The migration can only take place if both source and destination
of the migration both use or both do not use the CPU topology
facility.
We indicate a change in topology during migration postload for the
case the topology changed between source and destination.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
target/s390x/cpu.h | 1 +
hw/s390x/cpu-topology.c | 79 +++++++++++++++++++++++++++++++++++++++
target/s390x/cpu-sysemu.c | 8 ++++
3 files changed, 88 insertions(+)
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 70de251b07..53127c249c 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -857,6 +857,7 @@ void s390_do_cpu_set_diag318(CPUState *cs, run_on_cpu_data arg);
int s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch_id,
int vq, bool assign);
void s390_cpu_topology_reset(void);
+int s390_cpu_topology_mtcr_set(void);
#ifndef CONFIG_USER_ONLY
unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
#else
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 21d2785b37..df4470d2b4 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -19,6 +19,7 @@
#include "target/s390x/cpu.h"
#include "hw/s390x/s390-virtio-ccw.h"
#include "hw/s390x/cpu-topology.h"
+#include "migration/vmstate.h"
/*
* s390_topology_new_cpu:
@@ -105,6 +106,83 @@ static void s390_topology_reset(DeviceState *dev)
s390_cpu_topology_reset();
}
+/**
+ * cpu_topology_postload
+ * @opaque: a pointer to the S390Topology
+ * @version_id: version identifier
+ *
+ * We check that the topology is used or is not used
+ * on both side identically.
+ *
+ * If the topology is in use we set the Modified Topology Change Report
+ * on the destination host.
+ */
+static int cpu_topology_postload(void *opaque, int version_id)
+{
+ S390Topology *topo = opaque;
+ int ret;
+
+ if (topo->topology_needed != s390_has_topology()) {
+ if (topo->topology_needed) {
+ error_report("Topology facility is needed in destination");
+ } else {
+ error_report("Topology facility can not be used in destination");
+ }
+ return -EINVAL;
+ }
+
+ /* We do not support CPU Topology, all is good */
+ if (!s390_has_topology()) {
+ return 0;
+ }
+
+ /* We support CPU Topology, set the MTCR unconditionally */
+ ret = s390_cpu_topology_mtcr_set();
+ if (ret) {
+ error_report("Failed to set MTCR: %s", strerror(-ret));
+ }
+ return ret;
+}
+
+/**
+ * cpu_topology_presave:
+ * @opaque: The pointer to the S390Topology
+ *
+ * Save the usage of the CPU Topology in the VM State.
+ */
+static int cpu_topology_presave(void *opaque)
+{
+ S390Topology *topo = opaque;
+
+ topo->topology_needed = s390_has_topology();
+ return 0;
+}
+
+/**
+ * cpu_topology_needed:
+ * @opaque: The pointer to the S390Topology
+ *
+ * We always need to know if source and destination use the topology.
+ */
+static bool cpu_topology_needed(void *opaque)
+{
+ return true;
+}
+
+
+const VMStateDescription vmstate_cpu_topology = {
+ .name = "cpu_topology",
+ .version_id = 1,
+ .post_load = cpu_topology_postload,
+ .pre_save = cpu_topology_presave,
+ .minimum_version_id = 1,
+ .needed = cpu_topology_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_BOOL(topology_needed, S390Topology),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
/**
* topology_class_init:
* @oc: Object class
@@ -120,6 +198,7 @@ static void topology_class_init(ObjectClass *oc, void *data)
device_class_set_props(dc, s390_topology_properties);
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
dc->reset = s390_topology_reset;
+ dc->vmsd = &vmstate_cpu_topology;
}
static const TypeInfo cpu_topology_info = {
diff --git a/target/s390x/cpu-sysemu.c b/target/s390x/cpu-sysemu.c
index e27864c5f5..a8e3e6219d 100644
--- a/target/s390x/cpu-sysemu.c
+++ b/target/s390x/cpu-sysemu.c
@@ -319,3 +319,11 @@ void s390_cpu_topology_reset(void)
}
}
}
+
+int s390_cpu_topology_mtcr_set(void)
+{
+ if (kvm_enabled()) {
+ return kvm_s390_topology_set_mtcr(1);
+ }
+ return -ENOENT;
+}
--
2.31.1
