* [PULL 03/24] s390x/cpu topology: add topology entries on CPU hotplug
2023-10-20 5:20 [PULL v2 00/24] s390x patches Thomas Huth
@ 2023-10-20 5:20 ` Thomas Huth
2023-10-20 5:20 ` [PULL 06/24] s390x/cpu topology: resetting the Topology-Change-Report Thomas Huth
2023-10-20 16:07 ` [PULL v2 00/24] s390x patches Stefan Hajnoczi
2 siblings, 0 replies; 4+ messages in thread
From: Thomas Huth @ 2023-10-20 5:20 UTC (permalink / raw)
To: qemu-devel; +Cc: Stefan Hajnoczi, Nina Schoetterl-Glausch
From: Pierre Morel <pmorel@linux.ibm.com>
The topology information are attributes of the CPU and are
specified during the CPU device creation.
On hot plug we:
- calculate the default values for the topology for drawers,
books and sockets in the case they are not specified.
- verify the CPU attributes
- check that we have still room on the desired socket
The possibility to insert a CPU in a mask is dependent on the
number of cores allowed in a socket, a book or a drawer, the
checking is done during the hot plug of the CPU to have an
immediate answer.
If the complete topology is not specified, the core is added
in the physical topology based on its core ID and it gets
defaults values for the modifier attributes.
This way, starting QEMU without specifying the topology can
still get some advantage of the CPU topology.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Message-ID: <20231016183925.2384704-4-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
MAINTAINERS | 6 +
include/hw/s390x/cpu-topology.h | 54 +++++++
hw/s390x/cpu-topology.c | 259 ++++++++++++++++++++++++++++++++
hw/s390x/s390-virtio-ccw.c | 22 ++-
hw/s390x/meson.build | 1 +
5 files changed, 340 insertions(+), 2 deletions(-)
create mode 100644 include/hw/s390x/cpu-topology.h
create mode 100644 hw/s390x/cpu-topology.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 2bf3399b3b..8e2e828f7c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1710,6 +1710,12 @@ F: hw/s390x/event-facility.c
F: hw/s390x/sclp*.c
L: qemu-s390x@nongnu.org
+S390 CPU topology
+M: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
+S: Supported
+F: include/hw/s390x/cpu-topology.h
+F: hw/s390x/cpu-topology.c
+
X86 Machines
------------
PC
diff --git a/include/hw/s390x/cpu-topology.h b/include/hw/s390x/cpu-topology.h
new file mode 100644
index 0000000000..afef70a66d
--- /dev/null
+++ b/include/hw/s390x/cpu-topology.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * CPU Topology
+ *
+ * Copyright IBM Corp. 2022, 2023
+ * Author(s): Pierre Morel <pmorel@linux.ibm.com>
+ *
+ */
+#ifndef HW_S390X_CPU_TOPOLOGY_H
+#define HW_S390X_CPU_TOPOLOGY_H
+
+#ifndef CONFIG_USER_ONLY
+
+#include "qemu/queue.h"
+#include "hw/boards.h"
+#include "qapi/qapi-types-machine-target.h"
+
+typedef struct S390Topology {
+ uint8_t *cores_per_socket;
+} S390Topology;
+
+#ifdef CONFIG_KVM
+bool s390_has_topology(void);
+void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp);
+#else
+static inline bool s390_has_topology(void)
+{
+ return false;
+}
+static inline void s390_topology_setup_cpu(MachineState *ms,
+ S390CPU *cpu,
+ Error **errp) {}
+#endif
+
+extern S390Topology s390_topology;
+
+static inline int s390_std_socket(int n, CpuTopology *smp)
+{
+ return (n / smp->cores) % smp->sockets;
+}
+
+static inline int s390_std_book(int n, CpuTopology *smp)
+{
+ return (n / (smp->cores * smp->sockets)) % smp->books;
+}
+
+static inline int s390_std_drawer(int n, CpuTopology *smp)
+{
+ return (n / (smp->cores * smp->sockets * smp->books)) % smp->drawers;
+}
+
+#endif /* CONFIG_USER_ONLY */
+
+#endif
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
new file mode 100644
index 0000000000..cabd42e779
--- /dev/null
+++ b/hw/s390x/cpu-topology.c
@@ -0,0 +1,259 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * CPU Topology
+ *
+ * Copyright IBM Corp. 2022, 2023
+ * Author(s): Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * S390 topology handling can be divided in two parts:
+ *
+ * - The first part in this file is taking care of all common functions
+ * used by KVM and TCG to create and modify the topology.
