Re: [PATCH v2 03/25] hw/acpi: Rename and move build_x86_acpi_pci_hotplug to pcihp

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 27 May 2025 09:40:05 +0200
Eric Auger <eric.auger@redhat.com> wrote:

> We plan to reuse build_x86_acpi_pci_hotplug() implementation
> for ARM so let's move the code to generic pcihp.
> 
> Associated static aml_pci_pdsm() helper is also moved along.
> build_x86_acpi_pci_hotplug is renamed into build_acpi_pci_hotplug().
> 
> No code change intended.
> 
> Also fix the reference to acpi_pci_hotplug.rst documentation
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>

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

> 
> ---
> 
> v1 -> v2:
> - s/spec/specs in reference to rst (Gustavo)
> - fixed double space in commit msg (Gustavo)
> 
> rfc -> v1:
> - make build_append_pci_dsm_func0_common non static and move it to
>   pcihp
> ---
>  hw/i386/acpi-build.h    |   4 -
>  include/hw/acpi/pcihp.h |   9 +-
>  hw/acpi/pcihp.c         | 174 ++++++++++++++++++++++++++++++++++++++-
>  hw/i386/acpi-build.c    | 176 +---------------------------------------
>  4 files changed, 183 insertions(+), 180 deletions(-)
> 
> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> index 275ec058a1..8ba3c33e48 100644
> --- a/hw/i386/acpi-build.h
> +++ b/hw/i386/acpi-build.h
> @@ -5,10 +5,6 @@
>  
>  extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>  
> -/* PCI Hot-plug registers' base. See docs/specs/acpi_pci_hotplug.rst */
> -#define ACPI_PCIHP_SEJ_BASE 0x8
> -#define ACPI_PCIHP_BNMR_BASE 0x10
> -
>  void acpi_setup(void);
>  Object *acpi_get_i386_pci_host(void);
>  
> diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
> index a97904bada..971451e8ea 100644
> --- a/include/hw/acpi/pcihp.h
> +++ b/include/hw/acpi/pcihp.h
> @@ -3,7 +3,7 @@
>   *
>   * QEMU supports PCI hotplug via ACPI. This module
>   * implements the interface between QEMU and the ACPI BIOS.
> - * Interface specification - see docs/specs/acpi_pci_hotplug.txt
> + * Interface specification - see docs/specs/acpi_pci_hotplug.rst
>   *
>   * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
>   * Copyright (c) 2006 Fabrice Bellard
> @@ -33,6 +33,10 @@
>  #define ACPI_PCIHP_IO_BASE_PROP "acpi-pcihp-io-base"
>  #define ACPI_PCIHP_IO_LEN_PROP "acpi-pcihp-io-len"
>  
> +/* PCI Hot-plug registers bases. See docs/specs/acpi_pci_hotplug.rst */
> +#define ACPI_PCIHP_SEJ_BASE 0x8
> +#define ACPI_PCIHP_BNMR_BASE 0x10
> +
>  typedef struct AcpiPciHpPciStatus {
>      uint32_t up;
>      uint32_t down;
> @@ -69,6 +73,9 @@ void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>                                           AcpiPciHpState *s, DeviceState *dev,
>                                           Error **errp);
>  
> +void build_acpi_pci_hotplug(Aml *table, uint64_t pcihp_addr);
> +void build_append_pci_dsm_func0_common(Aml *ctx, Aml *retvar);
> +
>  /* Called on reset */
>  void acpi_pcihp_reset(AcpiPciHpState *s);
>  
> diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
> index aac90013d4..e0260f67e6 100644
> --- a/hw/acpi/pcihp.c
> +++ b/hw/acpi/pcihp.c
> @@ -26,7 +26,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "hw/acpi/pcihp.h"
> -
> +#include "hw/acpi/aml-build.h"
>  #include "hw/pci-host/i440fx.h"
>  #include "hw/pci/pci.h"
>  #include "hw/pci/pci_bridge.h"
> @@ -513,6 +513,178 @@ void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
>                                     OBJ_PROP_FLAG_READ);
>  }
>  
> +void build_append_pci_dsm_func0_common(Aml *ctx, Aml *retvar)
> +{
> +    Aml *UUID, *ifctx1;
