target/arm: Fix reported EL for mte_check_fail

The reporting in AArch64.TagCheckFail only depends on PSTATE.EL,
and not the AccType of the operation.  There are two guest
visible problems that affect LDTR and STTR because of this:

(1) Selecting TCF0 vs TCF1 to decide on reporting,
(2) Report "data abort same el" not "data abort lower el".

Reported-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Message-id: 20201008162155.161886-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 734cc5ca6757d686c9bdcd690877e6abdc3f9348..153bd1e9df889eb08259857daf3633ff9e39efde 100644 (file)
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -525,14 +525,10 @@ static void mte_check_fail(CPUARMState *env, uint32_t desc,
     reg_el = regime_el(env, arm_mmu_idx);
     sctlr = env->cp15.sctlr_el[reg_el];
 
-    switch (arm_mmu_idx) {
-    case ARMMMUIdx_E10_0:
-    case ARMMMUIdx_E20_0:
-        el = 0;
+    el = arm_current_el(env);
+    if (el == 0) {
         tcf = extract64(sctlr, 38, 2);
-        break;
-    default:
-        el = reg_el;
+    } else {
         tcf = extract64(sctlr, 40, 2);
     }