[PATCH 0/6 v2] EFI variable support via OP-TEE

[PATCH 0/6 v2] EFI variable support via OP-TEE

[Ilias Apalodimas]

Hi!

This is the v2 of the patchset adding EFI variable support via OP-TEE
originally posted here [1]

Changes since v1:
* patch #2: 
   - Fix Copyright issues
   - Merge the include files in mm_communication.h
   - Rename some variables and follow EDK2 naming
   - Added proper documentation on struct definitions
   - Add missing defines (unused but good to have there)
   - Use flexible array members on structs and replace data[1] with data[]
* patch #3: 
   - Adjust efi_variable_tee.c to header file changes and fix typos
* patch #4: 
   - Remove EFI_HANDLE_WIDTH on printing
   - Rephrase 'efidebug query' help message
* patch #5
   - Move mm_communication.h maintenership
* patch #6
   - Heinrich's suggestion, on the help file, was a lot cleaner and easier
     to understand.  Using it as-is

[1] https://lists.denx.de/pipermail/u-boot/2020-May/410772.html


Ilias Apalodimas (4):
  efi_loader: Implement EFI variable handling via OP-TEE
  cmd: efidebug: Add support for querying UEFI variable storage
  MAINTAINERS: Add maintainer for EFI variables via OP-TEE
  doc: uefi.rst: Add OP-TEE variable storage config options

Sughosh Ganu (1):
  efi_loader: Add headers for EDK2 StandAloneMM communication

 MAINTAINERS                       |   6 +
 cmd/efidebug.c                    |  44 +-
 doc/uefi/uefi.rst                 |  17 +
 include/mm_communication.h        | 207 ++++++++++
 lib/efi_loader/Kconfig            |   9 +
 lib/efi_loader/Makefile           |   4 +
 lib/efi_loader/efi_variable_tee.c | 643 ++++++++++++++++++++++++++++++
 7 files changed, 929 insertions(+), 1 deletion(-)
 create mode 100644 include/mm_communication.h
 create mode 100644 lib/efi_loader/efi_variable_tee.c

-- 
2.26.2

[PATCH 1/5 v2] efi_loader: Add headers for EDK2 StandAloneMM communication

[Ilias Apalodimas]

From: Sughosh Ganu <sughosh.ganu@linaro.org>

In Arm devices OP-TEE has the ability to run StandAloneMM (from EDK2)
in a separate partition and handle UEFI variables.
A following patch introduces this functionality.

Add the headers needed for OP-TEE <--> StandAloneMM communication

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 include/mm_communication.h | 207 +++++++++++++++++++++++++++++++++++++
 1 file changed, 207 insertions(+)
 create mode 100644 include/mm_communication.h

diff --git a/include/mm_communication.h b/include/mm_communication.h
new file mode 100644
index 000000000000..b9bfbe4cf0a1
--- /dev/null
+++ b/include/mm_communication.h
@@ -0,0 +1,207 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  Headers for EFI variable service via StandAloneMM, EDK2 application running
+ *  in OP-TEE
+ *
+ *  Copyright (c) 2017, Intel Corporation. All rights reserved.
+ *  Copyright (C) 2020 Linaro Ltd. <sughosh.ganu@linaro.org>
+ *  Copyright (C) 2020 Linaro Ltd. <ilias.apalodimas@linaro.org>
+ */
+
+#ifndef _MM_VARIABLE_H_
+#define _MM_VARIABLE_H_
+
+#include <part_efi.h>
+
+/*
+ * Interface to the pseudo TA, which provides a communication channel with
+ * the StandaloneMM Secure Partition (StMM) running at S-EL0
+ */
+
+#define PTA_STMM_CMDID_COMMUNICATE 0
+
+/* OP-TEE is using big endian GUIDs while UEFI uses little endian ones */
+#define PTA_STMM_UUID { 0xed32d533, 0x99e6, 0x4209, {\
+			0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7 } }
+
+#define EFI_MM_VARIABLE_GUID \
+	EFI_GUID(0xed32d533, 0x99e6, 0x4209, \
+		 0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7)
+
+/* Defined in EDK2 MdePkg/Include/Protocol/MmCommunication.h */
+
+/**
+ * struct efi_mm_communicate_header - Header used for SMM variable communication
+
+ * @header_guid:  header use for disambiguation of content
+ * @message_len:  length of the message. Does not include the size of the
+ *                header
+ * @data:         payload of the message
+ *
+ * Defined in EDK2 as EFI_MM_COMMUNICATE_HEADER
+ * To avoid confusion in interpreting frames, the communication buffer should
+ * always begin with efi_mm_communicate_header
+ */
+struct efi_mm_communicate_header {
+	efi_guid_t header_guid;
+	size_t     message_len;
+	u8         data[];
+};
+
+#define MM_COMMUNICATE_HEADER_SIZE \
+	(sizeof(struct efi_mm_communicate_header))
+
+/* Defined in EDK2 ArmPkg/Include/IndustryStandard/ArmStdSmc.h */
+
+/* MM return error codes */
+#define ARM_SMC_MM_RET_SUCCESS              0
+#define ARM_SMC_MM_RET_NOT_SUPPORTED       -1
+#define ARM_SMC_MM_RET_INVALID_PARAMS      -2
+#define ARM_SMC_MM_RET_DENIED              -3
+#define ARM_SMC_MM_RET_NO_MEMORY           -4
+
+/* Defined in EDK2 MdeModulePkg/Include/Guid/SmmVariableCommon.h */
+
+#define SMM_VARIABLE_FUNCTION_GET_VARIABLE  1
+/*
+ * The payload for this function is
+ * SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME.
+ */
+#define SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME  2
+/*
+ * The payload for this function is SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE.
+ */
+#define SMM_VARIABLE_FUNCTION_SET_VARIABLE  3
+/*
+ * The payload for this function is
+ * SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO.
+ */
+#define SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO  4
+/*
+ * It is a notify event, no extra payload for this function.
+ */
+#define SMM_VARIABLE_FUNCTION_READY_TO_BOOT  5
+/*
+ * It is a notify event, no extra payload for this function.
+ */
+#define SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE  6
+/*
+ * The payload for this function is VARIABLE_INFO_ENTRY.
+ * The GUID in EFI_SMM_COMMUNICATE_HEADER is gEfiSmmVariableProtocolGuid.
+ */
+#define SMM_VARIABLE_FUNCTION_GET_STATISTICS  7
+/*
+ * The payload for this function is SMM_VARIABLE_COMMUNICATE_LOCK_VARIABLE
+ */
+#define SMM_VARIABLE_FUNCTION_LOCK_VARIABLE   8
+
+#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET  9
+
+#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET  10
+
+#define SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE  11
+/*
+ * The payload for this function is
+ * SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
+ */
+#define SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT 12
+
+#define SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE  13
+/*
+ * The payload for this function is
+ * SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO
+ */
+#define SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO  14
+
+/**
+ * struct smm_variable_communicate_header - Used for SMM variable communication
+
+ * @function:     function to call in Smm.
+ * @ret_status:   return status
+ * @data:         payload
+ *
+ * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_HEADER
+ */
+struct smm_variable_communicate_header {
+	efi_uintn_t  function;
+	efi_status_t ret_status;
+	u8           data[];
+};
+
+#define MM_VARIABLE_COMMUNICATE_SIZE \
+	(sizeof(struct smm_variable_communicate_header))
+
+/**
+ * struct smm_variable_access - Used to communicate with StMM by
+ *                              SetVariable and GetVariable.
+
+ * @function:     vendor GUID to call in Smm
+ * @data_size:    size of EFI variable data
+ * @name_size:    size of EFI name
+ * @attr:         attributes
+ * @name:         variable name
+ *
+ * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE
+ *
+ */
+struct smm_variable_access {
+	efi_guid_t  guid;
+	efi_uintn_t data_size;
+	efi_uintn_t name_size;
+	u32         attr;
+	u16         name[];
+};
+
+#define MM_VARIABLE_ACCESS_HEADER_SIZE \
+	(sizeof(struct smm_variable_access))
+/**
+ * struct smm_variable_payload_size - Used to get the max allowed
+ *                                    payload used in StMM.
+ *
+ * @size:  size to fill in
+ *
+ * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
+ *
+ */
+struct smm_variable_payload_size {
+	efi_uintn_t size;
+};
+
+/**
+ * struct smm_variable_getnext - Used to communicate with StMM for
+ *                               GetNextVariableName.
+ *
+ * @size:       vendor GUID
+ * @name_size:  size of the name of the variable
+ * @name:       variable name
+ *
+ * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
+ */
+struct smm_variable_getnext {
+	efi_guid_t  guid;
+	efi_uintn_t name_size;
+	u16         name[];
+};
+
+#define MM_VARIABLE_GET_NEXT_HEADER_SIZE \
+	(sizeof(struct smm_variable_getnext))
+
+/**
+ * struct smm_variable_query_info - Used to communicate with StMM for
+ *                                  QueryVariableInfo.
+ *
+ * @max_variable_storage:        max available storage
+ * @remaining_variable_storage:  remaining available storage
+ * @max_variable_size:           max variable supported size
+ * @attr:                        attributes to query storage for
+ *
+ * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
+ */
+struct smm_variable_query_info {
+	u64 max_variable_storage;
+	u64 remaining_variable_storage;
+	u64 max_variable_size;
+	u32 attr;
+};
+
+#endif /* _MM_VARIABLE_H_ */
-- 
2.26.2

[PATCH 2/5 v2] efi_loader: Implement EFI variable handling via OP-TEE

[Ilias Apalodimas]

In OP-TEE we can run EDK2's StandAloneMM on a secure partition.
StandAloneMM is responsible for the UEFI variable support. In
combination with OP-TEE and it's U-Boot supplicant, variables are
authenticated/validated in secure world and stored on an RPMB partition.

