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

[Igor Mammedov <imammedo@redhat.com>]

On Tue,  8 Jul 2025 16:22:42 +0200
Eric Auger <eric.auger@redhat.com> 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.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> 
> 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
>