Re: [PATCH v3 01/10] tpm_util: Pass TPMVersion to function writing fatal error response

[Arun Menon <armenon@redhat.com>]

Hi Stefan,

On Fri, Oct 02, 2026 at 10:25:07AM -0400, Stefan Berger wrote:
> Have tpm_util_write_fatal_error_response write a TPM version specific
> error response with error code TPM_FAIL for a TPM 1.2 and TPM_RC_FAILURE
> for a TPM 2. Adjust the callers.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  backends/tpm/tpm_emulator.c    |  3 ++-
>  backends/tpm/tpm_passthrough.c |  2 +-
>  backends/tpm/tpm_util.c        | 17 ++++++++++++++---
>  include/system/tpm_util.h      |  3 ++-
>  4 files changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
> index 95d2de2f48..16ae44c8d7 100644
> --- a/backends/tpm/tpm_emulator.c
> +++ b/backends/tpm/tpm_emulator.c
> @@ -270,7 +270,8 @@ static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd,
>          tpm_emulator_unix_tx_bufs(tpm_emu, cmd->in, cmd->in_len,
>                                    cmd->out, cmd->out_len,
>                                    &cmd->selftest_done, errp) < 0) {
> -        tpm_util_write_fatal_error_response(cmd->out, cmd->out_len);
> +        tpm_util_write_fatal_error_response(cmd->out, cmd->out_len,
> +                                            TPM_EMULATOR(tb)->tpm_version);
nitpick,
+        tpm_util_write_fatal_error_response(cmd->out, cmd->out_len,
+                                            tpm_emu->tpm_version);
>      }
>  }
>  
> diff --git a/backends/tpm/tpm_passthrough.c b/backends/tpm/tpm_passthrough.c
> index a9f35ab7d6..8a4f8183c7 100644
> --- a/backends/tpm/tpm_passthrough.c
> +++ b/backends/tpm/tpm_passthrough.c
> @@ -118,7 +118,7 @@ static void tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
>  
>  err_exit:
>      if (ret < 0) {
> -        tpm_util_write_fatal_error_response(out, out_len);
> +        tpm_util_write_fatal_error_response(out, out_len, tpm_pt->tpm_version);
>      }
>  
>      tpm_pt->tpm_executing = false;
> diff --git a/backends/tpm/tpm_util.c b/backends/tpm/tpm_util.c
> index 264bff22a9..7019f7fd3e 100644
> --- a/backends/tpm/tpm_util.c
> +++ b/backends/tpm/tpm_util.c
> @@ -87,12 +87,23 @@ const PropertyInfo qdev_prop_tpm = {
>  /*
>   * Write an error message in the given output buffer.
>   */
> -void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len)
> +void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len,
> +                                         TPMVersion tpm_version)
>  {
>      if (out_len >= sizeof(struct tpm_resp_hdr)) {
> -        tpm_cmd_set_tag(out, TPM_TAG_RSP_COMMAND);
> +        switch (tpm_version) {
> +        case TPM_VERSION_1_2:
> +            tpm_cmd_set_tag(out, TPM_TAG_RSP_COMMAND);
> +            tpm_cmd_set_error(out, TPM_FAIL);
> +            break;
> +        case TPM_VERSION_2_0:
> +            tpm_cmd_set_tag(out, TPM2_ST_NO_SESSIONS);
> +            tpm_cmd_set_error(out, TPM_RC_FAILURE);
> +            break;
> +        default:
> +            g_assert_not_reached();
> +        }
>          tpm_cmd_set_size(out, sizeof(struct tpm_resp_hdr));
> -        tpm_cmd_set_error(out, TPM_FAIL);
>      }
>  }
>  
> diff --git a/include/system/tpm_util.h b/include/system/tpm_util.h
> index 1858693225..3ab2fe693d 100644
> --- a/include/system/tpm_util.h
> +++ b/include/system/tpm_util.h
> @@ -25,7 +25,8 @@
>  #include "system/tpm.h"
>  #include "qemu/bswap.h"
>  
> -void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len);
> +void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len,
> +                                         TPMVersion tpm_version);
>  
>  bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len);
>  
> -- 
> 2.55.0
> 

Reviewed-by: Arun Menon <armenon@redhat.com>