The secure-IPL-code-loading-attributes facility (SCLAF) provides additional security during IPL.
Availability of SCLAF is determined by byte 136 bit 3 of the SCLP Read Info block. Signed-off-by: Zhuoying Cai <zy...@linux.ibm.com> Reviewed-by: Collin Walling <wall...@linux.ibm.com> --- docs/specs/s390x-secure-ipl.rst | 25 +++++++++++++++++++++++++ target/s390x/cpu_features.c | 2 ++ target/s390x/cpu_features_def.h.inc | 1 + target/s390x/cpu_models.c | 3 +++ target/s390x/gen-features.c | 2 ++ target/s390x/kvm/kvm.c | 1 + 6 files changed, 34 insertions(+) diff --git a/docs/specs/s390x-secure-ipl.rst b/docs/specs/s390x-secure-ipl.rst index 4bc330c399..72ab901014 100644 --- a/docs/specs/s390x-secure-ipl.rst +++ b/docs/specs/s390x-secure-ipl.rst @@ -83,3 +83,28 @@ operations such as: * certificate data The guest kernel will inspect the IIRB and build the keyring. + + +Secure Code Loading Attributes Facility +--------------------------------- + +The Secure Code Loading Attributes Facility (SCLAF) enhances system security during the +IPL by enforcing additional verification rules. + +When SCLAF is available, its behavior depends on the IPL mode. It introduces verification +of both signed and unsigned components to help ensure that only authorized code is loaded +during the IPL process. Any errors detected by SCLAF are reported in the IIRB. + +Unsigned components are restricted to load addresses at or above absolute storage address +``0x2000``. + +Signed components must include a Secure Code Loading Attribute Block (SCLAB), which is +appended at the very end of the component. The SCLAB defines security attributes for +handling the signed code. Specifically, it may: + +* Provide direction on how to process the rest of the component. + +* Provide further validation of information on where to load the signed binary code + from the load device. + +* Specify where to start the execution of the loaded OS code. diff --git a/target/s390x/cpu_features.c b/target/s390x/cpu_features.c index 200bd8c15b..29ea3bfec2 100644 --- a/target/s390x/cpu_features.c +++ b/target/s390x/cpu_features.c @@ -120,6 +120,7 @@ void s390_fill_feat_block(const S390FeatBitmap features, S390FeatType type, * - All SIE facilities because SIE is not available * - DIAG318 * - Secure IPL Facility + * - Secure IPL Code Loading Attributes Facility * * As VMs can move in and out of protected mode the CPU model * doesn't protect us from that problem because it is only @@ -152,6 +153,7 @@ void s390_fill_feat_block(const S390FeatBitmap features, S390FeatType type, break; case S390_FEAT_TYPE_SCLP_FAC_IPL: clear_be_bit(s390_feat_def(S390_FEAT_SIPL)->bit, data); + clear_be_bit(s390_feat_def(S390_FEAT_SCLAF)->bit, data); break; default: return; diff --git a/target/s390x/cpu_features_def.h.inc b/target/s390x/cpu_features_def.h.inc index 55eef618b8..ecfca0faef 100644 --- a/target/s390x/cpu_features_def.h.inc +++ b/target/s390x/cpu_features_def.h.inc @@ -142,6 +142,7 @@ DEF_FEAT(CERT_STORE, "cstore", SCLP_FAC134, 5, "Provide Certificate Store functi /* Features exposed via SCLP SCCB Facilities byte 136 - 137 (bit numbers relative to byte-136) */ DEF_FEAT(SIPL, "sipl", SCLP_FAC_IPL, 1, "Secure-IPL facility") +DEF_FEAT(SCLAF, "sclaf", SCLP_FAC_IPL, 3, "Secure-IPL-code-loading-attributes facility") /* Features exposed via SCLP CPU info. */ DEF_FEAT(SIE_F2, "sief2", SCLP_CPU, 4, "SIE: interception format 2 (Virtual SIE)") diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c index f99536ef9a..7d214b5f72 100644 --- a/target/s390x/cpu_models.c +++ b/target/s390x/cpu_models.c @@ -264,6 +264,7 @@ bool s390_has_feat(S390Feat feat) case S390_FEAT_SIE_PFMFI: case S390_FEAT_SIE_IBS: case S390_FEAT_SIPL: + case S390_FEAT_SCLAF: case S390_FEAT_CONFIGURATION_TOPOLOGY: return false; break; @@ -509,6 +510,8 @@ static void check_consistency(const S390CPUModel *model) { S390_FEAT_DIAG_318, S390_FEAT_EXTENDED_LENGTH_SCCB }, { S390_FEAT_CERT_STORE, S390_FEAT_EXTENDED_LENGTH_SCCB }, { S390_FEAT_SIPL, S390_FEAT_EXTENDED_LENGTH_SCCB }, + { S390_FEAT_SCLAF, S390_FEAT_EXTENDED_LENGTH_SCCB }, + { S390_FEAT_SCLAF, S390_FEAT_SIPL }, { S390_FEAT_NNPA, S390_FEAT_VECTOR }, { S390_FEAT_RDP, S390_FEAT_LOCAL_TLB_CLEARING }, { S390_FEAT_UV_FEAT_AP, S390_FEAT_AP }, diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c index bd2060ab93..c3e0c6ceff 100644 --- a/target/s390x/gen-features.c +++ b/target/s390x/gen-features.c @@ -722,6 +722,7 @@ static uint16_t full_GEN16_GA1[] = { S390_FEAT_UV_FEAT_AP_INTR, S390_FEAT_CERT_STORE, S390_FEAT_SIPL, + S390_FEAT_SCLAF, }; static uint16_t full_GEN17_GA1[] = { @@ -924,6 +925,7 @@ static uint16_t qemu_MAX[] = { S390_FEAT_EXTENDED_LENGTH_SCCB, S390_FEAT_CERT_STORE, S390_FEAT_SIPL, + S390_FEAT_SCLAF, }; /****** END FEATURE DEFS ******/ diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c index 31bd574dec..2ed11fab52 100644 --- a/target/s390x/kvm/kvm.c +++ b/target/s390x/kvm/kvm.c @@ -2522,6 +2522,7 @@ bool kvm_s390_get_host_cpu_model(S390CPUModel *model, Error **errp) /* Some Secure IPL facilities are emulated by QEMU */ set_bit(S390_FEAT_SIPL, model->features); + set_bit(S390_FEAT_SCLAF, model->features); /* Test for Ultravisor features that influence secure guest behavior */ query_uv_feat_guest(model->features); -- 2.50.1