> +    uint8_t byte_list[1] = { 0 }; /* nothing supported yet */
> +
> +    aml_append(ctx, aml_store(aml_buffer(1, byte_list), retvar));
> +    /*
> +     * PCI Firmware Specification 3.1
> +     * 4.6.  _DSM Definitions for PCI
> +     */
> +    UUID = aml_touuid("E5C937D0-3553-4D7A-9117-EA4D19C3434D");
> +    ifctx1 = aml_if(aml_lnot(aml_equal(aml_arg(0), UUID)));
> +    {
> +        /* call is for unsupported UUID, bail out */
> +        aml_append(ifctx1, aml_return(retvar));
> +    }
> +    aml_append(ctx, ifctx1);
> +
> +    ifctx1 = aml_if(aml_lless(aml_arg(1), aml_int(2)));
> +    {
> +        /* call is for unsupported REV, bail out */
> +        aml_append(ifctx1, aml_return(retvar));
> +    }
> +    aml_append(ctx, ifctx1);
> +}
> +
> +static Aml *aml_pci_pdsm(void)
> +{
> +    Aml *method, *ifctx, *ifctx1;
> +    Aml *ret = aml_local(0);
> +    Aml *caps = aml_local(1);
> +    Aml *acpi_index = aml_local(2);
> +    Aml *zero = aml_int(0);
> +    Aml *one = aml_int(1);
> +    Aml *not_supp = aml_int(0xFFFFFFFF);
> +    Aml *func = aml_arg(2);
> +    Aml *params = aml_arg(4);
> +    Aml *bnum = aml_derefof(aml_index(params, aml_int(0)));
> +    Aml *sunum = aml_derefof(aml_index(params, aml_int(1)));
> +
> +    method = aml_method("PDSM", 5, AML_SERIALIZED);
> +
> +    /* get supported functions */
> +    ifctx = aml_if(aml_equal(func, zero));
> +    {
> +        build_append_pci_dsm_func0_common(ifctx, ret);
> +
> +        aml_append(ifctx, aml_store(zero, caps));
> +        aml_append(ifctx,
> +            aml_store(aml_call2("AIDX", bnum, sunum), acpi_index));
> +        /*
> +         * advertise function 7 if device has acpi-index
> +         * acpi_index values:
> +         *            0: not present (default value)
> +         *     FFFFFFFF: not supported (old QEMU without PIDX reg)
> +         *        other: device's acpi-index
> +         */
> +        ifctx1 = aml_if(aml_lnot(
> +                     aml_or(aml_equal(acpi_index, zero),
> +                            aml_equal(acpi_index, not_supp), NULL)
> +                 ));
> +        {
> +            /* have supported functions */
> +            aml_append(ifctx1, aml_or(caps, one, caps));
> +            /* support for function 7 */
> +            aml_append(ifctx1,
> +                aml_or(caps, aml_shiftleft(one, aml_int(7)), caps));
> +        }
> +        aml_append(ifctx, ifctx1);
> +
> +        aml_append(ifctx, aml_store(caps, aml_index(ret, zero)));
> +        aml_append(ifctx, aml_return(ret));
> +    }
> +    aml_append(method, ifctx);
> +
> +    /* handle specific functions requests */
> +    /*
> +     * PCI Firmware Specification 3.1
> +     * 4.6.7. _DSM for Naming a PCI or PCI Express Device Under
> +     *        Operating Systems
> +     */
> +    ifctx = aml_if(aml_equal(func, aml_int(7)));
> +    {
> +       Aml *pkg = aml_package(2);
> +
> +       aml_append(ifctx, aml_store(aml_call2("AIDX", bnum, sunum), acpi_index));
> +       aml_append(ifctx, aml_store(pkg, ret));
> +       /*
> +        * Windows calls func=7 without checking if it's available,
> +        * as workaround Microsoft has suggested to return invalid for func7
> +        * Package, so return 2 elements package but only initialize elements
> +        * when acpi_index is supported and leave them uninitialized, which
> +        * leads elements to being Uninitialized ObjectType and should trip
> +        * Windows into discarding result as an unexpected and prevent setting
> +        * bogus 'PCI Label' on the device.
