[PATCH v5 18/22] target/arm: Enable MTE

[Richard Henderson]

We now implement all of the components of MTE, without actually
supporting any tagged memory.  All MTE instructions will work,
trivially, so we can enable support.

Signed-off-by: Richard Henderson <address@hidden>
---
 target/arm/cpu.c   | 10 ++++++++++
 target/arm/cpu64.c |  1 +
 2 files changed, 11 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 2399c14471..12fffa3ee4 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -209,6 +209,16 @@ static void arm_cpu_reset(CPUState *s)
          * make no difference to the user-level emulation.
          */
         env->cp15.tcr_el[1].raw_tcr = (3ULL << 37);
+        /* Enable MTE allocation tags.  */
+        env->cp15.hcr_el2 |= HCR_ATA;
+        env->cp15.scr_el3 |= SCR_ATA;
+        env->cp15.sctlr_el[1] |= SCTLR_ATA0;
+        /* Enable synchronous tag check failures.  */
+        env->cp15.sctlr_el[1] |= 1ull << 38;
+#ifdef TARGET_AARCH64
+        /* Set MTE seed to non-zero value, otherwise RandomTag fails.  */
+        env->cp15.rgsr_el1 = 0x123400;
+#endif
 #else
         /* Reset into the highest available EL */
         if (arm_feature(env, ARM_FEATURE_EL3)) {
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index d7f5bf610a..ac1e2dc2c4 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -350,6 +350,7 @@ static void aarch64_max_initfn(Object *obj)
 
         t = cpu->isar.id_aa64pfr1;
         t = FIELD_DP64(t, ID_AA64PFR1, BT, 1);
+        t = FIELD_DP64(t, ID_AA64PFR1, MTE, 2);
         cpu->isar.id_aa64pfr1 = t;
 
         t = cpu->isar.id_aa64mmfr1;
-- 
2.17.1