target/arm: Make '-cpu max' have a 48-bit PA

QEMU supports a 48-bit physical address range, but we don't currently
expose it in the '-cpu max' ID registers (you get the same range as
Cortex-A57, which is 44 bits).

Set the ID_AA64MMFR0.PARange field to indicate 48 bits.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201001160116.18095-1-peter.maydell@linaro.org

target/arm/cpu64.c

@@ -653,6 +653,10 @@ static void aarch64_max_initfn(Object *obj)
         t = FIELD_DP64(t, ID_AA64PFR1, MTE, 2);
         cpu->isar.id_aa64pfr1 = t;
 
+        t = cpu->isar.id_aa64mmfr0;
+        t = FIELD_DP64(t, ID_AA64MMFR0, PARANGE, 5); /* PARange: 48 bits */
+        cpu->isar.id_aa64mmfr0 = t;
+
         t = cpu->isar.id_aa64mmfr1;
         t = FIELD_DP64(t, ID_AA64MMFR1, HPDS, 1); /* HPD */
         t = FIELD_DP64(t, ID_AA64MMFR1, LO, 1);