+ *
+ * - The second part, building the topology information data for the
+ * guest with CPU and KVM specificity will be implemented inside
+ * the target/s390/kvm sub tree.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "hw/qdev-properties.h"
+#include "hw/boards.h"
+#include "target/s390x/cpu.h"
+#include "hw/s390x/s390-virtio-ccw.h"
+#include "hw/s390x/cpu-topology.h"
+
+/*
+ * s390_topology is used to keep the topology information.
+ * .cores_per_socket: tracks information on the count of cores
+ * per socket.
+ */
+S390Topology s390_topology = {
+ /* will be initialized after the CPU model is realized */
+ .cores_per_socket = NULL,
+};
+
+/**
+ * s390_socket_nb:
+ * @cpu: s390x CPU
+ *
+ * Returns the socket number used inside the cores_per_socket array
+ * for a topology tree entry
+ */
+static int s390_socket_nb_from_ids(int drawer_id, int book_id, int socket_id)
+{
+ return (drawer_id * current_machine->smp.books + book_id) *
+ current_machine->smp.sockets + socket_id;
+}
+
+/**
+ * s390_socket_nb:
+ * @cpu: s390x CPU
+ *
+ * Returns the socket number used inside the cores_per_socket array
+ * for a cpu.
+ */
+static int s390_socket_nb(S390CPU *cpu)
+{
+ return s390_socket_nb_from_ids(cpu->env.drawer_id, cpu->env.book_id,
+ cpu->env.socket_id);
+}
+
+/**
+ * s390_has_topology:
+ *
+ * Return: true if the topology is supported by the machine.
+ */
+bool s390_has_topology(void)
+{
+ return false;
+}
+
+/**
+ * s390_topology_init:
+ * @ms: the machine state where the machine topology is defined
+ *
+ * Keep track of the machine topology.
+ *
+ * Allocate an array to keep the count of cores per socket.
+ * The index of the array starts at socket 0 from book 0 and
+ * drawer 0 up to the maximum allowed by the machine topology.
+ */
+static void s390_topology_init(MachineState *ms)
+{
+ CpuTopology *smp = &ms->smp;
+
+ s390_topology.cores_per_socket = g_new0(uint8_t, smp->sockets *
+ smp->books * smp->drawers);
+}
+
+/**
+ * s390_topology_cpu_default:
+ * @cpu: pointer to a S390CPU
+ * @errp: Error pointer
+ *
+ * Setup the default topology if no attributes are already set.
+ * Passing a CPU with some, but not all, attributes set is considered
+ * an error.
+ *
+ * The function calculates the (drawer_id, book_id, socket_id)
+ * topology by filling the cores starting from the first socket
+ * (0, 0, 0) up to the last (smp->drawers, smp->books, smp->sockets).
+ *
+ * CPU type and dedication have defaults values set in the
+ * s390x_cpu_properties, entitlement must be adjust depending on the
+ * dedication.
+ *
+ * Returns false if it is impossible to setup a default topology
+ * true otherwise.
+ */
+static bool s390_topology_cpu_default(S390CPU *cpu, Error **errp)
+{
+ CpuTopology *smp = ¤t_machine->smp;
+ CPUS390XState *env = &cpu->env;
+
+ /* All geometry topology attributes must be set or all unset */
+ if ((env->socket_id < 0 || env->book_id < 0 || env->drawer_id < 0) &&
+ (env->socket_id >= 0 || env->book_id >= 0 || env->drawer_id >= 0)) {
+ error_setg(errp,
+ "Please define all or none of the topology geometry attributes");
+ return false;
+ }
+
+ /* If one value is unset all are unset -> calculate defaults */
+ if (env->socket_id < 0) {
+ env->socket_id = s390_std_socket(env->core_id, smp);
+ env->book_id = s390_std_book(env->core_id, smp);
+ env->drawer_id = s390_std_drawer(env->core_id, smp);
+ }
+
+ /*
+ * When the user specifies the entitlement as 'auto' on the command line,
+ * QEMU will set the entitlement as:
+ * Medium when the CPU is not dedicated.
+ * High when dedicated is true.
