Hi Eric,

On 5/26/25 07:21, Eric Auger wrote:
Hi Gustavo,

On 5/26/25 7:55 AM, Gustavo Romero wrote:
Hi Eric,

On 5/14/25 14:00, Eric Auger wrote:
This series enables ACPI PCI hotplug/hotunplug on ARM
and makes it default for 10.1 machine type. This aligns with
x86 q35 machine. Expected benefits should be similar to
those listed in [1].

It is still possible to disable it using a virt machine
option: virt,acpi-pcihp=off and restore the legacy behavior.

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.

I have not noticed any tests/qtest/bios-tables-test failures
neither on x86 nor ARM. x86 DSDT table has not changed.
ARM DSDT table definitively has but there are no tests
impacted. ARM misses hotplug tests that do exist on x86. This
most probably should be considered in the future.

I've just posted a v1 for a acpi-pcihp=on test:

https://mail.gnu.org/archive/html/qemu-devel/2025-05/msg05824.html

The odd thing is that I noticed failures in the existing aarch64
acpi tests in tests/qtest/bios-tables-test. At least the rename
of the variable 'CTRL' to 'Local0' in the _OSC method should cause
a mismatch against the current base DSDT? So I had to handle it
via patches 1/5, 2/5, and 3/5. The diff is in the 3/5 commit body.

Thank you for contributing those tests.

Hum I think my mistake was to have executed the existing tests in KVM
acceleration mode only using
QTEST_QEMU_BINARY=qemu-system-aarch64 tests/qtest/bios-tables-test
direct execution.

The failing tests belong to the TCG category I think.

I will review your tests and if you allow me I may need to include
patches 1 and 3 in my series to prevent existing tests from failing, of
course with all your credits.

Yeah, absolutely!

I left some comments on you comments in 3/5 in [0] about the organization
and sequence of the patches, but I think we're in sync :)

[0] https://mail.gnu.org/archive/html/qemu-devel/2025-05/msg05824.html


Thank you again for reporting the issue!

Np! Glad to help :)


Cheers,
Gustavo
Eric





Cheers,
Gustavo

Best Regards

Eric

This series can be found at:
https://github.com/eauger/qemu/tree/arm-acpi-pcihp-v1

previous RFC:
https://github.com/eauger/qemu/tree/arm-acpi-pcihp-rfc

History:
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
    appreciated.

[1] [PATCH v6 0/6] Use ACPI PCI hot-plug for Q35
https://lore.kernel.org/all/20210713004205.775386-1-jus...@redhat.com/


Eric Auger (22):
    hw/i386/acpi-build: Make aml_pci_device_dsm() static
    hw/arm/virt: Introduce machine state acpi pcihp flags and props
    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/pci-host/gpex-acpi: Propagate hotplug type info from virt machine
      downto gpex
    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
    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: Introduce and use acpi_get_pci_host
    hw/i386/acpi-build: Move aml_pci_edsm to a generic place
    hw/arm/virt-acpi-build: Modify the DSDT ACPI table to enable ACPI PCI
      hotplug
    hw/acpi/ged: Prepare the device to react to PCI hotplug events
    hw/acpi/ged: Call pcihp plug callbacks in hotplug handler
      implementation
    hw/acpi/ged: Support migration of AcpiPciHpState
    hw/core/sysbus: Introduce sysbus_mmio_map_name() helper
    hw/arm/virt: Let virt support pci hotplug/unplug GED event
    hw/arm/virt: Plug pcihp hotplug/hotunplug callbacks
    hw/arm/virt: Use ACPI PCI hotplug by default

   hw/i386/acpi-build.h                   |   4 -
   include/hw/acpi/aml-build.h            |   2 +
   include/hw/acpi/generic_event_device.h |   5 +
   include/hw/acpi/pci.h                  |   4 +-
   include/hw/acpi/pcihp.h                |  19 +-
   include/hw/arm/virt.h                  |   4 +
   include/hw/pci-host/gpex.h             |   1 +
   include/hw/sysbus.h                    |   1 +
   hw/acpi/aml-build.c                    |  50 +++
   hw/acpi/generic_event_device.c         |  55 +++
   hw/acpi/pci.c                          |  20 +
   hw/acpi/pcihp.c                        | 482 ++++++++++++++++++++-
   hw/arm/virt-acpi-build.c               |  27 ++
   hw/arm/virt.c                          | 107 ++++-
   hw/core/sysbus.c                       |  11 +
   hw/i386/acpi-build.c                   | 552 +------------------------
   hw/pci-host/gpex-acpi.c                |  75 +---
   hw/arm/Kconfig                         |   2 +
   18 files changed, 806 insertions(+), 615 deletions(-)





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