From: Mark Brown Date: Thu, 18 Sep 2025 19:42:06 +0000 (+0100) Subject: KVM: arm64: Expose FEAT_LSFE to guests X-Git-Tag: v6.18-rc1~95^2~5^2~1^2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5d20605c8e7930254f7bee41336e421be247181c;p=thirdparty%2Fkernel%2Flinux.git KVM: arm64: Expose FEAT_LSFE to guests FEAT_LSFE (Large System Float Extension), providing atomic floating point memory operations, is optional from v9.5. This feature adds no new architectural state, expose the relevant ID register field to guests so they can discover it. Signed-off-by: Mark Brown Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index d1a55cf589b7..1099b815cd61 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1642,7 +1642,8 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, val &= ~ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_WFxT); break; case SYS_ID_AA64ISAR3_EL1: - val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX; + val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_LSFE | + ID_AA64ISAR3_EL1_FAMINMAX; break; case SYS_ID_AA64MMFR2_EL1: val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK; @@ -2991,6 +2992,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_AA64ISAR2_EL1_APA3 | ID_AA64ISAR2_EL1_GPA3)), ID_WRITABLE(ID_AA64ISAR3_EL1, (ID_AA64ISAR3_EL1_FPRCVT | + ID_AA64ISAR3_EL1_LSFE | ID_AA64ISAR3_EL1_FAMINMAX)), ID_UNALLOCATED(6,4), ID_UNALLOCATED(6,5),