Re: [PATCH for-5.1 1/2] Revert "tpm: Clean up error reporting in tpm_init_tpmdev()"

[Philippe Mathieu-Daudé]

On 7/23/20 1:58 PM, Markus Armbruster wrote:
> This reverts commit d10e05f15d5c3dd5e5cc59c5dfff460d89d48580.
> 
> We report some -tpmdev failures, but then continue as if all was fine.
> Reproducer:
> 
>     $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio -chardev 
> null,id=tpm0 -tpmdev emulator,id=tpm0,chardev=chrtpm -device 
> tpm-tis,tpmdev=tpm0
>     qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: 
> tpm-emulator: tpm chardev 'chrtpm' not found.
>     qemu-system-x86_64: -tpmdev emulator,id=tpm0,chardev=chrtpm: 
> tpm-emulator: Could not cleanly shutdown the TPM: No such file or directory
>     QEMU 5.0.90 monitor - type 'help' for more information
>     (qemu) qemu-system-x86_64: -device tpm-tis,tpmdev=tpm0: Property 
> 'tpm-tis.tpmdev' can't find value 'tpm0'
>     $ echo $?
>     1
> 
> This is a regression caused by commit d10e05f15d "tpm: Clean up error
> reporting in tpm_init_tpmdev()".  It's incomplete: be->create(opts)
> continues to use error_report(), and we don't set an error when it
> fails.
> 
> I figure converting the create() methods to Error would make some
> sense, but I'm not sure it's worth the effort right now.  Revert the
> broken commit instead, and add a comment to tpm_init_tpmdev().
> 
> Straightforward conflict in tpm.c resolved.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

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

> ---
>  include/sysemu/tpm.h |  2 +-
>  softmmu/vl.c         |  4 +++-
>  stubs/tpm.c          |  3 ++-
>  tpm.c                | 30 +++++++++++++++++++++---------
>  4 files changed, 27 insertions(+), 12 deletions(-)
> 
> diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
> index 03fb25941c..730c61ac97 100644
> --- a/include/sysemu/tpm.h
> +++ b/include/sysemu/tpm.h
> @@ -16,7 +16,7 @@
>  #include "qom/object.h"
>  
>  int tpm_config_parse(QemuOptsList *opts_list, const char *optarg);
> -void tpm_init(void);
> +int tpm_init(void);
>  void tpm_cleanup(void);
>  
>  typedef enum TPMVersion {
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index f476ef89ed..2c06cf0513 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -4262,7 +4262,9 @@ void qemu_init(int argc, char **argv, char **envp)
>                        user_creatable_add_opts_foreach,
>                        object_create_delayed, &error_fatal);
>  
> -    tpm_init();
> +    if (tpm_init() < 0) {
> +        exit(1);
> +    }
>  
>      blk_mig_init();
>      ram_mig_init();
> diff --git a/stubs/tpm.c b/stubs/tpm.c
> index 66c99d667d..9bded191d9 100644
> --- a/stubs/tpm.c
> +++ b/stubs/tpm.c
> @@ -10,8 +10,9 @@
>  #include "sysemu/tpm.h"
>  #include "hw/acpi/tpm.h"
>  
> -void tpm_init(void)
> +int tpm_init(void)
>  {
> +    return 0;
>  }
>  
>  void tpm_cleanup(void)
> diff --git a/tpm.c b/tpm.c
> index fe03b24858..f6045bb6da 100644
> --- a/tpm.c
> +++ b/tpm.c
> @@ -81,26 +81,33 @@ TPMBackend *qemu_find_tpm_be(const char *id)
>  
>  static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
>  {
> +    /*
> +     * Use of error_report() in a function with an Error ** parameter
> +     * is suspicious.  It is okay here.  The parameter only exists to
> +     * make the function usable with qemu_opts_foreach().  It is not
> +     * actually used.
> +     */
>      const char *value;
>      const char *id;
>      const TPMBackendClass *be;
>      TPMBackend *drv;
> +    Error *local_err = NULL;
>      int i;
>  
>      if (!QLIST_EMPTY(&tpm_backends)) {
> -        error_setg(errp, "Only one TPM is allowed.");
> +        error_report("Only one TPM is allowed.");
>          return 1;
>      }
>  
>      id = qemu_opts_id(opts);
>      if (id == NULL) {
> -        error_setg(errp, QERR_MISSING_PARAMETER, "id");
> +        error_report(QERR_MISSING_PARAMETER, "id");
>          return 1;
>      }
>  
>      value = qemu_opt_get(opts, "type");
>      if (!value) {
> -        error_setg(errp, QERR_MISSING_PARAMETER, "type");
> +        error_report(QERR_MISSING_PARAMETER, "type");
>          tpm_display_backend_drivers();
>          return 1;
>      }
> @@ -108,14 +115,15 @@ static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, 
> Error **errp)
>      i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
>      be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
>      if (be == NULL) {
> -        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
> -                   "a TPM backend type");
> +        error_report(QERR_INVALID_PARAMETER_VALUE,
> +                     "type", "a TPM backend type");
>          tpm_display_backend_drivers();
>          return 1;
>      }
>  
>      /* validate backend specific opts */
> -    if (!qemu_opts_validate(opts, be->opts, errp)) {
> +    if (!qemu_opts_validate(opts, be->opts, &local_err)) {
> +        error_report_err(local_err);
>          return 1;
>      }
>  
> @@ -148,10 +156,14 @@ void tpm_cleanup(void)
>   * Initialize the TPM. Process the tpmdev command line options describing the
>   * TPM backend.
>   */
> -void tpm_init(void)
> +int tpm_init(void)
>  {
> -    qemu_opts_foreach(qemu_find_opts("tpmdev"),
> -                      tpm_init_tpmdev, NULL, &error_fatal);
> +    if (qemu_opts_foreach(qemu_find_opts("tpmdev"),
> +                          tpm_init_tpmdev, NULL, NULL)) {
> +        return -1;
> +    }
> +
> +    return 0;
>  }
>  
>  /*
>