Message ID | 20220330125639.201937-3-damien.hedde@greensocs.com |
---|---|
State | New |
Headers | show |
Series | user-creatable cpu clusters | expand |
On 30/3/22 14:56, Damien Hedde wrote: > This object will be a _cpu-cluster_ generalization and > is meant to allow create cpus of the same type. > > The main goal is that this object, on contrary to _cpu-cluster-_, > can be used to dynamically create cpus: it does not rely on > external code to populate the object with cpus. > > Allowing the user to create a cpu cluster and each _cpu_ > separately would be hard because of the following reasons: > + cpu reset need to be handled > + instantiation and realize of cpu-cluster and the cpus > are interleaved > + cpu cluster must contains only identical cpus and it seems > difficult to check that at runtime. > Therefore we add a new type solving all this constraints. > > _cpu-cluster_ will be updated to inherit from this class > in following commits. > > Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> > --- > include/hw/cpu/cpus.h | 71 +++++++++++++++++++++++ > hw/cpu/cpus.c | 127 ++++++++++++++++++++++++++++++++++++++++++ > hw/cpu/meson.build | 2 +- > 3 files changed, 199 insertions(+), 1 deletion(-) > create mode 100644 include/hw/cpu/cpus.h > create mode 100644 hw/cpu/cpus.c > > diff --git a/include/hw/cpu/cpus.h b/include/hw/cpu/cpus.h > new file mode 100644 > index 0000000000..c65f568ef8 > --- /dev/null > +++ b/include/hw/cpu/cpus.h > @@ -0,0 +1,71 @@ > +/* > + * QEMU CPUs type > + * > + * Copyright (c) 2022 GreenSocs > + * > + * SPDX-License-Identifier: GPL-2.0-or-later > + */ > + > +#ifndef HW_CPU_CPUS_H > +#define HW_CPU_CPUS_H > + > +#include "qemu/typedefs.h" > +#include "hw/qdev-core.h" > +#include "qom/object.h" > + > +/* > + * This object represent several CPUs which are all identical. Typo "represents". > + * > + * If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 CPUs in an > + * Arm big.LITTLE system) they should be in different groups. If the CPUs do > + * not have the same view of memory (for example the main CPU and a management > + * controller processor) they should be in different groups. This description calls for a clearer CpusGroupState name instead of CpusState (which confuses me with CPUState). Alternatively CpusArrayState. > + * > + * This is an abstract class, subclasses are supposed to be created on > + * per-architecture basis to handle the specifics of the cpu architecture. > + * Subclasses are meant to be user-creatable (for cold-plug). > + */ > + > +#define TYPE_CPUS "cpus" > +OBJECT_DECLARE_TYPE(CpusState, CpusClass, CPUS) > + > +/** > + * CpusState: > + * @cpu_type: The type of cpu. > + * @topology.cpus: The number of cpus in this group. > + * Explicity put this field into a topology structure in > + * order to eventually update this smoothly with a full > + * CpuTopology structure in the future. > + * @cpus: Array of pointer to cpu objects. > + */ > +struct CpusState { > + /*< private >*/ > + DeviceState parent_obj; > + > + /*< public >*/ > + char *cpu_type; > + struct { > + uint16_t cpus; > + } topology; > + CPUState **cpus; > +};
On 4/16/22 19:52, Philippe Mathieu-Daudé wrote: > On 30/3/22 14:56, Damien Hedde wrote: >> This object will be a _cpu-cluster_ generalization and >> is meant to allow create cpus of the same type. >> >> The main goal is that this object, on contrary to _cpu-cluster-_, >> can be used to dynamically create cpus: it does not rely on >> external code to populate the object with cpus. >> >> Allowing the user to create a cpu cluster and each _cpu_ >> separately would be hard because of the following reasons: >> + cpu reset need to be handled >> + instantiation and realize of cpu-cluster and the cpus >> are interleaved >> + cpu cluster must contains only identical cpus and it seems >> difficult to check that at runtime. >> Therefore we add a new type solving all this constraints. >> >> _cpu-cluster_ will be updated to inherit from this class >> in following