+ */
+ if (env->entitlement == S390_CPU_ENTITLEMENT_AUTO) {
+ if (env->dedicated) {
+ env->entitlement = S390_CPU_ENTITLEMENT_HIGH;
+ } else {
+ env->entitlement = S390_CPU_ENTITLEMENT_MEDIUM;
+ }
+ }
+ return true;
+}
+
+/**
+ * s390_topology_check:
+ * @socket_id: socket to check
+ * @book_id: book to check
+ * @drawer_id: drawer to check
+ * @entitlement: entitlement to check
+ * @dedicated: dedication to check
+ * @errp: Error pointer
+ *
+ * The function checks if the topology
+ * attributes fits inside the system topology.
+ *
+ * Returns false if the specified topology does not match with
+ * the machine topology.
+ */
+static bool s390_topology_check(uint16_t socket_id, uint16_t book_id,
+ uint16_t drawer_id, uint16_t entitlement,
+ bool dedicated, Error **errp)
+{
+ CpuTopology *smp = ¤t_machine->smp;
+
+ if (socket_id >= smp->sockets) {
+ error_setg(errp, "Unavailable socket: %d", socket_id);
+ return false;
+ }
+ if (book_id >= smp->books) {
+ error_setg(errp, "Unavailable book: %d", book_id);
+ return false;
+ }
+ if (drawer_id >= smp->drawers) {
+ error_setg(errp, "Unavailable drawer: %d", drawer_id);
+ return false;
+ }
+ if (entitlement >= S390_CPU_ENTITLEMENT__MAX) {
+ error_setg(errp, "Unknown entitlement: %d", entitlement);
+ return false;
+ }
+ if (dedicated && (entitlement == S390_CPU_ENTITLEMENT_LOW ||
+ entitlement == S390_CPU_ENTITLEMENT_MEDIUM)) {
+ error_setg(errp, "A dedicated CPU implies high entitlement");
+ return false;
+ }
+ return true;
+}
+
+/**
+ * s390_update_cpu_props:
+ * @ms: the machine state
+ * @cpu: the CPU for which to update the properties from the environment.
+ *
+ */
+static void s390_update_cpu_props(MachineState *ms, S390CPU *cpu)
+{
+ CpuInstanceProperties *props;
+
+ props = &ms->possible_cpus->cpus[cpu->env.core_id].props;
+
+ props->socket_id = cpu->env.socket_id;
+ props->book_id = cpu->env.book_id;
+ props->drawer_id = cpu->env.drawer_id;
+}
+
+/**
+ * s390_topology_setup_cpu:
+ * @ms: MachineState used to initialize the topology structure on
+ * first call.
+ * @cpu: the new S390CPU to insert in the topology structure
+ * @errp: the error pointer
+ *
+ * Called from CPU hotplug to check and setup the CPU attributes
+ * before the CPU is inserted in the topology.
+ * There is no need to update the MTCR explicitly here because it
+ * will be updated by KVM on creation of the new CPU.
+ */
+void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp)
+{
+ int entry;
+
+ /*
+ * We do not want to initialize the topology if the CPU model
+ * does not support topology, consequently, we have to wait for
+ * the first CPU to be realized, which realizes the CPU model
+ * to initialize the topology structures.
+ *
+ * s390_topology_setup_cpu() is called from the CPU hotplug.
