Commit 679dd1a9 authored by Igor Mammedov's avatar Igor Mammedov Committed by Michael S. Tsirkin
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pc: use new CPU hotplug interface since 2.7 machine type 



For compatibility reasons PC/Q35 will start with legacy
CPU hotplug interface by default but with new CPU hotplug
AML code since 2.7 machine type. That way legacy firmware
that doesn't use QEMU generated ACPI tables will be
able to continue using legacy CPU hotplug interface.

While new machine type, with firmware supporting QEMU
provided ACPI tables, will generate new CPU hotplug AML,
which will switch to new CPU hotplug interface when
guest OS executes its _INI method on ACPI tables
loading.

Signed-off-by: default avatarIgor Mammedov <imammedo@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 76623d00

hw/acpi/cpu.c

+9 −0
Original line number Diff line number Diff line
@@ -373,6 +373,15 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, 
        aml_append(field, aml_named_field(CPU_DATA, 32));

        aml_append(cpu_ctrl_dev, field);



        if (opts.has_legacy_cphp) {

            method = aml_method("_INI", 0, AML_SERIALIZED);

            /* switch off legacy CPU hotplug HW and use new one,

             * on reboot system is in new mode and writing 0

             * in CPU_SELECTOR selects BSP, which is NOP at

             * the time _INI is called */

            aml_append(method, aml_store(zero, aml_name(CPU_SELECTOR)));

            aml_append(cpu_ctrl_dev, method);

        }

    }

    aml_append(sb_scope, cpu_ctrl_dev);

hw/acpi/cpu_hotplug.c

+20 −1
Original line number Diff line number Diff line
@@ -34,7 +34,15 @@ static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size) 
static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,

                             unsigned int size)

{

    /* TODO: implement VCPU removal on guest signal that CPU can be removed */

    /* firmware never used to write in CPU present bitmap so use

       this fact as means to switch QEMU into modern CPU hotplug

       mode by writing 0 at the beginning of legacy CPU bitmap

     */

    if (addr == 0 && data == 0) {

        AcpiCpuHotplug *cpus = opaque;

        object_property_set_bool(cpus->device, false, "cpu-hotplug-legacy",

                                 &error_abort);

    }

}



static const MemoryRegionOps AcpiCpuHotplug_ops = {
@@ -83,6 +91,17 @@ void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner, 
    memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,

                          gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);

    memory_region_add_subregion(parent, base, &gpe_cpu->io);

    gpe_cpu->device = owner;

}



void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,

                                CPUHotplugState *cpuhp_state,

                                uint16_t io_port)

{

    MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));



    memory_region_del_subregion(parent, &gpe_cpu->io);

    cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);

}



void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,

hw/acpi/ich9.c

+33 −0
Original line number Diff line number Diff line
@@ -189,6 +189,33 @@ static const VMStateDescription vmstate_tco_io_state = { 
    }

};



static bool vmstate_test_use_cpuhp(void *opaque)

{

    ICH9LPCPMRegs *s = opaque;

    return !s->cpu_hotplug_legacy;

}



static int vmstate_cpuhp_pre_load(void *opaque)

{

    ICH9LPCPMRegs *s = opaque;

    Object *obj = OBJECT(s->gpe_cpu.device);

    object_property_set_bool(obj, false, "cpu-hotplug-legacy", &error_abort);

    return 0;

}



static const VMStateDescription vmstate_cpuhp_state = {

    .name = "ich9_pm/cpuhp",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .needed = vmstate_test_use_cpuhp,

    .pre_load = vmstate_cpuhp_pre_load,

    .fields      = (VMStateField[]) {

        VMSTATE_CPU_HOTPLUG(cpuhp_state, ICH9LPCPMRegs),

        VMSTATE_END_OF_LIST()

    }

};



const VMStateDescription vmstate_ich9_pm = {

    .name = "ich9_pm",

    .version_id = 1,
@@ -209,6 +236,7 @@ const VMStateDescription vmstate_ich9_pm = { 
    .subsections = (const VMStateDescription*[]) {

