Commit 5d20605c authored by Mark Brown's avatar Mark Brown Committed by Marc Zyngier
Browse files

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: default avatarMark Brown <broonie@kernel.org>
Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 557c82a4

arch/arm64/kvm/sys_regs.c

+3 −1
Original line number Diff line number Diff line
@@ -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),