commits. >> >> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> >> --- >> include/hw/cpu/cpus.h | 71 +++++++++++++++++++++++ >> hw/cpu/cpus.c | 127 ++++++++++++++++++++++++++++++++++++++++++ >> hw/cpu/meson.build | 2 +- >> 3 files changed, 199 insertions(+), 1 deletion(-) >> create mode 100644 include/hw/cpu/cpus.h >> create mode 100644 hw/cpu/cpus.c >> >> diff --git a/include/hw/cpu/cpus.h b/include/hw/cpu/cpus.h >> new file mode 100644 >> index 0000000000..c65f568ef8 >> --- /dev/null >> +++ b/include/hw/cpu/cpus.h >> @@ -0,0 +1,71 @@ >> +/* >> + * QEMU CPUs type >> + * >> + * Copyright (c) 2022 GreenSocs >> + * >> + * SPDX-License-Identifier: GPL-2.0-or-later >> + */ >> + >> +#ifndef HW_CPU_CPUS_H >> +#define HW_CPU_CPUS_H >> + >> +#include "qemu/typedefs.h" >> +#include "hw/qdev-core.h" >> +#include "qom/object.h" >> + >> +/* >> + * This object represent several CPUs which are all identical. > > Typo "represents". > >> + * >> + * If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 >> CPUs in an >> + * Arm big.LITTLE system) they should be in different groups. If the >> CPUs do >> + * not have the same view of memory (for example the main CPU and a >> management >> + * controller processor) they should be in different groups. > > This description calls for a clearer CpusGroupState name instead > of CpusState (which confuses me with CPUState). Alternatively > CpusArrayState. Your are right, I'll add the "group" suffix. Thanks, Damien
diff --git a/include/hw/cpu/cpus.h b/include/hw/cpu/cpus.h new file mode 100644 index 0000000000..c65f568ef8 --- /dev/null +++ b/include/hw/cpu/cpus.h @@ -0,0 +1,71 @@ +/* + * QEMU CPUs type + * + * Copyright (c) 2022 GreenSocs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef HW_CPU_CPUS_H +#define HW_CPU_CPUS_H + +#include "qemu/typedefs.h" +#include "hw/qdev-core.h" +#include "qom/object.h" + +/* + * This object represent several CPUs which are all identical. + * + * If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 CPUs in an + * Arm big.LITTLE system) they should be in different groups. If the CPUs do + * not have the same view of memory (for example the main CPU and a management + * controller processor) they should be in different groups. + * + * This is an abstract class, subclasses are supposed to be created on + * per-architecture basis to handle the specifics of the cpu architecture. + * Subclasses are meant to be user-creatable (for cold-plug). + */ + +#define TYPE_CPUS "cpus" +OBJECT_DECLARE_TYPE(CpusState, CpusClass, CPUS) + +/** + * CpusState: + * @cpu_type: The type of cpu. + * @topology.cpus: The number of cpus in this group. + * Explicity put this field into a topology structure in + * order to eventually update this smoothly with a full + * CpuTopology structure in the future. + * @cpus: Array of pointer to cpu objects. + */ +struct CpusState { + /*< private >*/ + DeviceState parent_obj; + + /*< public >*/ + char *cpu_type; + struct { + uint16_t cpus; + } topology; + CPUState **cpus; +}; + +typedef void (*CpusConfigureCpu)(CpusState *s, CPUState *cpu, unsigned idx); + +/** + * CpusClass: + * @base_cpu_type: base cpu type accepted by this cpu group + * (the state cpu_type will be tested against it). + * @configure_cpu: method to configure a cpu (called between + * cpu init and realize) + * @skip_cpus_creation: CPUCLuster do not rely on creating + * cpus internally. This flag disables this feature. + */ +struct CpusClass { + DeviceClass parent_class; + const char *base_cpu_type; + CpusConfigureCpu configure_cpu; + bool skip_cpus_creation; +}; + +#endif /* HW_CPU_CPUS_H */ diff --git a/hw/cpu/cpus.c b/hw/cpu/cpus.c new file mode 100644 index 0000000000..5fad1de2c7 --- /dev/null +++ b/hw/cpu/cpus.c @@ -0,0 +1,127 @@ +/* + * QEMU CPUs type + * + * Copyright (c) 2022 GreenSocs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "hw/qdev-properties.h" +#include "qapi/error.h" +#include "qemu/module.h" +#include "qemu/cutils.h" +#include "hw/cpu/cpus.h" +#include "hw/core/cpu.h" +#include "hw/resettable.h" +#include "sysemu/reset.h" + +static Property