Re: [PATCH v6 00/36] ACPI PCI Hotplug support on ARM

[Eric Auger <eric.auger@redhat.com>]

On 7/10/25 4:51 PM, Michael S. Tsirkin wrote:
> On Thu, Jul 10, 2025 at 03:18:47PM +0200, Eric Auger wrote:
>> Hi Michael,
>>
>> On 7/8/25 4:22 PM, Eric Auger wrote:
>>> This series enables ACPI PCI hotplug/hotunplug on ARM.
>>> It is not enabled by default and ACPI PCI hotplug can
>>> be selected by setting: 
>>>
>>> -global acpi-ged.acpi-pci-hotplug-with-bridge-support=on
>>>
>>> Expected benefits should be similar to those listed in [1],
>>> ie. removal of some racy behaviors, improved latencies.
>>>
>>> The infrastructure used in x86 is heavily reused and a
>>> huge part of the series consists in moving code from
>>> hw/i386/acpi-build.c to a generic place and slightly
>>> adapting it to make it usable on ARM. The DSDT table is 
>>> augmented to support ACPI PCI hotplug elements.
>>>
>>> On ARM we use use a GED event to notify the OS about
>>> hotplug events.
>> This morning Peter applied several series on target-arm.next and
>> 9d8ade51a20d ("hw/arm/virt: Basic CXL enablement on pci_expander_bridge
>> instances pxb-cxl")
>> introduced a minor context conflict with my series  (with
>> hw/pci-host/gpex-acpi: Use GED acpi pcihp property),
>> in hw/arm/virt-acpi-build.c. This is straightforward to fix.
>>
>> I have a branch where this conflict is resolved
>> https://github.com/eauger/qemu.git
>> arm-acpi-pcihp-v6-on-target-arm.next
>> 6a8c8f69a0  hw/pci-host/gpex-acpi: Use GED acpi pcihp property
>>
>> Please let me know if you want me to respin
>>
>> Eric
> As that's not yet merged in master, too early I think.
OK

