tpm: Move getting TPM buffer size to backends

Rather than setting the size of the TPM buffer in the front-end,
query the backend for the size of the buffer. In this patch we
just move the hard-coded buffer size of 4096 to the backends.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
index 590e8b42de..7c98b6100d 100644
--- a/include/sysemu/tpm_backend.h
+++ b/include/sysemu/tpm_backend.h
@@ -81,6 +81,8 @@ struct TPMBackendClass {
 
     TPMVersion (*get_tpm_version)(TPMBackend *t);
 
+    size_t (*get_buffer_size)(TPMBackend *t);
+
     TpmTypeOptions *(*get_tpm_options)(TPMBackend *t);
 
     void (*handle_request)(TPMBackend *s, TPMBackendCmd *cmd);
@@ -183,6 +185,16 @@ int tpm_backend_reset_tpm_established_flag(TPMBackend *s, uint8_t locty);
 TPMVersion tpm_backend_get_tpm_version(TPMBackend *s);
 
 /**
+ * tpm_backend_get_buffer_size:
+ * @s: the backend to call into
+ *
+ * Get the TPM's buffer size.
+ *
+ * Returns buffer size.
+ */
+size_t tpm_backend_get_buffer_size(TPMBackend *s);
+
+/**
  * tpm_backend_query_tpm:
  * @s: the backend
  *