> +        */
> +       ifctx1 = aml_if(aml_lnot(aml_lor(
> +                    aml_equal(acpi_index, zero), aml_equal(acpi_index, not_supp)
> +                )));
> +       {
> +           aml_append(ifctx1, aml_store(acpi_index, aml_index(ret, zero)));
> +           /*
> +            * optional, if not impl. should return null string
> +            */
> +           aml_append(ifctx1, aml_store(aml_string("%s", ""),
> +                                        aml_index(ret, one)));
> +       }
> +       aml_append(ifctx, ifctx1);
> +
> +       aml_append(ifctx, aml_return(ret));
> +    }
> +
> +    aml_append(method, ifctx);
> +    return method;
> +}
> +
> +void build_acpi_pci_hotplug(Aml *table, uint64_t pcihp_addr)
> +{
> +    Aml *scope;
> +    Aml *field;
> +    Aml *method;
> +
> +    scope =  aml_scope("_SB.PCI0");
> +
> +    aml_append(scope,
> +        aml_operation_region("PCST", AML_SYSTEM_IO, aml_int(pcihp_addr), 0x08));
> +    field = aml_field("PCST", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> +    aml_append(field, aml_named_field("PCIU", 32));
> +    aml_append(field, aml_named_field("PCID", 32));
> +    aml_append(scope, field);
> +
> +    aml_append(scope,
> +        aml_operation_region("SEJ", AML_SYSTEM_IO,
> +                             aml_int(pcihp_addr + ACPI_PCIHP_SEJ_BASE), 0x04));
> +    field = aml_field("SEJ", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> +    aml_append(field, aml_named_field("B0EJ", 32));
> +    aml_append(scope, field);
> +
> +    aml_append(scope,
> +        aml_operation_region("BNMR", AML_SYSTEM_IO,
> +                             aml_int(pcihp_addr + ACPI_PCIHP_BNMR_BASE), 0x08));
> +    field = aml_field("BNMR", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> +    aml_append(field, aml_named_field("BNUM", 32));
> +    aml_append(field, aml_named_field("PIDX", 32));
> +    aml_append(scope, field);
> +
> +    aml_append(scope, aml_mutex("BLCK", 0));
> +
> +        method = aml_method("PCEJ", 2, AML_NOTSERIALIZED);
> +    aml_append(method, aml_acquire(aml_name("BLCK"), 0xFFFF));
> +    aml_append(method, aml_store(aml_arg(0), aml_name("BNUM")));
> +    aml_append(method,
> +        aml_store(aml_shiftleft(aml_int(1), aml_arg(1)), aml_name("B0EJ")));
> +    aml_append(method, aml_release(aml_name("BLCK")));
> +    aml_append(method, aml_return(aml_int(0)));
> +    aml_append(scope, method);
> +
> +    method = aml_method("AIDX", 2, AML_NOTSERIALIZED);
> +    aml_append(method, aml_acquire(aml_name("BLCK"), 0xFFFF));
> +    aml_append(method, aml_store(aml_arg(0), aml_name("BNUM")));
> +    aml_append(method,
> +        aml_store(aml_shiftleft(aml_int(1), aml_arg(1)), aml_name("PIDX")));
> +    aml_append(method, aml_store(aml_name("PIDX"), aml_local(0)));
> +    aml_append(method, aml_release(aml_name("BLCK")));
> +    aml_append(method, aml_return(aml_local(0)));
> +    aml_append(scope, method);
> +
> +    aml_append(scope, aml_pci_pdsm());
> +
> +    aml_append(table, scope);
> +}
> +
>  const VMStateDescription vmstate_acpi_pcihp_pci_status = {
>      .name = "acpi_pcihp_pci_status",
>      .version_id = 1,
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index f59026524f..4f8572eebe 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -361,32 +361,6 @@ static Aml *aml_pci_device_dsm(void)
>      return method;
>  }
>  
> -static void build_append_pci_dsm_func0_common(Aml *ctx, Aml *retvar)
> -{
> -    Aml *UUID, *ifctx1;
> -    uint8_t byte_list[1] = { 0 }; /* nothing supported yet */
> -
> -    aml_append(ctx, aml_store(aml_buffer(1, byte_list), retvar));
