Re: [PATCH v4 04/14] acpi/ghes: don't hard-code the number of sources for HEST table

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 21 Feb 2025 15:35:13 +0100
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:

> The current code is actually dependent on having just one error
> structure with a single source, as any change there would cause
> migration issues.
> 
> As the number of sources should be arch-dependent, as it will depend on
> what kind of notifications will exist, and how many errors can be
> reported at the same time, change the logic to be more flexible,
> allowing the number of sources to be defined when building the
> HEST table by the caller.
> 
> 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           | 38 +++++++++++++++++++++-----------------
>  hw/arm/virt-acpi-build.c |  8 +++++++-
>  include/hw/acpi/ghes.h   | 17 ++++++++++++-----
>  3 files changed, 40 insertions(+), 23 deletions(-)
> 
> diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> index 7efea519f766..4a4ea8f4be90 100644
> --- a/hw/acpi/ghes.c
> +++ b/hw/acpi/ghes.c
> @@ -238,17 +238,17 @@ ghes_gen_err_data_uncorrectable_recoverable(GArray *block,
>   * See docs/specs/acpi_hest_ghes.rst for blobs format.
>   */
>  static void build_ghes_error_table(AcpiGhesState *ags, GArray *hardware_errors,
> -                                   BIOSLinker *linker)
> +                                   BIOSLinker *linker, int num_sources)
>  {
>      int i, error_status_block_offset;
>  
>      /* Build error_block_address */
> -    for (i = 0; i < ACPI_GHES_ERROR_SOURCE_COUNT; i++) {
> +    for (i = 0; i < num_sources; i++) {
>          build_append_int_noprefix(hardware_errors, 0, sizeof(uint64_t));
>      }
>  
>      /* Build read_ack_register */
> -    for (i = 0; i < ACPI_GHES_ERROR_SOURCE_COUNT; i++) {
> +    for (i = 0; i < num_sources; i++) {
>          /*
>           * Initialize the value of read_ack_register to 1, so GHES can be
>           * writable after (re)boot.
> @@ -263,13 +263,13 @@ static void build_ghes_error_table(AcpiGhesState *ags, GArray *hardware_errors,
>  
>      /* Reserve space for Error Status Data Block */
>      acpi_data_push(hardware_errors,
> -        ACPI_GHES_MAX_RAW_DATA_LENGTH * ACPI_GHES_ERROR_SOURCE_COUNT);
> +        ACPI_GHES_MAX_RAW_DATA_LENGTH * num_sources);
>  
>      /* Tell guest firmware to place hardware_errors blob into RAM */
>      bios_linker_loader_alloc(linker, ACPI_HW_ERROR_FW_CFG_FILE,
>                               hardware_errors, sizeof(uint64_t), false);
>  
> -    for (i = 0; i < ACPI_GHES_ERROR_SOURCE_COUNT; i++) {
> +    for (i = 0; i < num_sources; i++) {
>          /*
>           * Tell firmware to patch error_block_address entries to point to
>           * corresponding "Generic Error Status Block"
> @@ -295,12 +295,14 @@ static void build_ghes_error_table(AcpiGhesState *ags, GArray *hardware_errors,
>  }
>  
>  /* Build Generic Hardware Error Source version 2 (GHESv2) */
> -static void build_ghes_v2(GArray *table_data,
> -                          BIOSLinker *linker,
> -                          enum AcpiGhesNotifyType notify,
> -                          uint16_t source_id)
> +static void build_ghes_v2_entry(GArray *table_data,
> +                                BIOSLinker *linker,
> +                                const AcpiNotificationSourceId *notif_src,
> +                                uint16_t index, int num_sources)
>  {
>      uint64_t address_offset;
> +    const uint16_t notify = notif_src->notify;
> +    const uint16_t source_id = notif_src->source_id;
>  
>      /*
>       * Type:
> @@ -331,7 +333,7 @@ static void build_ghes_v2(GArray *table_data,
>                                     address_offset + GAS_ADDR_OFFSET,
>                                     sizeof(uint64_t),
>                                     ACPI_HW_ERROR_FW_CFG_FILE,
> -                                   source_id * sizeof(uint64_t));
> +                                   index * sizeof(uint64_t));
>  
>      /* Notification Structure */
>      build_ghes_hw_error_notification(table_data, notify);
> @@ -351,8 +353,7 @@ static void build_ghes_v2(GArray *table_data,
>                                     address_offset + GAS_ADDR_OFFSET,
>                                     sizeof(uint64_t),
>                                     ACPI_HW_ERROR_FW_CFG_FILE,
> -                                   (ACPI_GHES_ERROR_SOURCE_COUNT + source_id)
> -                                   * sizeof(uint64_t));
> +                                   (num_sources + index) * sizeof(uint64_t));
>  
>      /*
>       * Read Ack Preserve field
> @@ -368,22 +369,26 @@ static void build_ghes_v2(GArray *table_data,
>  void acpi_build_hest(AcpiGhesState *ags, GArray *table_data,
>                       GArray *hardware_errors,
>                       BIOSLinker *linker,
> +                     const AcpiNotificationSourceId *notif_source,
> +                     int num_sources,
>                       const char *oem_id, const char *oem_table_id)
>  {
>      AcpiTable table = { .sig = "HEST", .rev = 1,
>                          .oem_id = oem_id, .oem_table_id = oem_table_id };
>      uint32_t hest_offset;
> +    int i;
>  
>      hest_offset = table_data->len;
>  
> -    build_ghes_error_table(ags, hardware_errors, linker);
> +    build_ghes_error_table(ags, hardware_errors, linker, num_sources);
>  
>      acpi_table_begin(&table, table_data);
>  
>      /* Error Source Count */
> -    build_append_int_noprefix(table_data, ACPI_GHES_ERROR_SOURCE_COUNT, 4);
> -    build_ghes_v2(table_data, linker,
> -                  ACPI_GHES_NOTIFY_SEA, ACPI_HEST_SRC_ID_SEA);
> +    build_append_int_noprefix(table_data, num_sources, 4);
> +    for (i = 0; i < num_sources; i++) {
> +        build_ghes_v2_entry(table_data, linker, &notif_source[i], i, num_sources);
> +    }
>  
>      acpi_table_end(linker, &table);
>  
> @@ -529,7 +534,6 @@ void ghes_record_cper_errors(const void *cper, size_t len,
>      }
>      ags = &acpi_ged_state->ghes_state;
>  
> -    assert(ACPI_GHES_ERROR_SOURCE_COUNT == 1);
I'd also remove one blank line here


