ref: 4a4d141f1f57a7831305e324410a8436cd5e8398
dir: /sys/src/9/xen/xen-public/io/tpmif.h/
/******************************************************************************
* tpmif.h
*
* TPM I/O interface for Xen guest OSes.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Copyright (c) 2005, IBM Corporation
*
* Author: Stefan Berger, [email protected]
* Grant table support: Mahadevan Gomathisankaran
*
* This code has been derived from tools/libxc/xen/io/netif.h
*
* Copyright (c) 2003-2004, Keir Fraser
*/
#ifndef __XEN_PUBLIC_IO_TPMIF_H__
#define __XEN_PUBLIC_IO_TPMIF_H__
#include "../grant_table.h"
struct tpmif_tx_request {
unsigned long addr; /* Machine address of packet. */
grant_ref_t ref; /* grant table access reference */
uint16_t unused;
uint16_t size; /* Packet size in bytes. */
};
typedef struct tpmif_tx_request tpmif_tx_request_t;
/*
* The TPMIF_TX_RING_SIZE defines the number of pages the
* front-end and backend can exchange (= size of array).
*/
typedef uint32_t TPMIF_RING_IDX;
#define TPMIF_TX_RING_SIZE 1
/* This structure must fit in a memory page. */
struct tpmif_ring {
struct tpmif_tx_request req;
};
typedef struct tpmif_ring tpmif_ring_t;
struct tpmif_tx_interface {
struct tpmif_ring ring[TPMIF_TX_RING_SIZE];
};
typedef struct tpmif_tx_interface tpmif_tx_interface_t;
/******************************************************************************
* TPM I/O interface for Xen guest OSes, v2
*
* Author: Daniel De Graaf <[email protected]>
*
* This protocol emulates the request/response behavior of a TPM using a Xen
* shared memory interface. All interaction with the TPM is at the direction
* of the frontend, since a TPM (hardware or virtual) is a passive device -
* the backend only processes commands as requested by the frontend.
*
* The frontend sends a request to the TPM by populating the shared page with
* the request packet, changing the state to TPMIF_STATE_SUBMIT, and sending
* and event channel notification. When the backend is finished, it will set
* the state to TPMIF_STATE_FINISH and send an event channel notification.
*
* In order to allow long-running commands to be canceled, the frontend can
* at any time change the state to TPMIF_STATE_CANCEL and send a notification.
* The TPM can either finish the command (changing state to TPMIF_STATE_FINISH)
* or can cancel the command and change the state to TPMIF_STATE_IDLE. The TPM
* can also change the state to TPMIF_STATE_IDLE instead of TPMIF_STATE_FINISH
* if another reason for cancellation is required - for example, a physical
* TPM may cancel a command if the interface is seized by another locality.
*
* The TPM command format is defined by the TCG, and is available at
* http://www.trustedcomputinggroup.org/resources/tpm_main_specification
*/
enum tpmif_state {
TPMIF_STATE_IDLE, /* no contents / vTPM idle / cancel complete */
TPMIF_STATE_SUBMIT, /* request ready / vTPM working */
TPMIF_STATE_FINISH, /* response ready / vTPM idle */
TPMIF_STATE_CANCEL, /* cancel requested / vTPM working */
};
/* Note: The backend should only change state to IDLE or FINISH, while the
* frontend should only change to SUBMIT or CANCEL. Status changes do not need
* to use atomic operations.
*/
/* The shared page for vTPM request/response packets looks like:
*
* Offset Contents
* =================================================
* 0 struct tpmif_shared_page
* 16 [optional] List of grant IDs
* 16+4*nr_extra_pages TPM packet data
*
* If the TPM packet data extends beyond the end of a single page, the grant IDs
* defined in extra_pages are used as if they were mapped immediately following
* the primary shared page. The grants are allocated by the frontend and mapped
* by the backend. Before sending a request spanning multiple pages, the
* frontend should verify that the TPM supports such large requests by querying
* the TPM_CAP_PROP_INPUT_BUFFER property from the TPM.
*/
struct tpmif_shared_page {
uint32_t length; /* request/response length in bytes */
uint8_t state; /* enum tpmif_state */
uint8_t locality; /* for the current request */
uint8_t pad; /* should be zero */
uint8_t nr_extra_pages; /* extra pages for long packets; may be zero */
uint32_t extra_pages[0]; /* grant IDs; length is actually nr_extra_pages */
};
typedef struct tpmif_shared_page tpmif_shared_page_t;
#endif
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/