[SeaBIOS] [PATCH v2 3/3] tcgbios: extend Physical Presence interface with more functions

[Kevin O'Connor]

On Tue, Jan 16, 2018 at 11:41:03AM -0500, Stefan Berger wrote:
> Implement more functions of the TPM Physical Presence interface.
> Some of the added functions will automatically reboot the machine.
> Thus we need to save the next step after the reboot in an additional
> variable.
> 
> Signed-off-by: Stefan Berger <stefanb at linux.vnet.ibm.com>
> ---
>  src/std/tcg.h |  7 ++++++
>  src/tcgbios.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 71 insertions(+), 5 deletions(-)
> 
> diff --git a/src/std/tcg.h b/src/std/tcg.h
> index 22353a9..aeee689 100644
> --- a/src/std/tcg.h
> +++ b/src/std/tcg.h
> @@ -548,8 +548,15 @@ struct pcctes_romex
>  #define TPM_PPI_OP_ACTIVATE 3
>  #define TPM_PPI_OP_DEACTIVATE 4
>  #define TPM_PPI_OP_CLEAR 5
> +#define TPM_PPI_OP_ENABLE_ACTIVATE 6
> +#define TPM_PPI_OP_DEACTIVATE_DISABLE 7
>  #define TPM_PPI_OP_SET_OWNERINSTALL_TRUE 8
>  #define TPM_PPI_OP_SET_OWNERINSTALL_FALSE 9
> +#define TPM_PPI_OP_ENABLE_ACTIVATE_SET_OWNERINSTALL_TRUE 10
> +#define TPM_PPI_OP_SET_OWNERINSTALL_FALSE_DEACTIVATE_DISABLE 11
> +#define TPM_PPI_OP_CLEAR_ENABLE_ACTIVATE 14
> +#define TPM_PPI_OP_ENABLE_ACTIVATE_CLEAR 21
> +#define TPM_PPI_OP_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE 22
>  
>  struct tpm_ppi {
>      u8 ppin;            /*  0: 1 = initialized */
> diff --git a/src/tcgbios.c b/src/tcgbios.c
> index c8e6ca2..e074d42 100644
> --- a/src/tcgbios.c
> +++ b/src/tcgbios.c
> @@ -1655,7 +1655,8 @@ tpm12_set_owner_install(int allow, int verbose, u32 *returnCode)
>  }
>  
>  static int
> -tpm12_process_cfg(tpm_ppi_code msgCode, int verbose, u32 *returnCode)
> +tpm12_process_cfg(tpm_ppi_code msgCode, int verbose, u32 *returnCode,
> +                  u8 *nextStep)
>  {
>      int ret = 0;
>  
> @@ -1683,6 +1684,18 @@ tpm12_process_cfg(tpm_ppi_code msgCode, int verbose, u32 *returnCode)
>              ret = tpm12_force_clear(1, 0, verbose, returnCode);
>              break;
>  
> +        case TPM_PPI_OP_ENABLE_ACTIVATE:
> +            ret = tpm12_enable_tpm(1, verbose, returnCode);
> +            if (!ret)
> +                ret = tpm12_activate_tpm(1, 1, verbose, returnCode);
> +            break;
> +
> +        case TPM_PPI_OP_DEACTIVATE_DISABLE:
> +            ret = tpm12_activate_tpm(0, 1, verbose, returnCode);
> +            if (!ret)
> +                ret = tpm12_enable_tpm(0, verbose, returnCode);
> +            break;
> +
>          case TPM_PPI_OP_SET_OWNERINSTALL_TRUE:
>              ret = tpm12_set_owner_install(1, verbose, returnCode);
>              break;
> @@ -1691,6 +1704,43 @@ tpm12_process_cfg(tpm_ppi_code msgCode, int verbose, u32 *returnCode)
>              ret = tpm12_set_owner_install(0, verbose, returnCode);
>              break;
>  
> +        case TPM_PPI_OP_ENABLE_ACTIVATE_SET_OWNERINSTALL_TRUE:
> +            *nextStep = TPM_PPI_OP_SET_OWNERINSTALL_TRUE;
> +            ret = tpm12_enable_activate(1, verbose, returnCode);
> +            if (!ret)
> +                ret = tpm12_set_owner_install(1, verbose, returnCode);
> +            break;
> +
> +        case TPM_PPI_OP_SET_OWNERINSTALL_FALSE_DEACTIVATE_DISABLE:
> +            ret = tpm12_set_owner_install(0, verbose, returnCode);
> +            if (!ret)
> +                ret = tpm12_activate_tpm(0, 0, verbose, returnCode);
> +            if (!ret)
> +                ret = tpm12_enable_tpm(0, verbose, returnCode);
> +            break;
> +
> +        case TPM_PPI_OP_CLEAR_ENABLE_ACTIVATE:
> +            ret = tpm12_force_clear(0, 1, verbose, returnCode);
> +            break;
> +
> +        case TPM_PPI_OP_ENABLE_ACTIVATE_CLEAR:
> +            *nextStep = TPM_PPI_OP_CLEAR;
> +            ret = tpm12_enable_activate(1, verbose, returnCode);
> +            /* no reboot happened */
> +            if (!ret)
> +                ret = tpm12_force_clear(0, 0, verbose, returnCode);
> +            break;
> +
> +        case TPM_PPI_OP_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE:
> +            *nextStep = TPM_PPI_OP_CLEAR_ENABLE_ACTIVATE;

I'm strugging to understand "nextStep".  I think it would be clearer
if the code could do a switch on the request and then execute all the
details of that request without the need to set flags indicating the
function should be rerun.  tpm12_process_cfg() can call itself
recursively if it needs to.

-Kevin