Re: [Qemu-devel] [PATCH 7/8] hw: acpi: Export and share the ARM RSDP build

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Samuel,

On 26/11/18 17:29, Samuel Ortiz wrote:
> Now that build_rsdp() supports building both legacy and current RSDP
> tables, we can move it to a generic folder (hw/acpi) and have the i386
> ACPI code reuse it in order to reduce code duplication.
> 
> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> ---
>  include/hw/acpi/aml-build.h |  5 +++
>  hw/acpi/aml-build.c         | 81 +++++++++++++++++++++++++++++++++++++
>  hw/arm/virt-acpi-build.c    | 81 -------------------------------------
>  hw/i386/acpi-build.c        | 34 ++--------------
>  4 files changed, 90 insertions(+), 111 deletions(-)
> 
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index 6c36903c0a..1bbe496e32 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -388,6 +388,11 @@ void acpi_add_table(GArray *table_offsets, GArray *table_data);
>  void acpi_build_tables_init(AcpiBuildTables *tables);
>  void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre);
>  void
> +build_rsdp(GArray *tbl, BIOSLinker *linker, AcpiRsdpData *rsdp_data);
> +void
> +init_rsdp_data(AcpiRsdpData *data, const char *oem_id, uint8_t revision,
> +               unsigned *rsdt_offset, unsigned *xsdt_offset);
> +void
>  build_rsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
>             const char *oem_id, const char *oem_table_id);
>  void
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 1e43cd736d..d4e15980f1 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1589,6 +1589,87 @@ void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre)
>      g_array_free(tables->vmgenid, mfre);
>  }
>  
> +/* RSDP */
> +void
> +build_rsdp(GArray *tbl, BIOSLinker *linker, AcpiRsdpData *rsdp_data)
> +{
> +    bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, tbl, 16,
> +                             true /* fseg memory */);
> +
> +    /* RSDP signature */
> +    g_array_append_vals(tbl, ACPI_RSDP_SIGNATURE, ACPI_RSDP_SIG_LEN);
> +
> +    /* Space for the checksum */
> +    build_append_int_noprefix(tbl, 0, ACPI_RSDP_CHECKSUM_LEN);
> +
> +    /* OEM ID */
> +    g_array_append_vals(tbl, rsdp_data->oem_id, ACPI_RSDP_OEMID_LEN);
> +
> +    /* Revision */
> +    build_append_int_noprefix(tbl, rsdp_data->revision,
> +                              ACPI_RSDP_REVISION_LEN);
> +
> +    /* Space for the RSDT address (32 bit) */
> +    build_append_int_noprefix(tbl, 0, 4);
> +
> +    if (rsdp_data->rsdt_tbl_offset) {
> +        /* RSDT address to be filled by guest linker */
> +        bios_linker_loader_add_pointer(linker,
> +                                       ACPI_BUILD_RSDP_FILE, 16, 4,
> +                                       ACPI_BUILD_TABLE_FILE,
> +                                       *rsdp_data->rsdt_tbl_offset);
> +    }
> +
> +    /* Checksum to be filled by guest linker */
> +    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, 0,
> +                                    ACPI_RSDP_REV_1_LEN,
> +                                    ACPI_RSDP_CHECKSUM_OFFSET);
> +
> +    if (rsdp_data->revision == ACPI_RSDP_REV_1) {
> +        /* Legacy RSDP, we're done */
> +        return;
> +    }
> +
> +    /* The RSDP revision is 2 and later, we must have an XSDT pointer */
> +    g_assert(rsdp_data->xsdt_tbl_offset != NULL);
> +
> +    /* Length */
> +    build_append_int_noprefix(tbl, ACPI_RSDP_REV_2_LEN, ACPI_RSDP_LEN_LEN);
> +
> +    /* XSDT address to be filled by guest linker */
> +    build_append_int_noprefix(tbl, 0, 8); /* XSDT address (64 bit) */
> +    bios_linker_loader_add_pointer(linker,
