Re: [PATCH v19 01/21] s390x/cpu topology: add s390 specifics to CPU topology

Pierre Morel <pmorel@xxxxxxxxxxxxx> · Tue, 4 Apr 2023 14:26:05 +0200

On 4/4/23 09:03, Cédric Le Goater wrote:
On 4/3/23 18:28, Pierre Morel wrote:
S390 adds two new SMP levels, drawers and books to the CPU
topology.
The S390 CPU have specific topology features like dedication
and entitlement to give to the guest indications on the host
vCPUs scheduling and help the guest take the best decisions
on the scheduling of threads on the vCPUs.

Let us provide the SMP properties with books and drawers levels
and S390 CPU with dedication and entitlement,

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>

Some minor comments below,

---
  MAINTAINERS                     |  5 ++++
  qapi/machine-common.json        | 22 ++++++++++++++
  qapi/machine-target.json        | 12 ++++++++
  qapi/machine.json               | 17 +++++++++--
  include/hw/boards.h             | 10 ++++++-
  include/hw/s390x/cpu-topology.h | 15 ++++++++++
  target/s390x/cpu.h              |  5 ++++
  hw/core/machine-smp.c           | 53 ++++++++++++++++++++++++++++-----
  hw/core/machine.c               |  4 +++
  hw/s390x/s390-virtio-ccw.c      |  2 ++
  softmmu/vl.c                    |  6 ++++
  target/s390x/cpu.c              |  7 +++++
  qapi/meson.build                |  1 +
  qemu-options.hx                 |  7 +++--
  14 files changed, 152 insertions(+), 14 deletions(-)
  create mode 100644 qapi/machine-common.json
  create mode 100644 include/hw/s390x/cpu-topology.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 5340de0515..9b1f80739e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1654,6 +1654,11 @@ F: hw/s390x/event-facility.c
  F: hw/s390x/sclp*.c
  L: qemu-s390x@xxxxxxxxxx
  +S390 CPU topology
+M: Pierre Morel <pmorel@xxxxxxxxxxxxx>
+S: Supported
+F: include/hw/s390x/cpu-topology.h
+
  X86 Machines
  ------------
  PC
diff --git a/qapi/machine-common.json b/qapi/machine-common.json
new file mode 100644
index 0000000000..73ea38d976
--- /dev/null
+++ b/qapi/machine-common.json
@@ -0,0 +1,22 @@
+# -*- Mode: Python -*-
+# vim: filetype=python
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or 
later.
+# See the COPYING file in the top-level directory.
+
+##
+# = Machines S390 data types
+##
+
+##
+# @CpuS390Entitlement:
+#
+# An enumeration of cpu entitlements that can be assumed by a virtual
+# S390 CPU
+#
+# Since: 8.1
+##
+{ 'enum': 'CpuS390Entitlement',
+  'prefix': 'S390_CPU_ENTITLEMENT',
+  'data': [ 'horizontal', 'low', 'medium', 'high' ] }
+
diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 2e267fa458..42a6a40333 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -342,3 +342,15 @@
                     'TARGET_S390X',
                     'TARGET_MIPS',
                     'TARGET_LOONGARCH64' ] } }
+
+##
+# @CpuS390Polarization:
+#
+# An enumeration of cpu polarization that can be assumed by a virtual
+# S390 CPU
+#
+# Since: 8.1
+##
+{ 'enum': 'CpuS390Polarization',
+  'prefix': 'S390_CPU_POLARIZATION',
+  'data': [ 'horizontal', 'vertical' ] }
diff --git a/qapi/machine.json b/qapi/machine.json
index 604b686e59..1cdd83f3fd 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -9,6 +9,7 @@
  ##
    { 'include': 'common.json' }
+{ 'include': 'machine-common.json' }
    ##
  # @SysEmuTarget:
@@ -70,7 +71,7 @@
  #
  # @thread-id: ID of the underlying host thread
  #
-# @props: properties describing to which node/socket/core/thread
+# @props: properties describing to which 
node/drawer/book/socket/core/thread
  #         virtual CPU belongs to, provided if supported by board
  #
  # @target: the QEMU system emulation target, which determines which
@@ -902,13 +903,15 @@
  # a CPU is being hotplugged.
  #
  # @node-id: NUMA node ID the CPU belongs to
-# @socket-id: socket number within node/board the CPU belongs to
+# @drawer-id: drawer number within node/board the CPU belongs to 
(since 8.1)
+# @book-id: book number within drawer/node/board the CPU belongs to 
(since 8.1)
+# @socket-id: socket number within book/node/board the CPU belongs to
  # @die-id: die number within socket the CPU belongs to (since 4.1)
  # @cluster-id: cluster number within die the CPU belongs to (since 
7.1)
  # @core-id: core number within cluster the CPU belongs to
  # @thread-id: thread number within core the CPU belongs to
  #
-# Note: currently there are 6 properties that could be present
+# Note: currently there are 8 properties that could be present
  #       but management should be prepared to pass through other
  #       properties with device_add command to allow for future
  #       interface extension. This also requires the filed names to 
be kept in
@@ -918,6 +921,8 @@
  ##
  { 'struct': 'CpuInstanceProperties',
    'data': { '*node-id': 'int',
+            '*drawer-id': 'int',
+            '*book-id': 'int',
              '*socket-id': 'int',
              '*die-id': 'int',
              '*cluster-id': 'int',
@@ -1467,6 +1472,10 @@
  #
  # @cpus: number of virtual CPUs in the virtual machine
  #
+# @drawers: number of drawers in the CPU topology (since 8.1)
+#
+# @books: number of books in the CPU topology (since 8.1)
+#
  # @sockets: number of sockets in the CPU topology
  #
  # @dies: number of dies per socket in the CPU topology
@@ -1483,6 +1492,8 @@
  ##
  { 'struct': 'SMPConfiguration', 'data': {
       '*cpus': 'int',
+     '*drawers': 'int',
+     '*books': 'int',
       '*sockets': 'int',
       '*dies': 'int',
       '*clusters': 'int',
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 6fbbfd56c8..9ef0bb76cf 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -131,12 +131,16 @@ typedef struct {
   * @clusters_supported - whether clusters are supported by the machine
   * @has_clusters - whether clusters are explicitly specified in the 
user
   *                 provided SMP configuration
+ * @books_supported - whether books are supported by the machine
+ * @drawers_supported - whether drawers are supported by the machine
   */
  typedef struct {
      bool prefer_sockets;
      bool dies_supported;
      bool clusters_supported;
      bool has_clusters;
+    bool books_supported;
+    bool drawers_supported;
  } SMPCompatProps;
    /**
@@ -301,7 +305,9 @@ typedef struct DeviceMemoryState {
  /**
   * CpuTopology:
   * @cpus: the number of present logical processors on the machine
- * @sockets: the number of sockets on the machine
+ * @drawers: the number of drawers on the machine
+ * @books: the number of books in one drawer
+ * @sockets: the number of sockets in one book
   * @dies: the number of dies in one socket
   * @clusters: the number of clusters in one die
   * @cores: the number of cores in one cluster
@@ -310,6 +316,8 @@ typedef struct DeviceMemoryState {
   */
  typedef struct CpuTopology {
      unsigned int cpus;
+    unsigned int drawers;
+    unsigned int books;
      unsigned int sockets;
      unsigned int dies;
      unsigned int clusters;
diff --git a/include/hw/s390x/cpu-topology.h 
b/include/hw/s390x/cpu-topology.h
new file mode 100644
index 0000000000..83f31604cc
--- /dev/null
+++ b/include/hw/s390x/cpu-topology.h
@@ -0,0 +1,15 @@
+/*
+ * CPU Topology
+ *
+ * Copyright IBM Corp. 2022

