target/arm: Enable MTE

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.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-46-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index a0c1d8894b77a9f75bc0cdb1a0eab8e5438b60fb..a2f4733eed61ad8e6f31eab04276e044ca7c60f9 100644 (file)
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -654,6 +654,11 @@ static void aarch64_max_initfn(Object *obj)
 
         t = cpu->isar.id_aa64pfr1;
         t = FIELD_DP64(t, ID_AA64PFR1, BT, 1);
+        /*
+         * Begin with full support for MTE; will be downgraded to MTE=1
+         * during realize if the board provides no tag memory.
+         */
+        t = FIELD_DP64(t, ID_AA64PFR1, MTE, 2);
         cpu->isar.id_aa64pfr1 = t;
 
         t = cpu->isar.id_aa64mmfr1;