[PATCH v4 3/5] s390x: topology: implementating Store Topology System Information

[Pierre Morel]

The handling of STSI is enhanced with the interception of the
function code 15 for storing CPU topology.

Using the objects built during the pluging of CPU, we build the
SYSIB 15_1_x structures.

With this patch the maximum MNEST level is 2, this is also
the only level allowed and only SYSIB 15_1_2 will be built.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 target/s390x/cpu.h          |   1 +
 target/s390x/cpu_topology.c | 113 ++++++++++++++++++++++++++++++++++++
 target/s390x/kvm/kvm.c      |   5 ++
 target/s390x/meson.build    |   1 +
 4 files changed, 120 insertions(+)
 create mode 100644 target/s390x/cpu_topology.c

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 9dfe183b89..de05cc48cc 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -897,4 +897,5 @@ typedef S390CPU ArchCPU;
 
 #include "exec/cpu-all.h"
 
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar);
 #endif
diff --git a/target/s390x/cpu_topology.c b/target/s390x/cpu_topology.c
new file mode 100644
index 0000000000..e74fbdabd2
--- /dev/null
+++ b/target/s390x/cpu_topology.c
@@ -0,0 +1,113 @@
+/*
+ * QEMU S390x CPU Topology
+ *
+ * Copyright IBM Corp. 2021
+ * Author(s): Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "hw/s390x/pv.h"
+#include "hw/sysbus.h"
+#include "hw/s390x/cpu-topology.h"
+
+static int stsi_15_container(void *p, int nl, int id)
+{
+    SysIBTl_container *tle = (SysIBTl_container *)p;
+
+    tle->nl = nl;
+    tle->id = id;
+
+    return sizeof(*tle);
+}
+
+static int stsi_15_cpus(void *p, S390TopologyCores *cd)
+{
+    SysIBTl_cpu *tle = (SysIBTl_cpu *)p;
+
+    tle->nl = 0;
+    tle->dedicated = cd->dedicated;
+    tle->polarity = cd->polarity;
+    tle->type = cd->cputype;
+    tle->origin = be16_to_cpu(cd->origin);
+    tle->mask = be64_to_cpu(cd->mask);
+
+    return sizeof(*tle);
+}
+
+static int set_socket(const MachineState *ms, void *p,
+                      S390TopologySocket *socket)
+{
+    BusChild *kid;
+    int l, len = 0;
+
+    len += stsi_15_container(p, 1, socket->socket_id);
+    p += len;
+
+    QTAILQ_FOREACH_REVERSE(kid, &socket->bus->children, sibling) {
+        l = stsi_15_cpus(p, S390_TOPOLOGY_CORES(kid->child));
+        p += l;
+        len += l;
+    }
+    return len;
+}
+
+static void insert_stsi_15_1_2(const MachineState *ms, void *p)
+{
+    S390TopologyBook *book;
+    SysIB_151x *sysib;
+    BusChild *kid;
+    int level = 2;
+    int len, l;
+
+    sysib = (SysIB_151x *)p;
+    sysib->mnest = level;
+    sysib->mag[TOPOLOGY_NR_MAG2] = ms->smp.sockets;
+    sysib->mag[TOPOLOGY_NR_MAG1] = ms->smp.cores;
+
+    book = s390_get_topology();
+    len = sizeof(SysIB_151x);
+    p += len;
+
+    QTAILQ_FOREACH_REVERSE(kid, &book->bus->children, sibling) {
+        l = set_socket(ms, p, S390_TOPOLOGY_SOCKET(kid->child));
+        p += l;
+        len += l;
+    }
+
+    sysib->length = be16_to_cpu(len);
+}
+
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar)
+{
+    const MachineState *machine = MACHINE(qdev_get_machine());
+    void *p;
+    int ret, cc;
+
+    /*
+     * Until the SCLP STSI Facility reporting the MNEST value is used,
+     * a sel2 value of 2 is the only value allowed in STSI 15.1.x.
+     */
+    if (sel2 != 2) {
+        setcc(cpu, 3);
+        return;
+    }
+
+    p = g_malloc0(TARGET_PAGE_SIZE);
+
+    insert_stsi_15_1_2(machine, p);
+
+    if (s390_is_pv()) {
+        ret = s390_cpu_pv_mem_write(cpu, 0, p, TARGET_PAGE_SIZE);
+    } else {
+        ret = s390_cpu_virt_mem_write(cpu, addr, ar, p, TARGET_PAGE_SIZE);
+    }
+    cc = ret ? 3 : 0;
+    setcc(cpu, cc);
+    g_free(p);
+}
+
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 5b1fdb55c4..c17e92fc9c 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -52,6 +52,7 @@
 #include "hw/s390x/s390-virtio-ccw.h"
 #include "hw/s390x/s390-virtio-hcall.h"
 #include "hw/s390x/pv.h"
+#include "hw/s390x/cpu-topology.h"
 
 #ifndef DEBUG_KVM
 #define DEBUG_KVM  0
@@ -1906,6 +1907,10 @@ static int handle_stsi(S390CPU *cpu)
         /* Only sysib 3.2.2 needs post-handling for now. */
         insert_stsi_3_2_2(cpu, run->s390_stsi.addr, run->s390_stsi.ar);
         return 0;
+    case 15:
+        insert_stsi_15_1_x(cpu, run->s390_stsi.sel2, run->s390_stsi.addr,
+                           run->s390_stsi.ar);
+        return 0;
     default:
         return 0;
     }
diff --git a/target/s390x/meson.build b/target/s390x/meson.build
index 84c1402a6a..890ccfa789 100644
--- a/target/s390x/meson.build
+++ b/target/s390x/meson.build
@@ -29,6 +29,7 @@ s390x_softmmu_ss.add(files(
   'sigp.c',
   'cpu-sysemu.c',
   'cpu_models_sysemu.c',
+  'cpu_topology.c',
 ))
 
 s390x_user_ss = ss.source_set()
-- 
2.27.0