Re: [Qemu-devel] [PATCH 06/19] pc: acpi: move SSDT part of memhp into a custom table

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Oct 23, 2015 at 04:57:09PM +0200, Igor Mammedov wrote:
> moves SSDT part to custom MHPT table, which is loaded
> at runtime by OSPM if it supports ACPIv2 revision and
> only if memory hotplug is enabled.
> That should reduce ACPI tables blob size if memory
> hotplug is not enabled (default case).
> 
> Checked for compatibility issues with:
>  * Windows XPsp3, Windows Server 2003: they don't load
>    the table as OSPM only reports revision 1 as supported.
>    And we don't care about memhp for these guests as they
>    do not support it anyway.
>  * Windows Server 2008, Windows Server 2008R2:
>    works as expected
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/acpi/Makefile.objs               |   2 +-
>  hw/acpi/memory_hotplug_acpi_table.c | 138 ++++++++++++++++++++++++++++++++++++
>  hw/i386/acpi-build.c                | 130 +++++----------------------------
>  include/hw/acpi/memory_hotplug.h    |   3 +
>  4 files changed, 159 insertions(+), 114 deletions(-)
>  create mode 100644 hw/acpi/memory_hotplug_acpi_table.c
> 
> diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
> index 7d3230c..c04064e 100644
> --- a/hw/acpi/Makefile.objs
> +++ b/hw/acpi/Makefile.objs
> @@ -1,7 +1,7 @@
>  common-obj-$(CONFIG_ACPI_X86) += core.o piix4.o pcihp.o
>  common-obj-$(CONFIG_ACPI_X86_ICH) += ich9.o tco.o
>  common-obj-$(CONFIG_ACPI_CPU_HOTPLUG) += cpu_hotplug.o
> -common-obj-$(CONFIG_ACPI_MEMORY_HOTPLUG) += memory_hotplug.o
> +common-obj-$(CONFIG_ACPI_MEMORY_HOTPLUG) += memory_hotplug.o memory_hotplug_acpi_table.o
>  common-obj-$(CONFIG_ACPI) += acpi_interface.o
>  common-obj-$(CONFIG_ACPI) += bios-linker-loader.o
>  common-obj-$(CONFIG_ACPI) += aml-build.o
> diff --git a/hw/acpi/memory_hotplug_acpi_table.c b/hw/acpi/memory_hotplug_acpi_table.c
> new file mode 100644
> index 0000000..28da13c

This diff is pretty hard to read. Isn't there some way
you could refactor this to make the diff smaller?
E.g. move the part that isn't changed into
a function first, then call it from a different place.

> --- /dev/null
> +++ b/hw/acpi/memory_hotplug_acpi_table.c
> @@ -0,0 +1,138 @@
> +#include <stdbool.h>
> +#include "hw/acpi/aml-build.h"
> +#include "hw/acpi/memory_hotplug.h"
> +#include "include/hw/acpi/pc-hotplug.h"
> +#include "hw/boards.h"
> +
> +#define BASEPATH "\\_SB.PCI0." stringify(MEMORY_HOTPLUG_DEVICE) "."
> +
> +void build_mhpt(GArray *table_data, GArray *linker, uint32_t nr_mem,
> +                uint16_t io_base, uint16_t io_len)
> +{
> +    int i;
> +    Aml *table, *sb_scope, *dev, *method, *ifctx, *ctrl_dev;
> +
> +    table = init_aml_allocator();
> +    acpi_data_push(table->buf, sizeof(AcpiTableHeader));
> +
> +    /* scope for memory hotplug controller device node */
> +    assert(nr_mem <= ACPI_MAX_RAM_SLOTS);
> +    ctrl_dev = aml_scope("\\_SB.PCI0." stringify(MEMORY_HOTPLUG_DEVICE));
> +    {
> +        Aml *crs, *field;
> +
> +        aml_append(ctrl_dev,
> +            aml_name_decl(stringify(MEMORY_SLOTS_NUMBER), aml_int(nr_mem))
> +        );
> +
> +        crs = aml_resource_template();
> +        aml_append(crs, aml_io(AML_DECODE16, io_base, io_base, 0, io_len));
> +        aml_append(ctrl_dev, aml_name_decl("_CRS", crs));
> +
> +        aml_append(ctrl_dev, aml_operation_region(
> +            stringify(MEMORY_HOTPLUG_IO_REGION), AML_SYSTEM_IO,
> +            io_base, io_len)
> +        );
> +
> +        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_DWORD_ACC,
> +                          AML_PRESERVE);
> +        aml_append(field, /* read only */
> +            aml_named_field(stringify(MEMORY_SLOT_ADDR_LOW), 32));
> +        aml_append(field, /* read only */
> +            aml_named_field(stringify(MEMORY_SLOT_ADDR_HIGH), 32));
> +        aml_append(field, /* read only */
> +            aml_named_field(stringify(MEMORY_SLOT_SIZE_LOW), 32));
> +        aml_append(field, /* read only */