So let's add a new config option in U-Boot implementing the necessary
calls to OP-TEE for the variable management.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Pipat Methavanitpong <pipat1010@gmail.com>
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
---
 lib/efi_loader/Kconfig            |   9 +
 lib/efi_loader/Makefile           |   4 +
 lib/efi_loader/efi_variable_tee.c | 643 ++++++++++++++++++++++++++++++
 3 files changed, 656 insertions(+)
 create mode 100644 lib/efi_loader/efi_variable_tee.c

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 1cfa24ffcf72..e385cd0b9dae 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -164,4 +164,13 @@ config EFI_SECURE_BOOT
 	  it is signed with a trusted key. To do that, you need to install,
 	  at least, PK, KEK and db.
 
+config EFI_MM_COMM_TEE
+	bool "UEFI variables storage service via OP-TEE"
+	depends on SUPPORT_EMMC_RPMB
+	default n
+	help
+	  If OP-TEE is present and running StandAloneMM dispatch all UEFI variable
+	  related operations to that. The application will verify, authenticate and
+	  store the variables on an RPMB
+
 endif
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index eff3c25ec301..dba652121eab 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -34,7 +34,11 @@ obj-y += efi_root_node.o
 obj-y += efi_runtime.o
 obj-y += efi_setup.o
 obj-$(CONFIG_EFI_UNICODE_COLLATION_PROTOCOL2) += efi_unicode_collation.o
+ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
+obj-y += efi_variable_tee.o
+else
 obj-y += efi_variable.o
+endif
 obj-y += efi_watchdog.o
 obj-$(CONFIG_LCD) += efi_gop.o
 obj-$(CONFIG_DM_VIDEO) += efi_gop.o
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
new file mode 100644
index 000000000000..f8857bb81e72
--- /dev/null
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -0,0 +1,643 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  EFI variable service via OP-TEE
+ *
+ *  Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org>
+ *  Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org>
+ */
+
+#include <common.h>
+#include <efi.h>
+#include <efi_api.h>
+#include <efi_loader.h>
+#include <tee.h>
+#include <malloc.h>
+#include <mm_communication.h>
+
+static efi_uintn_t max_buffer_size;	/* comm + var + func + data */
+static efi_uintn_t max_payload_size;	/* func + data */
+
+struct mm_connection {
+	struct udevice *tee;
+	u32 session;
+};
+
+/**
+ * get_connection() - Retrieve OP-TEE session for a specific UUID.
+ *
+ * @conn:   session buffer to fill
+ * Return:  status code
+ */
+static int get_connection(struct mm_connection *conn)
+{
+	static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID;
+	struct udevice *tee = NULL;
+	struct tee_open_session_arg arg;
+	int rc;
+
+	tee = tee_find_device(tee, NULL, NULL, NULL);
+	if (!tee)
+		return -ENODEV;
+
+	memset(&arg, 0, sizeof(arg));
+	tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
+	rc = tee_open_session(tee, &arg, 0, NULL);
+	if (!rc) {
+		conn->tee = tee;
+		conn->session = arg.session;
+	}
+
+	return rc;
+}
+
+/**
+ * optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE
+ *
+ * @comm_buf:		locally allocted communcation buffer
+ * @dsize:		buffer size
+ * Return:		status code
+ */
+static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
+{
+	ulong buf_size;
+	efi_status_t ret;
+	struct efi_mm_communicate_header *mm_hdr;
+	struct mm_connection conn = { NULL, 0 };
+	struct tee_invoke_arg arg;
+	struct tee_param param[2];
+	struct tee_shm *shm = NULL;
+	int rc;
+
+	if (!comm_buf)
+		return EFI_INVALID_PARAMETER;
+
+	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
+	buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
+
+	if (dsize != buf_size)
+		return EFI_INVALID_PARAMETER;
+
+	rc = get_connection(&conn);
+	if (rc) {
+		log_err("Unable to open OP-TEE session (err=%d)\n", rc);
+		return EFI_UNSUPPORTED;
+	}
+
+	if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) {
+		log_err("Unable to register shared memory\n");
+		return EFI_UNSUPPORTED;
+	}
+
+	memset(&arg, 0, sizeof(arg));
+	arg.func = PTA_STMM_CMDID_COMMUNICATE;
+	arg.session = conn.session;
+
+	memset(param, 0, sizeof(param));
+	param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
+	param[0].u.memref.size = buf_size;
+	param[0].u.memref.shm = shm;
+	param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+	rc = tee_invoke_func(conn.tee, &arg, 2, param);
+	if (rc)
+		return EFI_INVALID_PARAMETER;
+	tee_shm_free(shm);
+	tee_close_session(conn.tee, conn.session);
+
+	switch (param[1].u.value.a) {
+	case ARM_SMC_MM_RET_SUCCESS:
+		ret = EFI_SUCCESS;
+		break;
+
+	case ARM_SMC_MM_RET_INVALID_PARAMS:
+		ret = EFI_INVALID_PARAMETER;
+		break;
+
+	case ARM_SMC_MM_RET_DENIED:
+		ret = EFI_ACCESS_DENIED;
+		break;
+
+	case ARM_SMC_MM_RET_NO_MEMORY:
+		ret = EFI_OUT_OF_RESOURCES;
+		break;
+
+	default:
+		ret = EFI_ACCESS_DENIED;
+	}
+
+	return ret;
+}
+
+/**
+ * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send
+ * it to OP-TEE
+ *
+ * @comm_buf:		locally allocted communcation buffer
+ * @dsize:		buffer size
+ * Return:		status code
+ */
+static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize)
+{
+	efi_status_t ret;
+	struct efi_mm_communicate_header *mm_hdr;
+	struct smm_variable_communicate_header *var_hdr;
+
+	dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE;
+	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
+	var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
+
+	ret = optee_mm_communicate(comm_buf, dsize);
+	if (ret != EFI_SUCCESS) {
+		log_err("%s failed!\n", __func__);
+		return ret;
+	}
+
+	return var_hdr->ret_status;
+}
+
+/**
+ * setup_mm_hdr() -	Allocate a buffer for StandAloneMM and initialize the
+ *			header data.
+ *
+ * @dptr:		pointer address of the corresponding StandAloneMM
+ *			function
+ * @payload_size:	buffer size
+ * @func:		standAloneMM function number
+ * @ret:		EFI return code
+ * Return:		buffer or NULL
+ */
+static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size,
+			efi_uintn_t func, efi_status_t *ret)
+{
+	const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID;
+	struct efi_mm_communicate_header *mm_hdr;
+	struct smm_variable_communicate_header *var_hdr;
+	u8 *comm_buf;
+
+	/* In the init function we initialize max_buffer_size with
+	 * get_max_payload(). So skip the test if max_buffer_size is initialized
+	 * StandAloneMM will perform similar checks and drop the buffer if it's
+	 * too long
+	 */
+	if (max_buffer_size && max_buffer_size <
+			(MM_COMMUNICATE_HEADER_SIZE +
+			 MM_VARIABLE_COMMUNICATE_SIZE +
+			 payload_size)) {
+		*ret = EFI_INVALID_PARAMETER;
+		return NULL;
+	}
+
+	comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE +
+			  MM_VARIABLE_COMMUNICATE_SIZE +
+			  payload_size);
+	if (!comm_buf) {
+		*ret = EFI_OUT_OF_RESOURCES;
+		return NULL;
+	}
+
+	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
+	guidcpy(&mm_hdr->header_guid, &mm_var_guid);
+	mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size;
+
+	var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
+	var_hdr->function = func;
+	if (dptr)
+		*dptr = var_hdr->data;
+	*ret = EFI_SUCCESS;
+
+	return comm_buf;
+}
+
+/**
+ * get_max_payload() - Get variable payload size from StandAloneMM.
+ *
+ * @size:    size of the variable in storage
+ * Return:   status code
+ */
+efi_status_t EFIAPI get_max_payload(efi_uintn_t *size)
+{
+	struct smm_variable_payload_size *var_payload = NULL;
+	efi_uintn_t payload_size;
+	efi_status_t ret;
+	u8 *comm_buf;
+
+	if (!size)
+		return EFI_INVALID_PARAMETER;
+
+	payload_size = sizeof(*var_payload);
+	comm_buf = setup_mm_hdr((void **)&var_payload, payload_size,
+				SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret);
+	if (!comm_buf)
+		return EFI_EXIT(ret);
+
+	ret = mm_communicate(comm_buf, payload_size);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	*size = var_payload->size;
+
+out:
+	free(comm_buf);
+	return ret;
+}
+
+/**
+ * efi_get_variable() - retrieve value of a UEFI variable
+ *
+ * This function implements the GetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @name:		name of the variable
+ * @guid:		vendor GUID
+ * @attr:		attributes of the variable
+ * @data_size:		size of the buffer to which the variable value is copied
+ * @data:		buffer to which the variable value is copied
+ * Return:		status code
+ */
+efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
+				     u32 *attr, efi_uintn_t *data_size,
+				     void *data)
+{
+	struct smm_variable_access *var_acc;
+	efi_uintn_t payload_size;
+	efi_uintn_t name_size;
+	efi_uintn_t tmp_dsize;
+	efi_status_t ret;
+	u8 *comm_buf;
+
+	EFI_ENTRY("\"%ls\" %pUl %p %p %p", name, guid, attr, data_size, data);
+
+	if (!name || !guid || !data_size)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* Check payload size */
+	name_size = u16_strsize(name);
+	if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* Trim output buffer size */
+	tmp_dsize = *data_size;
+	if (name_size + tmp_dsize >
+			max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
+		tmp_dsize = max_payload_size -
+				MM_VARIABLE_ACCESS_HEADER_SIZE -
+				name_size;
+	}
+
+	/* Get communication buffer and initialize header */
+	payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize;
+	comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
+				SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret);
+	if (!comm_buf)
+		return EFI_EXIT(ret);
+
+	/* Fill in contents */
+	guidcpy(&var_acc->guid, guid);
+	var_acc->data_size = tmp_dsize;