+ */
+ if (!s390_topology.cores_per_socket) {
+ s390_topology_init(ms);
+ }
+
+ if (!s390_topology_cpu_default(cpu, errp)) {
+ return;
+ }
+
+ if (!s390_topology_check(cpu->env.socket_id, cpu->env.book_id,
+ cpu->env.drawer_id, cpu->env.entitlement,
+ cpu->env.dedicated, errp)) {
+ return;
+ }
+
+ /* Do we still have space in the socket */
+ entry = s390_socket_nb(cpu);
+ if (s390_topology.cores_per_socket[entry] >= ms->smp.cores) {
+ error_setg(errp, "No more space on this socket");
+ return;
+ }
+
+ /* Update the count of cores in sockets */
+ s390_topology.cores_per_socket[entry] += 1;
+
+ /* topology tree is reflected in props */
+ s390_update_cpu_props(ms, cpu);
+}
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index c1123a9b45..7fe2bce20c 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -45,6 +45,7 @@
#include "target/s390x/kvm/pv.h"
#include "migration/blocker.h"
#include "qapi/visitor.h"
+#include "hw/s390x/cpu-topology.h"
static Error *pv_mig_blocker;
@@ -309,10 +310,18 @@ static void s390_cpu_plug(HotplugHandler *hotplug_dev,
{
MachineState *ms = MACHINE(hotplug_dev);
S390CPU *cpu = S390_CPU(dev);
+ ERRP_GUARD();
g_assert(!ms->possible_cpus->cpus[cpu->env.core_id].cpu);
ms->possible_cpus->cpus[cpu->env.core_id].cpu = OBJECT(dev);
+ if (s390_has_topology()) {
+ s390_topology_setup_cpu(ms, cpu, errp);
+ if (*errp) {
+ return;
+ }
+ }
+
if (dev->hotplugged) {
raise_irq_cpu_hotplug();
}
@@ -562,11 +571,20 @@ static const CPUArchIdList *s390_possible_cpu_arch_ids(MachineState *ms)
sizeof(CPUArchId) * max_cpus);
ms->possible_cpus->len = max_cpus;
for (i = 0; i < ms->possible_cpus->len; i++) {
+ CpuInstanceProperties *props = &ms->possible_cpus->cpus[i].props;
+
ms->possible_cpus->cpus[i].type = ms->cpu_type;
ms->possible_cpus->cpus[i].vcpus_count = 1;
ms->possible_cpus->cpus[i].arch_id = i;
- ms->possible_cpus->cpus[i].props.has_core_id = true;
- ms->possible_cpus->cpus[i].props.core_id = i;
+
+ props->has_core_id = true;
+ props->core_id = i;
+ props->has_socket_id = true;
+ props->socket_id = s390_std_socket(i, &ms->smp);
+ props->has_book_id = true;
+ props->book_id = s390_std_book(i, &ms->smp);
+ props->has_drawer_id = true;
+ props->drawer_id = s390_std_drawer(i, &ms->smp);
}
return ms->possible_cpus;
diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
index 6fd096813a..482fd13420 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -23,6 +23,7 @@ s390x_ss.add(when: 'CONFIG_KVM', if_true: files(
's390-skeys-kvm.c',
's390-stattrib-kvm.c',
's390-pci-kvm.c',
+ 'cpu-topology.c',
))
s390x_ss.add(when: 'CONFIG_TCG', if_true: files(
'tod-tcg.c',
--
2.41.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PULL 06/24] s390x/cpu topology: resetting the Topology-Change-Report
2023-10-20 5:20 [PULL v2 00/24] s390x patches Thomas Huth
2023-10-20 5:20 ` [PULL 03/24] s390x/cpu topology: add topology entries on CPU hotplug Thomas Huth
@ 2023-10-20 5:20 ` Thomas Huth
2023-10-20 16:07 ` [PULL v2 00/24] s390x patches Stefan Hajnoczi
2 siblings, 0 replies; 4+ messages in thread
From: Thomas Huth @ 2023-10-20 5:20 UTC (permalink / raw)
To: qemu-devel; +Cc: Stefan Hajnoczi, Nina Schoetterl-Glausch
From: Pierre Morel <pmorel@linux.ibm.com>
During a subsystem reset the Topology-Change-Report is cleared
by the machine.
