1 files changed, 9 insertions, 1 deletions
diff --git a/target/s390x/cpu_models.h b/target/s390x/cpu_models.h
index fb1adc8b21..cc7305ec21 100644
--- a/target/s390x/cpu_models.h
+++ b/target/s390x/cpu_models.h
@@ -96,10 +96,18 @@ static inline bool s390_known_cpu_type(uint16_t type)
 {
     return s390_get_gen_for_cpu_type(type) != 0;
 }
+#define CPU_ID_SHIFT 32
+#define CPU_ID_BITS 24
+/*
+ * When cpu_id_format is 0 (basic mode), the leftmost 4 bits of cpu_id contain
+ * the rightmost 4 bits of the physical CPU address.
+ */
+#define CPU_PHYS_ADDR_BITS 4
+#define CPU_PHYS_ADDR_SHIFT (CPU_ID_SHIFT + CPU_ID_BITS - CPU_PHYS_ADDR_BITS)
 static inline uint64_t s390_cpuid_from_cpu_model(const S390CPUModel *model)
 {
     return ((uint64_t)model->cpu_ver << 56) |
-           ((uint64_t)model->cpu_id << 32) |
+           ((uint64_t)model->cpu_id << CPU_ID_SHIFT) |
            ((uint64_t)model->def->type << 16) |
            (model->def->gen == 7 ? 0 : (uint64_t)model->cpu_id_format << 15);
 }