> +            aml_named_field(stringify(MEMORY_SLOT_SIZE_HIGH), 32));
> +        aml_append(field, /* read only */
> +            aml_named_field(stringify(MEMORY_SLOT_PROXIMITY), 32));
> +        aml_append(ctrl_dev, field);
> +
> +        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_BYTE_ACC,
> +                          AML_WRITE_AS_ZEROS);
> +        aml_append(field, aml_reserved_field(160 /* bits, Offset(20) */));
> +        aml_append(field, /* 1 if enabled, read only */
> +            aml_named_field(stringify(MEMORY_SLOT_ENABLED), 1));
> +        aml_append(field,
> +            /*(read) 1 if has a insert event. (write) 1 to clear event */
> +            aml_named_field(stringify(MEMORY_SLOT_INSERT_EVENT), 1));
> +        aml_append(field,
> +            /* (read) 1 if has a remove event. (write) 1 to clear event */
> +            aml_named_field(stringify(MEMORY_SLOT_REMOVE_EVENT), 1));
> +        aml_append(field,
> +            /* initiates device eject, write only */
> +            aml_named_field(stringify(MEMORY_SLOT_EJECT), 1));
> +        aml_append(ctrl_dev, field);
> +
> +        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_DWORD_ACC,
> +                          AML_PRESERVE);
> +        aml_append(field, /* DIMM selector, write only */
> +            aml_named_field(stringify(MEMORY_SLOT_SLECTOR), 32));
> +        aml_append(field, /* _OST event code, write only */
> +            aml_named_field(stringify(MEMORY_SLOT_OST_EVENT), 32));
> +        aml_append(field, /* _OST status code, write only */
> +            aml_named_field(stringify(MEMORY_SLOT_OST_STATUS), 32));
> +        aml_append(ctrl_dev, field);
> +    }
> +    aml_append(table, ctrl_dev);
> +
> +    sb_scope = aml_scope("\\_SB");
> +    for (i = 0; i < nr_mem; i++) {
> +        const char *s;
> +
> +        dev = aml_device("MP%02X", i);
> +        aml_append(dev, aml_name_decl("_UID", aml_string("0x%02X", i)));
> +        aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0C80")));
> +
> +        method = aml_method("_CRS", 0);
> +        s = BASEPATH stringify(MEMORY_SLOT_CRS_METHOD);
> +        aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> +        aml_append(dev, method);
> +
> +        method = aml_method("_STA", 0);
> +        s = BASEPATH stringify(MEMORY_SLOT_STATUS_METHOD);
> +        aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> +        aml_append(dev, method);
> +
> +        method = aml_method("_PXM", 0);
> +        s = BASEPATH stringify(MEMORY_SLOT_PROXIMITY_METHOD);
> +        aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> +        aml_append(dev, method);
> +
> +        method = aml_method("_OST", 3);
> +        s = BASEPATH stringify(MEMORY_SLOT_OST_METHOD);
> +        aml_append(method, aml_return(aml_call4(
> +            s, aml_name("_UID"), aml_arg(0), aml_arg(1), aml_arg(2)
> +        )));
> +        aml_append(dev, method);
> +
> +        method = aml_method("_EJ0", 1);
> +        s = BASEPATH stringify(MEMORY_SLOT_EJECT_METHOD);
> +        aml_append(method, aml_return(aml_call2(
> +                   s, aml_name("_UID"), aml_arg(0))));
> +        aml_append(dev, method);
> +
> +        aml_append(sb_scope, dev);
> +    }
> +
> +    /* build Method(MEMORY_SLOT_NOTIFY_METHOD, 2) {
> +     *     If (LEqual(Arg0, 0x00)) {Notify(MP00, Arg1)} ... }
> +     */
> +    method = aml_method(stringify(MEMORY_SLOT_NOTIFY_METHOD), 2);
> +    for (i = 0; i < nr_mem; i++) {
> +        ifctx = aml_if(aml_equal(aml_arg(0), aml_int(i)));
> +        aml_append(ifctx,
> +            aml_notify(aml_name("MP%.02X", i), aml_arg(1))
> +        );
> +        aml_append(method, ifctx);
> +    }
> +    aml_append(sb_scope, method);
> +    aml_append(table, sb_scope);
> +
> +    /* copy AML table into ACPI tables blob and patch header there */
> +    g_array_append_vals(table_data, table->buf->data, table->buf->len);
> +    build_header(linker, table_data,
> +        (void *)(table_data->data + table_data->len - table->buf->len),
> +        "MHPT", table->buf->len, 2);