> +                                   ACPI_BUILD_RSDP_FILE,
> +                                   ACPI_RSDP_XSDT_OFFSET, 8,
> +                                   ACPI_BUILD_TABLE_FILE,
> +                                   *rsdp_data->xsdt_tbl_offset);
> +
> +    /* Space for the extended checksum */
> +    build_append_int_noprefix(tbl, 0, ACPI_RSDP_CHECKSUM_LEN);
> +
> +    /* Space for the reserved bytes */
> +    build_append_int_noprefix(tbl, 0, ACPI_RSDP_RESERVED_LEN);
> +
> +    /* Extended checksum to be filled by Guest linker */
> +    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, 0,
> +                                    ACPI_RSDP_REV_2_LEN,
> +                                    ACPI_RSDP_EXT_CHECKSUM_OFFSET);
> +}
> +
> +void
> +init_rsdp_data(AcpiRsdpData *data, const char *oem_id, uint8_t revision,
> +               unsigned *rsdt_offset, unsigned *xsdt_offset)
> +{
> +    /* Caller must provide an OEM ID */
> +    g_assert(oem_id);
> +    g_assert(strlen(oem_id) >= 6);
> +
> +    memcpy(data->oem_id, oem_id, 6);
> +    data->revision = revision;
> +    data->rsdt_tbl_offset = rsdt_offset;
> +    data->xsdt_tbl_offset = xsdt_offset;
> +}
> +
>  /* Build rsdt table */
>  void
>  build_rsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 10f8388b63..3fe86fd33e 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -366,87 +366,6 @@ static void acpi_dsdt_add_power_button(Aml *scope)
>      aml_append(scope, dev);
>  }
>  
> -/* RSDP */
> -static void
> -build_rsdp(GArray *tbl, BIOSLinker *linker, AcpiRsdpData *rsdp_data)
> -{
> -    bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, tbl, 16,
> -                             true /* fseg memory */);
> -
> -    /* RSDP signature */
> -    g_array_append_vals(tbl, ACPI_RSDP_SIGNATURE, ACPI_RSDP_SIG_LEN);
> -
> -    /* Space for the checksum */
> -    build_append_int_noprefix(tbl, 0, ACPI_RSDP_CHECKSUM_LEN);
> -
> -    /* OEM ID */
> -    g_array_append_vals(tbl, rsdp_data->oem_id, ACPI_RSDP_OEMID_LEN);
> -
> -    /* Revision */
> -    build_append_int_noprefix(tbl, rsdp_data->revision,
> -                              ACPI_RSDP_REVISION_LEN);
> -
> -    /* Space for the RSDT address (32 bit) */
> -    build_append_int_noprefix(tbl, 0, 4);
> -
> -    if (rsdp_data->rsdt_tbl_offset) {
> -        /* RSDT address to be filled by guest linker */
> -        bios_linker_loader_add_pointer(linker,
> -                                       ACPI_BUILD_RSDP_FILE, 16, 4,
> -                                       ACPI_BUILD_TABLE_FILE,
> -                                       *rsdp_data->rsdt_tbl_offset);
> -    }
> -
> -    /* Checksum to be filled by guest linker */
> -    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, 0,
> -                                    ACPI_RSDP_REV_1_LEN,
> -                                    ACPI_RSDP_CHECKSUM_OFFSET);
> -
> -    if (rsdp_data->revision == ACPI_RSDP_REV_1) {
> -        /* Legacy RSDP, we're done */
> -        return;
> -    }
> -
> -    /* The RSDP revision is 2 and later, we must have an XSDT pointer */
> -    g_assert(rsdp_data->xsdt_tbl_offset != NULL);
> -
> -    /* Length */
> -    build_append_int_noprefix(tbl, ACPI_RSDP_REV_2_LEN, ACPI_RSDP_LEN_LEN);
> -
> -    /* XSDT address to be filled by guest linker */
> -    build_append_int_noprefix(tbl, 0, 8); /* XSDT address (64 bit) */
> -    bios_linker_loader_add_pointer(linker,
> -                                   ACPI_BUILD_RSDP_FILE,
> -                                   ACPI_RSDP_XSDT_OFFSET, 8,
> -                                   ACPI_BUILD_TABLE_FILE,
> -                                   *rsdp_data->xsdt_tbl_offset);
> -
> -    /* Space for the extended checksum */