> -    /*
> -     * PCI Firmware Specification 3.1
> -     * 4.6.  _DSM Definitions for PCI
> -     */
> -    UUID = aml_touuid("E5C937D0-3553-4D7A-9117-EA4D19C3434D");
> -    ifctx1 = aml_if(aml_lnot(aml_equal(aml_arg(0), UUID)));
> -    {
> -        /* call is for unsupported UUID, bail out */
> -        aml_append(ifctx1, aml_return(retvar));
> -    }
> -    aml_append(ctx, ifctx1);
> -
> -    ifctx1 = aml_if(aml_lless(aml_arg(1), aml_int(2)));
> -    {
> -        /* call is for unsupported REV, bail out */
> -        aml_append(ifctx1, aml_return(retvar));
> -    }
> -    aml_append(ctx, ifctx1);
> -}
> -
>  static Aml *aml_pci_edsm(void)
>  {
>      Aml *method, *ifctx;
> @@ -647,96 +621,6 @@ static bool build_append_notification_callback(Aml *parent_scope,
>      return !!nr_notifiers;
>  }
>  
> -static Aml *aml_pci_pdsm(void)
> -{
> -    Aml *method, *ifctx, *ifctx1;
> -    Aml *ret = aml_local(0);
> -    Aml *caps = aml_local(1);
> -    Aml *acpi_index = aml_local(2);
> -    Aml *zero = aml_int(0);
> -    Aml *one = aml_int(1);
> -    Aml *not_supp = aml_int(0xFFFFFFFF);
> -    Aml *func = aml_arg(2);
> -    Aml *params = aml_arg(4);
> -    Aml *bnum = aml_derefof(aml_index(params, aml_int(0)));
> -    Aml *sunum = aml_derefof(aml_index(params, aml_int(1)));
> -
> -    method = aml_method("PDSM", 5, AML_SERIALIZED);
> -
> -    /* get supported functions */
> -    ifctx = aml_if(aml_equal(func, zero));
> -    {
> -        build_append_pci_dsm_func0_common(ifctx, ret);
> -
> -        aml_append(ifctx, aml_store(zero, caps));
> -        aml_append(ifctx,
> -            aml_store(aml_call2("AIDX", bnum, sunum), acpi_index));
> -        /*
> -         * advertise function 7 if device has acpi-index
> -         * acpi_index values:
> -         *            0: not present (default value)
> -         *     FFFFFFFF: not supported (old QEMU without PIDX reg)
> -         *        other: device's acpi-index
> -         */
> -        ifctx1 = aml_if(aml_lnot(
> -                     aml_or(aml_equal(acpi_index, zero),
> -                            aml_equal(acpi_index, not_supp), NULL)
> -                 ));
> -        {
> -            /* have supported functions */
> -            aml_append(ifctx1, aml_or(caps, one, caps));
> -            /* support for function 7 */
> -            aml_append(ifctx1,
> -                aml_or(caps, aml_shiftleft(one, aml_int(7)), caps));
> -        }
> -        aml_append(ifctx, ifctx1);
> -
> -        aml_append(ifctx, aml_store(caps, aml_index(ret, zero)));
> -        aml_append(ifctx, aml_return(ret));
> -    }
> -    aml_append(method, ifctx);
> -
> -    /* handle specific functions requests */
> -    /*
> -     * PCI Firmware Specification 3.1
> -     * 4.6.7. _DSM for Naming a PCI or PCI Express Device Under
> -     *        Operating Systems
> -     */
> -    ifctx = aml_if(aml_equal(func, aml_int(7)));
> -    {
> -       Aml *pkg = aml_package(2);
> -
> -       aml_append(ifctx, aml_store(aml_call2("AIDX", bnum, sunum), acpi_index));
> -       aml_append(ifctx, aml_store(pkg, ret));
> -       /*
> -        * Windows calls func=7 without checking if it's available,
> -        * as workaround Microsoft has suggested to return invalid for func7
> -        * Package, so return 2 elements package but only initialize elements
> -        * when acpi_index is supported and leave them uninitialized, which
> -        * leads elements to being Uninitialized ObjectType and should trip
> -        * Windows into discarding result as an unexpected and prevent setting
> -        * bogus 'PCI Label' on the device.