+	var_acc->name_size = name_size;
+	var_acc->attr = attr ? *attr : 0;
+	memcpy(var_acc->name, name, name_size);
+
+	/* Communicate */
+	ret = mm_communicate(comm_buf, payload_size);
+	if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
+		/* Update with reported data size for trimmed case */
+		*data_size = var_acc->data_size;
+	}
+	if (ret != EFI_SUCCESS)
+		goto done;
+
+	if (attr)
+		*attr = var_acc->attr;
+	if (data)
+		memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
+		       var_acc->data_size);
+	else
+		ret = EFI_INVALID_PARAMETER;
+
+done:
+	free(comm_buf);
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_get_next_variable_name() - enumerate the current variable names
+ *
+ * @variable_name_size:	size of variable_name buffer in byte
+ * @variable_name:	name of uefi variable's name in u16
+ * @guid:		vendor's guid
+ *
+ * This function implements the GetNextVariableName service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
+					       u16 *variable_name,
+					       efi_guid_t *guid)
+{
+	struct smm_variable_getnext *var_getnext;
+	efi_uintn_t payload_size;
+	efi_uintn_t tmp_dsize;
+	efi_uintn_t name_size;
+	efi_status_t ret;
+	efi_uintn_t out_name_size;
+	efi_uintn_t in_name_size;
+	u8 *comm_buf;
+
+	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, guid);
+
+	if (!variable_name_size || !variable_name || !guid)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	out_name_size = *variable_name_size;
+	in_name_size = u16_strsize(variable_name);
+
+	name_size = u16_strsize(variable_name);
+	if (name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* Trim output buffer size */
+	tmp_dsize = *variable_name_size;
+	if (name_size + tmp_dsize >
+			max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
+		tmp_dsize = max_payload_size -
+				MM_VARIABLE_GET_NEXT_HEADER_SIZE -
+				name_size;
+	}
+
+	payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE +
+			max(out_name_size, in_name_size);
+	comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size,
+				SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME,
+				&ret);
+	if (!comm_buf)
+		return EFI_EXIT(ret);
+
+	/* Fill in contents */
+	guidcpy(&var_getnext->guid, guid);
+	var_getnext->name_size = out_name_size;
+	memcpy(var_getnext->name, variable_name, in_name_size);
+	if (out_name_size > in_name_size) {
+		memset((u8 *)var_getnext->name + in_name_size, 0x0,
+		       out_name_size - in_name_size);
+	}
+
+	/* Communicate */
+	ret = mm_communicate(comm_buf, payload_size);
+	if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
+		/* Update with reported data size for trimmed case */
+		*variable_name_size = var_getnext->name_size;
+	}
+	if (ret != EFI_SUCCESS)
+		goto done;
+
+	guidcpy(guid, &var_getnext->guid);
+	memcpy(variable_name, (u8 *)var_getnext->name,
+	       var_getnext->name_size);
+
+done:
+	free(comm_buf);
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_set_variable() - set value of a UEFI variable
+ *
+ * This function implements the SetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @name:		name of the variable
+ * @guid:		vendor GUID
+ * @attr:		attributes of the variable
+ * @data_size:		size of the buffer with the variable value
+ * @data:		buffer with the variable value
+ * Return:		status code
+ */
+efi_status_t EFIAPI efi_set_variable(u16 *name, const efi_guid_t *guid,
+				     u32 attr, efi_uintn_t data_size,
+				     const void *data)
+{
+	struct smm_variable_access *var_acc;
+	efi_uintn_t payload_size;
+	efi_uintn_t name_size;
+	efi_status_t ret;
+	u8 *comm_buf;
+
+	EFI_ENTRY("\"%ls\" %pUl %x %zu %p", name, guid, attr, data_size, data);
+
+	if (!name || name[0] == 0 || !guid)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+	if (data_size > 0 && !data)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* Check payload size */
+	name_size = u16_strsize(name);
+	payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size;
+	if (payload_size > max_payload_size)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* Get communication buffer and initialize header */
+	comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
+				SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret);
+	if (!comm_buf)
+		return EFI_EXIT(ret);
+
+	/* Fill in contents */
+	guidcpy(&var_acc->guid, guid);
+	var_acc->data_size = data_size;
+	var_acc->name_size = name_size;
+	var_acc->attr = attr;
+	memcpy(var_acc->name, name, name_size);
+	memcpy((u8 *)var_acc->name + name_size, data, data_size);
+
+	/* Communicate */
+	ret = mm_communicate(comm_buf, payload_size);
+	free(comm_buf);
+
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_query_variable_info() - get information about EFI variables
+ *
+ * This function implements the QueryVariableInfo() runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @attributes:				bitmask to select variables to be
+ *					queried
+ * @maximum_variable_storage_size:	maximum size of storage area for the
+ *					selected variable types
+ * @remaining_variable_storage_size:	remaining size of storage are for the
+ *					selected variable types
+ * @maximum_variable_size:		maximum size of a variable of the
+ *					selected type
+ * Returns:				status code
+ */
+efi_status_t EFIAPI __efi_runtime
+efi_query_variable_info(u32 attributes, u64 *max_variable_storage_size,
+			u64 *remain_variable_storage_size,
+			u64 *max_variable_size)
+{
+	struct smm_variable_query_info *mm_query_info;
+	efi_uintn_t payload_size;
+	efi_status_t ret;
+	u8 *comm_buf;
+
+	EFI_ENTRY("%x %p %p %p", attributes, max_variable_storage_size,
+		  remain_variable_storage_size, max_variable_size);
+
+	payload_size = sizeof(*mm_query_info);
+	comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
+				SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
+				&ret);
+	if (!comm_buf)
+		return EFI_EXIT(ret);
+
+	mm_query_info->attr = attributes;
+	ret = mm_communicate(comm_buf, payload_size);
+	if (ret != EFI_SUCCESS)
+		goto out;
+	*max_variable_storage_size = mm_query_info->max_variable_storage;
+	*remain_variable_storage_size =
+			mm_query_info->remaining_variable_storage;
+	*max_variable_size = mm_query_info->max_variable_size;
+
+out:
+	free(comm_buf);
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_get_variable_runtime() - runtime implementation of GetVariable()
+ *
+ * @variable_name:	name of the variable
+ * @guid:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer to which the variable value is copied
+ * @data:		buffer to which the variable value is copied
+ * Return:		status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
+			 u32 *attributes, efi_uintn_t *data_size, void *data)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_get_next_variable_name_runtime() - runtime implementation of
+ *					  GetNextVariable()
+ *
+ * @variable_name_size:	size of variable_name buffer in byte
+ * @variable_name:	name of uefi variable's name in u16
+ * @guid:		vendor's guid
+ * Return:              status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
+				   u16 *variable_name, efi_guid_t *guid)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_query_variable_info() - get information about EFI variables
+ *
+ * This function implements the QueryVariableInfo() runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @attributes:				bitmask to select variables to be
+ *					queried
+ * @maximum_variable_storage_size:	maximum size of storage area for the
+ *					selected variable types
+ * @remaining_variable_storage_size:	remaining size of storage are for the
+ *					selected variable types
+ * @maximum_variable_size:		maximum size of a variable of the
+ *					selected type
+ * Return:				status code
+ */
+efi_status_t EFIAPI __efi_runtime
+efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size,
+				u64 *remain_variable_storage_size,
+				u64 *max_variable_size)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_set_variable_runtime() - runtime implementation of SetVariable()
+ *
+ * @variable_name:	name of the variable
+ * @guid:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer with the variable value
+ * @data:		buffer with the variable value
+ * Return:		status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
+			 u32 attributes, efi_uintn_t data_size,
+			 const void *data)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
+ */
+void efi_variables_boot_exit_notify(void)
+{
+	u8 *comm_buf;
+	efi_status_t ret;
+
+	comm_buf = setup_mm_hdr(NULL, 0,
+				SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret);
+	if (comm_buf)
+		ret = mm_communicate(comm_buf, 0);
+	else
+		ret = EFI_NOT_FOUND;
+
+	if (ret != EFI_SUCCESS)
+		log_err("Unable to notify StMM for ExitBootServices\n");
+	free(comm_buf);
+
+	/* Update runtime service table */
+	efi_runtime_services.query_variable_info =
+			efi_query_variable_info_runtime;
+	efi_runtime_services.get_variable = efi_get_variable_runtime;
+	efi_runtime_services.get_next_variable_name =
+			efi_get_next_variable_name_runtime;
+	efi_runtime_services.set_variable = efi_set_variable_runtime;
+	efi_update_table_header_crc32(&efi_runtime_services.hdr);
+}
+
+/**
+ * efi_init_variables() - initialize variable services
+ *
+ * Return:	status code
+ */
+efi_status_t efi_init_variables(void)
+{
+	efi_status_t ret;
+
+	ret = get_max_payload(&max_payload_size);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	max_buffer_size = MM_COMMUNICATE_HEADER_SIZE +
+			  MM_VARIABLE_COMMUNICATE_SIZE +
+			  max_payload_size;
+
+	return EFI_SUCCESS;
+}
-- 
2.26.2

