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 4:24 PM, Stefan Berger wrote:
> On 6/2/20 9:55 AM, Auger Eric wrote:
>> 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?
> 
> 
> If that's what they are saying... I would prefer filling out data
> structures with functions like cpu_to_acpi16() because that seems to be
> less error prone.
understood. Let's wait for other comments and we will make a decision
wrt direction.
> 
> 
>>>
>>>>        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);
> 
> Maybe this should be wrapped in an inline function like
> build_append_array() or so.
Hum OK
> 
> 
>>>>    -    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);
> 
> 
> At this point we have a double-allocation of log memory on x86_64. You'd
> need the patch I posted to create the TCPA table only for TPM 1.2.
This series applies on top of this patch (mentionned in the cover letter).
> 
> 
> 
>>>>        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);
>>>
> 
> 
> 
Thanks

Eric