target/arm: Disable HSTR_EL2 traps if EL2 is not enabled

The HSTR_EL2 register is not supposed to have an effect unless EL2 is
enabled in the current security state.  We weren't checking for this,
which meant that if the guest set up the HSTR_EL2 register we would
incorrectly trap even for accesses from Secure EL0 and EL1.

Add the missing checks. (Other places where we look at HSTR_EL2
for the not-in-v8A bits TTEE and TJDBX are already checking that
we are in NS EL0 or EL1, so there we alredy know EL2 is enabled.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-8-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-8-peter.maydell@linaro.org

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6f6772d8e043e97ab40404fb1264f7628f4dc1e3..669668692189a0173fbe78447db052aa16014f39 100644 (file)
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11716,7 +11716,7 @@ static CPUARMTBFlags rebuild_hflags_a32(CPUARMState *env, int fp_el,
         DP_TBFLAG_A32(flags, VFPEN, 1);
     }
 
-    if (el < 2 && env->cp15.hstr_el2 &&
+    if (el < 2 && env->cp15.hstr_el2 && arm_is_el2_enabled(env) &&
         (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
         DP_TBFLAG_A32(flags, HSTR_ACTIVE, 1);
     }

diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
index 7797a137af6ae8b5978b7b4613c889ced640367a..dec03310ad567a4d8bc31ccf6bca9d0f0290446a 100644 (file)
--- a/target/arm/op_helper.c
+++ b/target/arm/op_helper.c
@@ -663,6 +663,7 @@ const void *HELPER(access_check_cp_reg)(CPUARMState *env, uint32_t key,
      * we only need to check here for traps from EL0.
      */
     if (!is_a64(env) && arm_current_el(env) == 0 && ri->cp == 15 &&
+        arm_is_el2_enabled(env) &&
         (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
         uint32_t mask = 1 << ri->crn;