[SLOF] [PATCH 2/2] tpm: Implement firmware API call pass-through-to-tpm

[Alexey Kardashevskiy]

On Wed, 23 Oct 2024, at 11:13, Stefan Berger wrote:

A couple of line about who is going to call tpm-pass-through-to-tpm at all, and why?


> Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
> ---
> board-qemu/slof/vio-vtpm-cdriver.fs | 11 +++++++++++
> lib/libtpm/tcgbios.c                | 16 ++++++++++++++++
> lib/libtpm/tcgbios.h                |  1 +
> lib/libtpm/tpm.code                 | 12 ++++++++++++
> lib/libtpm/tpm.in                   |  1 +
> 5 files changed, 41 insertions(+)
> 
> diff --git a/board-qemu/slof/vio-vtpm-cdriver.fs b/board-qemu/slof/vio-vtpm-cdriver.fs
> index 21c2190..59ae5d2 100644
> --- a/board-qemu/slof/vio-vtpm-cdriver.fs
> +++ b/board-qemu/slof/vio-vtpm-cdriver.fs
> @@ -57,6 +57,17 @@ LOG-SIZE BUFFER: log-base
>      THEN
> ;
>  
> +\ firmware API call
> +: pass-through-to-tpm ( buf-addr buf-size -- rsp-size )
> +    vtpm-debug? IF
> +        ." Call to pass-through-to-tpm" cr
> +    THEN
> +    tpm-pass-through-to-tpm                ( rsp-size )
> +    vtpm-debug? IF
> +        ." VTPM: tpm-pass-through-to-tpm returned size: " dup . cr
> +    THEN
> +;
> +
> \ firmware API call
> : get-maximum-cmd-size ( -- max-size )
>      vtpm-debug? IF
> diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c
> index a64afde..9fc00fa 100644
> --- a/lib/libtpm/tcgbios.c
> +++ b/lib/libtpm/tcgbios.c
> @@ -972,6 +972,22 @@ uint32_t tpm_get_maximum_cmd_size(void)
> return PAPR_VTPM_MAX_BUFFER_SIZE;
> }
>  
> +uint32_t tpm_pass_through_to_tpm(void *buffer, uint32_t bufferlen)


bufferlen is not used.

> +{
> + unsigned char respbuffer[PAPR_VTPM_MAX_BUFFER_SIZE];
> + uint32_t respbufferlen = sizeof(respbuffer);
> + int ret;
> +
> + ret = spapr_transmit(0, buffer, respbuffer, &respbufferlen,
> +      TPM_DURATION_TYPE_LONG);
> + if (ret)
> + return 0;
> +
> + memcpy(buffer, respbuffer, respbufferlen);

s/respbufferlen/min(respbufferlen, bufferlen)/ may be? Thanks,

> +
> + return respbufferlen;
> +}
> +
> /*
>   * Add an EV_ACTION measurement to the list of measurements
>   */
> diff --git a/lib/libtpm/tcgbios.h b/lib/libtpm/tcgbios.h
> index 83148e0..74344f3 100644
> --- a/lib/libtpm/tcgbios.h
> +++ b/lib/libtpm/tcgbios.h
> @@ -42,5 +42,6 @@ uint32_t tpm_2hash_ext_log(uint32_t pcrindex,
>    const char *info, uint32_t infolen,
>    const void *data, uint64_t datalen);
> uint32_t tpm_get_maximum_cmd_size(void);
> +uint32_t tpm_pass_through_to_tpm(void *buffer, uint32_t bufferlen);
>  
> #endif /* TCGBIOS_H */
> diff --git a/lib/libtpm/tpm.code b/lib/libtpm/tpm.code
> index 23075b8..4a4418e 100644
> --- a/lib/libtpm/tpm.code
> +++ b/lib/libtpm/tpm.code
> @@ -216,3 +216,15 @@ PRIM(tpm_X2d_get_X2d_maximum_X2d_cmd_X2d_size)
> PUSH;
> TOS.u = tpm_get_maximum_cmd_size();
> MIRP
> +
> +
> +/****************************************************************************************/
> +/* SLOF:   tpm-pass-through-to-tpm ( buf-addr buf-size -- rsp-size )                    */
> +/* LIBTPM: rsp_size = tpm-pass-through-to-tpm                                           */
> +/****************************************************************************************/
> +PRIM(tpm_X2d_pass_X2d_through_X2d_to_X2d_tpm)
> + uint32_t buf_size = TOS.u; POP;
> + void *buf = TOS.a;
> +
> + TOS.u = tpm_pass_through_to_tpm(buf, buf_size);
> +MIRP
> diff --git a/lib/libtpm/tpm.in b/lib/libtpm/tpm.in
> index d76c479..b413a24 100644
> --- a/lib/libtpm/tpm.in
> +++ b/lib/libtpm/tpm.in
> @@ -31,3 +31,4 @@ cod(tpm-measure-gpt)
> cod(tpm-hash-log-extend-event-buffer)
> cod(tpm-2hash-ext-log)
> cod(tpm-get-maximum-cmd-size)
> +cod(tpm-pass-through-to-tpm)
> -- 
> 2.25.1
> 
>