[PULL 17/41] target/arm: Ignore HCR_EL2.ATA when {E2H,TGE} != 11

[Peter Maydell]

From: Richard Henderson <richard.hender...@linaro.org>

Unlike many other bits in HCR_EL2, the description for this
bit does not contain the phrase "if ... this field behaves
as 0 for all purposes other than", so do not squash the bit
in arm_hcr_el2_eff.

Instead, replicate the E2H+TGE test in the two places that
require it.

Reported-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
Message-id: 20201008162155.161886-4-richard.hender...@linaro.org
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
 target/arm/internals.h | 9 +++++----
 target/arm/helper.c    | 9 +++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index ae99725d2b5..5460678756d 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1252,10 +1252,11 @@ static inline bool 
allocation_tag_access_enabled(CPUARMState *env, int el,
         && !(env->cp15.scr_el3 & SCR_ATA)) {
         return false;
     }
-    if (el < 2
-        && arm_feature(env, ARM_FEATURE_EL2)
-        && !(arm_hcr_el2_eff(env) & HCR_ATA)) {
-        return false;
+    if (el < 2 && arm_feature(env, ARM_FEATURE_EL2)) {
+        uint64_t hcr = arm_hcr_el2_eff(env);
+        if (!(hcr & HCR_ATA) && (!(hcr & HCR_E2H) || !(hcr & HCR_TGE))) {
+            return false;
+        }
     }
     sctlr &= (el == 0 ? SCTLR_ATA0 : SCTLR_ATA);
     return sctlr != 0;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index f49b045d366..97bb6b8c01b 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6906,10 +6906,11 @@ static CPAccessResult access_mte(CPUARMState *env, 
const ARMCPRegInfo *ri,
 {
     int el = arm_current_el(env);
 
-    if (el < 2 &&
-        arm_feature(env, ARM_FEATURE_EL2) &&
-        !(arm_hcr_el2_eff(env) & HCR_ATA)) {
-        return CP_ACCESS_TRAP_EL2;
+    if (el < 2 && arm_feature(env, ARM_FEATURE_EL2)) {
+        uint64_t hcr = arm_hcr_el2_eff(env);
+        if (!(hcr & HCR_ATA) && (!(hcr & HCR_E2H) || !(hcr & HCR_TGE))) {
+            return CP_ACCESS_TRAP_EL2;
+        }
     }
     if (el < 3 &&
         arm_feature(env, ARM_FEATURE_EL3) &&
-- 
2.20.1