Re: [PATCH v3 17/29] hw/arm/virt-acpi-build: Modify the DSDT ACPI table to enable ACPI PCI hotplug

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 16 Jun 2025 11:46:46 +0200
Eric Auger <eric.auger@redhat.com> wrote:

> Modify the DSDT ACPI table to enable ACPI PCI hotplug.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> v2 -> v3:
> - use ACPI_PCIHP_SIZE instead of 0x1000 (Igor)
> - use cihp_state->use_acpi_hotplug_bridge
> ---
>  include/hw/acpi/pcihp.h  |  2 ++
>  include/hw/arm/virt.h    |  1 +
>  hw/arm/virt-acpi-build.c | 22 ++++++++++++++++++++++
>  hw/arm/virt.c            |  2 ++
>  hw/arm/Kconfig           |  2 ++
>  5 files changed, 29 insertions(+)
> 
> diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
> index 5506a58862..9ff548650b 100644
> --- a/include/hw/acpi/pcihp.h
> +++ b/include/hw/acpi/pcihp.h
> @@ -38,6 +38,8 @@
>  #define ACPI_PCIHP_SEJ_BASE 0x8
>  #define ACPI_PCIHP_BNMR_BASE 0x10
>  
> +#define ACPI_PCIHP_SIZE 0x0018
> +
>  typedef struct AcpiPciHpPciStatus {
>      uint32_t up;
>      uint32_t down;
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 9a1b0f53d2..0ed2e6b732 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -79,6 +79,7 @@ enum {
>      VIRT_ACPI_GED,
>      VIRT_NVDIMM_ACPI,
>      VIRT_PVTIME,
> +    VIRT_ACPI_PCIHP,
>      VIRT_LOWMEMMAP_LAST,
>  };
>  
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index d7547c8d3b..a2e58288f8 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -34,6 +34,7 @@
>  #include "hw/core/cpu.h"
>  #include "hw/acpi/acpi-defs.h"
>  #include "hw/acpi/acpi.h"
> +#include "hw/acpi/pcihp.h"
>  #include "hw/nvram/fw_cfg_acpi.h"
>  #include "hw/acpi/bios-linker-loader.h"
>  #include "hw/acpi/aml-build.h"
> @@ -809,6 +810,8 @@ static void
>  build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
> +    AcpiGedState *acpi_ged_state = ACPI_GED(vms->acpi_dev);
> +    AcpiPciHpState *pcihp_state = &acpi_ged_state->pcihp_state;
>      Aml *scope, *dsdt;
>      MachineState *ms = MACHINE(vms);
>      const MemMapEntry *memmap = vms->memmap;
> @@ -868,6 +871,25 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  
>      aml_append(dsdt, scope);
>  
> +    if (pcihp_state->use_acpi_hotplug_bridge) {

ditto, use property accessor


> +        Aml *pci0_scope = aml_scope("\\_SB.PCI0");
> +
> +        aml_append(pci0_scope, aml_pci_edsm());
> +        build_acpi_pci_hotplug(dsdt, AML_SYSTEM_MEMORY,
> +                               memmap[VIRT_ACPI_PCIHP].base);
> +        build_append_pcihp_resources(pci0_scope,
> +                                     memmap[VIRT_ACPI_PCIHP].base,
> +                                     memmap[VIRT_ACPI_PCIHP].size);
> +
> +        /* Scan all PCI buses. Generate tables to support hotplug. */
> +        build_append_pci_bus_devices(pci0_scope, vms->bus);
> +        if (object_property_find(OBJECT(vms->bus), ACPI_PCIHP_PROP_BSEL)) {
> +            build_append_pcihp_slots(pci0_scope, vms->bus);
> +        }
> +        build_append_notification_callback(pci0_scope, vms->bus);
> +        aml_append(dsdt, pci0_scope);
> +    }
> +
>      /* copy AML table into ACPI tables blob */
>      g_array_append_vals(table_data, dsdt->buf->data, dsdt->buf->len);
>  
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 9a6cd085a3..08bd808499 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -75,6 +75,7 @@
>  #include "standard-headers/linux/input.h"
>  #include "hw/arm/smmuv3.h"
>  #include "hw/acpi/acpi.h"
> +#include "hw/acpi/pcihp.h"
>  #include "target/arm/cpu-qom.h"
>  #include "target/arm/internals.h"
>  #include "target/arm/multiprocessing.h"
> @@ -183,6 +184,7 @@ static const MemMapEntry base_memmap[] = {
>      [VIRT_NVDIMM_ACPI] =        { 0x09090000, NVDIMM_ACPI_IO_LEN},
>      [VIRT_PVTIME] =             { 0x090a0000, 0x00010000 },
>      [VIRT_SECURE_GPIO] =        { 0x090b0000, 0x00001000 },
> +    [VIRT_ACPI_PCIHP] =         { 0x090c0000, ACPI_PCIHP_SIZE },
>      [VIRT_MMIO] =               { 0x0a000000, 0x00000200 },
>      /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
>      [VIRT_PLATFORM_BUS] =       { 0x0c000000, 0x02000000 },
> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index f543d944c3..dee4d6dd25 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -34,6 +34,8 @@ config ARM_VIRT
>      select ACPI_HW_REDUCED
>      select ACPI_APEI
>      select ACPI_VIOT
> +    select ACPI_PCIHP
> +    select ACPI_PCI_BRIDGE
>      select VIRTIO_MEM_SUPPORTED
>      select ACPI_CXL
>      select ACPI_HMAT