[PATCH 3/5 v2] cmd: efidebug: Add support for querying UEFI variable storage

[Ilias Apalodimas]

With the previous patches that use OP-TEE and StandAloneMM for UEFI
variable storage we've added functionality for efi_query_variable_info.
So let's add the relevant command to efidebug and retrieve information
about the container used to store UEFI variables

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 cmd/efidebug.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index d8a76d78a388..a3980772c934 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -1160,6 +1160,44 @@ static int do_efi_test(cmd_tbl_t *cmdtp, int flag,
 	return cp->cmd(cmdtp, flag, argc, argv);
 }
 
+/**
+ * do_efi_query_info() - QueryVariableInfo EFI service
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success,
+ *		CMD_RET_USAGE or CMD_RET_FAILURE on failure
+ *
+ * Implement efidebug "test" sub-command.
+ */
+
+static int do_efi_query_info(cmd_tbl_t *cmdtp, int flag,
+			     int argc, char * const argv[])
+{
+	efi_status_t ret;
+	u32 attr = EFI_VARIABLE_BOOTSERVICE_ACCESS |
+			EFI_VARIABLE_RUNTIME_ACCESS |
+			EFI_VARIABLE_NON_VOLATILE;
+	u64 max_variable_storage_size;
+	u64 remain_variable_storage_size;
+	u64 max_variable_size;
+
+	ret = EFI_CALL(efi_query_variable_info(attr,
+					       &max_variable_storage_size,
+					       &remain_variable_storage_size,
+					       &max_variable_size));
+	if (ret != EFI_SUCCESS)
+		return CMD_RET_FAILURE;
+
+	printf("Max storage size %llu\n", max_variable_storage_size);
+	printf("Remaining storage size %llu\n", remain_variable_storage_size);
+	printf("Max variable size %llu\n", max_variable_size);
+
+	return CMD_RET_SUCCESS;
+}
+
 static cmd_tbl_t cmd_efidebug_sub[] = {
 	U_BOOT_CMD_MKENT(boot, CONFIG_SYS_MAXARGS, 1, do_efi_boot_opt, "", ""),
 	U_BOOT_CMD_MKENT(devices, CONFIG_SYS_MAXARGS, 1, do_efi_show_devices,
@@ -1176,6 +1214,8 @@ static cmd_tbl_t cmd_efidebug_sub[] = {
 			 "", ""),
 	U_BOOT_CMD_MKENT(test, CONFIG_SYS_MAXARGS, 1, do_efi_test,
 			 "", ""),
+	U_BOOT_CMD_MKENT(query, CONFIG_SYS_MAXARGS, 1, do_efi_query_info,
+			 "", ""),
 };
 
 /**
@@ -1247,7 +1287,9 @@ static char efidebug_help_text[] =
 	"efidebug tables\n"
 	"  - show UEFI configuration tables\n"
 	"efidebug test bootmgr\n"
-	"  - run simple bootmgr for test\n";
+	"  - run simple bootmgr for test\n"
+	"efidebug query\n"
+	"  - show size of UEFI variables store\n";
 #endif
 
 U_BOOT_CMD(
-- 
2.26.2

[PATCH 4/5 v2] MAINTAINERS: Add maintainer for EFI variables via OP-TEE

[Ilias Apalodimas]

Add myself as maintainer for the OP-TEE related UEFI variable storage
and add the headers file on the existing EFI list

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 MAINTAINERS | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index ec59ce8b8802..0c38890be09c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -635,6 +635,12 @@ F:	cmd/efidebug.c
 F:	cmd/nvedit_efi.c
 F:	tools/file2include.c
 
+EFI VARIABLES VIA OP-TEE
+M:	Ilias Apalodimas <ilias.apalodimas@linaro.org>
+S:	Maintained
+F:	lib/efi_loader/efi_variable_tee.c
+F:	include/mm_communication.h
+
 ENVIRONMENT
 M:	Joe Hershberger <joe.hershberger@ni.com>
 R:	Wolfgang Denk <wd@denx.de>
-- 
2.26.2

[PATCH 5/5 v2] doc: uefi.rst: Add OP-TEE variable storage config options

[Ilias Apalodimas]

If OP-TEE is compiled with an EDK2 application running in secure world
it can process and store UEFI variables in an RPMB.
Add documentation for the config options enabling this

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 doc/uefi/uefi.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/doc/uefi/uefi.rst b/doc/uefi/uefi.rst
index 4fda00d68721..03d6fd0c6aa8 100644
--- a/doc/uefi/uefi.rst
+++ b/doc/uefi/uefi.rst
@@ -188,6 +188,23 @@ on the sandbox
     cd <U-Boot source directory>
     pytest.py test/py/tests/test_efi_secboot/test_signed.py --bd sandbox
 
+Using OP-TEE for EFI variables
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Instead of implementing UEFI variable services inside U-Boot they can
+also be provided in the secure world by a module for OP-TEE[1]. The
+interface between U-Boot and OP-TEE for variable services is enabled by
+CONFIG_EFI_MM_COMM_TEE=y.
+
+Tianocore EDK II's standalone management mode driver for variables can
+be linked to OP-TEE for this purpose. This module uses the Replay
+Protected Memory Block (RPMB) of an eMMC device for persisting
+non-volatile variables. When calling the variable services via the
+OP-TEE API U-Boot's OP-TEE supplicant relays calls to the RPMB driver
+which has to be enabled via CONFIG_SUPPORT_EMMC_RPMB=y.
+
+[1] https://optee.readthedocs.io/ - OP-TEE documentation
+
 Executing the boot manager
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.26.2

[PATCH 5/5 v2] doc: uefi.rst: Add OP-TEE variable storage config options

[Heinrich Schuchardt]

On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> If OP-TEE is compiled with an EDK2 application running in secure world
> it can process and store UEFI variables in an RPMB.
> Add documentation for the config options enabling this
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

> ---
>  doc/uefi/uefi.rst | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/doc/uefi/uefi.rst b/doc/uefi/uefi.rst
> index 4fda00d68721..03d6fd0c6aa8 100644
> --- a/doc/uefi/uefi.rst
> +++ b/doc/uefi/uefi.rst
> @@ -188,6 +188,23 @@ on the sandbox
>      cd <U-Boot source directory>
>      pytest.py test/py/tests/test_efi_secboot/test_signed.py --bd sandbox
>
> +Using OP-TEE for EFI variables
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +Instead of implementing UEFI variable services inside U-Boot they can
> +also be provided in the secure world by a module for OP-TEE[1]. The
> +interface between U-Boot and OP-TEE for variable services is enabled by
> +CONFIG_EFI_MM_COMM_TEE=y.
> +
> +Tianocore EDK II's standalone management mode driver for variables can
> +be linked to OP-TEE for this purpose. This module uses the Replay
> +Protected Memory Block (RPMB) of an eMMC device for persisting
> +non-volatile variables. When calling the variable services via the
> +OP-TEE API U-Boot's OP-TEE supplicant relays calls to the RPMB driver
> +which has to be enabled via CONFIG_SUPPORT_EMMC_RPMB=y.
> +
> +[1] https://optee.readthedocs.io/ - OP-TEE documentation
> +
>  Executing the boot manager
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>

[PATCH 4/5 v2] MAINTAINERS: Add maintainer for EFI variables via OP-TEE

[Heinrich Schuchardt]

On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> Add myself as maintainer for the OP-TEE related UEFI variable storage
> and add the headers file on the existing EFI list
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

> ---
>  MAINTAINERS | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ec59ce8b8802..0c38890be09c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -635,6 +635,12 @@ F:	cmd/efidebug.c
>  F:	cmd/nvedit_efi.c
>  F:	tools/file2include.c
>
> +EFI VARIABLES VIA OP-TEE
> +M:	Ilias Apalodimas <ilias.apalodimas@linaro.org>
> +S:	Maintained
> +F:	lib/efi_loader/efi_variable_tee.c
> +F:	include/mm_communication.h
> +
>  ENVIRONMENT
>  M:	Joe Hershberger <joe.hershberger@ni.com>
>  R:	Wolfgang Denk <wd@denx.de>
>

[PATCH 3/5 v2] cmd: efidebug: Add support for querying UEFI variable storage

[Heinrich Schuchardt]

On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> With the previous patches that use OP-TEE and StandAloneMM for UEFI
> variable storage we've added functionality for efi_query_variable_info.
> So let's add the relevant command to efidebug and retrieve information
> about the container used to store UEFI variables
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

For now attributes (e.g. EFI_VARIABLE_NON_VOLATILE) cannot be passed to
the 'efidebug query' sub-command instead a fixed value is used. We can
add attributes on the command line later.