Let's ask KVM to clear the Modified Topology Change Report (MTCR)
bit of the SCA in the case of a subsystem reset.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Message-ID: <20231016183925.2384704-7-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
include/hw/s390x/cpu-topology.h | 6 ++++++
target/s390x/cpu.h | 1 +
target/s390x/kvm/kvm_s390x.h | 1 +
hw/s390x/cpu-topology.c | 11 +++++++++++
hw/s390x/s390-virtio-ccw.c | 3 +++
target/s390x/cpu-sysemu.c | 13 +++++++++++++
target/s390x/kvm/kvm.c | 17 +++++++++++++++++
7 files changed, 52 insertions(+)
diff --git a/include/hw/s390x/cpu-topology.h b/include/hw/s390x/cpu-topology.h
index 85499fea3e..c064f427e9 100644
--- a/include/hw/s390x/cpu-topology.h
+++ b/include/hw/s390x/cpu-topology.h
@@ -45,6 +45,7 @@ typedef QTAILQ_HEAD(, S390TopologyEntry) S390TopologyList;
#ifdef CONFIG_KVM
bool s390_has_topology(void);
void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp);
+void s390_topology_reset(void);
#else
static inline bool s390_has_topology(void)
{
@@ -53,6 +54,11 @@ static inline bool s390_has_topology(void)
static inline void s390_topology_setup_cpu(MachineState *ms,
S390CPU *cpu,
Error **errp) {}
+static inline void s390_topology_reset(void)
+{
+ /* Unreachable, CPU topology not implemented for TCG */
+ assert(false);
+}
#endif
extern S390Topology s390_topology;
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 09bff39fe4..40c5cedd0e 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -654,6 +654,7 @@ typedef struct SysIBCPUListEntry {
QEMU_BUILD_BUG_ON(sizeof(SysIBCPUListEntry) != 16);
void insert_stsi_15_1_x(S390CPU *cpu, int sel2, uint64_t addr, uint8_t ar, uintptr_t ra);
+void s390_cpu_topology_set_changed(bool changed);
/* MMU defines */
#define ASCE_ORIGIN (~0xfffULL) /* segment table origin */
diff --git a/target/s390x/kvm/kvm_s390x.h b/target/s390x/kvm/kvm_s390x.h
index f9785564d0..649dae5948 100644
--- a/target/s390x/kvm/kvm_s390x.h
+++ b/target/s390x/kvm/kvm_s390x.h
@@ -47,5 +47,6 @@ void kvm_s390_crypto_reset(void);
void kvm_s390_restart_interrupt(S390CPU *cpu);
void kvm_s390_stop_interrupt(S390CPU *cpu);
void kvm_s390_set_diag318(CPUState *cs, uint64_t diag318_info);
+int kvm_s390_topology_set_mtcr(uint64_t attr);
#endif /* KVM_S390X_H */
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 13168341b6..7ec9319272 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -90,6 +90,17 @@ static void s390_topology_init(MachineState *ms)
smp->books * smp->drawers);
}
+/**
+ * s390_topology_reset:
+ *
+ * Generic reset for CPU topology, calls s390_topology_reset()
+ * to reset the kernel Modified Topology Change Record.
+ */
+void s390_topology_reset(void)
+{
+ s390_cpu_topology_set_changed(false);
+}
+
/**
* s390_topology_cpu_default:
* @cpu: pointer to a S390CPU
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 7fe2bce20c..6012165d41 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -124,6 +124,9 @@ static void subsystem_reset(void)
device_cold_reset(dev);
}
}
+ if (s390_has_topology()) {
+ s390_topology_reset();
+ }
}
static int virtio_ccw_hcall_notify(const uint64_t *args)
diff --git a/target/s390x/cpu-sysemu.c b/target/s390x/cpu-sysemu.c
index 8112561e5e..1cd30c1d84 100644
--- a/target/s390x/cpu-sysemu.c
+++ b/target/s390x/cpu-sysemu.c
@@ -307,3 +307,16 @@ void s390_do_cpu_set_diag318(CPUState *cs, run_on_cpu_data arg)
kvm_s390_set_diag318(cs, arg.host_ulong);
}
}
+
+void s390_cpu_topology_set_changed(bool changed)
+{
+ int ret;
+
+ if (kvm_enabled()) {
+ ret = kvm_s390_topology_set_mtcr(changed);
+ if (ret) {
+ error_report("Failed to set Modified Topology Change Report: %s",
+ strerror(-ret));
+ }
+ }
+}
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 53d6300809..d6bda3a2a8 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -2664,6 +2664,23 @@ int kvm_s390_get_zpci_op(void)
return cap_zpci_op;
}
+int kvm_s390_topology_set_mtcr(uint64_t attr)
+{
+ struct kvm_device_attr attribute = {
+ .group = KVM_S390_VM_CPU_TOPOLOGY,
+ .attr = attr,
+ };
+
+ if (!s390_has_feat(S390_FEAT_CONFIGURATION_TOPOLOGY)) {
+ return 0;
+ }
+ if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CPU_TOPOLOGY, attr)) {
+ return -ENOTSUP;
+ }
+
+ return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);
+}
+
void kvm_arch_accel_class_init(ObjectClass *oc)
{
}
--
2.41.0
^ permalink raw reply related [flat|nested] 4+ messages in thread