Re: [Qemu-devel] [PATCH v3 2/4] acpi: add fw_cfg file for TPM and PPI virtual memory device

[Marc-André Lureau]

Hi

On Thu, Jun 21, 2018 at 12:00 PM, Igor Mammedov <address@hidden> wrote:
> On Tue, 15 May 2018 14:14:31 +0200
> Marc-André Lureau <address@hidden> wrote:
>
>> From: Stefan Berger <address@hidden>
>>
>> To avoid having to hard code the base address of the PPI virtual
>> memory device we introduce a fw_cfg file etc/tpm/config that holds the
>> base address of the PPI device, the version of the PPI interface and
>> the version of the attached TPM.
> is it related to TPM_PPI_ADDR_BASE added in previous patch?
>
>>
>> Signed-off-by: Stefan Berger <address@hidden>
>> [ Marc-André: renamed to etc/tpm/config, made it static, document it ]
>> Signed-off-by: Marc-André Lureau <address@hidden>
>> ---
>>  include/hw/acpi/tpm.h |  3 +++
>>  hw/i386/acpi-build.c  | 17 +++++++++++++++++
>>  docs/specs/tpm.txt    | 20 ++++++++++++++++++++
>>  3 files changed, 40 insertions(+)
>>
>> diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
>> index c082df7d1d..f79d68a77a 100644
>> --- a/include/hw/acpi/tpm.h
>> +++ b/include/hw/acpi/tpm.h
>> @@ -193,4 +193,7 @@ REG32(CRB_DATA_BUFFER, 0x80)
>>  #define TPM_PPI_ADDR_SIZE           0x400
>>  #define TPM_PPI_ADDR_BASE           0xFED45000
>>
>> +#define TPM_PPI_VERSION_NONE        0
>> +#define TPM_PPI_VERSION_1_30        1
>> +
>>  #endif /* HW_ACPI_TPM_H */
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index 9bc6d97ea1..f6d447f03a 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -119,6 +119,12 @@ typedef struct AcpiBuildPciBusHotplugState {
>>      bool pcihp_bridge_en;
>>  } AcpiBuildPciBusHotplugState;
>>
>> +typedef struct FWCfgTPMConfig {
>> +    uint32_t tpmppi_address;
>> +    uint8_t tpm_version;
>> +    uint8_t tpmppi_version;
>> +} QEMU_PACKED FWCfgTPMConfig;
>> +
>>  static void init_common_fadt_data(Object *o, AcpiFadtData *data)
>>  {
>>      uint32_t io = object_property_get_uint(o, ACPI_PM_PROP_PM_IO_BASE, 
>> NULL);
>> @@ -2873,6 +2879,7 @@ void acpi_setup(void)
>>      AcpiBuildTables tables;
>>      AcpiBuildState *build_state;
>>      Object *vmgenid_dev;
>> +    static FWCfgTPMConfig tpm_config;
>>
>>      if (!pcms->fw_cfg) {
>>          ACPI_BUILD_DPRINTF("No fw cfg. Bailing out.\n");
>> @@ -2907,6 +2914,16 @@ void acpi_setup(void)
>>      fw_cfg_add_file(pcms->fw_cfg, ACPI_BUILD_TPMLOG_FILE,
>>                      tables.tcpalog->data, acpi_data_len(tables.tcpalog));
>>
>> +    if (tpm_find()) {
>> +        tpm_config = (FWCfgTPMConfig) {
>> +            .tpmppi_address = cpu_to_le32(TPM_PPI_ADDR_BASE),
>> +            .tpm_version = cpu_to_le32(tpm_get_version(tpm_find())),
>> +            .tpmppi_version = cpu_to_le32(TPM_PPI_VERSION_NONE)
>> +        };
>> +        fw_cfg_add_file(pcms->fw_cfg, "etc/tpm/config",
>> +                        &tpm_config, sizeof tpm_config);
>> +    }
> why it's in ACPI part of the code, shouldn't it be a part of device,
> could TPM be used without ACPI at all (-noacpi CLI option)?
>
> Wouldn't adding fwcfg entry unconditionally break migration?

Because of unstable entry IDs? that could be problematic. (especially
during boot time) What do you think Laszlo?

I guess we could have a "ppi" device property, that would imply having
the etc/tpm/config fw_cfg entry. We would enable it by default in
newer machine types (3.0?)

>
>> +
>>      vmgenid_dev = find_vmgenid_dev();
>>      if (vmgenid_dev) {
>>          vmgenid_add_fw_cfg(VMGENID(vmgenid_dev), pcms->fw_cfg,
>> diff --git a/docs/specs/tpm.txt b/docs/specs/tpm.txt
>> index c230c4c93e..2ddb768084 100644
>> --- a/docs/specs/tpm.txt
>> +++ b/docs/specs/tpm.txt
>> @@ -20,6 +20,26 @@ QEMU files related to TPM TIS interface:
>>   - hw/tpm/tpm_tis.h
>>
>>
>> += fw_cfg interface =
>> +
>> +The bios/firmware may use the "etc/tpm/config" fw_cfg entry for
>> +configuring the guest appropriately.
>> +
>> +The entry of 6 bytes has the following content, in little-endian:
>> +
>> +    #define TPM_VERSION_UNSPEC          0
>> +    #define TPM_VERSION_1_2             1
>> +    #define TPM_VERSION_2_0             2
>> +
>> +    #define TPM_PPI_VERSION_NONE        0
>> +    #define TPM_PPI_VERSION_1_30        1
>> +
>> +    struct FWCfgTPMConfig {
>> +        uint32_t tpmppi_address;         /* PPI memory location */
>> +        uint8_t tpm_version;             /* TPM version */
>> +        uint8_t tpmppi_version;          /* PPI version */
>> +    };
>> +
>>  = ACPI Interface =
>>
>>  The TPM device is defined with ACPI ID "PNP0C31". QEMU builds a SSDT and 
>> passes
>
>



-- 
Marc-André Lureau