On Mon, 4 Nov 2024 16:09:26 -0500 "Michael S. Tsirkin" <m...@redhat.com> wrote:
> From: Salil Mehta <salil.me...@huawei.com> > > Reflect the QOM vCPUs ACPI CPU hotplug states in the `_STA.Present` and > and `_STA.Enabled` bits when the guest kernel evaluates the ACPI > `_STA` method during initialization, as well as when vCPUs are > hot-plugged or hot-unplugged. If the CPU is present then the its > `enabled` status can be fetched using architecture-specific code [1]. > > Reference: > [1] Example implementation of architecture-specific hook to fetch CPU > `enabled status > Link: > https://github.com/salil-mehta/qemu/commit/c0b416b11e5af6505e558866f0eb6c9f3709173e > > Signed-off-by: Salil Mehta <salil.me...@huawei.com> > Message-Id: <20241103102419.202225-4-salil.me...@huawei.com> > Reviewed-by: Michael S. Tsirkin <m...@redhat.com> > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > --- > include/hw/core/cpu.h | 1 + > hw/acpi/cpu.c | 38 ++++++++++++++++++++++++++++++++++---- > 2 files changed, 35 insertions(+), 4 deletions(-) > > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > index e7de77dc6d..db8a6fbc6e 100644 > --- a/include/hw/core/cpu.h > +++ b/include/hw/core/cpu.h > @@ -159,6 +159,7 @@ struct CPUClass { > void (*query_cpu_fast)(CPUState *cpu, CpuInfoFast *value); > int64_t (*get_arch_id)(CPUState *cpu); > bool (*cpu_persistent_status)(CPUState *cpu); > + bool (*cpu_enabled_status)(CPUState *cpu); > void (*set_pc)(CPUState *cpu, vaddr value); > vaddr (*get_pc)(CPUState *cpu); > int (*gdb_read_register)(CPUState *cpu, GByteArray *buf, int reg); > diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c > index 9b03b4292e..23443f09a5 100644 > --- a/hw/acpi/cpu.c > +++ b/hw/acpi/cpu.c > @@ -50,6 +50,18 @@ void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, > ACPIOSTInfoList ***list) > } > } > > +static bool check_cpu_enabled_status(DeviceState *dev) > +{ > + CPUClass *k = dev ? CPU_GET_CLASS(dev) : NULL; > + CPUState *cpu = CPU(dev); > + > + if (cpu && (!k->cpu_enabled_status || k->cpu_enabled_status(cpu))) { > + return true; > + } > + > + return false; > +} > + > static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size) > { > uint64_t val = 0; > @@ -63,10 +75,11 @@ static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, > unsigned size) > cdev = &cpu_st->devs[cpu_st->selector]; > switch (addr) { > case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */ > - val |= cdev->cpu ? 1 : 0; > + val |= check_cpu_enabled_status(DEVICE(cdev->cpu)) ? 1 : 0; > val |= cdev->is_inserting ? 2 : 0; > val |= cdev->is_removing ? 4 : 0; > val |= cdev->fw_remove ? 16 : 0; > + val |= cdev->cpu ? 32 : 0; > trace_cpuhp_acpi_read_flags(cpu_st->selector, val); > break; > case ACPI_CPU_CMD_DATA_OFFSET_RW: > @@ -349,6 +362,7 @@ const VMStateDescription vmstate_cpu_hotplug = { > #define CPU_REMOVE_EVENT "CRMV" > #define CPU_EJECT_EVENT "CEJ0" > #define CPU_FW_EJECT_EVENT "CEJF" > +#define CPU_PRESENT "CPRS" > > void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures > opts, > build_madt_cpu_fn build_madt_cpu, hwaddr base_addr, > @@ -409,7 +423,9 @@ void build_cpus_aml(Aml *table, MachineState *machine, > CPUHotplugFeatures opts, > aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1)); > /* tell firmware to do device eject, write only */ > aml_append(field, aml_named_field(CPU_FW_EJECT_EVENT, 1)); > - aml_append(field, aml_reserved_field(3)); > + /* 1 if present, read only */ > + aml_append(field, aml_named_field(CPU_PRESENT, 1)); > + aml_append(field, aml_reserved_field(2)); > aml_append(field, aml_named_field(CPU_COMMAND, 8)); > aml_append(cpu_ctrl_dev, field); > > @@ -439,6 +455,7 @@ void build_cpus_aml(Aml *table, MachineState *machine, > CPUHotplugFeatures opts, > Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK); > Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR); > Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED); > + Aml *is_present = aml_name("%s.%s", cphp_res_path, CPU_PRESENT); > Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND); > Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA); > Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT); > @@ -467,13 +484,26 @@ void build_cpus_aml(Aml *table, MachineState *machine, > CPUHotplugFeatures opts, > { > Aml *idx = aml_arg(0); > Aml *sta = aml_local(0); > + Aml *ifctx2; > + Aml *else_ctx; > > aml_append(method, aml_acquire(ctrl_lock, 0xFFFF)); > aml_append(method, aml_store(idx, cpu_selector)); > aml_append(method, aml_store(zero, sta)); > - ifctx = aml_if(aml_equal(is_enabled, one)); > + ifctx = aml_if(aml_equal(is_present, one)); very likely this will break hotplug on after migration to older QEMU. > { > - aml_append(ifctx, aml_store(aml_int(0xF), sta)); > + ifctx2 = aml_if(aml_equal(is_enabled, one)); > + { > + /* cpu is present and enabled */ > + aml_append(ifctx2, aml_store(aml_int(0xF), sta)); > + } > + aml_append(ifctx, ifctx2); > + else_ctx = aml_else(); > + { > + /* cpu is present but disabled */ > + aml_append(else_ctx, aml_store(aml_int(0xD), sta)); > + } > + aml_append(ifctx, else_ctx); > } > aml_append(method, ifctx); > aml_append(method, aml_release(ctrl_lock));
