target/arm: Enable FEAT_FGT on '-cpu max'

Update the ID registers for TCG's '-cpu max' to report the
presence of FEAT_FGT Fine-Grained Traps support.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-24-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-24-peter.maydell@linaro.org

docs/system/arm/emulation.rst

@@ -30,6 +30,7 @@ the following architecture extensions:
 - FEAT_ETS (Enhanced Translation Synchronization)
 - FEAT_EVT (Enhanced Virtualization Traps)
 - FEAT_FCMA (Floating-point complex number instructions)
+- FEAT_FGT (Fine-Grained Traps)
 - FEAT_FHM (Floating-point half-precision multiplication instructions)
 - FEAT_FP16 (Half-precision floating-point data processing)
 - FEAT_FRINTTS (Floating-point to integer instructions)

target/arm/cpu64.c

@@ -1224,6 +1224,7 @@ static void aarch64_max_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64MMFR0, TGRAN16_2, 2); /* 16k stage2 supported */
     t = FIELD_DP64(t, ID_AA64MMFR0, TGRAN64_2, 2); /* 64k stage2 supported */
     t = FIELD_DP64(t, ID_AA64MMFR0, TGRAN4_2, 2);  /*  4k stage2 supported */
+    t = FIELD_DP64(t, ID_AA64MMFR0, FGT, 1);       /* FEAT_FGT */
     cpu->isar.id_aa64mmfr0 = t;
 
     t = cpu->isar.id_aa64mmfr1;