[PATCH RFC v2 3/8] tee: optee: add RPMI shared-memory and parameter support
Jens Wiklander
jens.wiklander at oss.qualcomm.com
Thu Oct 8 00:10:41 PDT 2026
Hi Amir,
On Tue, Oct 6, 2026 at 2:40 AM Amirreza Zarrabi
<amirreza.zarrabi at oss.qualcomm.com> wrote:
>
> OP-TEE commands and RPCs need shared memory that secure world can
> identify through RPMI parcels.
>
> Register normal-world pages as read-write parcels shared with the
> OP-TEE endpoint. Track each parcel ID and nonce in a hash table and
> store the combined identity in tee_shm.sec_world_id. Use a fixed
> nonzero nonce to distinguish registered memory from NULL references.
>
> Add conversions between TEE parameters and parcel memory references.
>
> On client memory unregistration, ask OP-TEE to release its mapping
> before reclaiming the parcel. Supplicant memory has already been
> released by OP-TEE through its SHM_FREE RPC and only needs reclaiming.
>
> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi at oss.qualcomm.com>
> ---
> drivers/tee/optee/Makefile | 1 +
> drivers/tee/optee/optee_private.h | 27 +++
> drivers/tee/optee/rpmi_abi.c | 417 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 445 insertions(+)
>
> diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
> index 183cdde1ac04..8576cc73a922 100644
> --- a/drivers/tee/optee/Makefile
> +++ b/drivers/tee/optee/Makefile
> @@ -9,6 +9,7 @@ optee-objs += supp.o
> optee-objs += device.o
> optee-$(CONFIG_HAVE_ARM_SMCCC) += smc_abi.o
> optee-$(CONFIG_ARM_FFA_TRANSPORT) += ffa_abi.o
> +optee-$(CONFIG_RISCV_RPMI_TEE_TRANSPORT) += rpmi_abi.o
>
> # for tracing framework to find optee_trace.h
> CFLAGS_smc_abi.o := -I$(src)
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 02d6f79df407..2422caf3c883 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -180,6 +180,28 @@ struct optee_ffa {
> };
> #endif
>
> +#if IS_REACHABLE(CONFIG_RISCV_RPMI_TEE_TRANSPORT)
> +struct rpmi_tee_device;
> +
> +/**
> + * struct optee_rpmi - RPMI shared-memory identity state
> + * @rdev: owning RPMI service device
> + * @shm_rht_lock: protects parcel lookup, insertion, removal and publication
> + * @shm_rht: lookup by the host-endian parcel ID and nonce pair
> + *
> + * Callers keep their tee_shm alive while using its registration. Lookup
> + * returns a raw pointer; the mutex does not protect its lifetime after
> + * unlocking. Never hold @shm_rht_lock across a transport operation, RPC or
> + * thread-availability wait.
> + */
> +struct optee_rpmi {
> + struct rpmi_tee_device *rdev;
> + /* Protects parcel lookup, insertion, removal and publication. */
> + struct mutex shm_rht_lock;
> + struct rhashtable shm_rht;
> +};
> +#endif
> +
> struct optee;
>
> /**
> @@ -240,6 +262,7 @@ struct optee_ops {
> * @ctx: driver internal TEE context
> * @smc: specific to SMC ABI
> * @ffa: specific to FF-A ABI
> + * @rpmi: specific to RPMI ABI
> * @shm_arg_cache: shared memory cache argument
> * @call_queue: queue of threads waiting to call @invoke_fn
> * @notif: notification synchronization struct
> @@ -271,6 +294,9 @@ struct optee {
> #endif
> #if IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)
> struct optee_ffa ffa;
> +#endif
> +#if IS_REACHABLE(CONFIG_RISCV_RPMI_TEE_TRANSPORT)
> + struct optee_rpmi rpmi;
> #endif
> };
> struct optee_shm_arg_cache shm_arg_cache;
> @@ -464,4 +490,5 @@ static inline void optee_ffa_abi_unregister(void)
> }
> #endif
>
> +
> #endif /*OPTEE_PRIVATE_H*/
> diff --git a/drivers/tee/optee/rpmi_abi.c b/drivers/tee/optee/rpmi_abi.c
> new file mode 100644
> index 000000000000..e7fc853cfb15
> --- /dev/null
> +++ b/drivers/tee/optee/rpmi_abi.c
> @@ -0,0 +1,417 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/cleanup.h>
> +#include <linux/mailbox/riscv-rpmi-message.h>
> +#include <linux/overflow.h>
> +#include <linux/rpmi_tee.h>
> +#include <linux/slab.h>
> +#include <linux/unaligned.h>
> +#include "optee_private.h"
> +#include "optee_rpmi.h"
> +
> +/* Nonzero nonce keeps parcel ID zero distinct from a null reference. */
> +#define OPTEE_RPMI_SHM_NONCE 1
The spec describes this as:
A token nonce which receivers will need to present to the framework,
together with MEM_PARCEL_ID, to accept the memory.