> ---
>  cmd/efidebug.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 43 insertions(+), 1 deletion(-)
>
> diff --git a/cmd/efidebug.c b/cmd/efidebug.c
> index d8a76d78a388..a3980772c934 100644
> --- a/cmd/efidebug.c
> +++ b/cmd/efidebug.c
> @@ -1160,6 +1160,44 @@ static int do_efi_test(cmd_tbl_t *cmdtp, int flag,
>  	return cp->cmd(cmdtp, flag, argc, argv);
>  }
>
> +/**
> + * do_efi_query_info() - QueryVariableInfo EFI service
> + *
> + * @cmdtp:	Command table
> + * @flag:	Command flag
> + * @argc:	Number of arguments
> + * @argv:	Argument array
> + * Return:	CMD_RET_SUCCESS on success,
> + *		CMD_RET_USAGE or CMD_RET_FAILURE on failure
> + *
> + * Implement efidebug "test" sub-command.
> + */
> +
> +static int do_efi_query_info(cmd_tbl_t *cmdtp, int flag,
> +			     int argc, char * const argv[])
> +{
> +	efi_status_t ret;
> +	u32 attr = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +			EFI_VARIABLE_RUNTIME_ACCESS |
> +			EFI_VARIABLE_NON_VOLATILE;

As we do not support variables at runtime currently shouldn't we remove
EFI_VARIABLE_RUNTIME_ACCESS from the default value? I could do that when
merging.

Otherwise:

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>


> +	u64 max_variable_storage_size;
> +	u64 remain_variable_storage_size;
> +	u64 max_variable_size;
> +
> +	ret = EFI_CALL(efi_query_variable_info(attr,
> +					       &max_variable_storage_size,
> +					       &remain_variable_storage_size,
> +					       &max_variable_size));
> +	if (ret != EFI_SUCCESS)
> +		return CMD_RET_FAILURE;
> +
> +	printf("Max storage size %llu\n", max_variable_storage_size);
> +	printf("Remaining storage size %llu\n", remain_variable_storage_size);
> +	printf("Max variable size %llu\n", max_variable_size);
> +
> +	return CMD_RET_SUCCESS;
> +}
> +
>  static cmd_tbl_t cmd_efidebug_sub[] = {
>  	U_BOOT_CMD_MKENT(boot, CONFIG_SYS_MAXARGS, 1, do_efi_boot_opt, "", ""),
>  	U_BOOT_CMD_MKENT(devices, CONFIG_SYS_MAXARGS, 1, do_efi_show_devices,
> @@ -1176,6 +1214,8 @@ static cmd_tbl_t cmd_efidebug_sub[] = {
>  			 "", ""),
>  	U_BOOT_CMD_MKENT(test, CONFIG_SYS_MAXARGS, 1, do_efi_test,
>  			 "", ""),
> +	U_BOOT_CMD_MKENT(query, CONFIG_SYS_MAXARGS, 1, do_efi_query_info,
> +			 "", ""),
>  };
>
>  /**
> @@ -1247,7 +1287,9 @@ static char efidebug_help_text[] =
>  	"efidebug tables\n"
>  	"  - show UEFI configuration tables\n"
>  	"efidebug test bootmgr\n"
> -	"  - run simple bootmgr for test\n";
> +	"  - run simple bootmgr for test\n"
> +	"efidebug query\n"
> +	"  - show size of UEFI variables store\n";
>  #endif
>
>  U_BOOT_CMD(
>

[PATCH 1/5 v2] efi_loader: Add headers for EDK2 StandAloneMM communication

[Heinrich Schuchardt]

On 5/11/20 8:13 PM, Ilias Apalodimas wrote:
> From: Sughosh Ganu <sughosh.ganu@linaro.org>
>
> In Arm devices OP-TEE has the ability to run StandAloneMM (from EDK2)
> in a separate partition and handle UEFI variables.
> A following patch introduces this functionality.
>
> Add the headers needed for OP-TEE <--> StandAloneMM communication
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
>  include/mm_communication.h | 207 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 207 insertions(+)
>  create mode 100644 include/mm_communication.h
>
> diff --git a/include/mm_communication.h b/include/mm_communication.h
> new file mode 100644
> index 000000000000..b9bfbe4cf0a1
> --- /dev/null
> +++ b/include/mm_communication.h
> @@ -0,0 +1,207 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + *  Headers for EFI variable service via StandAloneMM, EDK2 application running
> + *  in OP-TEE
> + *
> + *  Copyright (c) 2017, Intel Corporation. All rights reserved.
> + *  Copyright (C) 2020 Linaro Ltd. <sughosh.ganu@linaro.org>
> + *  Copyright (C) 2020 Linaro Ltd. <ilias.apalodimas@linaro.org>
> + */
> +
> +#ifndef _MM_VARIABLE_H_
> +#define _MM_VARIABLE_H_
> +
> +#include <part_efi.h>
> +
> +/*
> + * Interface to the pseudo TA, which provides a communication channel with

U-Boot developers might not know the OP-TEE terms. So I would tend to
avoid abbreviations at least in the first reference.

%s/pseudo TA/Pseudo Trusted Application/

> + * the StandaloneMM Secure Partition (StMM) running at S-EL0

What does MM stand for? Management Mode?

> + */
> +
> +#define PTA_STMM_CMDID_COMMUNICATE 0
> +
> +/* OP-TEE is using big endian GUIDs while UEFI uses little endian ones */
> +#define PTA_STMM_UUID { 0xed32d533, 0x99e6, 0x4209, {\
> +			0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7 } }
> +
> +#define EFI_MM_VARIABLE_GUID \
> +	EFI_GUID(0xed32d533, 0x99e6, 0x4209, \
> +		 0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7)
> +
> +/* Defined in EDK2 MdePkg/Include/Protocol/MmCommunication.h */
> +
> +/**
> + * struct efi_mm_communicate_header - Header used for SMM variable communication
> +
> + * @header_guid:  header use for disambiguation of content
> + * @message_len:  length of the message. Does not include the size of the
> + *                header
> + * @data:         payload of the message
> + *
> + * Defined in EDK2 as EFI_MM_COMMUNICATE_HEADER
> + * To avoid confusion in interpreting frames, the communication buffer should
> + * always begin with efi_mm_communicate_header

%s/efi_mm_communicate_header/efi_mm_communicate_header./

> + */
> +struct efi_mm_communicate_header {
> +	efi_guid_t header_guid;
> +	size_t     message_len;
> +	u8         data[];
> +};
> +
> +#define MM_COMMUNICATE_HEADER_SIZE \
> +	(sizeof(struct efi_mm_communicate_header))
> +
> +/* Defined in EDK2 ArmPkg/Include/IndustryStandard/ArmStdSmc.h */
> +
> +/* MM return error codes */
> +#define ARM_SMC_MM_RET_SUCCESS              0
> +#define ARM_SMC_MM_RET_NOT_SUPPORTED       -1
> +#define ARM_SMC_MM_RET_INVALID_PARAMS      -2
> +#define ARM_SMC_MM_RET_DENIED              -3
> +#define ARM_SMC_MM_RET_NO_MEMORY           -4
> +
> +/* Defined in EDK2 MdeModulePkg/Include/Guid/SmmVariableCommon.h */
> +
> +#define SMM_VARIABLE_FUNCTION_GET_VARIABLE  1
> +/*
> + * The payload for this function is
> + * SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME.
> + */
> +#define SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME  2
> +/*
> + * The payload for this function is SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE.
> + */
> +#define SMM_VARIABLE_FUNCTION_SET_VARIABLE  3
> +/*
> + * The payload for this function is
> + * SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO.
> + */
> +#define SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO  4
> +/*
> + * It is a notify event, no extra payload for this function.
> + */
> +#define SMM_VARIABLE_FUNCTION_READY_TO_BOOT  5
> +/*
> + * It is a notify event, no extra payload for this function.
> + */
> +#define SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE  6
> +/*
> + * The payload for this function is VARIABLE_INFO_ENTRY.
> + * The GUID in EFI_SMM_COMMUNICATE_HEADER is gEfiSmmVariableProtocolGuid.
> + */
> +#define SMM_VARIABLE_FUNCTION_GET_STATISTICS  7
> +/*
> + * The payload for this function is SMM_VARIABLE_COMMUNICATE_LOCK_VARIABLE
> + */
> +#define SMM_VARIABLE_FUNCTION_LOCK_VARIABLE   8
> +
> +#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET  9
> +
> +#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET  10
> +
> +#define SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE  11
> +/*
> + * The payload for this function is
> + * SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT
> + */
> +#define SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT 12
> +
> +#define SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE  13
> +/*
> + * The payload for this function is
> + * SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO
> + */
> +#define SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO  14
> +
> +/**
> + * struct smm_variable_communicate_header - Used for SMM variable communication
> +
> + * @function:     function to call in Smm.
> + * @ret_status:   return status
> + * @data:         payload
> + *
> + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_HEADER
> + */
> +struct smm_variable_communicate_header {
> +	efi_uintn_t  function;
> +	efi_status_t ret_status;
> +	u8           data[];
> +};
> +
> +#define MM_VARIABLE_COMMUNICATE_SIZE \
> +	(sizeof(struct smm_variable_communicate_header))
> +
> +/**
> + * struct smm_variable_access - Used to communicate with StMM by
> + *                              SetVariable and GetVariable.
> +
> + * @function:     vendor GUID to call in Smm
> + * @data_size:    size of EFI variable data
> + * @name_size:    size of EFI name
> + * @attr:         attributes
> + * @name:         variable name
> + *
> + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE
> + *
> + */
> +struct smm_variable_access {
> +	efi_guid_t  guid;
> +	efi_uintn_t data_size;
> +	efi_uintn_t name_size;
> +	u32         attr;
> +	u16         name[];
> +};
> +
> +#define MM_VARIABLE_ACCESS_HEADER_SIZE \
> +	(sizeof(struct smm_variable_access))
> +/**
> + * struct smm_variable_payload_size - Used to get the max allowed
> + *                                    payload used in StMM.
> + *
> + * @size:  size to fill in
> + *
> + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE

