Re: [Qemu-devel] [PATCH v5 05/24] hw: acpi: Implement XSDT support for RSDP

[Igor Mammedov <imammedo@redhat.com>]

On Mon,  5 Nov 2018 02:40:28 +0100
Samuel Ortiz <sameo@linux.intel.com> wrote:

> XSDT is the 64-bit version of the legacy ACPI RSDT (Root System
> Description Table). RSDT only allow for 32-bit addressses and have thus
> been deprecated. Since ACPI version 2.0, RSDPs should point at XSDTs and
> no longer RSDTs, although RSDTs are still supported for backward
> compatibility.
> 
> Since version 2.0, RSDPs should add an extended checksum, a complete table
> length and a version field to the table.

This patch re-implements what arm/virt board already does
and fixes checksum bug in the later and at the same time
without a user (within the patch).

I'd suggest redo it a way similar to FADT refactoring
  patch 1: fix checksum bug in virt/arm
  patch 2: update reference tables in test
  patch 3: introduce AcpiRsdpData similar to commit 937d1b587
             (both arm and x86) wich stores all data in hos byte order
  patch 4: convert arm's impl. to build_append_int_noprefix() API (commit 5d7a334f7)
           ... move out to aml-build.c
  patch 5: reuse generalized arm's build_rsdp() for x86, dropping x86 specific one
      amending it to generate rev1 variant defined by revision in AcpiRsdpData
      (commit dd1b2037a)

  'make check V=1' shouldn't observe any ACPI tables changes after patch 2.

> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> ---
>  include/hw/acpi/aml-build.h |  3 +++
>  hw/acpi/aml-build.c         | 37 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index c9bcb32d81..3580d0ce90 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -393,6 +393,9 @@ void
>  build_rsdp(GArray *table_data,
>             BIOSLinker *linker, unsigned rsdt_tbl_offset);
>  void
> +build_rsdp_xsdt(GArray *table_data,
> +                BIOSLinker *linker, unsigned xsdt_tbl_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 51b608432f..a030d40674 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1651,6 +1651,43 @@ build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
>                   (void *)xsdt, "XSDT", xsdt_len, 1, oem_id, oem_table_id);
>  }
>  
> +/* RSDP pointing at an XSDT */
> +void
> +build_rsdp_xsdt(GArray *rsdp_table,
> +                BIOSLinker *linker, unsigned xsdt_tbl_offset)
> +{
> +    AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);
> +    unsigned xsdt_pa_offset =
> +        (char *)&rsdp->xsdt_physical_address - rsdp_table->data;
> +    unsigned xsdt_offset =
> +        (char *)&rsdp->length - 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);
> +    rsdp->length = cpu_to_le32(sizeof(*rsdp));
> +    /* version 2, we will use the XSDT pointer */
> +    rsdp->revision = 0x02;
> +
> +    /* Address to be filled by Guest linker */
> +    bios_linker_loader_add_pointer(linker,
> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,
> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);
> +
> +    /* Legacy checksum to be filled by Guest linker */
> +    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> +        (char *)rsdp - rsdp_table->data, xsdt_offset,
> +        (char *)&rsdp->checksum - rsdp_table->data);
> +
> +    /* Extended checksum to be filled by Guest linker */
> +    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> +        (char *)rsdp - rsdp_table->data, sizeof *rsdp,
> +        (char *)&rsdp->extended_checksum - rsdp_table->data);
> +}
> +
>  void build_srat_memory(AcpiSratMemoryAffinity *numamem, uint64_t base,
>                         uint64_t len, int node, MemoryAffinityFlags flags)
>  {