>  
>      if (!ags->use_hest_addr) {
>          get_hw_error_offsets(le64_to_cpu(ags->hw_error_le),
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 8ab8d11b6536..4439252e1a75 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -893,6 +893,10 @@ static void acpi_align_size(GArray *blob, unsigned align)
>      g_array_set_size(blob, ROUND_UP(acpi_data_len(blob), align));
>  }
>  
> +static const AcpiNotificationSourceId hest_ghes_notify[] = {
> +    { ACPI_HEST_SRC_ID_SYNC, ACPI_GHES_NOTIFY_SEA },
> +};
> +
>  static
>  void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>  {
> @@ -956,7 +960,9 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>  
>              acpi_add_table(table_offsets, tables_blob);
>              acpi_build_hest(ags, tables_blob, tables->hardware_errors,
> -                            tables->linker, vms->oem_id, vms->oem_table_id);
> +                            tables->linker, hest_ghes_notify,
> +                            ARRAY_SIZE(hest_ghes_notify),
> +                            vms->oem_id, vms->oem_table_id);
>          }
>      }
>  
> diff --git a/include/hw/acpi/ghes.h b/include/hw/acpi/ghes.h
> index 2f06e433ce04..51c6b6b33327 100644
> --- a/include/hw/acpi/ghes.h
> +++ b/include/hw/acpi/ghes.h
> @@ -57,13 +57,18 @@ enum AcpiGhesNotifyType {
>      ACPI_GHES_NOTIFY_RESERVED = 12
>  };
>  
> -enum {
> -    ACPI_HEST_SRC_ID_SEA = 0,
> -    /* future ids go here */
> -
> -    ACPI_GHES_ERROR_SOURCE_COUNT
> +/*
> + * ID numbers used to fill HEST source ID field
> + */
> +enum AcpiGhesSourceID {
> +    ACPI_HEST_SRC_ID_SYNC,
>  };
>  
> +typedef struct AcpiNotificationSourceId {
> +    enum AcpiGhesSourceID source_id;
> +    enum AcpiGhesNotifyType notify;
> +} AcpiNotificationSourceId;
> +
>  /*
>   * AcpiGhesState stores an offset that will be used to fill HEST entries.
>   *
> @@ -86,6 +91,8 @@ typedef struct AcpiGhesState {
>  void acpi_build_hest(AcpiGhesState *ags, GArray *table_data,
>                       GArray *hardware_errors,
>                       BIOSLinker *linker,
> +                     const AcpiNotificationSourceId * const notif_source,
> +                     int num_sources,
>                       const char *oem_id, const char *oem_table_id);
>  void acpi_ghes_add_fw_cfg(AcpiGhesState *vms, FWCfgState *s,
>                            GArray *hardware_errors);