Re: [RFC PATCH v3 2/7] hw/i386/acpi-build: Add ACPI PCI hot-plug methods to Q35

[Ani Sinha <ani@anisinha.ca>]

On Thu, 24 Sep 2020, Julia Suvorova wrote:

> Implement notifications and gpe to support q35 ACPI PCI hot-plug.
> Use 0xcc4 - 0xcd7 range for 'acpi-pci-hotplug' io ports.
>

For this patch, I would suggest maybe you can also add a diff of the
disassembly of the DSDT table so that we know what changes exactly we
shall see in the table as a result of this patch.
Add the diff to this commit message as it will be helpful for anyone
to take a look at it when they look at this patch.

> Signed-off-by: Julia Suvorova <jusual@redhat.com>
> ---
> hw/i386/acpi-build.h    |  4 ++++
> include/hw/acpi/ich9.h  |  2 ++
> include/hw/acpi/pcihp.h |  3 ++-
> hw/acpi/pcihp.c         |  8 ++++----
> hw/acpi/piix4.c         |  4 +++-
> hw/i386/acpi-build.c    | 27 ++++++++++++++++-----------
> 6 files changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> index 74df5fc612..487ec7710f 100644
> --- a/hw/i386/acpi-build.h
> +++ b/hw/i386/acpi-build.h
> @@ -5,6 +5,10 @@
>
> extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>
> +/* PCI Hot-plug registers bases. See docs/spec/acpi_pci_hotplug.txt */
> +#define ACPI_PCIHP_SEJ_BASE 0x8
> +#define ACPI_PCIHP_BNMR_BASE 0x10
> +
> void acpi_setup(void);
>
> #endif
> diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
> index 28a53181cb..4d19571ed7 100644
> --- a/include/hw/acpi/ich9.h
> +++ b/include/hw/acpi/ich9.h
> @@ -28,6 +28,8 @@
> #include "hw/acpi/acpi_dev_interface.h"
> #include "hw/acpi/tco.h"
>
> +#define ACPI_PCIHP_ADDR_ICH9 0x0cc4
> +
> typedef struct ICH9LPCPMRegs {
>     /*
>      * In ich9 spec says that pm1_cnt register is 32bit width and
> diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
> index 02f4665767..ce49fb03b9 100644
> --- a/include/hw/acpi/pcihp.h
> +++ b/include/hw/acpi/pcihp.h
> @@ -54,7 +54,8 @@ typedef struct AcpiPciHpState {
> } AcpiPciHpState;
>
> void acpi_pcihp_init(Object *owner, AcpiPciHpState *, PCIBus *root,
> -                     MemoryRegion *address_space_io, bool bridges_enabled);
> +                     MemoryRegion *address_space_io, bool bridges_enabled,
> +                     uint16_t io_base);
>
> void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>                                    DeviceState *dev, Error **errp);
> diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
> index ff23104aea..bb457bc279 100644
> --- a/hw/acpi/pcihp.c
> +++ b/hw/acpi/pcihp.c
> @@ -38,7 +38,6 @@
> #include "qom/qom-qobject.h"
> #include "trace.h"
>
> -#define ACPI_PCIHP_ADDR 0xae00
> #define ACPI_PCIHP_SIZE 0x0014
> #define PCI_UP_BASE 0x0000
> #define PCI_DOWN_BASE 0x0004
> @@ -381,12 +380,13 @@ static const MemoryRegionOps acpi_pcihp_io_ops = {
> };
>
> void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
> -                     MemoryRegion *address_space_io, bool bridges_enabled)
> +                     MemoryRegion *address_space_io, bool bridges_enabled,
> +                     uint16_t io_base)
> {
>     s->io_len = ACPI_PCIHP_SIZE;
> -    s->io_base = ACPI_PCIHP_ADDR;
> +    s->io_base = io_base;

Maybe you want to remove ACPI_PCIHP_ADDR ?