> -    build_append_int_noprefix(tbl, 0, ACPI_RSDP_CHECKSUM_LEN);
> -
> -    /* Space for the reserved bytes */
> -    build_append_int_noprefix(tbl, 0, ACPI_RSDP_RESERVED_LEN);
> -
> -    /* Extended checksum to be filled by Guest linker */
> -    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, 0,
> -                                    ACPI_RSDP_REV_2_LEN,
> -                                    ACPI_RSDP_EXT_CHECKSUM_OFFSET);
> -}
> -
> -static void
> -init_rsdp_data(AcpiRsdpData *data, const char *oem_id, uint8_t revision,
> -               unsigned *rsdt_offset, unsigned *xsdt_offset)
> -{
> -    /* Caller must provide an OEM ID */
> -    g_assert(oem_id);
> -    g_assert(strlen(oem_id) >= 6);
> -
> -    memcpy(data->oem_id, oem_id, 6);
> -    data->revision = revision;
> -    data->rsdt_tbl_offset = rsdt_offset;
> -    data->xsdt_tbl_offset = xsdt_offset;
> -}
> -
>  static void
>  build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index fb877648ac..f7ab112599 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2547,35 +2547,6 @@ build_amd_iommu(GArray *table_data, BIOSLinker *linker)
>                   "IVRS", table_data->len - iommu_start, 1, NULL, NULL);
>  }
>  
> -static void
> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
> -{
> -    /* AcpiRsdpDescriptor describes revision 2 RSDP table and as result we
> -     * allocate extra 16 bytes for pc/q35 RSDP rev1 as well. Keep extra 16 bytes
> -     * wasted to make sure we won't breake migration for machine types older
> -     * than 2.3 due to size mismatch.
> -     */
> -    AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
> -    unsigned rsdt_pa_size = sizeof(rsdp->rsdt_physical_address);
> -    unsigned rsdt_pa_offset =
> -        (char *)&rsdp->rsdt_physical_address - rsdp_table->data;
> -
> -    bios_linker_loader_alloc(linker, ACPI_BUILD_RSDP_FILE, rsdp_table, 16,
> -                             true /* fseg memory */);
> -
> -    memcpy(&rsdp->signature, "RSD PTR ", 8);
> -    memcpy(rsdp->oem_id, ACPI_BUILD_APPNAME6, 6);
> -    /* Address to be filled by Guest linker */
> -    bios_linker_loader_add_pointer(linker,
> -        ACPI_BUILD_RSDP_FILE, rsdt_pa_offset, rsdt_pa_size,
> -        ACPI_BUILD_TABLE_FILE, rsdt_tbl_offset);
> -
> -    /* Checksum to be filled by Guest linker */
> -    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> -        (char *)rsdp - rsdp_table->data, 20 /* ACPI rev 1.0 RSDP size */,
> -        (char *)&rsdp->checksum - rsdp_table->data);
> -}
> -
>  typedef
>  struct AcpiBuildState {
>      /* Copy of table in RAM (for patching). */
> @@ -2625,6 +2596,7 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine)
>      GArray *tables_blob = tables->table_data;
>      AcpiSlicOem slic_oem = { .id = NULL, .table_id = NULL };
>      Object *vmgenid_dev;
> +    AcpiRsdpData rsdp;
>  
>      acpi_get_pm_info(&pm);
>      acpi_get_misc_info(&misc);
> @@ -2732,7 +2704,9 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine)
>                 slic_oem.id, slic_oem.table_id);
>  
>      /* RSDP is in FSEG memory, so allocate it separately */
> -    build_rsdp(tables->rsdp, tables->linker, rsdt);
> +    init_rsdp_data(&rsdp, ACPI_BUILD_APPNAME6, ACPI_RSDP_REV_1,
> +                   &rsdt, NULL);

If you ever respin this series, please consider split this patch in 2:
- Export/use init_rsdp_data()
- current patch
This will ease review. The patch is fine regardless :)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +    build_rsdp(tables->rsdp, tables->linker, &rsdp);
>  
>      /* We'll expose it all to Guest so we want to reduce
>       * chance of size changes.
>