@@ -49,13 +49,30 @@ static inline bool sclp_command_code_valid(uint32_t code)
return false;
}
-static bool sccb_verify_boundary(uint64_t sccb_addr, uint16_t sccb_len)
+static bool sccb_verify_boundary(uint64_t sccb_addr, uint16_t sccb_len,
+ uint32_t code)
{
uint64_t sccb_max_addr = sccb_addr + sccb_len - 1;
uint64_t sccb_boundary = (sccb_addr & PAGE_MASK) + PAGE_SIZE;
- if (sccb_max_addr < sccb_boundary) {
- return true;
+ switch (code & SCLP_CMD_CODE_MASK) {
+ case SCLP_CMDW_READ_SCP_INFO:
+ case SCLP_CMDW_READ_SCP_INFO_FORCED:
+ case SCLP_CMDW_READ_CPU_INFO:
+ /*
+ * An extended-length SCCB is only allowed for Read SCP/CPU Info and
+ * is allowed to exceed the 4k boundary. The respective commands will
+ * set the length field to the required length if an insufficient
+ * SCCB length is provided.
+ */
+ if (s390_has_feat(S390_FEAT_EXTENDED_LENGTH_SCCB)) {
+ return true;
+ }
+ /* fallthrough */
+ default:
+ if (sccb_max_addr < sccb_boundary) {
+ return true;
+ }
}
return false;
@@ -80,6 +97,12 @@ static void prepare_cpu_entries(MachineState *ms, CPUEntry *entry, int *count)
#define SCCB_REQ_LEN(s, max_cpus) (sizeof(s) + max_cpus * sizeof(CPUEntry))
+static inline bool ext_len_sccb_supported(SCCBHeader header)
+{
+ return s390_has_feat(S390_FEAT_EXTENDED_LENGTH_SCCB) &&
+ header.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE;
+}
+
/* Provide information about the configuration, CPUs and storage */
static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
{
@@ -89,10 +112,15 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
int rnsize, rnmax;
IplParameterBlock *ipib = s390_ipl_get_iplb();
int required_len = SCCB_REQ_LEN(ReadInfo, machine->possible_cpus->len);
- int offset_cpu = offsetof(ReadInfo, entries);
+ int offset_cpu = s390_has_feat(S390_FEAT_EXTENDED_LENGTH_SCCB) ?
+ offsetof(ReadInfo, entries) :
+ SCLP_READ_SCP_INFO_FIXED_CPU_OFFSET;
CPUEntry *entries_start = (void *)sccb + offset_cpu;
if (be16_to_cpu(sccb->h.length) < required_len) {
+ if (ext_len_sccb_supported(sccb->h)) {
+ sccb->h.length = cpu_to_be16(required_len);
+ }
sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
return;
}
@@ -153,6 +181,9 @@ static void sclp_read_cpu_info(SCLPDevice *sclp, SCCB *sccb)
int required_len = SCCB_REQ_LEN(ReadCpuInfo, machine->possible_cpus->len);
if (be16_to_cpu(sccb->h.length) < required_len) {
+ if (ext_len_sccb_supported(sccb->h)) {
+ sccb->h.length = cpu_to_be16(required_len);
+ }
sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
return;
}
@@ -249,7 +280,7 @@ int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
goto out_write;
}
- if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb->h.length))) {
+ if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb->h.length), code)) {
work_sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
goto out_write;
}
@@ -302,7 +333,7 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
goto out_write;
}
- if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb->h.length))) {
+ if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb->h.length), code)) {
work_sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
goto out_write;
}
@@ -111,6 +111,7 @@ typedef struct CPUEntry {
uint8_t reserved1;
} QEMU_PACKED CPUEntry;
+#define SCLP_READ_SCP_INFO_FIXED_CPU_OFFSET 128
typedef struct ReadInfo {
SCCBHeader h;
uint16_t rnmax;
@@ -97,6 +97,7 @@ DEF_FEAT(GUARDED_STORAGE, "gs", STFL, 133, "Guarded-storage facility")
DEF_FEAT(VECTOR_PACKED_DECIMAL, "vxpd", STFL, 134, "Vector packed decimal facility")
DEF_FEAT(VECTOR_ENH, "vxeh", STFL, 135, "Vector enhancements facility")
DEF_FEAT(MULTIPLE_EPOCH, "mepoch", STFL, 139, "Multiple-epoch facility")
+DEF_FEAT(EXTENDED_LENGTH_SCCB, "els", STFL, 140, "Extended-length SCCB facility")
DEF_FEAT(TEST_PENDING_EXT_INTERRUPTION, "tpei", STFL, 144, "Test-pending-external-interruption facility")
DEF_FEAT(INSERT_REFERENCE_BITS_MULT, "irbm", STFL, 145, "Insert-reference-bits-multiple facility")
DEF_FEAT(MSA_EXT_8, "msa8-base", STFL, 146, "Message-security-assist-extension-8 facility (excluding subfunctions)")
@@ -522,6 +522,7 @@ static uint16_t full_GEN12_GA1[] = {
S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL,
S390_FEAT_AP_FACILITIES_TEST,
S390_FEAT_AP,
+ S390_FEAT_EXTENDED_LENGTH_SCCB,
};
static uint16_t full_GEN12_GA2[] = {
@@ -2456,6 +2456,14 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, Error **errp)
KVM_S390_VM_CRYPTO_ENABLE_APIE)) {
set_bit(S390_FEAT_AP, model->features);
}
+
+ /*
+ * Extended-Length SCCB is handled entirely within QEMU.
+ * For PV guests this is completely fenced by the Ultravisor, as Service
+ * Call error checking and STFLE interpretation are handled via SIE.
+ */
+ set_bit(S390_FEAT_EXTENDED_LENGTH_SCCB, model->features);
+
/* strip of features that are not part of the maximum model */
bitmap_and(model->features, model->features, model->def->full_feat,
S390_FEAT_MAX);