s390x/sclp: reporting the maximum nested topology entries

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>
qemu · Oct 18, 2023 · 71e3e48 · 71e3e48
1 parent 28c0ac0
commit 71e3e48
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git 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);

diff --git 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 */