Re: [Qemu-devel] [qemu PATCH for 2.10] i386: acpi: provide an XSDT instead of an RSDT

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

On Wed, Jul 26, 2017 at 11:31:36AM +0200, Paolo Bonzini wrote:
> The tables that QEMU provides are not ACPI 1.0 compatible since commit
> 77af8a2b95 ("hw/i386: Use Rev3 FADT (ACPI 2.0) instead of Rev1 to improve
> guest OS support.", 2017-05-03).  This is visible with Windows 2000,
> which refuses to parse the rev3 FADT and fails to boot.
> 
> The recommended solution in this case is to build two FADTs, v1 being
> pointed to by the RSDT and v3 by the XSDT.  However, we leave this task
> to the firmware.  This patch simply switches the RSDT to the XSDT, which
> is valid for all ACPI 2.0-friendly operating systems and also leaves
> SeaBIOS the freedom to build an RSDT that points to the compatibility
> FADT.
> 
> When running Windows 2000 with an old BIOS, Windows would simply fall
> back to a non-ACPI HAL; however, the plan should be to include a BIOS with
> the new feature in 2.10.
> 
> Reported-by: Programmingkid <programmingkidx@gmail.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

I'm not against this but let's do it for q35 only please. PC is a legacy
machine type and let's just leave it alone.

> ---
>  hw/acpi/aml-build.c         | 27 ---------------------------
>  hw/i386/acpi-build.c        | 30 ++++++++++++++++++------------
>  include/hw/acpi/aml-build.h |  3 ---
>  3 files changed, 18 insertions(+), 42 deletions(-)
> 
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 36a6cc450e..ea750d54d9 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1573,33 +1573,6 @@ void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre)
>      g_array_free(tables->vmgenid, mfre);
>  }
>  
> -/* Build rsdt table */
> -void
> -build_rsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
> -           const char *oem_id, const char *oem_table_id)
> -{
> -    int i;
> -    unsigned rsdt_entries_offset;
> -    AcpiRsdtDescriptorRev1 *rsdt;
> -    const unsigned table_data_len = (sizeof(uint32_t) * table_offsets->len);
> -    const unsigned rsdt_entry_size = sizeof(rsdt->table_offset_entry[0]);
> -    const size_t rsdt_len = sizeof(*rsdt) + table_data_len;
> -
> -    rsdt = acpi_data_push(table_data, rsdt_len);
> -    rsdt_entries_offset = (char *)rsdt->table_offset_entry - table_data->data;
> -    for (i = 0; i < table_offsets->len; ++i) {
> -        uint32_t ref_tbl_offset = g_array_index(table_offsets, uint32_t, i);
> -        uint32_t rsdt_entry_offset = rsdt_entries_offset + rsdt_entry_size * i;
> -
> -        /* rsdt->table_offset_entry to be filled by Guest linker */
> -        bios_linker_loader_add_pointer(linker,
> -            ACPI_BUILD_TABLE_FILE, rsdt_entry_offset, rsdt_entry_size,
> -            ACPI_BUILD_TABLE_FILE, ref_tbl_offset);
> -    }
> -    build_header(linker, table_data,
> -                 (void *)rsdt, "RSDT", rsdt_len, 1, oem_id, oem_table_id);
> -}
> -
>  /* Build xsdt table */
>  void
>  build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 6b7bade183..e76cad2ad7 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2557,27 +2557,33 @@ build_amd_iommu(GArray *table_data, BIOSLinker *linker)
>  }
>  
>  static GArray *
> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset)
> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
>  {
>      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;
> +    unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);
> +    unsigned xsdt_pa_offset =
> +        (char *)&rsdp->xsdt_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);
> +    rsdp->length = cpu_to_le32(sizeof(*rsdp));
> +    rsdp->revision = 0x02;
> +
>      /* 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);
> +        ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,
> +        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);
>  
>      /* 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 - rsdp_table->data, offsetof(AcpiRsdpDescriptor, length),
>          (char *)&rsdp->checksum - rsdp_table->data);
> +    bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> +        (char *)rsdp - rsdp_table->data, sizeof *rsdp,
> +        (char *)&rsdp->extended_checksum - rsdp_table->data);
>  
>      return rsdp_table;
>  }
> @@ -2621,7 +2627,7 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine)
>      PCMachineState *pcms = PC_MACHINE(machine);
>      PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
>      GArray *table_offsets;
> -    unsigned facs, dsdt, rsdt, fadt;
> +    unsigned facs, dsdt, xsdt, fadt;
>      AcpiPmInfo pm;
>      AcpiMiscInfo misc;
>      AcpiMcfgInfo mcfg;
> @@ -2729,13 +2735,13 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine)
>          g_array_append_vals(tables_blob, u, len);
>      }
>  
> -    /* RSDT is pointed to by RSDP */
> -    rsdt = tables_blob->len;
> -    build_rsdt(tables_blob, tables->linker, table_offsets,
> +    /* XSDT is pointed to by RSDP */
> +    xsdt = tables_blob->len;
> +    build_xsdt(tables_blob, tables->linker, table_offsets,
>                 slic_oem.id, slic_oem.table_id);
>  
>      /* RSDP is in FSEG memory, so allocate it separately */
> -    build_rsdp(tables->rsdp, tables->linker, rsdt);
> +    build_rsdp(tables->rsdp, tables->linker, xsdt);
>  
>      /* We'll expose it all to Guest so we want to reduce
>       * chance of size changes.
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index 88d0738d76..4bdd88ee23 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -379,9 +379,6 @@ 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_rsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
> -           const char *oem_id, const char *oem_table_id);
> -void
>  build_xsdt(GArray *table_data, BIOSLinker *linker, GArray *table_offsets,
>             const char *oem_id, const char *oem_table_id);
>  
> -- 
> 2.13.3