Re: [PATCH v5 06/21] acpi/ghes: add a firmware file with HEST address

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 27 Feb 2025 12:03:36 +0100
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:

> Store HEST table address at GPA, placing its the start of the table at
> hest_addr_le variable.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/acpi/ghes.c         | 20 +++++++++++++++++++-
>  include/hw/acpi/ghes.h |  7 ++++++-
>  2 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> index 9243b5ad4acb..8ec423726b3f 100644
> --- a/hw/acpi/ghes.c
> +++ b/hw/acpi/ghes.c
> @@ -30,6 +30,7 @@
>  
>  #define ACPI_HW_ERROR_FW_CFG_FILE           "etc/hardware_errors"
>  #define ACPI_HW_ERROR_ADDR_FW_CFG_FILE      "etc/hardware_errors_addr"
> +#define ACPI_HEST_ADDR_FW_CFG_FILE          "etc/acpi_table_hest_addr"
>  
>  /* The max size in bytes for one error block */
>  #define ACPI_GHES_MAX_RAW_DATA_LENGTH   (1 * KiB)
> @@ -341,6 +342,9 @@ void acpi_build_hest(AcpiGhesState *ags, GArray *table_data,
>  {
>      AcpiTable table = { .sig = "HEST", .rev = 1,
>                          .oem_id = oem_id, .oem_table_id = oem_table_id };
> +    uint32_t hest_offset;
> +
> +    hest_offset = table_data->len;
>  
>      build_ghes_error_table(ags, hardware_errors, linker);
>  
> @@ -352,6 +356,17 @@ void acpi_build_hest(AcpiGhesState *ags, GArray *table_data,
>                    ACPI_GHES_NOTIFY_SEA, ACPI_HEST_SRC_ID_SEA);
>  
>      acpi_table_end(linker, &table);
> +
> +    if (ags->use_hest_addr) {
> +        /*
> +         * Tell firmware to write into GPA the address of HEST via fw_cfg,
> +         * once initialized.
> +         */
> +        bios_linker_loader_write_pointer(linker,
> +                                         ACPI_HEST_ADDR_FW_CFG_FILE, 0,
> +                                         sizeof(uint64_t),
> +                                         ACPI_BUILD_TABLE_FILE, hest_offset);
> +    }
>  }
>  
>  void acpi_ghes_add_fw_cfg(AcpiGhesState *ags, FWCfgState *s,
> @@ -361,7 +376,10 @@ void acpi_ghes_add_fw_cfg(AcpiGhesState *ags, FWCfgState *s,
>      fw_cfg_add_file(s, ACPI_HW_ERROR_FW_CFG_FILE, hardware_error->data,
>                      hardware_error->len);
>  
> -    if (!ags->use_hest_addr) {
> +    if (ags->use_hest_addr) {
> +        fw_cfg_add_file_callback(s, ACPI_HEST_ADDR_FW_CFG_FILE, NULL, NULL,
> +            NULL, &(ags->hest_addr_le), sizeof(ags->hest_addr_le), false);
> +    } else {
>          /* Create a read-write fw_cfg file for Address */
>          fw_cfg_add_file_callback(s, ACPI_HW_ERROR_ADDR_FW_CFG_FILE, NULL, NULL,
>              NULL, &(ags->hw_error_le), sizeof(ags->hw_error_le), false);
> diff --git a/include/hw/acpi/ghes.h b/include/hw/acpi/ghes.h
> index 5000891f163f..38abe6e3db52 100644
> --- a/include/hw/acpi/ghes.h
> +++ b/include/hw/acpi/ghes.h
> @@ -70,9 +70,14 @@ enum {
>   * When use_hest_addr is false, the GPA of the etc/hardware_errors firmware
>   * is stored at hw_error_le. This is the default on QEMU 9.x.
>   *
> - * An GPA value equal to zero means that GHES is not present.
> + * When use_hest_addr is true, the stored offset is placed at hest_addr_le,
                                             ^^^^^ it's not offset, it's GPA
please get rid of offset language in this comment.
        
> + * meaning an offset from the HEST table address from etc/acpi/tables firmware.
> + * This is the default for QEMU 10.x and above.
> + *
> + * Whe both GPA values are equal to zero means that GHES is not present.
>   */
>  typedef struct AcpiGhesState {
> +    uint64_t hest_addr_le;
>      uint64_t hw_error_le;
>      bool use_hest_addr;         /* Currently, always false */
>  } AcpiGhesState;