target/arm: Improve masking in arm_hcr_el2_eff

Update the {TGE,E2H} == '11' masking to ARMv8.6.
If EL2 is configured for aarch32, disable all of
the bits that are RES0 in aarch32 mode.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200229012811.24129-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 27 insertions, 4 deletions

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 19a8be8493..4ddb9443fb 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -5196,14 +5196,37 @@ uint64_t arm_hcr_el2_eff(CPUARMState *env)
          * Since the v8.4 language applies to the entire register, and
          * appears to be backward compatible, use that.
          */
-        ret = 0;
-    } else if (ret & HCR_TGE) {
-        /* These bits are up-to-date as of ARMv8.4.  */
+        return 0;
+    }
+
+    /*
+     * For a cpu that supports both aarch64 and aarch32, we can set bits
+     * in HCR_EL2 (e.g. via EL3) that are RES0 when we enter EL2 as aa32.
+     * Ignore all of the bits in HCR+HCR2 that are not valid for aarch32.
+     */
+    if (!arm_el_is_aa64(env, 2)) {
+        uint64_t aa32_valid;
+
+        /*
+         * These bits are up-to-date as of ARMv8.6.
+         * For HCR, it's easiest to list just the 2 bits that are invalid.
+         * For HCR2, list those that are valid.
+         */
+        aa32_valid = MAKE_64BIT_MASK(0, 32) & ~(HCR_RW | HCR_TDZ);
+        aa32_valid |= (HCR_CD | HCR_ID | HCR_TERR | HCR_TEA | HCR_MIOCNCE |
+                       HCR_TID4 | HCR_TICAB | HCR_TOCU | HCR_TTLBIS);
+        ret &= aa32_valid;
+    }
+
+    if (ret & HCR_TGE) {
+        /* These bits are up-to-date as of ARMv8.6.  */
         if (ret & HCR_E2H) {
             ret &= ~(HCR_VM | HCR_FMO | HCR_IMO | HCR_AMO |
                      HCR_BSU_MASK | HCR_DC | HCR_TWI | HCR_TWE |
                      HCR_TID0 | HCR_TID2 | HCR_TPCP | HCR_TPU |
-                     HCR_TDZ | HCR_CD | HCR_ID | HCR_MIOCNCE);
+                     HCR_TDZ | HCR_CD | HCR_ID | HCR_MIOCNCE |
+                     HCR_TID4 | HCR_TICAB | HCR_TOCU | HCR_ENSCXT |
+                     HCR_TTLBIS | HCR_TTLBOS | HCR_TID5);
         } else {
             ret |= HCR_FMO | HCR_IMO | HCR_AMO;
         }