It is intended as a way to reduce the likelihood of accidental
collisions on MEM_PARCEL_ID values, which can be reused by the
framework after they have been destroyed.
Why don't we change the nonce with each new parcel to live up to that?
> +
> +struct optee_rpmi_parcel_key {
> + u32 parcel_id;
> + u32 nonce;
> +};
> +
> +struct optee_rpmi_shm_rht_entry {
> + struct rhash_head node;
> + struct optee_rpmi_parcel_key key;
> + struct tee_shm *shm;
> +};
> +
> +static const struct rhashtable_params optee_rpmi_shm_rht_params = {
> + .head_offset = offsetof(struct optee_rpmi_shm_rht_entry, node),
> + .key_offset = offsetof(struct optee_rpmi_shm_rht_entry, key),
> + .key_len = sizeof(struct optee_rpmi_parcel_key),
> + .automatic_shrinking = true,
> +};
> +
> +/* Keep transport errors separate from the control status in a response. */
> +static int optee_rpmi_call_with_status(struct optee *optee,
> + const void *req, size_t req_len,
> + void *resp, size_t resp_size,
> + s32 *status)
> +{
> + struct rpmi_tee_device *rdev = optee->rpmi.rdev;
> + size_t received = resp_size;
> + int ret;
> +
> + ret = rdev->ops->msg_ops->call(rdev, req, req_len, resp, &received);
> + if (ret)
> + return ret;
> +
> + if (received != resp_size)
> + return -EPROTO;
> +
> + *status = get_unaligned_le32(resp);
> +
> + return 0;
> +}
> +
> +/**
> + * optee_rpmi_call - Send a control request and decode its RPMI status
> + * @optee: OP-TEE instance.
> + * @req: Control request, including the operation number.
> + * @req_len: Request size in bytes.
> + * @resp: Response buffer, beginning with a little-endian RPMI status.
> + * @resp_size: Exact expected response size, including the status field.
> + *
> + * Return: 0 on success, a transport error, -EPROTO for an unexpected response
> + * size, or the control status converted to a Linux error code.
> + */
> +static int optee_rpmi_call(struct optee *optee, const void *req, size_t req_len,
> + void *resp, size_t resp_size)
> +{
> + s32 status;
> + int ret;
> +
> + ret = optee_rpmi_call_with_status(optee, req, req_len, resp, resp_size,
> + &status);
> + if (ret)
> + return ret;
> +
> + return rpmi_to_linux_error(status);
> +}
> +
> +static int optee_rpmi_shm_rht_init(struct optee *optee)
> +{
> + int ret;
> +
> + mutex_init(&optee->rpmi.shm_rht_lock);
> + ret = rhashtable_init(&optee->rpmi.shm_rht, &optee_rpmi_shm_rht_params);
> + if (ret)
> + mutex_destroy(&optee->rpmi.shm_rht_lock);
> +
> + return ret;
> +}
> +
> +static void optee_rpmi_shm_rht_free(void *ptr, void *arg)
> +{
> + kfree(ptr);
> +}
> +
> +static void optee_rpmi_shm_rht_uninit(struct optee *optee)
> +{