%s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE./

> + *
> + */
> +struct smm_variable_payload_size {
> +	efi_uintn_t size;
> +};
> +
> +/**
> + * struct smm_variable_getnext - Used to communicate with StMM for
> + *                               GetNextVariableName.
> + *
> + * @size:       vendor GUID
> + * @name_size:  size of the name of the variable
> + * @name:       variable name
> + *
> + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE

%s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME./

Too much copy and paste ;)

> + */
> +struct smm_variable_getnext {
> +	efi_guid_t  guid;
> +	efi_uintn_t name_size;
> +	u16         name[];
> +};
> +
> +#define MM_VARIABLE_GET_NEXT_HEADER_SIZE \
> +	(sizeof(struct smm_variable_getnext))
> +
> +/**
> + * struct smm_variable_query_info - Used to communicate with StMM for
> + *                                  QueryVariableInfo.
> + *
> + * @max_variable_storage:        max available storage
> + * @remaining_variable_storage:  remaining available storage
> + * @max_variable_size:           max variable supported size
> + * @attr:                        attributes to query storage for
> + *
> + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE

%s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO./

I hope I caught all comment errors. Please, recheck.

Otherwise:
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

> + */
> +struct smm_variable_query_info {
> +	u64 max_variable_storage;
> +	u64 remaining_variable_storage;
> +	u64 max_variable_size;
> +	u32 attr;
> +};
> +
> +#endif /* _MM_VARIABLE_H_ */
>

[PATCH 3/5 v2] cmd: efidebug: Add support for querying UEFI variable storage

[Ilias Apalodimas]

On Mon, May 11, 2020 at 08:54:04PM +0200, Heinrich Schuchardt wrote:
> On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> > With the previous patches that use OP-TEE and StandAloneMM for UEFI
> > variable storage we've added functionality for efi_query_variable_info.
> > So let's add the relevant command to efidebug and retrieve information
> > about the container used to store UEFI variables
> >
> > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> 
> For now attributes (e.g. EFI_VARIABLE_NON_VOLATILE) cannot be passed to
> the 'efidebug query' sub-command instead a fixed value is used. We can
> add attributes on the command line later.

Good point, I'll add it on the commit message for v3

> 
> > ---
> >  cmd/efidebug.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 43 insertions(+), 1 deletion(-)
> >
> > diff --git a/cmd/efidebug.c b/cmd/efidebug.c
> > index d8a76d78a388..a3980772c934 100644
> > --- a/cmd/efidebug.c
> > +++ b/cmd/efidebug.c
> > @@ -1160,6 +1160,44 @@ static int do_efi_test(cmd_tbl_t *cmdtp, int flag,
> >  	return cp->cmd(cmdtp, flag, argc, argv);
> >  }
> >
> > +/**
> > + * do_efi_query_info() - QueryVariableInfo EFI service
> > + *
> > + * @cmdtp:	Command table
> > + * @flag:	Command flag
> > + * @argc:	Number of arguments
> > + * @argv:	Argument array
> > + * Return:	CMD_RET_SUCCESS on success,
> > + *		CMD_RET_USAGE or CMD_RET_FAILURE on failure
> > + *
> > + * Implement efidebug "test" sub-command.
> > + */
> > +
> > +static int do_efi_query_info(cmd_tbl_t *cmdtp, int flag,
> > +			     int argc, char * const argv[])
> > +{
> > +	efi_status_t ret;
> > +	u32 attr = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> > +			EFI_VARIABLE_RUNTIME_ACCESS |
> > +			EFI_VARIABLE_NON_VOLATILE;
> 
> As we do not support variables at runtime currently shouldn't we remove
> EFI_VARIABLE_RUNTIME_ACCESS from the default value? I could do that when
> merging.

We can still add variables marked as runtime in U-Boot's cmd line although we
don't support those in Linux. So I'd keep that flag on the defaults.

> 
> Otherwise:
> 
> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> 

Regards
/Ilias

[PATCH 1/5 v2] efi_loader: Add headers for EDK2 StandAloneMM communication

[Ilias Apalodimas]

Hi Heinrich

On Mon, May 11, 2020 at 09:39:51PM +0200, Heinrich Schuchardt wrote:
> On 5/11/20 8:13 PM, Ilias Apalodimas wrote:
> > +

[...] 

> > +/*
> > + * Interface to the pseudo TA, which provides a communication channel with
> 
> U-Boot developers might not know the OP-TEE terms. So I would tend to
> avoid abbreviations at least in the first reference.
> 
> %s/pseudo TA/Pseudo Trusted Application/
> 
> > + * the StandaloneMM Secure Partition (StMM) running at S-EL0
> 
> What does MM stand for? Management Mode?
> 

Yes 

> > + */
> > +
> > +#define PTA_STMM_CMDID_COMMUNICATE 0
> > +
> > +			0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7 } }

[...]

> > +
> > +#define EFI_MM_VARIABLE_GUID \
> > + *
> > + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
> 
> %s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME./
> 
> Too much copy and paste ;)
> 

Indeed! Thanks for cathcing those

> > + */
> > +struct smm_variable_getnext {
> > +	efi_guid_t  guid;
> > +	efi_uintn_t name_size;
> > +	u16         name[];
> > +};
> > +
> > +#define MM_VARIABLE_GET_NEXT_HEADER_SIZE \
> > +	(sizeof(struct smm_variable_getnext))
> > +
> > +/**
> > + * struct smm_variable_query_info - Used to communicate with StMM for
> > + *                                  QueryVariableInfo.
> > + *
> > + * @max_variable_storage:        max available storage
> > + * @remaining_variable_storage:  remaining available storage
> > + * @max_variable_size:           max variable supported size
> > + * @attr:                        attributes to query storage for
> > + *
> > + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
> 
> %s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO./
> 
> I hope I caught all comment errors. Please, recheck.

Ok will do

> 
> Otherwise:
> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> 

Thanks!
/Ilias

[PATCH 1/5 v2] efi_loader: Add headers for EDK2 StandAloneMM communication

[Ilias Apalodimas]

> 
> %s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE./
> 
> > + * @size:       vendor GUID

[...]

> > + * @name_size:  size of the name of the variable
> > + * @name:       variable name
> > + *
> > + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
> 
> %s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME./
> 
> Too much copy and paste ;)
> 
> > + */
> > + * @attr:                        attributes to query storage for

[...]

> > + *
> > + * Defined in EDK2 as SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE
> 
> %s/SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE/SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO./
> 
> I hope I caught all comment errors. Please, recheck.
> 

There were 3-4 more c/p trainwrecks in there. I'll post a v3 once you are done
with your testing.