Shouldn't we have some range : 2022-2023 ?

There was a discussion on this in the first spins, I think to remember 
that Nina wanted 22 and Thomas 23,

now we have a third opinion :) .

I must say that all three have their reasons and I take what the 
majority wants.

A vote?



+ *
+ * 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.
+ */

QEMU uses a SPDX tag like the kernel now :

/* SPDX-License-Identifier: GPL-2.0-or-later */


OK, so I will add it on all .c and .h new files



+#ifndef HW_S390X_CPU_TOPOLOGY_H
+#define HW_S390X_CPU_TOPOLOGY_H
+
+#define S390_TOPOLOGY_CPU_IFL   0x03

This definition is only used in patch 3. May be introduce it then,
it would cleaner.


yes.



+
+#endif
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 7d6d01325b..f2b2a38fe7 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -131,6 +131,11 @@ struct CPUArchState {
    #if !defined(CONFIG_USER_ONLY)
      uint32_t core_id; /* PoP "CPU address", same as cpu_index */
+    int32_t socket_id;
+    int32_t book_id;
+    int32_t drawer_id;
+    bool dedicated;
+    uint8_t entitlement;        /* Used only for vertical 
polarization */
      uint64_t cpuid;
  #endif
  diff --git a/hw/core/machine-smp.c b/hw/core/machine-smp.c
index c3dab007da..6f5622a024 100644
--- a/hw/core/machine-smp.c
+++ b/hw/core/machine-smp.c
@@ -30,8 +30,19 @@ static char *cpu_hierarchy_to_string(MachineState 
*ms)
  {
      MachineClass *mc = MACHINE_GET_CLASS(ms);
      GString *s = g_string_new(NULL);
+    const char *multiply = " * ", *prefix = "";
  -    g_string_append_printf(s, "sockets (%u)", ms->smp.sockets);
+    if (mc->smp_props.drawers_supported) {
+        g_string_append_printf(s, "drawers (%u)", ms->smp.drawers);
+    prefix = multiply;

indent issue.

right, seems I forgot to update the patch set after the checkpatch.



+    }
+
+    if (mc->smp_props.books_supported) {
+        g_string_append_printf(s, "%sbooks (%u)", prefix, 
ms->smp.books);
+    prefix = multiply;

ditto.

+    }
+

[...]

Thanks

Regards,

Pierre