> + rhashtable_free_and_destroy(&optee->rpmi.shm_rht,
> + optee_rpmi_shm_rht_free, NULL);
> + mutex_destroy(&optee->rpmi.shm_rht_lock);
> +}
> +
> +/* Allocate and publish a parcel-to-SHM mapping. */
> +static int optee_rpmi_shm_rht_add(struct optee *optee, struct tee_shm *shm,
> + u32 parcel_id, u32 nonce)
> +{
> + struct optee_rpmi_shm_rht_entry *entry;
> + int ret;
> +
> + entry = kzalloc_obj(*entry);
> + if (!entry)
> + return -ENOMEM;
> +
> + entry->shm = shm;
> + entry->key.parcel_id = parcel_id;
> + entry->key.nonce = nonce;
> +
> + scoped_guard(mutex, &optee->rpmi.shm_rht_lock)
> + ret = rhashtable_lookup_insert_fast(&optee->rpmi.shm_rht,
> + &entry->node,
> + optee_rpmi_shm_rht_params);
> + if (ret)
> + kfree(entry);
> +
> + return ret;
> +}
> +
> +/* Remove and free a parcel-to-SHM mapping. */
> +static int optee_rpmi_shm_rht_rm(struct optee *optee, u32 parcel_id, u32 nonce)
> +{
> + struct optee_rpmi_shm_rht_entry *entry;
> + struct optee_rpmi_parcel_key key = {
> + .parcel_id = parcel_id,
> + .nonce = nonce,
> + };
> + int ret = -ENOENT;
> +
> + scoped_guard(mutex, &optee->rpmi.shm_rht_lock) {
> + entry = rhashtable_lookup_fast(&optee->rpmi.shm_rht, &key,
> + optee_rpmi_shm_rht_params);
> + if (entry)
> + ret = rhashtable_remove_fast(&optee->rpmi.shm_rht,
> + &entry->node,
> + optee_rpmi_shm_rht_params);
> + }
> +
> + if (!ret)
> + kfree(entry);
> +
> + return ret;
> +}
> +
> +/* Return a raw pointer; the surrounding call or RPC owns the SHM lifetime. */
> +static struct tee_shm *
> +optee_rpmi_get_shm_for_parcel(struct optee *optee, u32 parcel_id, u32 nonce)
> +{
> + struct optee_rpmi_shm_rht_entry *entry;
> + struct optee_rpmi_parcel_key key = {
> + .parcel_id = parcel_id,
> + .nonce = nonce,
> + };
> +
> + guard(mutex)(&optee->rpmi.shm_rht_lock);
> + entry = rhashtable_lookup_fast(&optee->rpmi.shm_rht, &key,
> + optee_rpmi_shm_rht_params);
> +
> + return entry ? entry->shm : NULL;
Please use a full if statement instead of the ternary operator
> +}
> +
> +/* Extract the parcel ID and nonce stored in the SHM identity. */
> +static void optee_rpmi_shm_get_identity(const struct tee_shm *shm,
> + u32 *parcel_id, u32 *nonce)
> +{
> + *parcel_id = lower_32_bits(shm->sec_world_id);
> + *nonce = upper_32_bits(shm->sec_world_id);
By keeping parcel_id and nonce in separate fields, we add quite a bit
of code only to handle u64 -> u32 + u32 and vice versa. I wonder if it
wouldn't be easier always to keep them in a u64 and say that the upper
32 bits are a nonce, or something. With that, we could make the
optee_shm_rem_ffa_handle() function and friends common helpers in the
optee driver.
