Re: [Qemu-devel] [PATCH 16/33] acpi: hardware side of CPU hotplug

[Marcel Apfelbaum <marcel@redhat.com>]

On 05/17/2016 05:43 PM, Igor Mammedov wrote:
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

Maybe it worth adding some kind of explanation
of the functionality added here.

Thanks,
Marcel

> ---
> v1:
>    - drop CPUHotplugState.is_enabled field
> ---
>   hw/acpi/Makefile.objs |   1 +
>   hw/acpi/cpu.c         | 206 ++++++++++++++++++++++++++++++++++++++++++++++++++
>   include/hw/acpi/cpu.h |  52 +++++++++++++
>   trace-events          |   9 +++
>   4 files changed, 268 insertions(+)
>   create mode 100644 hw/acpi/cpu.c
>   create mode 100644 include/hw/acpi/cpu.h
>
> diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
> index 66bd727..f200419 100644
> --- a/hw/acpi/Makefile.objs
> +++ b/hw/acpi/Makefile.objs
> @@ -2,6 +2,7 @@ common-obj-$(CONFIG_ACPI_X86) += core.o piix4.o pcihp.o
>   common-obj-$(CONFIG_ACPI_X86_ICH) += ich9.o tco.o
>   common-obj-$(CONFIG_ACPI_CPU_HOTPLUG) += cpu_hotplug.o
>   common-obj-$(CONFIG_ACPI_MEMORY_HOTPLUG) += memory_hotplug.o memory_hotplug_acpi_table.o
> +common-obj-$(CONFIG_ACPI_CPU_HOTPLUG) += cpu.o
>   obj-$(CONFIG_ACPI_NVDIMM) += nvdimm.o
>   common-obj-$(CONFIG_ACPI) += acpi_interface.o
>   common-obj-$(CONFIG_ACPI) += bios-linker-loader.o
> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
> new file mode 100644
> index 0000000..171a5f5
> --- /dev/null
> +++ b/hw/acpi/cpu.c
> @@ -0,0 +1,206 @@
> +#include "qemu/osdep.h"
> +#include "hw/boards.h"
> +#include "hw/acpi/cpu.h"
> +#include "qapi/error.h"
> +#include "trace.h"
> +
> +#define ACPI_CPU_HOTPLUG_REG_LEN 12
> +#define ACPI_CPU_SELECTOR_OFFSET_WR 0
> +#define ACPI_CPU_FLAGS_OFFSET_RW 4
> +
> +static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
> +{
> +    uint64_t val = ~0;
> +    CPUHotplugState *cpu_st = opaque;
> +    AcpiCpuStatus *cdev;
> +
> +    if (cpu_st->selector >= cpu_st->dev_count) {
> +        return val;
> +    }
> +
> +    cdev = &cpu_st->devs[cpu_st->selector];
> +    switch (addr) {
> +    case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */
> +        val = 0;
> +        val |= cdev->is_enabled   ? 1 : 0;
> +        val |= cdev->is_inserting ? 2 : 0;
> +        val |= cdev->is_removing  ? 4 : 0;
> +        trace_cpuhp_acpi_read_flags(cpu_st->selector, val);
> +        break;
> +    default:
> +        break;
> +    }
> +    return val;
> +}
> +
> +static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
> +                           unsigned int size)
> +{
> +    CPUHotplugState *cpu_st = opaque;
> +    AcpiCpuStatus *cdev;
> +    Error *local_err = NULL;
> +
> +    assert(cpu_st->dev_count);
> +
> +    if (addr) {
> +        if (cpu_st->selector >= cpu_st->dev_count) {
> +            trace_cpuhp_acpi_invalid_idx_selected(cpu_st->selector);
> +            return;
> +        }
> +    }
> +
> +    switch (addr) {
> +    case ACPI_CPU_SELECTOR_OFFSET_WR: /* current CPU selector */
> +        cpu_st->selector = data;
> +        trace_cpuhp_acpi_write_idx(cpu_st->selector);
> +        break;
> +    case ACPI_CPU_FLAGS_OFFSET_RW: /* set is_* fields  */
> +        cdev = &cpu_st->devs[cpu_st->selector];
> +        if (data & 2) { /* clear insert event */
> +            cdev->is_inserting = false;
> +            trace_cpuhp_acpi_clear_inserting_evt(cpu_st->selector);
> +        } else if (data & 4) { /* clear remove event */
> +            cdev->is_removing = false;
> +            trace_cpuhp_acpi_clear_remove_evt(cpu_st->selector);
