hw/acpi: Update ACPI GED framework to support vCPU Hotplug

ACPI GED (as described in the ACPI 6.4 spec) uses an interrupt listed in the
_CRS object of GED to intimate OSPM about an event. Later then

hw/acpi: Update ACPI GED framework to support vCPU Hotplug

ACPI GED (as described in the ACPI 6.4 spec) uses an interrupt listed in the
_CRS object of GED to intimate OSPM about an event. Later then demultiplexes the
notified event by evaluating ACPI _EVT method to know the type of event. Use
ACPI GED to also notify the guest kernel about any CPU hot(un)plug events.

Note, GED interface is used by many hotplug events like memory hotplug, NVDIMM
hotplug and non-hotplug events like system power down event. Each of these can
be selected using a bit in the 32 bit GED IO interface. A bit has been reserved
for the CPU hotplug event.

ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG
support has been enabled for particular architecture. Add cpu_hotplug_hw_init()
stub to avoid compilation break.

Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Xianglai Li <lixianglai@loongson.cn>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20240716111502.202344-4-salil.mehta@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>

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hw/acpi: refactor acpi hp modules so that targets can just use what they need

Currently various acpi hotplug modules like cpu hotplug, memory hotplug, pci
hotplug, nvdimm hotplug are all pulled in w

hw/acpi: refactor acpi hp modules so that targets can just use what they need

Currently various acpi hotplug modules like cpu hotplug, memory hotplug, pci
hotplug, nvdimm hotplug are all pulled in when CONFIG_ACPI_X86 is turned on.
This brings in support for whole lot of subsystems that some targets like
mips does not need. They are added just to satisfy symbol dependencies. This
is ugly and should be avoided. Targets should be able to pull in just what they
need and no more. For example, mips only needs support for PIIX4 and does not
need acpi pci hotplug support or cpu hotplug support or memory hotplug support
etc. This change is an effort to clean this up.
In this change, new config variables are added for various acpi hotplug
subsystems. Targets like mips can only enable PIIX4 support and not the rest
of all the other modules which were being previously pulled in as a part of
CONFIG_ACPI_X86. Function stubs make sure that symbols which piix4 needs but
are not required by mips (for example, symbols specific to pci hotplug etc)
are available to satisfy the dependencies.

Currently, this change only addresses issues with mips malta targets. In future
we might be able to clean up other targets which are similarly pulling in lot
of unnecessary hotplug modules by enabling ACPI_X86.

This change should also address issues such as the following:
https://gitlab.com/qemu-project/qemu/-/issues/221
https://gitlab.com/qemu-project/qemu/-/issues/193

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Message-Id: <20210812071409.492299-1-ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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