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authorMark Brown <broonie@kernel.org>2025-09-18 20:42:06 +0100
committerMarc Zyngier <maz@kernel.org>2025-09-19 15:34:40 +0100
commit5d20605c8e7930254f7bee41336e421be247181c (patch)
tree6ddcedb69f392d74d5890caa35a8c3b1336bc780
parent557c82a4480719f64cf6530b5090001e9d908904 (diff)
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 <broonie@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
-rw-r--r--arch/arm64/kvm/sys_regs.c4
1 files changed, 3 insertions, 1 deletions
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),