From eb851c1151252158ab5b5917c5d386e1d69de3a2 Mon Sep 17 00:00:00 2001 From: Damien Hedde Date: Wed, 27 Apr 2022 11:01:17 +0200 Subject: [PATCH] target/arm: Disable cryptographic instructions when neon is disabled As of now, cryptographic instructions ISAR fields are never cleared so we can end up with a cpu with cryptographic instructions but no floating-point/neon instructions which is not a possible configuration according to Arm specifications. In QEMU, we have 3 kinds of cpus regarding cryptographic instructions: + no support + cortex-a57/a72: cryptographic extension is optional, floating-point/neon is not. + cortex-a53: crytographic extension is optional as well as floating-point/neon. But cryptographic requires floating-point/neon support. Therefore we can safely clear the ISAR fields when neon is disabled. Note that other Arm cpus seem to follow this. For example cortex-a55 is like cortex-a53 and cortex-a76/cortex-a710 are like cortex-a57/a72. Signed-off-by: Damien Hedde Reviewed-by: Richard Henderson Message-id: 20220427090117.6954-1-damien.hedde@greensocs.com [PMM: fixed commit message typos] Signed-off-by: Peter Maydell --- target/arm/cpu.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/target/arm/cpu.c b/target/arm/cpu.c index e3f8215203..e46a766d77 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -1587,6 +1587,12 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) unset_feature(env, ARM_FEATURE_NEON); t = cpu->isar.id_aa64isar0; + t = FIELD_DP64(t, ID_AA64ISAR0, AES, 0); + t = FIELD_DP64(t, ID_AA64ISAR0, SHA1, 0); + t = FIELD_DP64(t, ID_AA64ISAR0, SHA2, 0); + t = FIELD_DP64(t, ID_AA64ISAR0, SHA3, 0); + t = FIELD_DP64(t, ID_AA64ISAR0, SM3, 0); + t = FIELD_DP64(t, ID_AA64ISAR0, SM4, 0); t = FIELD_DP64(t, ID_AA64ISAR0, DP, 0); cpu->isar.id_aa64isar0 = t; @@ -1601,6 +1607,9 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) cpu->isar.id_aa64pfr0 = t; u = cpu->isar.id_isar5; + u = FIELD_DP32(u, ID_ISAR5, AES, 0); + u = FIELD_DP32(u, ID_ISAR5, SHA1, 0); + u = FIELD_DP32(u, ID_ISAR5, SHA2, 0); u = FIELD_DP32(u, ID_ISAR5, RDM, 0); u = FIELD_DP32(u, ID_ISAR5, VCMA, 0); cpu->isar.id_isar5 = u; -- 2.30.2