> +        } else if (data & 8) {
> +            DeviceState *dev = NULL;
> +            HotplugHandler *hotplug_ctrl = NULL;
> +
> +            if (!cdev->is_enabled) {
> +                trace_cpuhp_acpi_ejecting_invalid_cpu(cpu_st->selector);
> +                break;
> +            }
> +
> +            trace_cpuhp_acpi_ejecting_cpu(cpu_st->selector);
> +            dev = DEVICE(cdev->cpu);
> +            hotplug_ctrl = qdev_get_hotplug_handler(dev);
> +            hotplug_handler_unplug(hotplug_ctrl, dev, &local_err);
> +            if (local_err) {
> +                break;
> +            }
> +        }
> +        break;
> +    default:
> +        break;
> +    }
> +    error_free(local_err);
> +}
> +
> +static const MemoryRegionOps cpu_hotplug_ops = {
> +    .read = cpu_hotplug_rd,
> +    .write = cpu_hotplug_wr,
> +    .endianness = DEVICE_LITTLE_ENDIAN,
> +    .valid = {
> +        .min_access_size = 1,
> +        .max_access_size = 4,
> +    },
> +};
> +
> +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
> +                         CPUHotplugState *state, hwaddr base_addr)
> +{
> +    MachineState *machine = MACHINE(qdev_get_machine());
> +    MachineClass *mc = MACHINE_GET_CLASS(machine);
> +    CPUArchIdList *id_list;
> +    int i;
> +
> +    id_list = mc->possible_cpu_arch_ids(machine);
> +    state->dev_count = id_list->len;
> +    state->devs = g_new0(typeof(*state->devs), state->dev_count);
> +    for (i = 0; i < id_list->len; i++) {
> +        state->devs[i].cpu =  id_list->cpus[i].cpu;
> +        state->devs[i].arch_id = id_list->cpus[i].arch_id;
> +        state->devs[i].is_enabled =  id_list->cpus[i].cpu ? true : false;
> +    }
> +    g_free(id_list);
> +    memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
> +                          "acpi-mem-hotplug", ACPI_CPU_HOTPLUG_REG_LEN);
> +    memory_region_add_subregion(as, base_addr, &state->ctrl_reg);
> +}
> +
> +static AcpiCpuStatus *get_cpu_status(CPUHotplugState *cpu_st, DeviceState *dev)
> +{
> +    CPUClass *k = CPU_GET_CLASS(dev);
> +    uint64_t cpu_arch_id = k->get_arch_id(CPU(dev));
> +    int i;
> +
> +    for (i = 0; i < cpu_st->dev_count; i++) {
> +        if (cpu_arch_id == cpu_st->devs[i].arch_id) {
> +            return &cpu_st->devs[i];
> +        }
> +    }
> +    return NULL;
> +}
> +
> +void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
> +                      CPUHotplugState *cpu_st, DeviceState *dev, Error **errp)
> +{
> +    AcpiCpuStatus *cdev;
> +
> +    cdev = get_cpu_status(cpu_st, dev);
> +    if (!cdev) {
> +        return;
> +    }
> +
> +    cdev->cpu = CPU(dev);
> +    cdev->is_enabled = true;
> +    if (dev->hotplugged) {
> +        cdev->is_inserting = true;
> +        ACPI_SEND_EVENT(hotplug_dev, ACPI_CPU_HOTPLUG_STATUS);
> +    }
> +}
> +
> +void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                CPUHotplugState *cpu_st,
> +                                DeviceState *dev, Error **errp)
> +{
> +    AcpiCpuStatus *cdev;
> +
> +    cdev = get_cpu_status(cpu_st, dev);
> +    if (!cdev) {
> +        return;
> +    }
> +
> +    cdev->is_removing = true;
> +    ACPI_SEND_EVENT(hotplug_dev, ACPI_CPU_HOTPLUG_STATUS);
> +}
> +
> +void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
> +                        DeviceState *dev, Error **errp)
> +{
> +    AcpiCpuStatus *cdev;
> +
> +    cdev = get_cpu_status(cpu_st, dev);
> +    if (!cdev) {
> +        return;
> +    }
> +
> +    cdev->cpu = NULL;
> +    cdev->is_enabled = false;
