[Qemu-devel] [PATCH] target-arm: Avoid calling arm_el_is_aa64() function for unimplemented EL

[Sergey Sorokin]

It is incorrect to call arm_el_is_aa64() function for unimplemented EL.
This patch fixes several attempts to do so.

Signed-off-by: Sergey Sorokin <address@hidden>
---
 target-arm/cpu.h    |  8 +++++---
 target-arm/helper.c | 15 +++++++++++++--
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index cc1578c..df456a5 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -1015,11 +1015,11 @@ static inline bool access_secure_reg(CPUARMState *env)
  */
 #define A32_BANKED_CURRENT_REG_GET(_env, _regname)        \
     A32_BANKED_REG_GET((_env), _regname,                \
-                       ((!arm_el_is_aa64((_env), 3) && arm_is_secure(_env))))
+                       (arm_is_secure(_env) && !arm_el_is_aa64((_env), 3)))
 
 #define A32_BANKED_CURRENT_REG_SET(_env, _regname, _val)                       
\
     A32_BANKED_REG_SET((_env), _regname,                                    \
-                       ((!arm_el_is_aa64((_env), 3) && arm_is_secure(_env))),  
\
+                       (arm_is_secure(_env) && !arm_el_is_aa64((_env), 3)), \
                        (_val))
 
 void arm_cpu_list(FILE *f, fprintf_function cpu_fprintf);
@@ -1586,7 +1586,9 @@ static inline bool arm_excp_unmasked(CPUState *cs, 
unsigned int excp_idx,
      * interrupt.
      */
     if ((target_el > cur_el) && (target_el != 1)) {
-        if (arm_el_is_aa64(env, 3) || ((scr || hcr) && (!secure))) {
+        /* ARM_FEATURE_AARCH64 enabled means the higher EL is AArch64. */
+        if (arm_feature(env, ARM_FEATURE_AARCH64) ||
+            ((scr || hcr) && (!secure))) {
             unmasked = 1;
         }
     }
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 8367997..1f11dbd 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5220,11 +5220,22 @@ uint32_t arm_phys_excp_target_el(CPUState *cs, uint32_t 
excp_idx,
                                  uint32_t cur_el, bool secure)
 {
     CPUARMState *env = cs->env_ptr;
-    int rw = ((env->cp15.scr_el3 & SCR_RW) == SCR_RW);
+    int rw;
     int scr;
     int hcr;
     int target_el;
-    int is64 = arm_el_is_aa64(env, 3);
+    /* Is the higher EL AArch64? */
+    int is64 = arm_feature(env, ARM_FEATURE_AARCH64);
+
+    /* If the highest EL is in AArch64 state, and EL3 is not implemented,
+     * we must behave as if EL3 is implemented and is in AArch64 state.
+     * Therefore we need appropriate RW bit.
+     */
+    if (arm_feature(env, ARM_FEATURE_EL3)) {
+        rw = ((env->cp15.scr_el3 & SCR_RW) == SCR_RW);
+    } else {
+        rw = is64;
+    }
 
     switch (excp_idx) {
     case EXCP_IRQ:
-- 
1.9.3