Thanks
/Ilias

[PATCH 2/5 v2] efi_loader: Implement EFI variable handling via OP-TEE

[Heinrich Schuchardt]

On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> In OP-TEE we can run EDK2's StandAloneMM on a secure partition.
> StandAloneMM is responsible for the UEFI variable support. In
> combination with OP-TEE and it's U-Boot supplicant, variables are
> authenticated/validated in secure world and stored on an RPMB partition.
>
> So let's add a new config option in U-Boot implementing the necessary
> calls to OP-TEE for the variable management.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Signed-off-by: Pipat Methavanitpong <pipat1010@gmail.com>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
>  lib/efi_loader/Kconfig            |   9 +
>  lib/efi_loader/Makefile           |   4 +
>  lib/efi_loader/efi_variable_tee.c | 643 ++++++++++++++++++++++++++++++
>  3 files changed, 656 insertions(+)
>  create mode 100644 lib/efi_loader/efi_variable_tee.c
>
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index 1cfa24ffcf72..e385cd0b9dae 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -164,4 +164,13 @@ config EFI_SECURE_BOOT
>  	  it is signed with a trusted key. To do that, you need to install,
>  	  at least, PK, KEK and db.
>
> +config EFI_MM_COMM_TEE
> +	bool "UEFI variables storage service via OP-TEE"
> +	depends on SUPPORT_EMMC_RPMB
> +	default n
> +	help
> +	  If OP-TEE is present and running StandAloneMM dispatch all UEFI variable
> +	  related operations to that. The application will verify, authenticate and
> +	  store the variables on an RPMB
> +
>  endif
> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> index eff3c25ec301..dba652121eab 100644
> --- a/lib/efi_loader/Makefile
> +++ b/lib/efi_loader/Makefile
> @@ -34,7 +34,11 @@ obj-y += efi_root_node.o
>  obj-y += efi_runtime.o
>  obj-y += efi_setup.o
>  obj-$(CONFIG_EFI_UNICODE_COLLATION_PROTOCOL2) += efi_unicode_collation.o
> +ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
> +obj-y += efi_variable_tee.o
> +else
>  obj-y += efi_variable.o
> +endif
>  obj-y += efi_watchdog.o
>  obj-$(CONFIG_LCD) += efi_gop.o
>  obj-$(CONFIG_DM_VIDEO) += efi_gop.o
> diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
> new file mode 100644
> index 000000000000..f8857bb81e72
> --- /dev/null
> +++ b/lib/efi_loader/efi_variable_tee.c
> @@ -0,0 +1,643 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + *  EFI variable service via OP-TEE
> + *
> + *  Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org>
> + *  Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org>
> + */
> +
> +#include <common.h>
> +#include <efi.h>
> +#include <efi_api.h>
> +#include <efi_loader.h>
> +#include <tee.h>
> +#include <malloc.h>
> +#include <mm_communication.h>
> +
> +static efi_uintn_t max_buffer_size;	/* comm + var + func + data */
> +static efi_uintn_t max_payload_size;	/* func + data */
> +
> +struct mm_connection {
> +	struct udevice *tee;
> +	u32 session;
> +};
> +
> +/**
> + * get_connection() - Retrieve OP-TEE session for a specific UUID.
> + *
> + * @conn:   session buffer to fill
> + * Return:  status code
> + */
> +static int get_connection(struct mm_connection *conn)
> +{
> +	static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID;
> +	struct udevice *tee = NULL;
> +	struct tee_open_session_arg arg;
> +	int rc;
> +
> +	tee = tee_find_device(tee, NULL, NULL, NULL);
> +	if (!tee)
> +		return -ENODEV;
> +
> +	memset(&arg, 0, sizeof(arg));
> +	tee_optee_ta_uuid_to_octets(arg.uuid, &uuid);
> +	rc = tee_open_session(tee, &arg, 0, NULL);
> +	if (!rc) {
> +		conn->tee = tee;
> +		conn->session = arg.session;
> +	}
> +
> +	return rc;
> +}
> +
> +/**
> + * optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE
> + *
> + * @comm_buf:		locally allocted communcation buffer
> + * @dsize:		buffer size
> + * Return:		status code
> + */
> +static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
> +{
> +	ulong buf_size;
> +	efi_status_t ret;
> +	struct efi_mm_communicate_header *mm_hdr;
> +	struct mm_connection conn = { NULL, 0 };
> +	struct tee_invoke_arg arg;
> +	struct tee_param param[2];
> +	struct tee_shm *shm = NULL;
> +	int rc;
> +
> +	if (!comm_buf)
> +		return EFI_INVALID_PARAMETER;
> +
> +	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
> +	buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
> +
> +	if (dsize != buf_size)
> +		return EFI_INVALID_PARAMETER;
> +
> +	rc = get_connection(&conn);
> +	if (rc) {
> +		log_err("Unable to open OP-TEE session (err=%d)\n", rc);
> +		return EFI_UNSUPPORTED;
> +	}
> +
> +	if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) {
> +		log_err("Unable to register shared memory\n");
> +		return EFI_UNSUPPORTED;
> +	}
> +
> +	memset(&arg, 0, sizeof(arg));
> +	arg.func = PTA_STMM_CMDID_COMMUNICATE;
> +	arg.session = conn.session;
> +
> +	memset(param, 0, sizeof(param));
> +	param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT;
> +	param[0].u.memref.size = buf_size;
> +	param[0].u.memref.shm = shm;
> +	param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT;
> +
> +	rc = tee_invoke_func(conn.tee, &arg, 2, param);
> +	if (rc)
> +		return EFI_INVALID_PARAMETER;
> +	tee_shm_free(shm);
> +	tee_close_session(conn.tee, conn.session);
> +
> +	switch (param[1].u.value.a) {
> +	case ARM_SMC_MM_RET_SUCCESS:
> +		ret = EFI_SUCCESS;
> +		break;
> +
> +	case ARM_SMC_MM_RET_INVALID_PARAMS:
> +		ret = EFI_INVALID_PARAMETER;
> +		break;
> +
> +	case ARM_SMC_MM_RET_DENIED:
> +		ret = EFI_ACCESS_DENIED;
> +		break;
> +
> +	case ARM_SMC_MM_RET_NO_MEMORY:
> +		ret = EFI_OUT_OF_RESOURCES;
> +		break;
> +
> +	default:
> +		ret = EFI_ACCESS_DENIED;
> +	}
> +
> +	return ret;
> +}
> +
> +/**
> + * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send
> + * it to OP-TEE
> + *
> + * @comm_buf:		locally allocted communcation buffer
> + * @dsize:		buffer size
> + * Return:		status code
> + */
> +static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize)
> +{
> +	efi_status_t ret;
> +	struct efi_mm_communicate_header *mm_hdr;
> +	struct smm_variable_communicate_header *var_hdr;
> +
> +	dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE;
> +	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
> +	var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
> +
> +	ret = optee_mm_communicate(comm_buf, dsize);
> +	if (ret != EFI_SUCCESS) {
> +		log_err("%s failed!\n", __func__);
> +		return ret;
> +	}
> +
> +	return var_hdr->ret_status;
> +}
> +
> +/**
> + * setup_mm_hdr() -	Allocate a buffer for StandAloneMM and initialize the
> + *			header data.
> + *
> + * @dptr:		pointer address of the corresponding StandAloneMM
> + *			function
> + * @payload_size:	buffer size
> + * @func:		standAloneMM function number
> + * @ret:		EFI return code
> + * Return:		buffer or NULL
> + */
> +static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size,
> +			efi_uintn_t func, efi_status_t *ret)
> +{
> +	const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID;
> +	struct efi_mm_communicate_header *mm_hdr;
> +	struct smm_variable_communicate_header *var_hdr;
> +	u8 *comm_buf;
> +
> +	/* In the init function we initialize max_buffer_size with
> +	 * get_max_payload(). So skip the test if max_buffer_size is initialized
> +	 * StandAloneMM will perform similar checks and drop the buffer if it's
> +	 * too long
> +	 */
> +	if (max_buffer_size && max_buffer_size <
> +			(MM_COMMUNICATE_HEADER_SIZE +
> +			 MM_VARIABLE_COMMUNICATE_SIZE +
> +			 payload_size)) {
> +		*ret = EFI_INVALID_PARAMETER;
> +		return NULL;
> +	}
> +
> +	comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE +
> +			  MM_VARIABLE_COMMUNICATE_SIZE +
> +			  payload_size);
> +	if (!comm_buf) {
> +		*ret = EFI_OUT_OF_RESOURCES;
> +		return NULL;
> +	}
> +
> +	mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
> +	guidcpy(&mm_hdr->header_guid, &mm_var_guid);
> +	mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size;
> +
> +	var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
> +	var_hdr->function = func;
> +	if (dptr)
> +		*dptr = var_hdr->data;
> +	*ret = EFI_SUCCESS;
> +
> +	return comm_buf;
> +}
> +
> +/**
> + * get_max_payload() - Get variable payload size from StandAloneMM.
> + *
> + * @size:    size of the variable in storage
> + * Return:   status code
> + */
> +efi_status_t EFIAPI get_max_payload(efi_uintn_t *size)
> +{
> +	struct smm_variable_payload_size *var_payload = NULL;
> +	efi_uintn_t payload_size;
> +	efi_status_t ret;
> +	u8 *comm_buf;
> +
> +	if (!size)
> +		return EFI_INVALID_PARAMETER;
> +
> +	payload_size = sizeof(*var_payload);
> +	comm_buf = setup_mm_hdr((void **)&var_payload, payload_size,
> +				SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret);
> +	if (!comm_buf)
> +		return EFI_EXIT(ret);
> +
> +	ret = mm_communicate(comm_buf, payload_size);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	*size = var_payload->size;
> +
> +out:
> +	free(comm_buf);
> +	return ret;
> +}
> +
> +/**
> + * efi_get_variable() - retrieve value of a UEFI variable
> + *
> + * This function implements the GetVariable runtime service.
> + *
> + * See the Unified Extensible Firmware Interface (UEFI) specification for
> + * details.
> + *
> + * @name:		name of the variable
> + * @guid:		vendor GUID
> + * @attr:		attributes of the variable
> + * @data_size:		size of the buffer to which the variable value is copied
> + * @data:		buffer to which the variable value is copied
> + * Return:		status code
> + */
> +efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
> +				     u32 *attr, efi_uintn_t *data_size,
> +				     void *data)
> +{
> +	struct smm_variable_access *var_acc;
> +	efi_uintn_t payload_size;
> +	efi_uintn_t name_size;
> +	efi_uintn_t tmp_dsize;
> +	efi_status_t ret;
> +	u8 *comm_buf;
> +
> +	EFI_ENTRY("\"%ls\" %pUl %p %p %p", name, guid, attr, data_size, data);
> +
> +	if (!name || !guid || !data_size)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	/* Check payload size */
> +	name_size = u16_strsize(name);
> +	if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	/* Trim output buffer size */
> +	tmp_dsize = *data_size;
> +	if (name_size + tmp_dsize >
> +			max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
> +		tmp_dsize = max_payload_size -
> +				MM_VARIABLE_ACCESS_HEADER_SIZE -
> +				name_size;
> +	}
> +
> +	/* Get communication buffer and initialize header */
> +	payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize;
> +	comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
> +				SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret);
> +	if (!comm_buf)
> +		return EFI_EXIT(ret);
> +
> +	/* Fill in contents */
> +	guidcpy(&var_acc->guid, guid);
> +	var_acc->data_size = tmp_dsize;
> +	var_acc->name_size = name_size;
> +	var_acc->attr = attr ? *attr : 0;
> +	memcpy(var_acc->name, name, name_size);
> +
> +	/* Communicate */
> +	ret = mm_communicate(comm_buf, payload_size);
> +	if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
> +		/* Update with reported data size for trimmed case */
> +		*data_size = var_acc->data_size;
> +	}
> +	if (ret != EFI_SUCCESS)
> +		goto done;
> +
> +	if (attr)
> +		*attr = var_acc->attr;
> +	if (data)
> +		memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
> +		       var_acc->data_size);
> +	else
> +		ret = EFI_INVALID_PARAMETER;
> +
> +done:
> +	free(comm_buf);
> +	return EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_get_next_variable_name() - enumerate the current variable names
> + *
> + * @variable_name_size:	size of variable_name buffer in byte
> + * @variable_name:	name of uefi variable's name in u16
> + * @guid:		vendor's guid
> + *
> + * This function implements the GetNextVariableName service.
> + *
> + * See the Unified Extensible Firmware Interface (UEFI) specification for
> + * details.
> + *
> + * Return: status code
> + */
> +efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
> +					       u16 *variable_name,
> +					       efi_guid_t *guid)
> +{
> +	struct smm_variable_getnext *var_getnext;
> +	efi_uintn_t payload_size;
> +	efi_uintn_t tmp_dsize;
> +	efi_uintn_t name_size;
> +	efi_status_t ret;
> +	efi_uintn_t out_name_size;
> +	efi_uintn_t in_name_size;
> +	u8 *comm_buf;
> +
> +	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, guid);
> +
> +	if (!variable_name_size || !variable_name || !guid)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	out_name_size = *variable_name_size;
> +	in_name_size = u16_strsize(variable_name);