Eric
>
>
>>> Best Regards
>>>
>>> Eric
>>>
>>> This series can be found at:
>>> https://github.com/eauger/qemu/tree/arm-acpi-pcihp-v6
>>>
>>> previous series:
>>> https://github.com/eauger/qemu/tree/arm-acpi-pcihp-v5
>>>
>>> History:
>>> v5 -> v6:
>>> - collected Jonathan's R-bs
>>> - cropped last 2 patch commit messages (Jonathan)
>>>
>>> v4 -> v5:
>>> - Collected Jonathan's R-bs (many thanks!)
>>> - fixed the tests/qtest/bios-tables-test issue by
>>>   creating a variant for the viot test
>>> - use the 3 phase reset API
>>> - fixed qom-test failures that were due to unconditionnal
>>>   fetches of the GED property
>>>
>>> v3 -> v4:
>>> - toook into account all comments on v3
>>> - static acpi-index is now supported unconditionally
>>>   from acpi pcihp option. See indiviual patches.
>>> - I hit a problem with ref block generation at
>>>   [19/32] tests/qtest/bios-tables-test: Update ARM DSDT reference
>>>   blobs: despite I regenerate the blobs, I get some errors.
>>>
>>> v2 -> v3:
>>> - lot of changes taking into account various feedbacks
>>>   (many thanks to all reviewers). Please refer to
>>>   individual patches for details. Main changes:
>>>   - no more machine option, acpi pci hp is not set by
>>>     default.
>>>   - removal of 2 unused variables in the osc method
>>>   - introduction of GED property to set the bus
>>>   - rework of the init/reset sequence
>>>   - fix virtio-mem-pci hotplug regression
>>>
>>> v1 -> v2:
>>> - collected a bunch of R-bs from Gustavo (many thanks!)
>>> - Fixed the breakage of bios-tables-test in TCG mode by
>>>   incorporating Gustavo's patches (part of
>>>   [PATCH 0/5] ACPI tests for PCI Hotplug on ARM
>>>   https://lore.kernel.org/all/20250526053123.1434204-1-gustavo.romero@linaro.org/)
>>> - Tweeked the dsdt aml changes to avoid any dsdt blob difference when
>>>   acpi-pcihp is off.
>>>
>>> RFC -> v1:
>>> - First 3 trivial patches were pulled separately
>>> - Fix of the register region size (0x18), ie. ACPI_PCIHP_SIZE
>>> - addition of aml_pci_edsm which was not called in RFC
>>> - acpi-index feature is now fixed. vms->bus was not set on
>>>   acpi_pcihp_init. The init sequence is still hacky though. Suggestions
>>>   are welcome.
>>>
>>> [1] [PATCH v6 0/6] Use ACPI PCI hot-plug for Q35
>>> https://lore.kernel.org/all/20210713004205.775386-1-jusual@redhat.com/
>>>
>>>
>>> Eric Auger (32):
>>>   hw/i386/acpi-build: Make aml_pci_device_dsm() static
>>>   hw/acpi: Rename and move build_x86_acpi_pci_hotplug to pcihp
>>>   hw/pci-host/gpex-acpi: Add native_pci_hotplug arg to
>>>     acpi_dsdt_add_pci_osc
>>>   hw/pci-host/gpex-acpi: Split host bridge OSC and DSM generation
>>>   hw/acpi/ged: Add a acpi-pci-hotplug-with-bridge-support property
>>>   hw/pci-host/gpex-acpi: Use GED acpi pcihp property
>>>   hw/i386/acpi-build: Turn build_q35_osc_method into a generic method
>>>   hw/pci-host/gpex-acpi: Use build_pci_host_bridge_osc_method
>>>   tests/qtest/bios-tables-test: Update DSDT blobs after GPEX _OSC change
>>>   hw/i386/acpi-build: Introduce build_append_pcihp_resources() helper
>>>   hw/acpi/pcihp: Add an AmlRegionSpace arg to build_acpi_pci_hotplug
>>>   hw/i386/acpi-build: Move build_append_notification_callback to pcihp
>>>   hw/i386/acpi-build: Move build_append_pci_bus_devices/pcihp_slots to
>>>     pcihp
>>>   hw/i386/acpi-build: Use AcpiPciHpState::root in acpi_set_pci_info
>>>   hw/i386/acpi-build: Move aml_pci_edsm to a generic place
>>>   qtest/bios-tables-test: Prepare for fixing the aarch64 viot test
>>>   qtest/bios-tables-test: Add a variant to the aarch64 viot test
>>>   qtest/bios-tables-test: Generate DSDT.viot
>>>   hw/arm/virt-acpi-build: Let non hotplug ports support static
>>>     acpi-index
>>>   tests/qtest/bios-tables-test: Update ARM DSDT reference blobs
>>>   hw/arm/virt-acpi-build: Modify the DSDT ACPI table to enable ACPI PCI
>>>     hotplug
>>>   hw/acpi/ged: Add a bus link property
>>>   hw/arm/virt: Pass the bus on the ged creation
>>>   hw/acpi/ged: Call pcihp plug callbacks in hotplug handler
>>>     implementation
>>>   hw/acpi/pcihp: Remove root arg in acpi_pcihp_init
>>>   hw/acpi/ged: Prepare the device to react to PCI hotplug events
>>>   hw/acpi/ged: Support migration of AcpiPciHpState
>>>   hw/core/sysbus: Introduce sysbus_mmio_map_name() helper
>>>   hw/arm/virt: Minor code reshuffling in create_acpi_ged
>>>   hw/arm/virt: Let virt support pci hotplug/unplug GED event
>>>   qtest/bios-tables-test: Generate reference blob for
>>>     DSDT.hpoffacpiindex
>>>   qtest/bios-tables-test: Generate reference blob for DSDT.acpipcihp
>>>
>>> Gustavo Romero (4):
>>>   tests/qtest/bios-tables-test: Prepare for changes in the DSDT table
>>>   tests/qtest/bios-tables-test: Prepare for changes in the arm virt DSDT
>>>     table
>>>   tests/qtest/bios-tables-test: Prepare for addition of acpi pci hp
>>>     tests
>>>   tests/qtest/bios-tables-test: Add aarch64 ACPI PCI hotplug test
>>>
>>>  hw/i386/acpi-build.h                          |   4 -
>>>  include/hw/acpi/generic_event_device.h        |  17 +-
>>>  include/hw/acpi/pci.h                         |   5 +-
>>>  include/hw/acpi/pcihp.h                       |  17 +-
>>>  include/hw/arm/virt.h                         |   1 +
>>>  include/hw/pci-host/gpex.h                    |   1 +
>>>  include/hw/sysbus.h                           |   1 +
>>>  hw/acpi/acpi-pci-hotplug-stub.c               |   2 +-
>>>  hw/acpi/generic_event_device.c                |  77 +++
>>>  hw/acpi/ich9.c                                |   7 +-
>>>  hw/acpi/pci-bridge.c                          |  54 ++
>>>  hw/acpi/pci.c                                 |  50 ++
>>>  hw/acpi/pcihp.c                               | 439 ++++++++++++++-
>>>  hw/acpi/piix4.c                               |   5 +-
>>>  hw/arm/virt-acpi-build.c                      |  38 ++
>>>  hw/arm/virt.c                                 |  27 +-
>>>  hw/core/sysbus.c                              |  11 +
>>>  hw/i386/acpi-build.c                          | 532 +-----------------
>>>  hw/pci-host/gpex-acpi.c                       |  74 +--
>>>  tests/qtest/bios-tables-test.c                |  53 ++
>>>  hw/arm/Kconfig                                |   2 +
>>>  hw/pci-host/Kconfig                           |   1 +
>>>  tests/data/acpi/aarch64/virt/DSDT             | Bin 5196 -> 5293 bytes
>>>  .../data/acpi/aarch64/virt/DSDT.acpihmatvirt  | Bin 5282 -> 5379 bytes
>>>  tests/data/acpi/aarch64/virt/DSDT.acpipcihp   | Bin 0 -> 6202 bytes
>>>  .../acpi/aarch64/virt/DSDT.hpoffacpiindex     | Bin 0 -> 5347 bytes
>>>  tests/data/acpi/aarch64/virt/DSDT.memhp       | Bin 6557 -> 6654 bytes
>>>  tests/data/acpi/aarch64/virt/DSDT.pxb         | Bin 7679 -> 7768 bytes
>>>  tests/data/acpi/aarch64/virt/DSDT.topology    | Bin 5398 -> 5495 bytes
>>>  tests/data/acpi/aarch64/virt/DSDT.viot        | Bin 0 -> 5310 bytes
>>>  tests/data/acpi/riscv64/virt/DSDT             | Bin 3576 -> 3538 bytes
>>>  tests/data/acpi/x86/microvm/DSDT.pcie         | Bin 3023 -> 2985 bytes
>>>  32 files changed, 811 insertions(+), 607 deletions(-)
>>>  create mode 100644 tests/data/acpi/aarch64/virt/DSDT.acpipcihp
>>>  create mode 100644 tests/data/acpi/aarch64/virt/DSDT.hpoffacpiindex
>>>  create mode 100644 tests/data/acpi/aarch64/virt/DSDT.viot
>>>