On Tue, 26 Sep 2023 11:04:18 +0100
Salil Mehta via <qemu-devel@nongnu.org> wrote:
> ACPI AML changes to properly reflect the _STA.PRES and _STA.ENA Bits to the
> guest during initialzation, when CPUs are hotplugged and after CPUs are
> hot-unplugged.
>
> Signed-off-by: Salil Mehta <salil.me...@huawei.com>
Hi Salil,
Just brought up a qemu on qemu test setup again to poke
the kernel series and hopefully resolve a few questions there.
Ran into a trivial problem in which the kernel was trying and
failing to attach an ACPI handler before these were hotplugged.
Came down to the kernel code now treating functional in _STA as
meaning can be enumerated and effectively
ignoring all the other bits.
Requires a change to the value presented by default...
See below. Fix may well be completely wrong even though it works ;)
Thanks,
Jonathan
> ---
> hw/acpi/cpu.c | 49 +++++++++++++++++++++++++++++++---
> hw/acpi/generic_event_device.c | 11 ++++++++
> include/hw/acpi/cpu.h | 2 ++
> 3 files changed, 58 insertions(+), 4 deletions(-)
>
> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
> index 232720992d..e1299696d3 100644
> --- a/hw/acpi/cpu.c
> +++ b/hw/acpi/cpu.c
> @@ -63,10 +63,11 @@ 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 |= cdev->is_enabled ? 1 : 0;
> val |= cdev->is_inserting ? 2 : 0;
> val |= cdev->is_removing ? 4 : 0;
> val |= cdev->fw_remove ? 16 : 0;
> + val |= cdev->is_present ? 32 : 0;
> trace_cpuhp_acpi_read_flags(cpu_st->selector, val);
> break;
> case ACPI_CPU_CMD_DATA_OFFSET_RW:
> @@ -228,7 +229,21 @@ void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
> struct CPUState *cpu = CPU(id_list->cpus[i].cpu);
> if (qemu_present_cpu(cpu)) {
> state->devs[i].cpu = cpu;
> + state->devs[i].is_present = true;
> + } else {
> + if (qemu_persistent_cpu(cpu)) {
> + state->devs[i].is_present = true;
> + } else {
> + state->devs[i].is_present = false;
> + }
> }
> +
> + if (qemu_enabled_cpu(cpu)) {
> + state->devs[i].is_enabled = true;
> + } else {
> + state->devs[i].is_enabled = false;
> + }
> +
> state->devs[i].arch_id = id_list->cpus[i].arch_id;
> }
> memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
> @@ -261,6 +276,8 @@ void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
> }
>
> cdev->cpu = CPU(dev);
> + cdev->is_present = true;
> + cdev->is_enabled = true;
> if (dev->hotplugged) {
> cdev->is_inserting = true;
> acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
> @@ -292,6 +309,11 @@ void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
> return;
> }
>
> + cdev->is_enabled = false;
> + if (!qemu_persistent_cpu(CPU(dev))) {
> + cdev->is_present = false;
> + }
> +
> cdev->cpu = NULL;
> }
>
> @@ -302,6 +324,8 @@ static const VMStateDescription vmstate_cpuhp_sts = {
> .fields = (VMStateField[]) {
> VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
> VMSTATE_BOOL(is_removing, AcpiCpuStatus),
> + VMSTATE_BOOL(is_present, AcpiCpuStatus),
> + VMSTATE_BOOL(is_enabled, AcpiCpuStatus),
> VMSTATE_UINT32(ost_event, AcpiCpuStatus),
> VMSTATE_UINT32(ost_status, AcpiCpuStatus),
> VMSTATE_END_OF_LIST()
> @@ -339,6 +363,7 @@ 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,
> hwaddr base_addr,
> @@ -399,7 +424,9 @@ 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);
>
> @@ -429,6 +456,7 @@ 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);
> @@ -457,13 +485,26 @@ 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));
> {
> - 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));
For the current kernel patches, functional should not be set. So this should
be something like 0x5.
> + }
> + aml_append(ifctx, else_ctx);
> }
> aml_append(method, ifctx);
> aml_append(method, aml_release(ctrl_lock));