> +    free_aml_allocator();
> +}
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 95e0c65..8add4d9 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -925,6 +925,16 @@ build_ssdt(GArray *table_data, GArray *linker,
>      /* Reserve space for header */
>      acpi_data_push(ssdt->buf, sizeof(AcpiTableHeader));
>  
> +    sb_scope = aml_scope("\\_SB");
> +    method = aml_method("_INI", 0);
> +    ifctx = aml_if(aml_lgreater_equal(aml_name("_REV"), aml_int(2)));
> +    if (nr_mem) {
> +        aml_append(ifctx, aml_load_table("MHPT"));
> +    }
> +    aml_append(method, ifctx);
> +    aml_append(sb_scope, method);
> +    aml_append(ssdt, sb_scope);
> +
>      /* Extra PCI root buses are implemented  only for i440fx */
>      bus = find_i440fx();
>      if (bus) {
> @@ -1200,119 +1210,6 @@ build_ssdt(GArray *table_data, GArray *linker,
>          }
>          aml_append(sb_scope, aml_name_decl("CPON", pkg));
>  
> -        /* build memory devices */
> -        assert(nr_mem <= ACPI_MAX_RAM_SLOTS);
> -        scope = aml_scope("\\_SB.PCI0." stringify(MEMORY_HOTPLUG_DEVICE));
> -        aml_append(scope,
> -            aml_name_decl(stringify(MEMORY_SLOTS_NUMBER), aml_int(nr_mem))
> -        );
> -
> -        crs = aml_resource_template();
> -        aml_append(crs,
> -            aml_io(AML_DECODE16, pm->mem_hp_io_base, pm->mem_hp_io_base, 0,
> -                   pm->mem_hp_io_len)
> -        );
> -        aml_append(scope, aml_name_decl("_CRS", crs));
> -
> -        aml_append(scope, aml_operation_region(
> -            stringify(MEMORY_HOTPLUG_IO_REGION), AML_SYSTEM_IO,
> -            pm->mem_hp_io_base, pm->mem_hp_io_len)
> -        );
> -
> -        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_DWORD_ACC,
> -                          AML_PRESERVE);
> -        aml_append(field, /* read only */
> -            aml_named_field(stringify(MEMORY_SLOT_ADDR_LOW), 32));
> -        aml_append(field, /* read only */
> -            aml_named_field(stringify(MEMORY_SLOT_ADDR_HIGH), 32));
> -        aml_append(field, /* read only */
> -            aml_named_field(stringify(MEMORY_SLOT_SIZE_LOW), 32));
> -        aml_append(field, /* read only */
> -            aml_named_field(stringify(MEMORY_SLOT_SIZE_HIGH), 32));
> -        aml_append(field, /* read only */
> -            aml_named_field(stringify(MEMORY_SLOT_PROXIMITY), 32));
> -        aml_append(scope, field);
> -
> -        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_BYTE_ACC,
> -                          AML_WRITE_AS_ZEROS);
> -        aml_append(field, aml_reserved_field(160 /* bits, Offset(20) */));
> -        aml_append(field, /* 1 if enabled, read only */
> -            aml_named_field(stringify(MEMORY_SLOT_ENABLED), 1));
> -        aml_append(field,
> -            /*(read) 1 if has a insert event. (write) 1 to clear event */
> -            aml_named_field(stringify(MEMORY_SLOT_INSERT_EVENT), 1));
> -        aml_append(field,
> -            /* (read) 1 if has a remove event. (write) 1 to clear event */
> -            aml_named_field(stringify(MEMORY_SLOT_REMOVE_EVENT), 1));
> -        aml_append(field,
> -            /* initiates device eject, write only */
> -            aml_named_field(stringify(MEMORY_SLOT_EJECT), 1));
> -        aml_append(scope, field);
> -
> -        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), AML_DWORD_ACC,
> -                          AML_PRESERVE);
> -        aml_append(field, /* DIMM selector, write only */
> -            aml_named_field(stringify(MEMORY_SLOT_SLECTOR), 32));
> -        aml_append(field, /* _OST event code, write only */
> -            aml_named_field(stringify(MEMORY_SLOT_OST_EVENT), 32));
> -        aml_append(field, /* _OST status code, write only */
> -            aml_named_field(stringify(MEMORY_SLOT_OST_STATUS), 32));
> -        aml_append(scope, field);
> -
> -        aml_append(sb_scope, scope);
> -
> -        for (i = 0; i < nr_mem; i++) {
> -            #define BASEPATH "\\_SB.PCI0." stringify(MEMORY_HOTPLUG_DEVICE) "."
