Re: [PATCH v6 1/3] acpi: Some build_tpm2() code reshape

[Stefan Berger <stefanb@linux.ibm.com>]

On 6/19/20 10:18 AM, Eric Auger wrote:
> Remove any reference to Acpi20TPM2 and adopt an implementation
> similar to build_ghes_v2().
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Suggested-by: Igor Mammedov <imammedo@redhat.com>
>
> ---
>
> v5 -> v6:
> - add reference to the spec + comment about LAML and LASA fields
> - also moved LASA intro comment above build_append_int_noprefix()
>    as requested by Igor
> ---
>   hw/acpi/aml-build.c | 54 +++++++++++++++++++++++++++++----------------
>   1 file changed, 35 insertions(+), 19 deletions(-)
>
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 2cb7b991ef..1cc08a3eb9 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1878,48 +1878,64 @@ build_hdr:
>                    "FACP", tbl->len - fadt_start, f->rev, oem_id, oem_table_id);
>   }
>   
> +/*
> + * build_tpm2 - Build the TPM2 table as specified in table 7 of
> + * "TCG ACPI Specification; Family 1.2 and 2.0;
> + * Level 00 Revision 00.37, December 19, 2014"
> + * Note: the LASA and LAML fields are optional for TPM-2.0 (the above
> + * table does not mention them) but are needed at least for SeaBIOS.
> + * See the Acpi20TPM2 struct for the corresponding layout.
> + */
>   void build_tpm2(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
>   {
> -    Acpi20TPM2 *tpm2_ptr = acpi_data_push(table_data, sizeof(AcpiTableHeader));
> -    unsigned log_addr_size = sizeof(tpm2_ptr->log_area_start_address);
> -    unsigned log_addr_offset =
> -        (char *)&tpm2_ptr->log_area_start_address - table_data->data;
>       uint8_t start_method_params[12] = {};
> +    unsigned log_addr_offset, tpm2_start;
> +    uint64_t control_area_start_address;
>       TPMIf *tpmif = tpm_find();
> +    uint32_t start_method;
> +    void *tpm2_ptr;
>   
> -    /* platform class */
> +    tpm2_start = table_data->len;
> +    tpm2_ptr = acpi_data_push(table_data, sizeof(AcpiTableHeader));
> +
> +    /* Platform Class */
>       build_append_int_noprefix(table_data, TPM2_ACPI_CLASS_CLIENT, 2);
> -    /* reserved */
> +    /* Reserved */
>       build_append_int_noprefix(table_data, 0, 2);
>       if (TPM_IS_TIS_ISA(tpmif) || TPM_IS_TIS_SYSBUS(tpmif)) {
> -        /* address of control area */
> -        build_append_int_noprefix(table_data, 0, 8);
> -        /* start method */
> -        build_append_int_noprefix(table_data, TPM2_START_METHOD_MMIO, 4);
> +        control_area_start_address = 0;
> +        start_method = TPM2_START_METHOD_MMIO;
>       } else if (TPM_IS_CRB(tpmif)) {
> -        build_append_int_noprefix(table_data, TPM_CRB_ADDR_CTRL, 8);
> -        build_append_int_noprefix(table_data, TPM2_START_METHOD_CRB, 4);
> +        control_area_start_address = TPM_CRB_ADDR_CTRL;
> +        start_method = TPM2_START_METHOD_CRB;
>       } else {
> -        g_warn_if_reached();
> +        g_assert_not_reached();
>       }
> +    /* Address of Control Area */
> +    build_append_int_noprefix(table_data, control_area_start_address, 8);
> +    /* Start Method */
> +    build_append_int_noprefix(table_data, start_method, 4);
>   
> -    /* platform specific parameters */
> -    g_array_append_vals(table_data, &start_method_params, 12);
> +    /* Platform Specific Parameters */
> +    g_array_append_vals(table_data, &start_method_params,
> +                        ARRAY_SIZE(start_method_params));
>   
> -    /* log area minimum length */
> +    /* Log Area Minimum Length */
>       build_append_int_noprefix(table_data, TPM_LOG_AREA_MINIMUM_SIZE, 4);
>   
>       acpi_data_push(tcpalog, TPM_LOG_AREA_MINIMUM_SIZE);
>       bios_linker_loader_alloc(linker, ACPI_BUILD_TPMLOG_FILE, tcpalog, 1,
>                                false);
>   
> -    /* log area start address to be filled by Guest linker */
> +    log_addr_offset = table_data->len;
> +

Don't have to subtract tpm2_start from it ?


> +    /* Log Area Start Address to be filled by Guest linker */
>       build_append_int_noprefix(table_data, 0, 8);
>       bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
> -                                   log_addr_offset, log_addr_size,
> +                                   log_addr_offset, 8,
>                                      ACPI_BUILD_TPMLOG_FILE, 0);
>       build_header(linker, table_data,
> -                 (void *)tpm2_ptr, "TPM2", sizeof(*tpm2_ptr), 4, NULL, NULL);
> +                 tpm2_ptr, "TPM2", table_data->len - tpm2_start, 4, NULL, NULL);
>   }
>   
>   /* ACPI 5.0: 6.4.3.8.2 Serial Bus Connection Descriptors */