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authorPierre Morel <pmorel@linux.ibm.com>2023-10-16 20:39:07 +0200
committerThomas Huth <thuth@redhat.com>2023-10-20 07:16:53 +0200
commitc809bbc8e98cf7fa254fac91084ade0a22877dec (patch)
tree91eb2c24f2632769869b09be6446a11edaa69701 /include
parent5de1aff2555275ef182197eddcadb276364ace38 (diff)
s390x/cpu topology: add topology entries on CPU hotplug
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>
Diffstat (limited to 'include')
-rw-r--r--include/hw/s390x/cpu-topology.h54
1 files changed, 54 insertions, 0 deletions
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