---
 Documentation/driver-api/coco/index.rst            |  12 +
 .../driver-api/coco/measurement-registers.rst      |  12 +
 Documentation/driver-api/index.rst                 |   1 +
 MAINTAINERS                                        |   4 +-
 drivers/virt/coco/Kconfig                          |   5 +
 drivers/virt/coco/Makefile                         |   1 +
 drivers/virt/coco/tsm-mr.c                         | 247 +++++++++++++++++++++
 include/linux/tsm-mr.h                             |  94 ++++++++
 include/trace/events/tsm_mr.h                      |  80 +++++++
 9 files changed, 454 insertions(+), 2 deletions(-)

diff --git a/Documentation/driver-api/coco/index.rst b/Documentation/driver-api/coco/index.rst
new file mode 100644
index 000000000000..af9f08ca0cfd
--- /dev/null
+++ b/Documentation/driver-api/coco/index.rst

@@ -0,0 +1,12 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+Confidential Computing
+======================
+
+.. toctree::
+   :maxdepth: 1
+
+   measurement-registers
+
+.. only::  subproject and html

diff --git a/Documentation/driver-api/coco/measurement-registers.rst b/Documentation/driver-api/coco/measurement-registers.rst
new file mode 100644
index 000000000000..cef85945a9a7
--- /dev/null
+++ b/Documentation/driver-api/coco/measurement-registers.rst

@@ -0,0 +1,12 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+=====================
+Measurement Registers
+=====================
+
+.. kernel-doc:: include/linux/tsm-mr.h
+   :internal:
+
+.. kernel-doc:: drivers/virt/coco/tsm-mr.c
+   :export:

diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index 16e2c4ec3c01..3e2a270bd828 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst

@@ -81,6 +81,7 @@ Subsystem-specific APIs
    acpi/index
    backlight/lp855x-driver.rst
    clk
+   coco/index
    console
    crypto/index
    dmaengine/index

diff --git a/MAINTAINERS b/MAINTAINERS
index fa1e04e87d1d..1d1426af3a68 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -24616,8 +24616,8 @@ M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-coco@lists.linux.dev
 S:	Maintained
 F:	Documentation/ABI/testing/configfs-tsm
-F:	drivers/virt/coco/tsm.c
-F:	include/linux/tsm.h
+F:	drivers/virt/coco/tsm*.c
+F:	include/linux/tsm*.h

 
 TRUSTED SERVICES TEE DRIVER
 M:	Balint Dobszay [off-list ref]

diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig
index ff869d883d95..737106d5dcbc 100644
--- a/drivers/virt/coco/Kconfig
+++ b/drivers/virt/coco/Kconfig

@@ -7,6 +7,11 @@ config TSM_REPORTS
 	select CONFIGFS_FS
 	tristate
 
+config TSM_MEASUREMENTS
+	select CRYPTO_HASH_INFO
+	select CRYPTO
+	bool
+
 source "drivers/virt/coco/efi_secret/Kconfig"
 
 source "drivers/virt/coco/pkvm-guest/Kconfig"

diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile
index c3d07cfc087e..eb6ec5c1d2e1 100644
--- a/drivers/virt/coco/Makefile
+++ b/drivers/virt/coco/Makefile

@@ -3,6 +3,7 @@
 # Confidential computing related collateral
 #
 obj-$(CONFIG_TSM_REPORTS)	+= tsm.o
+obj-$(CONFIG_TSM_MEASUREMENTS)	+= tsm-mr.o
 obj-$(CONFIG_EFI_SECRET)	+= efi_secret/
 obj-$(CONFIG_ARM_PKVM_GUEST)	+= pkvm-guest/
 obj-$(CONFIG_SEV_GUEST)		+= sev-guest/

diff --git a/drivers/virt/coco/tsm-mr.c b/drivers/virt/coco/tsm-mr.c
new file mode 100644
index 000000000000..adc32328018e
--- /dev/null
+++ b/drivers/virt/coco/tsm-mr.c

