Am 08.12.22 um 10:44 schrieb Pierre Morel:
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.
I dont get why we need this? If the target QEMU has topology it should already create this according to the configuration. WHy do we need a trigger?
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> --- target/s390x/cpu.h | 1 + hw/s390x/cpu-topology.c | 49 +++++++++++++++++++++++++++++++++++++++ target/s390x/cpu-sysemu.c | 8 +++++++ 3 files changed, 58 insertions(+) diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h index bc1a7de932..284c708a6c 100644 --- a/target/s390x/cpu.h +++ b/target/s390x/cpu.h @@ -854,6 +854,7 @@ 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 f54afcf550..8a2fe041d4 100644 --- a/hw/s390x/cpu-topology.c +++ b/hw/s390x/cpu-topology.c @@ -18,6 +18,7 @@ #include "target/s390x/cpu.h" #include "hw/s390x/s390-virtio-ccw.h" #include "hw/s390x/cpu-topology.h" +#include "migration/vmstate.h"/*** s390_has_topology @@ -129,6 +130,53 @@ 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) +{ + int ret; + + /* 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_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 s390_has_topology(); +} + +const VMStateDescription vmstate_cpu_topology = { + .name = "cpu_topology", + .version_id = 1, + .post_load = cpu_topology_postload, + .minimum_version_id = 1, + .needed = cpu_topology_needed, +}; + /** * topology_class_init: * @oc: Object class @@ -145,6 +193,7 @@ 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; +}
