Re: [PATCH v4 02/14] acpi/ghes: add a firmware file with HEST address

Igor Mammedov
2025-02-26T14:48:08Z

On Fri, 21 Feb 2025 15:35:11 +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 | 22 ++++++++++++++++++++--
> include/hw/acpi/ghes.h | 7 ++++++-
> 2 files changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> index e49a03fdb94e..ba37be9e7022 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);
> @@ -501,7 +519,7 @@ bool acpi_ghes_present(void)
> return false;
> }
> ags = &acpi_ged_state->ghes_state;
> - if (!ags->hw_error_le)
> + if (!ags->hw_error_le && !ags->hest_addr_le)
> return false;
>
> return true;
> diff --git a/include/hw/acpi/ghes.h b/include/hw/acpi/ghes.h
> index a3d62b96584f..454e97b5341c 100644
> --- a/include/hw/acpi/ghes.h
> +++ b/include/hw/acpi/ghes.h
> @@ -71,9 +71,14 @@ enum {
> * meaning an offset from the etc/hardware_errors firmware address. This
> * is the default on QEMU 9.x.
> *
> - * An offset 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,
> + * meaning an offset from theHEST table address from etc/acpi/tables firmware.
^^^^^^ missing whitespace

'offset' language is confusing here, is asks for explanation offset from what?

what is kept in hest_addr_le is GPA of HEST table, it would be better to address
wording here.
The same applies to similar comment in previous patch

> + * This is the default for QEMU 10.x and above.
> + *
> + * If both offset values are equal to zero, it 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;