15261b 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -1485,7 +1485,7 @@ static void disas_exc(DisasContext *s, uint32_t insn)
             gen_exception_insn(s, 0, EXCP_SWI, syn_aa64_svc(imm16));
             break;
         case 2:
-            if (!arm_dc_feature(s, ARM_FEATURE_EL2) || s->current_pl == 0) {
+            if (s->current_pl == 0) {
                 unallocated_encoding(s);
                 break;
             }
@@ -1498,7 +1498,7 @@ static void disas_exc(DisasContext *s, uint32_t insn)
             gen_exception_insn(s, 0, EXCP_HVC, syn_aa64_hvc(imm16));
             break;
         case 3:
-            if (!arm_dc_feature(s, ARM_FEATURE_EL3) || s->current_pl == 0) {
+            if (s->current_pl == 0) {
                 unallocated_encoding(s);
                 break;
             }
-- 
1.9.1