@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2024-2025 Intel Corporation. All rights reserved. */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/tsm_mr.h>
+
+/*
+ * struct tm_context - contains everything necessary to implement sysfs
+ * attributes for MRs.
+ * @rwsem: protects the MR cache from concurrent access.
+ * @agrp: contains all MR attributes created by tsm_mr_create_attribute_group().
+ * @tm: input to tsm_mr_create_attribute_group() containing MR definitions/ops.
+ * @in_sync: %true if MR cache is up-to-date.
+ * @mrs: array of &struct bin_attribute, one for each MR.
+ *
+ * This internal structure contains everything needed to implement
+ * tm_digest_read() and tm_digest_write().
+ *
+ * Given tm->refresh() is potentially expensive, tm_digest_read() caches MR
+ * values and calls tm->refresh() only when necessary. Only live MRs (i.e., with
+ * %TSM_MR_F_LIVE set) can trigger tm->refresh(), while others are assumed to
+ * retain their values from the last tm->write(). @in_sync tracks if there have
+ * been tm->write() calls since the last tm->refresh(). That is, tm->refresh()
+ * will be called only when a live MR is being read and the cache is stale
+ * (@in_sync is %false).
+ *
+ * tm_digest_write() sets @in_sync to %false and calls tm->write(), whose
+ * semantics is arch and MR specific. Most (if not all) writable MRs support the
+ * extension semantics (i.e., tm->write() extends the input buffer into the MR).
+ */
+struct tm_context {
+	struct rw_semaphore rwsem;
+	struct attribute_group agrp;
+	const struct tsm_measurements *tm;
+	bool in_sync;
+	struct bin_attribute mrs[];
+};
+
+static ssize_t tm_digest_read(struct file *filp, struct kobject *kobj,
+			      const struct bin_attribute *attr, char *buffer,
+			      loff_t off, size_t count)
+{
+	struct tm_context *ctx;
+	const struct tsm_measurement_register *mr;
+	int rc;
+
+	ctx = attr->private;
+	rc = down_read_interruptible(&ctx->rwsem);
+	if (rc)
+		return rc;
+
+	mr = &ctx->tm->mrs[attr - ctx->mrs];
+
+	/*
+	 * @ctx->in_sync indicates if the MR cache is stale. It is a global
+	 * instead of a per-MR flag for simplicity, as most (if not all) archs
+	 * allow reading all MRs in oneshot.
+	 *
+	 * ctx->refresh() is necessary only for LIVE MRs, while others retain
+	 * their values from their respective last ctx->write().
+	 */
+	if ((mr->mr_flags & TSM_MR_F_LIVE) && !ctx->in_sync) {
+		up_read(&ctx->rwsem);
+
+		rc = down_write_killable(&ctx->rwsem);
+		if (rc)
+			return rc;
+
+		if (!ctx->in_sync) {
+			rc = ctx->tm->refresh(ctx->tm, mr);
+			ctx->in_sync = !rc;
+			trace_tsm_mr_refresh(mr, rc);
+		}
+
+		downgrade_write(&ctx->rwsem);
+	}
+
+	memcpy(buffer, mr->mr_value + off, count);
+	trace_tsm_mr_read(mr);
+
+	up_read(&ctx->rwsem);
+	return rc ?: count;
+}
+
+static ssize_t tm_digest_write(struct file *filp, struct kobject *kobj,
+			       const struct bin_attribute *attr, char *buffer,
+			       loff_t off, size_t count)
+{
+	struct tm_context *ctx;
+	const struct tsm_measurement_register *mr;
+	ssize_t rc;
+
+	/* partial writes are not supported */
+	if (off != 0 || count != attr->size)
+		return -EINVAL;
+
+	ctx = attr->private;
+	mr = &ctx->tm->mrs[attr - ctx->mrs];
+	trace_tsm_mr_write(mr, buffer);