> +}
> +
> +static int optee_rpmi_shm_register(struct tee_context *ctx, struct tee_shm *shm,
> + struct page **pages, size_t num_pages,
> + unsigned long start)
> +{
> + struct optee *optee = tee_get_drvdata(ctx->teedev);
> + struct rpmi_tee_device *rdev = optee->rpmi.rdev;
> + struct rpmi_tee_mem_receiver receiver = {
> + .endpoint_id = rdev->endpoint_id,
> + .access = RPMI_TEE_MEM_ACCESS_READ | RPMI_TEE_MEM_ACCESS_WRITE,
> + };
> + struct rpmi_tee_mem_args args = {
> + .nonce = OPTEE_RPMI_SHM_NONCE,
> + .receivers = &receiver,
> + .receiver_count = 1,
> + .creator_access = RPMI_TEE_MEM_ACCESS_READ |
> + RPMI_TEE_MEM_ACCESS_WRITE,
> + };
> + struct sg_table sgt;
> + int ret;
> +
> + ret = optee_check_mem_type(start, num_pages);
> + if (ret)
> + return ret;
> +
> + ret = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0,
> + num_pages * PAGE_SIZE, GFP_KERNEL);
> + if (ret)
> + return ret;
> +
> + args.sg = sgt.sgl;
> + ret = rdev->ops->mem_ops->memory_share(rdev, &args);
> + sg_free_table(&sgt);
> + if (ret)
> + return ret;
> +
> + ret = optee_rpmi_shm_rht_add(optee, shm, args.parcel_id, args.nonce);
> + if (ret) {
> + int reclaim_ret;
> +
> + reclaim_ret = rdev->ops->mem_ops->memory_reclaim(rdev, args.parcel_id);
> + if (reclaim_ret)
> + dev_err(&rdev->dev, "reclaim parcel %#x failed: %d\n",
> + args.parcel_id, reclaim_ret);
> + return ret;
> + }
> +
> + shm->sec_world_id = ((u64)args.nonce << 32) | args.parcel_id;
> +
> + return 0;
> +}
> +
> +static int optee_rpmi_shm_unregister(struct tee_context *ctx,
> + struct tee_shm *shm)
> +{
> + struct optee *optee = tee_get_drvdata(ctx->teedev);
> + struct rpmi_tee_device *rdev = optee->rpmi.rdev;
> + struct optee_rpmi_unregister_req req;
> + struct optee_rpmi_status_resp resp;
> + u32 parcel_id, nonce;
> + int ret;
> +
> + optee_rpmi_shm_get_identity(shm, &parcel_id, &nonce);
> + optee_rpmi_shm_rht_rm(optee, parcel_id, nonce);
> + shm->sec_world_id = 0;
> +
> + req.op = cpu_to_le32(OPTEE_RPMI_UNREGISTER_SHM);
> + req.parcel_id = cpu_to_le32(parcel_id);
> + req.nonce = cpu_to_le32(nonce);
> + ret = optee_rpmi_call(optee, &req, sizeof(req), &resp, sizeof(resp));
> + if (ret)
> + dev_err(&rdev->dev, "unregister parcel %#x failed: %d\n",
> + parcel_id, ret);
> +
> + ret = rdev->ops->mem_ops->memory_reclaim(rdev, parcel_id);
> + if (ret)
> + dev_err(&rdev->dev, "reclaim parcel %#x failed: %d\n",
> + parcel_id, ret);
> +
> + return ret;
> +}
> +
> +static int optee_rpmi_shm_unregister_supp(struct tee_context *ctx,
> + struct tee_shm *shm)
> +{
> + struct optee *optee = tee_get_drvdata(ctx->teedev);
> + struct rpmi_tee_device *rdev = optee->rpmi.rdev;
> + u32 parcel_id, nonce;
> + int ret;
> +
> + optee_rpmi_shm_get_identity(shm, &parcel_id, &nonce);
> + optee_rpmi_shm_rht_rm(optee, parcel_id, nonce);
> + shm->sec_world_id = 0;
> + /* OP-TEE has already retired the parcel through SHM_FREE RPC. */
> + ret = rdev->ops->mem_ops->memory_reclaim(rdev, parcel_id);
> + if (ret)
> + dev_err(&rdev->dev, "reclaim parcel %#x failed: %d\n",
> + parcel_id, ret);
> +
> + return ret;
> +}
> +
> +/* Convert a memory reference to an OP-TEE RPMI parcel reference. */
> +static int to_msg_param_rpmi_mem(struct optee_msg_param *mp,
> + const struct tee_param *p)
> +{
> + struct tee_shm *shm = p->u.memref.shm;
> +
> + mp->attr = OPTEE_MSG_ATTR_TYPE_PMEM_INPUT + p->attr -
> + TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
> + memset(&mp->u, 0, sizeof(mp->u));
> + /* For !shm, return parcel_id = 0 and nonce = 0 to represent NULL. */
> + if (shm) {
> + if (check_add_overflow((u64)shm->offset,
> + (u64)p->u.memref.shm_offs,
> + &mp->u.pmem.offs))
> + return -EINVAL;
By combining the shm->offset with p->u.memref.shm_offs, OP-TEE
requires an explicit call to register the shared memory so it knows
the initial page offset. Compared with the FF-A ABI, which can tell
the initial page offset from mp->u.fmem.internal_offs. See also the
mobj_ffa_get_by_cookie() call in set_fmem_param() in
core/tee/entry_std.c in optee_os.git
> +
> + optee_rpmi_shm_get_identity(shm, &mp->u.pmem.parcel_id,
> + &mp->u.pmem.nonce);
> + }
> +
> + mp->u.pmem.size = p->u.memref.size;
> +
> + return 0;
> +}
> +
> +static int optee_rpmi_to_msg_param(struct optee *optee,
> + struct optee_msg_param *msg_params,
> + size_t num_params,
> + const struct tee_param *params)
> +{
> + size_t n;
> +
> + for (n = 0; n < num_params; n++) {
> + const struct tee_param *p = params + n;
> + struct optee_msg_param *mp = msg_params + n;
Please add an empty line after the variables.
