On 9/27/22 14:03, Cédric Le Goater wrote:
On 9/2/22 09:55, Pierre Morel wrote:
In the S390x CPU topology the core_id specifies the CPU address
and the position of the core withing the topology.
Let's build the topology based on the core_id.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
hw/s390x/cpu-topology.c | 135 ++++++++++++++++++++++++++++++++
hw/s390x/meson.build | 1 +
hw/s390x/s390-virtio-ccw.c | 10 +++
include/hw/s390x/cpu-topology.h | 42 ++++++++++
4 files changed, 188 insertions(+)
create mode 100644 hw/s390x/cpu-topology.c
create mode 100644 include/hw/s390x/cpu-topology.h
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
new file mode 100644
index 0000000000..a6ca006ec5
--- /dev/null
+++ b/hw/s390x/cpu-topology.c
@@ -0,0 +1,135 @@
+/*
+ * CPU Topology
+ *
+ * Copyright IBM Corp. 2022
+ * Author(s): Pierre Morel <pmorel@xxxxxxxxxxxxx>
+
+ * 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 "qapi/error.h"
+#include "qemu/error-report.h"
+#include "hw/sysbus.h"
+#include "hw/qdev-properties.h"
+#include "hw/boards.h"
+#include "qemu/typedefs.h"
+#include "target/s390x/cpu.h"
+#include "hw/s390x/s390-virtio-ccw.h"
+#include "hw/s390x/cpu-topology.h"
+
+S390Topology *s390_get_topology(void)
+{
+ static S390Topology *s390Topology;
+
+ if (!s390Topology) {
+ s390Topology = S390_CPU_TOPOLOGY(
+ object_resolve_path(TYPE_S390_CPU_TOPOLOGY, NULL));
+ }
+
+ return s390Topology;
+}
+
+/*
+ * s390_topology_new_cpu:
+ * @core_id: the core ID is machine wide
+ *
+ * The topology returned by s390_get_topology(), gives us the CPU
+ * topology established by the -smp QEMU aruments.
+ * The core-id gives:
+ * - the Container TLE (Topology List Entry) containing the CPU TLE.
+ * - in the CPU TLE the origin, or offset of the first bit in the
core mask
+ * - the bit in the CPU TLE core mask
+ */
+void s390_topology_new_cpu(int core_id)
+{
+ S390Topology *topo = s390_get_topology();
+ int socket_id;
+ int bit, origin;
+
+ /* In the case no Topology is used nothing is to be done here */
+ if (!topo) {
+ return;
+ }
+
+ socket_id = core_id / topo->cores;
+
+ bit = core_id;
+ origin = bit / 64;
+ bit %= 64;
+ bit = 63 - bit;
+
+ /*
+ * At the core level, each CPU is represented by a bit in a 64bit
+ * unsigned long. Set on plug and clear on unplug of a CPU.
Do we have CPU unplug on s390x ?
not in QEMU.
I will change this sentence.
+ * The firmware assume that all CPU in a CPU TLE have the same
+ * type, polarization and are all dedicated or shared.
+ * In the case a socket contains CPU with different type,
polarization
+ * or entitlement then they will be defined in different CPU
containers.
+ * Currently we assume all CPU are identical IFL CPUs and that
they are
+ * all dedicated CPUs.
+ * The only reason to have several S390TopologyCores inside a
socket is
+ * to have more than 64 CPUs.
+ * In that case the origin field, representing the offset of the
first CPU
+ * in the CPU container allows to represent up to the maximal
number of
+ * CPU inside several CPU containers inside the socket container.
+ */
+ topo->socket[socket_id].active_count++;
+ topo->tle[socket_id].active_count++;
+ set_bit(bit, &topo->tle[socket_id].mask[origin]);
+}
+
+/**
+ * s390_topology_realize:
+ * @dev: the device state
+ * @errp: the error pointer (not used)
+ *
+ * During realize the machine CPU topology is initialized with the
+ * QEMU -smp parameters.
+ * The maximum count of CPU TLE in the all Topology can not be greater
+ * than the maximum CPUs.
+ */
+static void s390_topology_realize(DeviceState *dev, Error **errp)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
Using qdev_get_machine() is suspicious :)
OK
+ S390Topology *topo = S390_CPU_TOPOLOGY(dev);
+ int n;
+
+ topo->sockets = ms->smp.sockets;
+ topo->cores = ms->smp.cores;
+ topo->tles = ms->smp.max_cpus;
These look like object properties to me.
It is a temporary store to keep them at hand.
I will see if I keep them afterall.
If I keep them I will make them property.
+
+ n = topo->sockets;
+ topo->socket = g_malloc0(n * sizeof(S390TopoContainer));
+ topo->tle = g_malloc0(topo->tles * sizeof(S390TopoTLE));
+}
+
+/**
+ * topology_class_init:
+ * @oc: Object class
+ * @data: (not used)
+ *
+ * A very simple object we will need for reset and migration.
+ */
+static void topology_class_init(ObjectClass *oc, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(oc);
+
+ dc->realize = s390_topology_realize;
+ set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
no vmstate ?
it is added in a later patch
+static const TypeInfo cpu_topology_info = {
+ .name = TYPE_S390_CPU_TOPOLOGY,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(S390Topology),
+ .class_init = topology_class_init,
+};
+
+static void topology_register(void)
+{
+ type_register_static(&cpu_topology_info);
+}
+type_init(topology_register);
diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
index de28a90a57..96d7d7d231 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -2,6 +2,7 @@ s390x_ss = ss.source_set()
s390x_ss.add(files(
'ap-bridge.c',
'ap-device.c',
+ 'cpu-topology.c',
'ccw-device.c',
'css-bridge.c',
'css.c',
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index b5ca154e2f..15cefd104b 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -43,6 +43,7 @@
#include "sysemu/sysemu.h"
#include "hw/s390x/pv.h"
#include "migration/blocker.h"
+#include "hw/s390x/cpu-topology.h"
static Error *pv_mig_blocker;
@@ -247,6 +248,12 @@ static void ccw_init(MachineState *machine)
/* init memory + setup max page size. Required for the CPU model */
s390_memory_init(machine->ram);
+ /* Adding the topology must be done before CPU intialization*/
+ dev = qdev_new(TYPE_S390_CPU_TOPOLOGY);
+ object_property_add_child(qdev_get_machine(),
TYPE_S390_CPU_TOPOLOGY,
No need to use qdev_get_machine(), you have 'machine' above.
OK
+ OBJECT(dev));
+ sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
why not store a TYPE_S390_CPU_TOPOLOGY object pointer under the machine
state for later use ?
May be, I will think about it.
+
/* init CPUs (incl. CPU model) early so s390_has_feature() works */
s390_init_cpus(machine);
@@ -309,6 +316,9 @@ static void s390_cpu_plug(HotplugHandler
*hotplug_dev,
g_assert(!ms->possible_cpus->cpus[cpu->env.core_id].cpu);
ms->possible_cpus->cpus[cpu->env.core_id].cpu = OBJECT(dev);
+ /* Inserting the CPU in the Topology can not fail */
+ s390_topology_new_cpu(cpu->env.core_id);
+
in which case, we could use the topo object pointer to insert a new CPU
id and drop s390_get_topology() which looks overkill.
I would add the test :
if (!S390_CCW_MACHINE(machine)->topology_disable) {
before inserting to be consistent. But I am anticipating some other
patch.
It belongs here for bisect so I will add it here.
Thanks.
C.
Thanks,
Pierre
--
Pierre Morel
IBM Lab Boeblingen
