target/arm: Enable FEAT_Spec_FPACC for -cpu max
FEAT_Spec_FPACC is a feature describing speculative behaviour in the
event of a PAC authontication failure when FEAT_FPACCOMBINE is
implemented. FEAT_Spec_FPACC means that the speculative use of
pointers processed by a PAC Authentication is not materially
different in terms of the impact on cached microarchitectural state
(caches, TLBs, etc) between passing and failing of the PAC
Authentication.
QEMU doesn't do speculative execution, so we can advertise
this feature.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240418152004.2106516-6-peter.maydell@linaro.org
diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 307539c..7fcea54 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -61,6 +61,7 @@
- FEAT_FP16 (Half-precision floating-point data processing)
- FEAT_FPAC (Faulting on AUT* instructions)
- FEAT_FPACCOMBINE (Faulting on combined pointer authentication instructions)
+- FEAT_FPACC_SPEC (Speculative behavior of combined pointer authentication instructions)
- FEAT_FRINTTS (Floating-point to integer instructions)
- FEAT_FlagM (Flag manipulation instructions v2)
- FEAT_FlagM2 (Enhancements to flag manipulation instructions)
diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
index ebb585a..443cffe 100644
--- a/target/arm/tcg/cpu64.c
+++ b/target/arm/tcg/cpu64.c
@@ -1217,6 +1217,10 @@
t = FIELD_DP64(t, ID_AA64MMFR2, E0PD, 1); /* FEAT_E0PD */
cpu->isar.id_aa64mmfr2 = t;
+ t = cpu->isar.id_aa64mmfr3;
+ t = FIELD_DP64(t, ID_AA64MMFR3, SPEC_FPACC, 1); /* FEAT_FPACC_SPEC */
+ cpu->isar.id_aa64mmfr3 = t;
+
t = cpu->isar.id_aa64zfr0;
t = FIELD_DP64(t, ID_AA64ZFR0, SVEVER, 1);
t = FIELD_DP64(t, ID_AA64ZFR0, AES, 2); /* FEAT_SVE_PMULL128 */