> -            const char *s;
> -
> -            dev = aml_device("MP%02X", i);
> -            aml_append(dev, aml_name_decl("_UID", aml_string("0x%02X", i)));
> -            aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0C80")));
> -
> -            method = aml_method("_CRS", 0);
> -            s = BASEPATH stringify(MEMORY_SLOT_CRS_METHOD);
> -            aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> -            aml_append(dev, method);
> -
> -            method = aml_method("_STA", 0);
> -            s = BASEPATH stringify(MEMORY_SLOT_STATUS_METHOD);
> -            aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> -            aml_append(dev, method);
> -
> -            method = aml_method("_PXM", 0);
> -            s = BASEPATH stringify(MEMORY_SLOT_PROXIMITY_METHOD);
> -            aml_append(method, aml_return(aml_call1(s, aml_name("_UID"))));
> -            aml_append(dev, method);
> -
> -            method = aml_method("_OST", 3);
> -            s = BASEPATH stringify(MEMORY_SLOT_OST_METHOD);
> -            aml_append(method, aml_return(aml_call4(
> -                s, aml_name("_UID"), aml_arg(0), aml_arg(1), aml_arg(2)
> -            )));
> -            aml_append(dev, method);
> -
> -            method = aml_method("_EJ0", 1);
> -            s = BASEPATH stringify(MEMORY_SLOT_EJECT_METHOD);
> -            aml_append(method, aml_return(aml_call2(
> -                       s, aml_name("_UID"), aml_arg(0))));
> -            aml_append(dev, method);
> -
> -            aml_append(sb_scope, dev);
> -        }
> -
> -        /* build Method(MEMORY_SLOT_NOTIFY_METHOD, 2) {
> -         *     If (LEqual(Arg0, 0x00)) {Notify(MP00, Arg1)} ... }
> -         */
> -        method = aml_method(stringify(MEMORY_SLOT_NOTIFY_METHOD), 2);
> -        for (i = 0; i < nr_mem; i++) {
> -            ifctx = aml_if(aml_equal(aml_arg(0), aml_int(i)));
> -            aml_append(ifctx,
> -                aml_notify(aml_name("MP%.02X", i), aml_arg(1))
> -            );
> -            aml_append(method, ifctx);
> -        }
> -        aml_append(sb_scope, method);
> -
>          {
>              Object *pci_host;
>              PCIBus *bus = NULL;
> @@ -1671,6 +1568,7 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables *tables)
>      uint8_t *u;
>      size_t aml_len = 0;
>      GArray *tables_blob = tables->table_data;
> +    MachineState *machine = MACHINE(qdev_get_machine());
>  
>      acpi_get_cpu_info(&cpu);
>      acpi_get_pm_info(&pm);
> @@ -1742,6 +1640,12 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables *tables)
>          build_dmar_q35(tables_blob, tables->linker);
>      }
>  
> +    if (machine->ram_slots) {
> +        acpi_add_table(table_offsets, tables_blob);
> +        build_mhpt(tables_blob, tables->linker, machine->ram_slots,
> +                   pm.mem_hp_io_base, pm.mem_hp_io_len);
> +    }
> +
>      /* Add tables supplied by user (if any) */
>      for (u = acpi_table_first(); u; u = acpi_table_next(u)) {
>          unsigned len = acpi_table_len(u);
> diff --git a/include/hw/acpi/memory_hotplug.h b/include/hw/acpi/memory_hotplug.h
> index 1342adb..5fd2854 100644
> --- a/include/hw/acpi/memory_hotplug.h
> +++ b/include/hw/acpi/memory_hotplug.h
> @@ -45,4 +45,7 @@ extern const VMStateDescription vmstate_memory_hotplug;
>                     vmstate_memory_hotplug, MemHotplugState)
>  
>  void acpi_memory_ospm_status(MemHotplugState *mem_st, ACPIOSTInfoList ***list);
> +
> +void build_mhpt(GArray *table_data, GArray *linker, uint32_t nr_mem,
> +                uint16_t io_base, uint16_t io_len);
>  #endif
> -- 
> 1.8.3.1