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1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef __TSM_MR_H
4#define __TSM_MR_H
5
6#include <crypto/hash_info.h>
7
8/**
9 * struct tsm_measurement_register - describes an architectural measurement
10 * register (MR)
11 * @mr_name: name of the MR
12 * @mr_value: buffer containing the current value of the MR
13 * @mr_size: size of the MR - typically the digest size of @mr_hash
14 * @mr_flags: bitwise OR of one or more flags, detailed below
15 * @mr_hash: optional hash identifier defined in include/uapi/linux/hash_info.h.
16 *
17 * A CC guest driver encloses an array of this structure in struct
18 * tsm_measurements to detail the measurement facility supported by the
19 * underlying CC hardware.
20 *
21 * @mr_name and @mr_value must stay valid until this structure is no longer in
22 * use.
23 *
24 * @mr_flags is the bitwise-OR of zero or more of the flags below.
25 *
26 * * %TSM_MR_F_READABLE - the sysfs attribute corresponding to this MR is readable.
27 * * %TSM_MR_F_WRITABLE - the sysfs attribute corresponding to this MR is writable.
28 * The semantics is typically to extend the MR but could vary depending on the
29 * architecture and the MR.
30 * * %TSM_MR_F_LIVE - this MR's value may differ from the last value written, so
31 * must be read back from the underlying CC hardware/firmware.
32 * * %TSM_MR_F_RTMR - bitwise-OR of %TSM_MR_F_LIVE and %TSM_MR_F_WRITABLE.
33 * * %TSM_MR_F_NOHASH - this MR does NOT have an associated hash algorithm.
34 * @mr_hash will be ignored when this flag is set.
35 */
36struct tsm_measurement_register {
37 const char *mr_name;
38 void *mr_value;
39 u32 mr_size;
40 u32 mr_flags;
41 enum hash_algo mr_hash;
42};
43
44#define TSM_MR_F_NOHASH 1
45#define TSM_MR_F_WRITABLE 2
46#define TSM_MR_F_READABLE 4
47#define TSM_MR_F_LIVE 8
48#define TSM_MR_F_RTMR (TSM_MR_F_LIVE | TSM_MR_F_WRITABLE)
49
50#define TSM_MR_(mr, hash) \
51 .mr_name = #mr, .mr_size = hash##_DIGEST_SIZE, \
52 .mr_hash = HASH_ALGO_##hash, .mr_flags = TSM_MR_F_READABLE
53
54/**
55 * struct tsm_measurements - defines the CC architecture specific measurement
56 * facility and methods for updating measurement registers (MRs)
57 * @mrs: Array of MR definitions.
58 * @nr_mrs: Number of elements in @mrs.
59 * @refresh: Callback function to load/sync all MRs from TVM hardware/firmware
60 * into the kernel cache.
61 * @write: Callback function to write to the MR specified by the parameter @mr.
62 * Typically, writing to an MR extends the input buffer to that MR.
63 *
64 * The @refresh callback is invoked when an MR with %TSM_MR_F_LIVE set is being
65 * read and the cache is stale. It must reload all MRs with %TSM_MR_F_LIVE set.
66 * The function parameter @tm is a pointer pointing back to this structure.
67 *
68 * The @write callback is invoked whenever an MR is being written. It takes two
69 * additional parameters besides @tm:
70 *
71 * * @mr - points to the MR (an element of @tm->mrs) being written.
72 * * @data - contains the bytes to write and whose size is @mr->mr_size.
73 *
74 * Both @refresh and @write should return 0 on success and an appropriate error
75 * code on failure.
76 */
77struct tsm_measurements {
78 const struct tsm_measurement_register *mrs;
79 size_t nr_mrs;
80 int (*refresh)(const struct tsm_measurements *tm);
81 int (*write)(const struct tsm_measurements *tm,
82 const struct tsm_measurement_register *mr, const u8 *data);
83};
84
85const struct attribute_group *
86tsm_mr_create_attribute_group(const struct tsm_measurements *tm);
87void tsm_mr_free_attribute_group(const struct attribute_group *attr_grp);
88
89#endif