linux/drivers/virt/coco/tsm.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2023 Intel Corporation. All rights reserved. */

#define pr_fmt(fmt) …

#include <linux/tsm.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/cleanup.h>
#include <linux/configfs.h>

static struct tsm_provider { … } provider;
static DECLARE_RWSEM(tsm_rwsem);

/**
 * DOC: Trusted Security Module (TSM) Attestation Report Interface
 *
 * The TSM report interface is a common provider of blobs that facilitate
 * attestation of a TVM (confidential computing guest) by an attestation
 * service. A TSM report combines a user-defined blob (likely a public-key with
 * a nonce for a key-exchange protocol) with a signed attestation report. That
 * combined blob is then used to obtain secrets provided by an agent that can
 * validate the attestation report. The expectation is that this interface is
 * invoked infrequently, however configfs allows for multiple agents to
 * own their own report generation instances to generate reports as
 * often as needed.
 *
 * The attestation report format is TSM provider specific, when / if a standard
 * materializes that can be published instead of the vendor layout. Until then
 * the 'provider' attribute indicates the format of 'outblob', and optionally
 * 'auxblob' and 'manifestblob'.
 */

struct tsm_report_state { … };

enum tsm_data_select { … };

static struct tsm_report *to_tsm_report(struct config_item *cfg)
{ … }

static struct tsm_report_state *to_state(struct tsm_report *report)
{ … }

static int try_advance_write_generation(struct tsm_report *report)
{ … }

static ssize_t tsm_report_privlevel_store(struct config_item *cfg,
					  const char *buf, size_t len)
{ … }
CONFIGFS_ATTR_WO(…);

static ssize_t tsm_report_privlevel_floor_show(struct config_item *cfg,
					       char *buf)
{ … }
CONFIGFS_ATTR_RO(…);

static ssize_t tsm_report_service_provider_store(struct config_item *cfg,
						 const char *buf, size_t len)
{ … }
CONFIGFS_ATTR_WO(…);

static ssize_t tsm_report_service_guid_store(struct config_item *cfg,
					     const char *buf, size_t len)
{ … }
CONFIGFS_ATTR_WO(…);

static ssize_t tsm_report_service_manifest_version_store(struct config_item *cfg,
							 const char *buf, size_t len)
{ … }
CONFIGFS_ATTR_WO(…);

static ssize_t tsm_report_inblob_write(struct config_item *cfg,
				       const void *buf, size_t count)
{ … }
CONFIGFS_BIN_ATTR_WO(…);

static ssize_t tsm_report_generation_show(struct config_item *cfg, char *buf)
{ … }
CONFIGFS_ATTR_RO(…);

static ssize_t tsm_report_provider_show(struct config_item *cfg, char *buf)
{ … }
CONFIGFS_ATTR_RO(…);

static ssize_t __read_report(struct tsm_report *report, void *buf, size_t count,
			     enum tsm_data_select select)
{ … }

static ssize_t read_cached_report(struct tsm_report *report, void *buf,
				  size_t count, enum tsm_data_select select)
{ … }

static ssize_t tsm_report_read(struct tsm_report *report, void *buf,
			       size_t count, enum tsm_data_select select)
{ … }

static ssize_t tsm_report_outblob_read(struct config_item *cfg, void *buf,
				       size_t count)
{ … }
CONFIGFS_BIN_ATTR_RO(…);

static ssize_t tsm_report_auxblob_read(struct config_item *cfg, void *buf,
				       size_t count)
{ … }
CONFIGFS_BIN_ATTR_RO(…);

static ssize_t tsm_report_manifestblob_read(struct config_item *cfg, void *buf,
					    size_t count)
{ … }
CONFIGFS_BIN_ATTR_RO(…);

static struct configfs_attribute *tsm_report_attrs[] = …;

static struct configfs_bin_attribute *tsm_report_bin_attrs[] = …;

static void tsm_report_item_release(struct config_item *cfg)
{ … }

static struct configfs_item_operations tsm_report_item_ops = …;

static bool tsm_report_is_visible(struct config_item *item,
				  struct configfs_attribute *attr, int n)
{ … }

static bool tsm_report_is_bin_visible(struct config_item *item,
				      struct configfs_bin_attribute *attr, int n)
{ … }

static struct configfs_group_operations tsm_report_attr_group_ops = …;

static const struct config_item_type tsm_report_type = …;

static struct config_item *tsm_report_make_item(struct config_group *group,
						const char *name)
{ … }

static struct configfs_group_operations tsm_report_group_ops = …;

static const struct config_item_type tsm_reports_type = …;

static const struct config_item_type tsm_root_group_type = …;

static struct configfs_subsystem tsm_configfs = …;

int tsm_register(const struct tsm_ops *ops, void *priv)
{ … }
EXPORT_SYMBOL_GPL(…);

int tsm_unregister(const struct tsm_ops *ops)
{ … }
EXPORT_SYMBOL_GPL(…);

static struct config_group *tsm_report_group;

static int __init tsm_init(void)
{ … }
module_init(…) …;

static void __exit tsm_exit(void)
{ … }
module_exit(tsm_exit);

MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;