cpus_properties[] = { + DEFINE_PROP_STRING("cpu-type", CpusState, cpu_type), + DEFINE_PROP_UINT16("num-cpus", CpusState, topology.cpus, 0), + DEFINE_PROP_END_OF_LIST() +}; + +static void cpus_reset(Object *obj) +{ + CpusState *s = CPUS(obj); + for (unsigned i = 0; i < s->topology.cpus; i++) { + cpu_reset(s->cpus[i]); + } +} + +static void cpus_create_cpus(CpusState *s, Error **errp) +{ + Error *err = NULL; + CpusClass *cgc = CPUS_GET_CLASS(s); + s->cpus = g_new0(CPUState *, s->topology.cpus); + + for (unsigned i = 0; i < s->topology.cpus; i++) { + CPUState *cpu = CPU(object_new(s->cpu_type)); + s->cpus[i] = cpu; + + /* set child property and release the initial ref */ + object_property_add_child(OBJECT(s), "cpu[*]", OBJECT(cpu)); + object_unref(OBJECT(cpu)); + + /* let subclass configure the cpu */ + if (cgc->configure_cpu) { + cgc->configure_cpu(s, cpu, i); + } + + /* finally realize the cpu */ + qdev_realize(DEVICE(cpu), NULL, &err); + if (err) { + error_propagate(errp, err); + return; + } + } +} + +static void cpus_realize(DeviceState *dev, Error **errp) +{ + CpusState *s = CPUS(dev); + CpusClass *cgc = CPUS_GET_CLASS(s); + + /* if subclass defined a base type, let's check it */ + if (cgc->base_cpu_type && + !object_class_dynamic_cast(object_class_by_name(s->cpu_type), + cgc->base_cpu_type)) { + error_setg(errp, "bad cpu-type '%s' (expected '%s')", s->cpu_type, + cgc->base_cpu_type); + return; + } + + if (s->topology.cpus == 0) { + error_setg(errp, "num-cpus is zero"); + return; + } + + /* create the cpus if needed */ + if (!cgc->skip_cpus_creation) { + cpus_create_cpus(s, errp); + qemu_register_reset(resettable_cold_reset_fn, s); + } +} + +static void cpus_finalize(Object *obj) +{ + CpusState *s = CPUS(obj); + + g_free(s->cpus); +} + +static void cpus_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + ResettableClass *rc = RESETTABLE_CLASS(klass); + + device_class_set_props(dc, cpus_properties); + dc->realize = cpus_realize; + + rc->phases.exit = cpus_reset; + + /* + * Subclasses are expected to be user-creatable. + * They may provide support to hotplug cpus, but they are + * not expected to be hotpluggable themselves. + */ + dc->hotpluggable = false; +} + +static const TypeInfo cpus_type_info = { + .name = TYPE_CPUS, + .parent = TYPE_DEVICE, + .abstract = true, + .instance_size = sizeof(CpusState), + .instance_finalize = cpus_finalize, + .class_size = sizeof(CpusClass), + .class_init = cpus_class_init, +}; + +static void cpus_register_types(void) +{ + type_register_static(&cpus_type_info); +} + +type_init(cpus_register_types) diff --git a/hw/cpu/meson.build b/hw/cpu/meson.build index 9e52fee9e7..ca4dda4f88 100644 --- a/hw/cpu/meson.build +++ b/hw/cpu/meson.build @@ -1,4 +1,4 @@ -softmmu_ss.add(files('core.c', 'cluster.c')) +softmmu_ss.add(files('core.c', 'cluster.c', 'cpus.c')) specific_ss.add(when: 'CONFIG_ARM11MPCORE', if_true: files('arm11mpcore.c')) specific_ss.add(when: 'CONFIG_REALVIEW', if_true: files('realview_mpcore.c'))
This object will be a _cpu-cluster_ generalization and is meant to allow create cpus of the same type. The main goal is that this object, on contrary to _cpu-cluster-_, can be used to dynamically create cpus: it does not rely on external code to populate the object with cpus. Allowing the user to create a cpu cluster and each _cpu_ separately would be hard because of the following reasons: + cpu reset need to be handled + instantiation and realize of cpu-cluster and the cpus are interleaved + cpu cluster must contains only identical cpus and it seems difficult to check that at runtime. Therefore we add a new type solving all this constraints. _cpu-cluster_ will be updated to inherit from this class in following commits. Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> --- include/hw/cpu/cpus.h | 71 +++++++++++++++++++++++ hw/cpu/cpus.c | 127 ++++++++++++++++++++++++++++++++++++++++++ hw/cpu/meson.build | 2 +- 3 files changed, 199 insertions(+), 1 deletion(-) create mode 100644 include/hw/cpu/cpus.h create mode 100644 hw/cpu/cpus.c