Re: [Qemu-devel] [PATCH v13 3/6] acpi: expose TPM/PPI configuration parameters to firmware via fw_cfg

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 12/12/18 11:26 PM, Marc-André Lureau wrote:
> From: Stefan Berger <stefanb@linux.vnet.ibm.com>
> 
> 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.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> [ Marc-André: renamed to etc/tpm/config, made it static, document it ]
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  include/hw/acpi/tpm.h |  3 +++
>  hw/i386/acpi-build.c  | 19 +++++++++++++++++++
>  docs/specs/tpm.txt    | 19 +++++++++++++++++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
> index b8796df916..a6109a97fc 100644
> --- a/include/hw/acpi/tpm.h
> +++ b/include/hw/acpi/tpm.h
> @@ -194,4 +194,7 @@ 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 236a20eaa8..7b5c67e202 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);
> @@ -2855,6 +2861,8 @@ void acpi_setup(void)
>      AcpiBuildTables tables;
>      AcpiBuildState *build_state;
>      Object *vmgenid_dev;
> +    TPMIf *tpm;
> +    static FwCfgTPMConfig tpm_config;
>  
>      if (!pcms->fw_cfg) {
>          ACPI_BUILD_DPRINTF("No fw cfg. Bailing out.\n");
> @@ -2889,6 +2897,17 @@ void acpi_setup(void)
>      fw_cfg_add_file(pcms->fw_cfg, ACPI_BUILD_TPMLOG_FILE,
>                      tables.tcpalog->data, acpi_data_len(tables.tcpalog));
>  
> +    tpm = tpm_find();
> +    if (tpm && object_property_get_bool(OBJECT(tpm), "ppi", &error_abort)) {
> +        tpm_config = (FwCfgTPMConfig) {
> +            .tpmppi_address = cpu_to_le32(TPM_PPI_ADDR_BASE),
> +            .tpm_version = tpm_get_version(tpm),
> +            .tpmppi_version = TPM_PPI_VERSION_NONE
> +        };
> +        fw_cfg_add_file(pcms->fw_cfg, "etc/tpm/config",
> +                        &tpm_config, sizeof tpm_config);
> +    }
> +
>      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 1af82bba86..e4bb094700 100644
> --- a/docs/specs/tpm.txt
> +++ b/docs/specs/tpm.txt
> @@ -34,6 +34,25 @@ The CRB interface makes a memory mapped IO region in the area 0xfed40000 -
>  QEMU files related to TPM CRB interface:
>   - hw/tpm/tpm_crb.c
>  
> += fw_cfg interface =
> +
> +The bios/firmware may read 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 =
>  
>