[PATCH v14 09/11] qapi/s390/cpu topology: monitor query topology information

[Pierre Morel <pmorel@linux.ibm.com>]

Reporting the current topology informations to the admin through
the QEMU monitor.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 qapi/machine-target.json | 66 ++++++++++++++++++++++++++++++++++
 include/monitor/hmp.h    |  1 +
 hw/s390x/cpu-topology.c  | 76 ++++++++++++++++++++++++++++++++++++++++
 hmp-commands-info.hx     | 16 +++++++++
 4 files changed, 159 insertions(+)

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 75b0aa254d..927618a78f 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -371,3 +371,69 @@
   },
   'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
 }
+
+##
+# @S390CpuTopology:
+#
+# CPU Topology information
+#
+# @drawer: the destination drawer where to move the vCPU
+#
+# @book: the destination book where to move the vCPU
+#
+# @socket: the destination socket where to move the vCPU
+#
+# @polarity: optional polarity, default is last polarity set by the guest
+#
+# @dedicated: optional, if the vCPU is dedicated to a real CPU
+#
+# @origin: offset of the first bit of the core mask
+#
+# @mask: mask of the cores sharing the same topology
+#
+# Since: 8.0
+##
+{ 'struct': 'S390CpuTopology',
+  'data': {
+      'drawer': 'int',
+      'book': 'int',
+      'socket': 'int',
+      'polarity': 'int',
+      'dedicated': 'bool',
+      'origin': 'int',
+      'mask': 'str'
+  },
+  'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
+}
+
+##
+# @query-topology:
+#
+# Return information about CPU Topology
+#
+# Returns a @CpuTopology instance describing the CPU Toplogy
+# being currently used by QEMU.
+#
+# Since: 8.0
+#
+# Example:
+#
+# -> { "execute": "cpu-topology" }
+# <- {"return": [
+#     {
+#         "drawer": 0,
+#         "book": 0,
+#         "socket": 0,
+#         "polarity": 0,
+#         "dedicated": true,
+#         "origin": 0,
+#         "mask": 0xc000000000000000,
+#     },
+#    ]
+#   }
+#
+##
+{ 'command': 'query-topology',
+  'returns': ['S390CpuTopology'],
+  'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
+}
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 15c36bf549..0b3c758231 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -145,5 +145,6 @@ void hmp_human_readable_text_helper(Monitor *mon,
 void hmp_info_stats(Monitor *mon, const QDict *qdict);
 void hmp_pcie_aer_inject_error(Monitor *mon, const QDict *qdict);
 void hmp_change_topology(Monitor *mon, const QDict *qdict);
+void hmp_query_topology(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 0faffe657e..c3748654ff 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -524,3 +524,79 @@ void hmp_change_topology(Monitor *mon, const QDict *qdict)
         return;
     }
 }
+
+static S390CpuTopologyList *s390_cpu_topology_list(void)
+{
+    S390CpuTopologyList *head = NULL;
+    S390TopologyEntry *entry;
+
+    QTAILQ_FOREACH_REVERSE(entry, &s390_topology.list, next) {
+        S390CpuTopology *item = g_new0(typeof(*item), 1);
+
+        item->drawer = entry->id.drawer;
+        item->book = entry->id.book;
+        item->socket = entry->id.socket;
+        item->polarity = entry->id.p;
+        if (entry->id.d) {
+            item->dedicated = true;
+        }
+        item->origin = entry->id.origin;
+        item->mask = g_strdup_printf("0x%016lx", entry->mask);
+
+        QAPI_LIST_PREPEND(head, item);
+    }
+    return head;
+}
+
+S390CpuTopologyList *qmp_query_topology(Error **errp)
+{
+    if (!s390_has_topology()) {
+        error_setg(errp, "This machine doesn't support topology");
+        return NULL;
+    }
+
+    return s390_cpu_topology_list();
+}
+
+void hmp_query_topology(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+    S390CpuTopologyList *l = qmp_query_topology(&err);
+
+    if (hmp_handle_error(mon, err)) {
+        return;
+    }
+
+    monitor_printf(mon, "CPU Topology:\n");
+    while (l) {
+        uint64_t d = -1UL;
+        uint64_t b = -1UL;
+        uint64_t s = -1UL;
+        uint64_t p = -1UL;
+        uint64_t dd = -1UL;
+
+        if (d != l->value->drawer) {
+            monitor_printf(mon, "  drawer   : \"%" PRIu64 "\"\n",
+                           l->value->drawer);
+        }
+        if (b != l->value->book) {
+            monitor_printf(mon, "  book     : \"%" PRIu64 "\"\n",
+                           l->value->book);
+        }
+        if (s != l->value->socket) {
+            monitor_printf(mon, "  socket   : \"%" PRIu64 "\"\n",
+                           l->value->socket);
+        }
+        if (p != l->value->polarity) {
+            monitor_printf(mon, "  polarity : \"%" PRIu64 "\"\n",
+                           l->value->polarity);
+        }
+        if (dd != l->value->dedicated) {
+            monitor_printf(mon, "  dedicated: \"%d\"\n", l->value->dedicated);
+        }
+        monitor_printf(mon, "  mask  : \"%s\"\n", l->value->mask);
+
+
+        l = l->next;
+    }
+}
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 754b1e8408..5730a47f71 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -993,3 +993,19 @@ SRST
   ``info virtio-queue-element`` *path* *queue* [*index*]
     Display element of a given virtio queue
 ERST
+
+#if defined(TARGET_S390X) && defined(CONFIG_KVM)
+    {
+        .name       = "query-topology",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Show information about CPU topology",
+        .cmd        = hmp_query_topology,
+        .flags      = "p",
+    },
+
+SRST
+  ``info query-topology``
+    Show information about CPU topology
+ERST
+#endif
-- 
2.31.1