target/arm: add 64-bit S-EL2 to EL exception table

With the ARMv8.4-SEL2 extension, EL2 is a legal exception level in
secure mode, though it can only be AArch64.

This patch adds the target EL for exceptions from 64-bit S-EL2.

It also fixes the target EL to EL2 when HCR.{A,F,I}MO are set in secure
mode. Those values were never used in practice as the effective value of
HCR was always 0 in secure mode.

Signed-off-by: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210112104511.36576-7-remi.denis.courmont@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/helper.c

@@ -9002,13 +9002,13 @@ static const int8_t target_el_table[2][2][2][2][2][4] = {
       {{/* 0   1   1   0 */{ 3,  3,  3, -1 },{ 3, -1, -1,  3 },},
        {/* 0   1   1   1 */{ 3,  3,  3, -1 },{ 3, -1, -1,  3 },},},},},
     {{{{/* 1   0   0   0 */{ 1,  1,  2, -1 },{ 1,  1, -1,  1 },},
-       {/* 1   0   0   1 */{ 2,  2,  2, -1 },{ 1,  1, -1,  1 },},},
-      {{/* 1   0   1   0 */{ 1,  1,  1, -1 },{ 1,  1, -1,  1 },},
-       {/* 1   0   1   1 */{ 2,  2,  2, -1 },{ 1,  1, -1,  1 },},},},
+       {/* 1   0   0   1 */{ 2,  2,  2, -1 },{ 2,  2, -1,  1 },},},
+      {{/* 1   0   1   0 */{ 1,  1,  1, -1 },{ 1,  1,  1,  1 },},
+       {/* 1   0   1   1 */{ 2,  2,  2, -1 },{ 2,  2,  2,  1 },},},},
      {{{/* 1   1   0   0 */{ 3,  3,  3, -1 },{ 3,  3, -1,  3 },},
        {/* 1   1   0   1 */{ 3,  3,  3, -1 },{ 3,  3, -1,  3 },},},
-      {{/* 1   1   1   0 */{ 3,  3,  3, -1 },{ 3,  3, -1,  3 },},
-       {/* 1   1   1   1 */{ 3,  3,  3, -1 },{ 3,  3, -1,  3 },},},},},
+      {{/* 1   1   1   0 */{ 3,  3,  3, -1 },{ 3,  3,  3,  3 },},
+       {/* 1   1   1   1 */{ 3,  3,  3, -1 },{ 3,  3,  3,  3 },},},},},
 };
 
 /*

target/arm/op_helper.c

@@ -652,10 +652,10 @@ void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome,
         target_el = exception_target_el(env);
         break;
     case CP_ACCESS_TRAP_EL2:
-        /* Requesting a trap to EL2 when we're in EL3 or S-EL0/1 is
+        /* Requesting a trap to EL2 when we're in EL3 is
          * a bug in the access function.
          */
-        assert(!arm_is_secure(env) && arm_current_el(env) != 3);
+        assert(arm_current_el(env) != 3);
         target_el = 2;
         break;
     case CP_ACCESS_TRAP_EL3: