[PATCH v7 04/13] 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>
---
 hw/s390x/cpu-topology.c     |  12 ++--
 target/s390x/cpu.h          |   1 +
 target/s390x/cpu_topology.c | 112 ++++++++++++++++++++++++++++++++++++
 target/s390x/kvm/kvm.c      |   5 ++
 target/s390x/meson.build    |   1 +
 5 files changed, 124 insertions(+), 7 deletions(-)
 create mode 100644 target/s390x/cpu_topology.c

diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index b7131b4ac3..74e04fd68e 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -127,15 +127,14 @@ void s390_topology_new_cpu(int core_id)
     S390TopologyBook *book;
     S390TopologySocket *socket;
     S390TopologyCores *cores;
-    int cores_per_socket, sock_idx;
     int origin, bit;
+    int nb_cores_per_socket;
 
     book = s390_get_topology();
 
-    cores_per_socket = ms->smp.max_cpus / ms->smp.sockets;
-
-    sock_idx = (core_id / cores_per_socket);
-    socket = s390_get_socket(book, sock_idx);
+    /* Cores for the S390 topology are cores and threads of the QEMU topology 
*/
+    nb_cores_per_socket = ms->smp.cores * ms->smp.threads;
+    socket = s390_get_socket(book, core_id / nb_cores_per_socket);
 
     /*
      * At the core level, each CPU is represented by a bit in a 64bit
@@ -151,12 +150,11 @@ void s390_topology_new_cpu(int core_id)
      * CPU inside several CPU containers inside the socket container.
      */
     origin = 64 * (core_id / 64);
-
     cores = s390_get_cores(socket, origin);
+    cores->origin = origin;
 
     bit = 63 - (core_id - origin);
     set_bit(bit, &cores->mask);
-    cores->origin = origin;
 }
 
 /*
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index f6969b76c5..a617c943ff 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -889,4 +889,5 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
 
 #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..7f6db18829
--- /dev/null
+++ b/target/s390x/cpu_topology.c
@@ -0,0 +1,112 @@
+/*
+ * 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 setup_stsi(const MachineState *ms, void *p, int level)
+{
+    S390TopologyBook *book;
+    SysIB_151x *sysib;
+    BusChild *kid;
+    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 * ms->smp.threads;
+
+    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);
+
+    setup_stsi(machine, p, 2);
+
+    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 6acf14d5ec..27b3fbfa09 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
@@ -1910,6 +1911,10 @@ 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