Cheers,
Jens
> + switch (p->attr) {
> + case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
> + mp->attr = OPTEE_MSG_ATTR_TYPE_NONE;
> + memset(&mp->u, 0, sizeof(mp->u));
> + break;
> + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
> + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
> + case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
> + optee_to_msg_param_value(mp, p);
> + break;
> + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
> + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
> + case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
> + if (to_msg_param_rpmi_mem(mp, p))
> + return -EINVAL;
> + break;
> + default:
> + return -EINVAL;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/* Convert an RPMI parcel reference to a memref; callers own SHM lifetime. */
> +static int from_msg_param_rpmi_mem(struct optee *optee, struct tee_param *p,
> + u32 attr, const struct optee_msg_param *mp)
> +{
> + struct tee_shm *shm;
> + u64 offset;
> +
> + p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT + attr -
> + OPTEE_MSG_ATTR_TYPE_PMEM_INPUT;
> +
> + if (mp->u.pmem.size > SIZE_MAX)
> + return -EOVERFLOW;
> + p->u.memref.size = mp->u.pmem.size;
> +
> + if (!mp->u.pmem.nonce) {
> + /* Return NULL shm. */
> + if (mp->u.pmem.offs || mp->u.pmem.parcel_id)
> + return -EINVAL;
> + p->u.memref.shm = NULL;
> + p->u.memref.shm_offs = 0;
> + return 0;
> + }
> +
> + shm = optee_rpmi_get_shm_for_parcel(optee, mp->u.pmem.parcel_id,
> + mp->u.pmem.nonce);
> + if (!shm || mp->u.pmem.offs < shm->offset)
> + return -EINVAL;
> +
> + offset = mp->u.pmem.offs - shm->offset;
> + if (offset > SIZE_MAX)
> + return -EOVERFLOW;
> +
> + p->u.memref.shm = shm;
> + p->u.memref.shm_offs = offset;
> +
> + return 0;
> +}
> +
> +static int optee_rpmi_from_msg_param(struct optee *optee,
> + struct tee_param *params,
> + size_t num_params,
> + const struct optee_msg_param *msg_params)
> +{
> + size_t n;
> +
> + for (n = 0; n < num_params; n++) {
> + const struct optee_msg_param *mp = msg_params + n;
> + struct tee_param *p = params + n;
> + u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
> + int ret;
> +
> + switch (attr) {
> + case OPTEE_MSG_ATTR_TYPE_NONE:
> + p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
> + memset(&p->u, 0, sizeof(p->u));
> + break;
> + case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
> + case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
> + case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
> + optee_from_msg_param_value(p, attr, mp);
> + break;
> + case OPTEE_MSG_ATTR_TYPE_PMEM_INPUT:
> + case OPTEE_MSG_ATTR_TYPE_PMEM_OUTPUT:
> + case OPTEE_MSG_ATTR_TYPE_PMEM_INOUT:
> + ret = from_msg_param_rpmi_mem(optee, p, attr, mp);
> + if (ret)
> + return ret;
> + break;
> + default:
> + return -EINVAL;
> + }
> + }
> + return 0;
> +}
>
> --
> 2.34.1
>
More information about the linux-riscv
mailing list