On 25/04/2023 18.14, Pierre Morel wrote:
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@xxxxxxxxxxxxx> ---
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diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c new file mode 100644 index 0000000000..471e0e7292 --- /dev/null +++ b/hw/s390x/cpu-topology.c @@ -0,0 +1,259 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * CPU Topology
Since you later introduce a file with almost the same name in the target/s390x/ folder, it would be fine to have some more explanation here what this file is all about (especially with regards to the other file in target/s390x/).
+ * + * Copyright IBM Corp. 2022,2023 + * Author(s): Pierre Morel <pmorel@xxxxxxxxxxxxx> + * + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qemu/error-report.h" +#include "hw/qdev-properties.h" +#include "hw/boards.h" +#include "qemu/typedefs.h"
qemu/typedefs.h is already included by osdep.h by default, no need to re-include it here.
+#include "target/s390x/cpu.h" +#include "hw/s390x/s390-virtio-ccw.h" +#include "hw/s390x/cpu-topology.h"
...> +
+/** + * 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
s/Hotplug/hotplug/
+ * before the CPU is inserted in the topology. + * There is no need to update the MTCR explicitely here because it
s/explicitely/explicitly/
+ * will be updated by KVM on creation of the new CPU. + */ +void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp)
... Thomas