        &vmstate_memhp_state,

        &vmstate_tco_io_state,

        &vmstate_cpuhp_state,

        NULL

    }

};
@@ -318,6 +346,11 @@ static void ich9_pm_set_cpu_hotplug_legacy(Object *obj, bool value, 
{

    ICH9LPCState *s = ICH9_LPC_DEVICE(obj);



    assert(!value);

    if (s->pm.cpu_hotplug_legacy && value == false) {

        acpi_switch_to_modern_cphp(&s->pm.gpe_cpu, &s->pm.cpuhp_state,

                                   ICH9_CPU_HOTPLUG_IO_BASE);

    }

    s->pm.cpu_hotplug_legacy = value;

}

hw/acpi/piix4.c

+32 −0
Original line number Diff line number Diff line
@@ -276,6 +276,32 @@ static const VMStateDescription vmstate_memhp_state = { 
    }

};



static bool vmstate_test_use_cpuhp(void *opaque)

{

    PIIX4PMState *s = opaque;

    return !s->cpu_hotplug_legacy;

}



static int vmstate_cpuhp_pre_load(void *opaque)

{

    Object *obj = OBJECT(opaque);

    object_property_set_bool(obj, false, "cpu-hotplug-legacy", &error_abort);

    return 0;

}



static const VMStateDescription vmstate_cpuhp_state = {

    .name = "piix4_pm/cpuhp",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .needed = vmstate_test_use_cpuhp,

    .pre_load = vmstate_cpuhp_pre_load,

    .fields      = (VMStateField[]) {

        VMSTATE_CPU_HOTPLUG(cpuhp_state, PIIX4PMState),

        VMSTATE_END_OF_LIST()

    }

};



/* qemu-kvm 1.2 uses version 3 but advertised as 2

 * To support incoming qemu-kvm 1.2 migration, change version_id

 * and minimum_version_id to 2 below (which breaks migration from
@@ -310,6 +336,7 @@ static const VMStateDescription vmstate_acpi = { 
    },

    .subsections = (const VMStateDescription*[]) {

         &vmstate_memhp_state,

         &vmstate_cpuhp_state,

         NULL

    }

};
@@ -585,6 +612,11 @@ static void piix4_set_cpu_hotplug_legacy(Object *obj, bool value, Error **errp) 
{

    PIIX4PMState *s = PIIX4_PM(obj);



    assert(!value);

    if (s->cpu_hotplug_legacy && value == false) {

        acpi_switch_to_modern_cphp(&s->gpe_cpu, &s->cpuhp_state,

                                   PIIX4_CPU_HOTPLUG_IO_BASE);

    }

    s->cpu_hotplug_legacy = value;

}

hw/i386/acpi-build.c

+11 −1
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include "hw/timer/hpet.h"

#include "hw/acpi/acpi-defs.h"

#include "hw/acpi/acpi.h"

#include "hw/acpi/cpu.h"

#include "hw/nvram/fw_cfg.h"

#include "hw/acpi/bios-linker-loader.h"

#include "hw/loader.h"
@@ -1895,6 +1896,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, 
    GPtrArray *mem_ranges = g_ptr_array_new_with_free_func(crs_range_free);

    GPtrArray *io_ranges = g_ptr_array_new_with_free_func(crs_range_free);

    PCMachineState *pcms = PC_MACHINE(machine);

    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);

    uint32_t nr_mem = machine->ram_slots;

    int root_bus_limit = 0xFF;

    PCIBus *bus = NULL;
@@ -1950,7 +1952,15 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, 
        build_q35_pci0_int(dsdt);

    }



    if (pcmc->legacy_cpu_hotplug) {

        build_legacy_cpu_hotplug_aml(dsdt, machine, pm->cpu_hp_io_base);

    } else {

        CPUHotplugFeatures opts = {

            .apci_1_compatible = true, .has_legacy_cphp = true

        };

        build_cpus_aml(dsdt, machine, opts, pm->cpu_hp_io_base,

                       "\\_SB.PCI0", "\\_GPE._E02");

    }

    build_memory_hotplug_aml(dsdt, nr_mem, pm->mem_hp_io_base,

                             pm->mem_hp_io_len);