> -        */
> -       ifctx1 = aml_if(aml_lnot(aml_lor(
> -                    aml_equal(acpi_index, zero), aml_equal(acpi_index, not_supp)
> -                )));
> -       {
> -           aml_append(ifctx1, aml_store(acpi_index, aml_index(ret, zero)));
> -           /*
> -            * optional, if not impl. should return null string
> -            */
> -           aml_append(ifctx1, aml_store(aml_string("%s", ""),
> -                                        aml_index(ret, one)));
> -       }
> -       aml_append(ifctx, ifctx1);
> -
> -       aml_append(ifctx, aml_return(ret));
> -    }
> -
> -    aml_append(method, ifctx);
> -    return method;
> -}
> -
>  /*
>   * build_prt - Define interrupt routing rules
>   *
> @@ -1227,62 +1111,6 @@ static Aml *build_q35_dram_controller(const AcpiMcfgInfo *mcfg)
>      return dev;
>  }
>  
> -static void build_x86_acpi_pci_hotplug(Aml *table, uint64_t pcihp_addr)
> -{
> -    Aml *scope;
> -    Aml *field;
> -    Aml *method;
> -
> -    scope =  aml_scope("_SB.PCI0");
> -
> -    aml_append(scope,
> -        aml_operation_region("PCST", AML_SYSTEM_IO, aml_int(pcihp_addr), 0x08));
> -    field = aml_field("PCST", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> -    aml_append(field, aml_named_field("PCIU", 32));
> -    aml_append(field, aml_named_field("PCID", 32));
> -    aml_append(scope, field);
> -
> -    aml_append(scope,
> -        aml_operation_region("SEJ", AML_SYSTEM_IO,
> -                             aml_int(pcihp_addr + ACPI_PCIHP_SEJ_BASE), 0x04));
> -    field = aml_field("SEJ", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> -    aml_append(field, aml_named_field("B0EJ", 32));
> -    aml_append(scope, field);
> -
> -    aml_append(scope,
> -        aml_operation_region("BNMR", AML_SYSTEM_IO,
> -                             aml_int(pcihp_addr + ACPI_PCIHP_BNMR_BASE), 0x08));
> -    field = aml_field("BNMR", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
> -    aml_append(field, aml_named_field("BNUM", 32));
> -    aml_append(field, aml_named_field("PIDX", 32));
> -    aml_append(scope, field);
> -
> -    aml_append(scope, aml_mutex("BLCK", 0));
> -
> -    method = aml_method("PCEJ", 2, AML_NOTSERIALIZED);
> -    aml_append(method, aml_acquire(aml_name("BLCK"), 0xFFFF));
> -    aml_append(method, aml_store(aml_arg(0), aml_name("BNUM")));
> -    aml_append(method,
> -        aml_store(aml_shiftleft(aml_int(1), aml_arg(1)), aml_name("B0EJ")));
> -    aml_append(method, aml_release(aml_name("BLCK")));
> -    aml_append(method, aml_return(aml_int(0)));
> -    aml_append(scope, method);
> -
> -    method = aml_method("AIDX", 2, AML_NOTSERIALIZED);
> -    aml_append(method, aml_acquire(aml_name("BLCK"), 0xFFFF));
> -    aml_append(method, aml_store(aml_arg(0), aml_name("BNUM")));
> -    aml_append(method,
> -        aml_store(aml_shiftleft(aml_int(1), aml_arg(1)), aml_name("PIDX")));
> -    aml_append(method, aml_store(aml_name("PIDX"), aml_local(0)));
> -    aml_append(method, aml_release(aml_name("BLCK")));
> -    aml_append(method, aml_return(aml_local(0)));
> -    aml_append(scope, method);
> -
> -    aml_append(scope, aml_pci_pdsm());
> -
> -    aml_append(table, scope);
> -}
> -
>  static Aml *build_q35_osc_method(bool enable_native_pcie_hotplug)
>  {
>      Aml *if_ctx;
> @@ -1394,7 +1222,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>          aml_append(dsdt, sb_scope);
>  
>          if (pm->pcihp_bridge_en || pm->pcihp_root_en) {
> -            build_x86_acpi_pci_hotplug(dsdt, pm->pcihp_io_base);
> +            build_acpi_pci_hotplug(dsdt, pm->pcihp_io_base);
>          }
>          build_piix4_pci0_int(dsdt);
>      } else if (q35) {
> @@ -1438,7 +1266,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>          aml_append(dsdt, sb_scope);
>  
>          if (pm->pcihp_bridge_en) {
> -            build_x86_acpi_pci_hotplug(dsdt, pm->pcihp_io_base);
> +            build_acpi_pci_hotplug(dsdt, pm->pcihp_io_base);
>          }
>          build_q35_pci0_int(dsdt);
>      }