[PULL 05/25] s390x/sclp: reporting the maximum nested topology entries

[Thomas Huth <thuth@redhat.com>]

From: Pierre Morel <pmorel@linux.ibm.com>

The maximum nested topology entries is used by the guest to
know how many nested topology are available on the machine.

Let change the MNEST value from 2 to 4 in the SCLP READ INFO
structure now that we support books and drawers.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20231016183925.2384704-6-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 include/hw/s390x/sclp.h | 5 +++--
 hw/s390x/sclp.c         | 5 +++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index c49051e17e..9aef6d9370 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -112,12 +112,13 @@ typedef struct CPUEntry {
 } QEMU_PACKED CPUEntry;
 
 #define SCLP_READ_SCP_INFO_FIXED_CPU_OFFSET     128
-#define SCLP_READ_SCP_INFO_MNEST                2
+#define SCLP_READ_SCP_INFO_MNEST                4
 typedef struct ReadInfo {
     SCCBHeader h;
     uint16_t rnmax;
     uint8_t rnsize;
-    uint8_t  _reserved1[16 - 11];       /* 11-15 */
+    uint8_t  _reserved1[15 - 11];       /* 11-14 */
+    uint8_t stsi_parm;                  /* 15-15 */
     uint16_t entries_cpu;               /* 16-17 */
     uint16_t offset_cpu;                /* 18-19 */
     uint8_t  _reserved2[24 - 20];       /* 20-23 */
diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index eff74479f4..d339cbb7e4 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -20,6 +20,7 @@
 #include "hw/s390x/event-facility.h"
 #include "hw/s390x/s390-pci-bus.h"
 #include "hw/s390x/ipl.h"
+#include "hw/s390x/cpu-topology.h"
 
 static inline SCLPDevice *get_sclp_device(void)
 {
@@ -123,6 +124,10 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
         return;
     }
 
+    if (s390_has_topology()) {
+        read_info->stsi_parm = SCLP_READ_SCP_INFO_MNEST;
+    }
+
     /* CPU information */
     prepare_cpu_entries(machine, entries_start, &cpu_count);
     read_info->entries_cpu = cpu_to_be16(cpu_count);
-- 
2.41.0