s390x: kvm: Fix number of cpu reports for stsi 3.2.2

The cpu number reporting is handled by KVM and QEMU only fills in the
VM name, uuid and other values.

Unfortunately KVM doesn't report reserved cpus and doesn't even know
they exist until the are created via the ioctl.

So let's fix up the cpu values after KVM has written its values to the
3.2.2 sysib. To be consistent, we use the same code to retrieve the cpu
numbers as the STSI TCG code in target/s390x/misc_helper.c:HELPER(stsi).

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200331110123.3774-1-frankja@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 1d6fd6a..7f7ebab 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -1768,8 +1768,10 @@
 
 static void insert_stsi_3_2_2(S390CPU *cpu, __u64 addr, uint8_t ar)
 {
+    const MachineState *ms = MACHINE(qdev_get_machine());
+    uint16_t conf_cpus = 0, reserved_cpus = 0;
     SysIB_322 sysib;
-    int del;
+    int del, i;
 
     if (s390_cpu_virt_mem_read(cpu, addr, ar, &sysib, sizeof(sysib))) {
         return;
@@ -1789,6 +1791,19 @@
         memset(sysib.ext_names[del], 0,
                sizeof(sysib.ext_names[0]) * (sysib.count - del));
     }
+
+    /* count the cpus and split them into configured and reserved ones */
+    for (i = 0; i < ms->possible_cpus->len; i++) {
+        if (ms->possible_cpus->cpus[i].cpu) {
+            conf_cpus++;
+        } else {
+            reserved_cpus++;
+        }
+    }
+    sysib.vm[0].total_cpus = conf_cpus + reserved_cpus;
+    sysib.vm[0].conf_cpus = conf_cpus;
+    sysib.vm[0].reserved_cpus = reserved_cpus;
+
     /* Insert short machine name in EBCDIC, padded with blanks */
     if (qemu_name) {
         memset(sysib.vm[0].name, 0x40, sizeof(sysib.vm[0].name));