qemu-kvm/kvm-target-s390x-Add-a-CONFIG-switch-to-disable-legacy-C.patch

117 lines
4.4 KiB
Diff

From d0f88c7a0c95b4d9ab03221400736cb17cb4b995 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Thu, 13 Jun 2024 16:14:22 +0200
Subject: [PATCH 10/14] target/s390x: Add a CONFIG switch to disable legacy
CPUs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Thomas Huth <thuth@redhat.com>
RH-MergeRequest: 252: s390x: remove legacy CPU types
RH-Jira: RHEL-39898
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [3/5] f8e78c8e0349c8645e7df7b0bebed1635865b454 (thuth/qemu-kvm-cs9)
The oldest model that IBM still supports is the z13. Considering
that each generation can "emulate" the previous two generations
in hardware (via the "IBC" feature of the CPUs), this means that
everything that is older than z114/196 is not an officially supported
CPU model anymore. The Linux kernel still support the z10, so if
we also take this into account, everything older than that can
definitely be considered as a legacy CPU model.
For downstream builds of QEMU, we would like to be able to disable
these legacy CPUs in the build. Thus add a CONFIG switch that can be
used to disable them (and old machine types that use them by default).
Message-Id: <20240614125019.588928-1-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit d6a7c3f44cf3f60c066dbf087ef79d4b12acc642)
---
hw/s390x/s390-virtio-ccw.c | 4 ++++
target/s390x/Kconfig | 5 +++++
target/s390x/cpu_models.c | 9 +++++++++
3 files changed, 18 insertions(+)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index b0b903b78c..527b05d1d6 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -46,6 +46,7 @@
#include "migration/blocker.h"
#include "qapi/visitor.h"
#include "hw/s390x/cpu-topology.h"
+#include CONFIG_DEVICES
static Error *pv_mig_blocker;
@@ -1130,6 +1131,8 @@ static void ccw_machine_2_12_class_options(MachineClass *mc)
}
DEFINE_CCW_MACHINE(2_12, "2.12", false);
+#ifdef CONFIG_S390X_LEGACY_CPUS
+
static void ccw_machine_2_11_instance_options(MachineState *machine)
{
static const S390FeatInit qemu_cpu_feat = { S390_FEAT_LIST_QEMU_V2_11 };
@@ -1277,6 +1280,7 @@ static void ccw_machine_2_4_class_options(MachineClass *mc)
DEFINE_CCW_MACHINE(2_4, "2.4", false);
#endif
+#endif
static void ccw_machine_rhel940_instance_options(MachineState *machine)
{
diff --git a/target/s390x/Kconfig b/target/s390x/Kconfig
index d886be48b4..8a95f2bc3f 100644
--- a/target/s390x/Kconfig
+++ b/target/s390x/Kconfig
@@ -2,3 +2,8 @@ config S390X
bool
select PCI
select S390_FLIC
+
+config S390X_LEGACY_CPUS
+ bool
+ default y
+ depends on S390X
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index 370b3b3065..f4dbcc67bb 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -25,6 +25,7 @@
#ifndef CONFIG_USER_ONLY
#include "sysemu/sysemu.h"
#include "target/s390x/kvm/pv.h"
+#include CONFIG_DEVICES
#endif
#define CPUDEF_INIT(_type, _gen, _ec_ga, _mha_pow, _hmfai, _name, _desc) \
@@ -50,6 +51,13 @@
#define RHEL_CPU_DEPRECATION "use at least 'z14', or 'host' / 'qemu' / 'max'"
static S390CPUDef s390_cpu_defs[] = {
+ /*
+ * Linux requires at least z10 nowadays, and IBM only supports recent CPUs
+ * (see https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history),
+ * so we consider older CPUs as legacy that can optionally be disabled via
+ * the CONFIG_S390X_LEGACY_CPUS config switch.
+ */
+#if defined(CONFIG_S390X_LEGACY_CPUS) || defined(CONFIG_USER_ONLY)
CPUDEF_INIT(0x2064, 7, 1, 38, 0x00000000U, "z900", "IBM zSeries 900 GA1"),
CPUDEF_INIT(0x2064, 7, 2, 38, 0x00000000U, "z900.2", "IBM zSeries 900 GA2"),
CPUDEF_INIT(0x2064, 7, 3, 38, 0x00000000U, "z900.3", "IBM zSeries 900 GA3"),
@@ -67,6 +75,7 @@ static S390CPUDef s390_cpu_defs[] = {
CPUDEF_INIT(0x2096, 9, 2, 40, 0x00000000U, "z9BC", "IBM System z9 BC GA1"),
CPUDEF_INIT(0x2094, 9, 3, 40, 0x00000000U, "z9EC.3", "IBM System z9 EC GA3"),
CPUDEF_INIT(0x2096, 9, 3, 40, 0x00000000U, "z9BC.2", "IBM System z9 BC GA2"),
+#endif
CPUDEF_INIT(0x2097, 10, 1, 43, 0x00000000U, "z10EC", "IBM System z10 EC GA1"),
CPUDEF_INIT(0x2097, 10, 2, 43, 0x00000000U, "z10EC.2", "IBM System z10 EC GA2"),
CPUDEF_INIT(0x2098, 10, 2, 43, 0x00000000U, "z10BC", "IBM System z10 BC GA1"),
--
2.39.3