>
> -    s->root= root_bus;
> +    s->root = root_bus;
>     s->legacy_piix = !bridges_enabled;
>
>     memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index 832f8fba82..a505ab5bcf 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -50,6 +50,8 @@
> #define GPE_BASE 0xafe0
> #define GPE_LEN 4
>
> +#define ACPI_PCIHP_ADDR_PIIX4 0xae00
> +
> struct pci_status {
>     uint32_t up; /* deprecated, maintained for migration compatibility */
>     uint32_t down;
> @@ -597,7 +599,7 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
>     memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
>
>     acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent,
> -                    s->use_acpi_hotplug_bridge);
> +                    s->use_acpi_hotplug_bridge, ACPI_PCIHP_ADDR_PIIX4);
>
>     s->cpu_hotplug_legacy = true;
>     object_property_add_bool(OBJECT(s), "cpu-hotplug-legacy",
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 0e0535d2e3..cf503b16af 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -201,10 +201,6 @@ static void acpi_get_pm_info(MachineState *machine, AcpiPmInfo *pm)
>         /* w2k requires FADT(rev1) or it won't boot, keep PC compatible */
>         pm->fadt.rev = 1;
>         pm->cpu_hp_io_base = PIIX4_CPU_HOTPLUG_IO_BASE;
> -        pm->pcihp_io_base =
> -            object_property_get_uint(obj, ACPI_PCIHP_IO_BASE_PROP, NULL);
> -        pm->pcihp_io_len =
> -            object_property_get_uint(obj, ACPI_PCIHP_IO_LEN_PROP, NULL);
>     }
>     if (lpc) {
>         struct AcpiGenericAddress r = { .space_id = AML_AS_SYSTEM_IO,
> @@ -214,6 +210,10 @@ static void acpi_get_pm_info(MachineState *machine, AcpiPmInfo *pm)
>         pm->fadt.flags |= 1 << ACPI_FADT_F_RESET_REG_SUP;
>         pm->cpu_hp_io_base = ICH9_CPU_HOTPLUG_IO_BASE;
>     }
> +    pm->pcihp_io_base =
> +        object_property_get_uint(obj, ACPI_PCIHP_IO_BASE_PROP, NULL);
> +    pm->pcihp_io_len =
> +        object_property_get_uint(obj, ACPI_PCIHP_IO_LEN_PROP, NULL);
>
>     /* The above need not be conditional on machine type because the reset port
>      * happens to be the same on PIIX (pc) and ICH9 (q35). */
> @@ -472,7 +472,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
>         QLIST_FOREACH(sec, &bus->child, sibling) {
>             int32_t devfn = sec->parent_dev->devfn;
>
> -            if (pci_bus_is_root(sec) || pci_bus_is_express(sec)) {
> +            if (pci_bus_is_root(sec)) {
>                 continue;
>             }
>
> @@ -1368,7 +1368,7 @@ static void build_piix4_isa_bridge(Aml *table)
>     aml_append(table, scope);
> }
>
> -static void build_piix4_pci_hotplug(Aml *table)
> +static void build_x86_pci_hotplug(Aml *table, uint64_t pcihp_addr)
> {
>     Aml *scope;
>     Aml *field;
> @@ -1377,20 +1377,22 @@ static void build_piix4_pci_hotplug(Aml *table)
>     scope =  aml_scope("_SB.PCI0");
>
>     aml_append(scope,
> -        aml_operation_region("PCST", AML_SYSTEM_IO, aml_int(0xae00), 0x08));
> +        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(0xae08), 0x04));
> +    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(0xae10), 0x04));
> +        aml_operation_region("BNMR", AML_SYSTEM_IO,
> +                             aml_int(pcihp_addr + ACPI_PCIHP_BNMR_BASE), 0x04));
>     field = aml_field("BNMR", AML_DWORD_ACC, AML_NOLOCK, AML_WRITE_AS_ZEROS);
>     aml_append(field, aml_named_field("BNUM", 32));
>     aml_append(scope, field);
> @@ -1504,7 +1506,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>         build_hpet_aml(dsdt);
>         build_piix4_isa_bridge(dsdt);
>         build_isa_devices_aml(dsdt);
> -        build_piix4_pci_hotplug(dsdt);
> +        build_x86_pci_hotplug(dsdt, pm->pcihp_io_base);

This will conflict here with my patch. I think you need to do something 
like this:

   if (pm->pcihp_bridge_en || pm->pcihp_root_en) {

You'll get this from my patch.


>         build_piix4_pci0_int(dsdt);
>     } else {
>         sb_scope = aml_scope("_SB");
> @@ -1520,6 +1522,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>         build_hpet_aml(dsdt);
>         build_q35_isa_bridge(dsdt);
>         build_isa_devices_aml(dsdt);
> +        if (pm->pcihp_bridge_en) {
> +            build_x86_pci_hotplug(dsdt, pm->pcihp_io_base);
> +        }

ditto as above.

>         build_q35_pci0_int(dsdt);
>         if (pcms->smbus && !pcmc->do_not_add_smb_acpi) {
>             build_smb0(dsdt, pcms->smbus, ICH9_SMB_DEV, ICH9_SMB_FUNC);
> @@ -1546,7 +1551,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>     {
>         aml_append(scope, aml_name_decl("_HID", aml_string("ACPI0006")));
>
> -        if (misc->is_piix4) {
> +        if (misc->is_piix4 || pm->pcihp_bridge_en) {
>             method = aml_method("_E01", 0, AML_NOTSERIALIZED);
>             aml_append(method,
>                 aml_acquire(aml_name("\\_SB.PCI0.BLCK"), 0xFFFF));
> -- 
> 2.25.4
>
>