Re: [PATCH v3 1/4] acpi: Convert build_tpm2() to build_append* API

[Auger Eric <eric.auger@redhat.com>]

Hi Stefan,
On 6/2/20 3:30 PM, Stefan Berger wrote:
> On 6/1/20 5:57 AM, Eric Auger wrote:
>> In preparation of its move to the generic acpi code,
>> let's convert build_tpm2() to use build_append API. This
>> latter now is prefered in place of direct ACPI struct field
>> settings with manual endianness conversion.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> ---
>>   hw/i386/acpi-build.c | 28 +++++++++++++++++++---------
>>   1 file changed, 19 insertions(+), 9 deletions(-)
>>
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index b5669d6c65..f0d35d7b17 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -2298,30 +2298,40 @@ build_tpm_tcpa(GArray *table_data, BIOSLinker
>> *linker, GArray *tcpalog)
>>   static void
>>   build_tpm2(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
>>   {
>> -    Acpi20TPM2 *tpm2_ptr = acpi_data_push(table_data, sizeof *tpm2_ptr);
>> +    Acpi20TPM2 *tpm2_ptr = acpi_data_push(table_data,
>> sizeof(AcpiTableHeader));
> 
> And now you want to build the data structure by pushing fields? I would
> definitely NOT do this.

If I didn't misinterpret things, this was recommended by Drew and Igor
as buid_append* API avoids to take care of endianness and this is the
API now used in the generic ACPI code. Besides I also think that in that
case it does not simplify things but maybe I did that the wrong way? Or
maybe I didn't understand your remark?

Thanks

Eric
> 
> 
>>       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] = {};
>>   -    tpm2_ptr->platform_class = cpu_to_le16(TPM2_ACPI_CLASS_CLIENT);
>> +    /* platform class */
>> +    build_append_int_noprefix(table_data, TPM2_ACPI_CLASS_CLIENT, 2);
>> +    /* reserved */
>> +    build_append_int_noprefix(table_data, 0, 2);
>>       if (TPM_IS_TIS_ISA(tpm_find())) {
>> -        tpm2_ptr->control_area_address = cpu_to_le64(0);
>> -        tpm2_ptr->start_method = cpu_to_le32(TPM2_START_METHOD_MMIO);
>> +        /* 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);
>>       } else if (TPM_IS_CRB(tpm_find())) {
>> -        tpm2_ptr->control_area_address = cpu_to_le64(TPM_CRB_ADDR_CTRL);
>> -        tpm2_ptr->start_method = cpu_to_le32(TPM2_START_METHOD_CRB);
>> +        build_append_int_noprefix(table_data, TPM_CRB_ADDR_CTRL, 8);
>> +        build_append_int_noprefix(table_data, TPM2_START_METHOD_CRB, 4);
>>       } else {
>>           g_warn_if_reached();
>>       }
>>   -    tpm2_ptr->log_area_minimum_length =
>> -        cpu_to_le32(TPM_LOG_AREA_MINIMUM_SIZE);
>> +    /* platform specific parameters */
>> +    g_array_append_vals(table_data, &start_method_params, 12);
>>   -    acpi_data_push(tcpalog,
>> le32_to_cpu(tpm2_ptr->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 */
>> +    build_append_int_noprefix(table_data, 0, 8);
>>       bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
>>                                      log_addr_offset, log_addr_size,
>>                                      ACPI_BUILD_TPMLOG_FILE, 0);
> 
>