> +}
> +
> +static const VMStateDescription vmstate_cpuhp_sts = {
> +    .name = "CPU hotplug device state",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .minimum_version_id_old = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_BOOL(is_enabled, AcpiCpuStatus),
> +        VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
> +        VMSTATE_BOOL(is_removing, AcpiCpuStatus),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +const VMStateDescription vmstate_cpu_hotplug = {
> +    .name = "CPU hotplug state",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .minimum_version_id_old = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT32(selector, CPUHotplugState),
> +        VMSTATE_STRUCT_VARRAY_POINTER_UINT32(devs, CPUHotplugState, dev_count,
> +                                             vmstate_cpuhp_sts, AcpiCpuStatus),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> diff --git a/include/hw/acpi/cpu.h b/include/hw/acpi/cpu.h
> new file mode 100644
> index 0000000..3fdf4eb
> --- /dev/null
> +++ b/include/hw/acpi/cpu.h
> @@ -0,0 +1,52 @@
> +/*
> + * QEMU ACPI hotplug utilities
> + *
> + * Copyright (C) 2016 Red Hat Inc
> + *
> + * Authors:
> + *   Igor Mammedov <imammedo@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +#ifndef ACPI_CPU_H
> +#define ACPI_CPU_H
> +
> +#include "hw/qdev-core.h"
> +#include "hw/acpi/acpi.h"
> +#include "hw/hotplug.h"
> +
> +typedef struct AcpiCpuStatus {
> +    struct CPUState *cpu;
> +    uint64_t arch_id;
> +    bool is_enabled;
> +    bool is_inserting;
> +    bool is_removing;
> +} AcpiCpuStatus;
> +
> +typedef struct CPUHotplugState {
> +    MemoryRegion ctrl_reg;
> +    uint32_t selector;
> +    uint32_t dev_count;
> +    AcpiCpuStatus *devs;
> +} CPUHotplugState;
> +
> +void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
> +                      CPUHotplugState *cpu_st, DeviceState *dev, Error **errp);
> +
> +void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                CPUHotplugState *cpu_st,
> +                                DeviceState *dev, Error **errp);
> +
> +void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
> +                        DeviceState *dev, Error **errp);
> +
> +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
> +                         CPUHotplugState *state, hwaddr base_addr);
> +
> +extern const VMStateDescription vmstate_cpu_hotplug;
> +#define VMSTATE_CPU_HOTPLUG(cpuhp, state) \
> +    VMSTATE_STRUCT(cpuhp, state, 1, \
> +                   vmstate_cpu_hotplug, CPUHotplugState)
> +
> +#endif
> diff --git a/trace-events b/trace-events
> index 4fce005..7101ba9 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1908,3 +1908,12 @@ aspeed_vic_update_fiq(int flags) "Raising FIQ: %d"
>   aspeed_vic_update_irq(int flags) "Raising IRQ: %d"
>   aspeed_vic_read(uint64_t offset, unsigned size, uint32_t value) "From 0x%" PRIx64 " of size %u: 0x%" PRIx32
>   aspeed_vic_write(uint64_t offset, unsigned size, uint32_t data) "To 0x%" PRIx64 " of size %u: 0x%" PRIx32
> +
> +# hw/acpi/cpu.c
> +cpuhp_acpi_invalid_idx_selected(uint32_t idx) "0x%"PRIx32
> +cpuhp_acpi_read_flags(uint32_t idx, uint8_t flags) "idx[0x%"PRIx32"] flags: 0x%"PRIx8
> +cpuhp_acpi_clear_inserting_evt(uint32_t idx) "idx[0x%"PRIx32"]"
> +cpuhp_acpi_clear_remove_evt(uint32_t idx) "idx[0x%"PRIx32"]"
> +cpuhp_acpi_write_idx(uint32_t idx) "set active cpu idx: 0x%"PRIx32
> +cpuhp_acpi_ejecting_invalid_cpu(uint32_t idx) "0x%"PRIx32
> +cpuhp_acpi_ejecting_cpu(uint32_t idx) "0x%"PRIx32
>