Re: [Qemu-devel] [PATCH 31/42] tpm-backend: move set 'id' to common code

["Valluri, Amarnath" <amarnath.valluri@intel.com>]

On Tue, 2017-10-10 at 00:56 +0200, Marc-André Lureau wrote:
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  include/sysemu/tpm_backend.h |  2 +-
>  hw/tpm/tpm_emulator.c        | 12 +++---------
>  hw/tpm/tpm_passthrough.c     |  9 +++------
>  tpm.c                        |  3 ++-
>  4 files changed, 9 insertions(+), 17 deletions(-)
> 
> diff --git a/include/sysemu/tpm_backend.h
> b/include/sysemu/tpm_backend.h
> index 594bb50782..881be97ee3 100644
> --- a/include/sysemu/tpm_backend.h
> +++ b/include/sysemu/tpm_backend.h
> @@ -64,7 +64,7 @@ struct TPMBackendClass {
>      /* get a descriptive text of the backend to display to the user
> */
>      const char *desc;
>  
> -    TPMBackend *(*create)(QemuOpts *opts, const char *id);
> +    TPMBackend *(*create)(QemuOpts *opts);
>  
>      /* start up the TPM on the backend - optional */
>      int (*startup_tpm)(TPMBackend *t);
> diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c
> index 36454837b3..315819329b 100644
> --- a/hw/tpm/tpm_emulator.c
> +++ b/hw/tpm/tpm_emulator.c
> @@ -453,22 +453,16 @@ err:
>      return -1;
>  }
>  
> -static TPMBackend *tpm_emulator_create(QemuOpts *opts, const char
> *id)
> +static TPMBackend *tpm_emulator_create(QemuOpts *opts)
>  {
>      TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
>  
> -    tb->id = g_strdup(id);
> -
>      if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
> -        goto err_exit;
> +        object_unref(OBJECT(tb));
> +        return NULL;
>      }
>  
>      return tb;
> -
> -err_exit:
> -    object_unref(OBJECT(tb));
> -
> -    return NULL;
>  }
>  
>  static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
> diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
> index 9326cbfdc9..7371d50739 100644
> --- a/hw/tpm/tpm_passthrough.c
> +++ b/hw/tpm/tpm_passthrough.c
> @@ -284,13 +284,10 @@
> tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, QemuOpts
> *opts)
>      return 1;
>  }
>  
> -static TPMBackend *tpm_passthrough_create(QemuOpts *opts, const char
> *id)
> +static TPMBackend *tpm_passthrough_create(QemuOpts *opts)
>  {
>      Object *obj = object_new(TYPE_TPM_PASSTHROUGH);
> -    TPMBackend *tb = TPM_BACKEND(obj);
> -    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
> -
> -    tb->id = g_strdup(id);
> +    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(obj);
>  
>      if (tpm_passthrough_handle_device_opts(tpm_pt, opts)) {
>          goto err_exit;
> @@ -301,7 +298,7 @@ static TPMBackend
> *tpm_passthrough_create(QemuOpts *opts, const char *id)
>          goto err_exit;
>      }
>  
> -    return tb;
> +    return TPM_BACKEND(obj);
>  
>  err_exit:
>      object_unref(obj);
> diff --git a/tpm.c b/tpm.c
> index a46ee5f144..37298f3f03 100644
> --- a/tpm.c
> +++ b/tpm.c
> @@ -129,11 +129,12 @@ static int tpm_init_tpmdev(void *dummy,
> QemuOpts *opts, Error **errp)
>          return 1;
>      }
>  
> -    drv = be->create(opts, id);
> +    drv = be->create(opts);
>      if (!drv) {
>          return 1;
>      }
>  
> +    drv->id = g_strdup(id);
I kind of oppose this change, instead what about adding new TPMBackend
api say - TPMBackend* tpm_backend_create(const char *type, const
QemuOpts *opts), that should handle this common code, and returns the
newly instantiated backend object.

- Amarnath