The UEFI spec requires that EFI_INVALID_PARAMETER should be returned if
there is no '\0' character in the first *variable_name_size words of
variable_name. I think we should add this test here instead of using
max(out_name_size, in_name_size) later in the code.

You are currently calling EFI_EXIT() in many places. Depending on the
level of code optimizations done by the compiler and the debug settings
this may need to unnecessary code size. I suggest to use a single exit
point in each of the functions, e.g.

	if (out_name_size > in_name_size) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}
...
out:
	EFI_EXIT(ret);
}

Best regards

Heinrich

> +
> +	name_size = u16_strsize(variable_name);
> +	if (name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	/* Trim output buffer size */
> +	tmp_dsize = *variable_name_size;
> +	if (name_size + tmp_dsize >
> +			max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
> +		tmp_dsize = max_payload_size -
> +				MM_VARIABLE_GET_NEXT_HEADER_SIZE -
> +				name_size;
> +	}
> +
> +	payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE +
> +			max(out_name_size, in_name_size);
> +	comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size,
> +				SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME,
> +				&ret);
> +	if (!comm_buf)
> +		return EFI_EXIT(ret);
> +
> +	/* Fill in contents */
> +	guidcpy(&var_getnext->guid, guid);
> +	var_getnext->name_size = out_name_size;
> +	memcpy(var_getnext->name, variable_name, in_name_size);
> +	if (out_name_size > in_name_size) {
> +		memset((u8 *)var_getnext->name + in_name_size, 0x0,
> +		       out_name_size - in_name_size);
> +	}
> +
> +	/* Communicate */
> +	ret = mm_communicate(comm_buf, payload_size);
> +	if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
> +		/* Update with reported data size for trimmed case */
> +		*variable_name_size = var_getnext->name_size;
> +	}
> +	if (ret != EFI_SUCCESS)
> +		goto done;
> +
> +	guidcpy(guid, &var_getnext->guid);
> +	memcpy(variable_name, (u8 *)var_getnext->name,
> +	       var_getnext->name_size);
> +
> +done:
> +	free(comm_buf);
> +	return EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_set_variable() - set value of a UEFI variable
> + *
> + * This function implements the SetVariable runtime service.
> + *
> + * See the Unified Extensible Firmware Interface (UEFI) specification for
> + * details.
> + *
> + * @name:		name of the variable
> + * @guid:		vendor GUID
> + * @attr:		attributes of the variable
> + * @data_size:		size of the buffer with the variable value
> + * @data:		buffer with the variable value
> + * Return:		status code
> + */
> +efi_status_t EFIAPI efi_set_variable(u16 *name, const efi_guid_t *guid,
> +				     u32 attr, efi_uintn_t data_size,
> +				     const void *data)
> +{
> +	struct smm_variable_access *var_acc;
> +	efi_uintn_t payload_size;
> +	efi_uintn_t name_size;
> +	efi_status_t ret;
> +	u8 *comm_buf;
> +
> +	EFI_ENTRY("\"%ls\" %pUl %x %zu %p", name, guid, attr, data_size, data);
> +
> +	if (!name || name[0] == 0 || !guid)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +	if (data_size > 0 && !data)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	/* Check payload size */
> +	name_size = u16_strsize(name);
> +	payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size;
> +	if (payload_size > max_payload_size)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +
> +	/* Get communication buffer and initialize header */
> +	comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
> +				SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret);
> +	if (!comm_buf)
> +		return EFI_EXIT(ret);
> +
> +	/* Fill in contents */
> +	guidcpy(&var_acc->guid, guid);
> +	var_acc->data_size = data_size;
> +	var_acc->name_size = name_size;
> +	var_acc->attr = attr;
> +	memcpy(var_acc->name, name, name_size);
> +	memcpy((u8 *)var_acc->name + name_size, data, data_size);
> +
> +	/* Communicate */
> +	ret = mm_communicate(comm_buf, payload_size);
> +	free(comm_buf);
> +
> +	return EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_query_variable_info() - get information about EFI variables
> + *
> + * This function implements the QueryVariableInfo() runtime service.
> + *
> + * See the Unified Extensible Firmware Interface (UEFI) specification for
> + * details.
> + *
> + * @attributes:				bitmask to select variables to be
> + *					queried
> + * @maximum_variable_storage_size:	maximum size of storage area for the
> + *					selected variable types
> + * @remaining_variable_storage_size:	remaining size of storage are for the
> + *					selected variable types
> + * @maximum_variable_size:		maximum size of a variable of the
> + *					selected type
> + * Returns:				status code
> + */
> +efi_status_t EFIAPI __efi_runtime
> +efi_query_variable_info(u32 attributes, u64 *max_variable_storage_size,
> +			u64 *remain_variable_storage_size,
> +			u64 *max_variable_size)
> +{
> +	struct smm_variable_query_info *mm_query_info;
> +	efi_uintn_t payload_size;
> +	efi_status_t ret;
> +	u8 *comm_buf;
> +
> +	EFI_ENTRY("%x %p %p %p", attributes, max_variable_storage_size,
> +		  remain_variable_storage_size, max_variable_size);
> +
> +	payload_size = sizeof(*mm_query_info);
> +	comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
> +				SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
> +				&ret);
> +	if (!comm_buf)
> +		return EFI_EXIT(ret);
> +
> +	mm_query_info->attr = attributes;
> +	ret = mm_communicate(comm_buf, payload_size);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +	*max_variable_storage_size = mm_query_info->max_variable_storage;
> +	*remain_variable_storage_size =
> +			mm_query_info->remaining_variable_storage;
> +	*max_variable_size = mm_query_info->max_variable_size;
> +
> +out:
> +	free(comm_buf);
> +	return EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_get_variable_runtime() - runtime implementation of GetVariable()
> + *
> + * @variable_name:	name of the variable
> + * @guid:		vendor GUID
> + * @attributes:		attributes of the variable
> + * @data_size:		size of the buffer to which the variable value is copied
> + * @data:		buffer to which the variable value is copied
> + * Return:		status code
> + */
> +static efi_status_t __efi_runtime EFIAPI
> +efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
> +			 u32 *attributes, efi_uintn_t *data_size, void *data)
> +{
> +	return EFI_UNSUPPORTED;
> +}
> +
> +/**
> + * efi_get_next_variable_name_runtime() - runtime implementation of
> + *					  GetNextVariable()
> + *
> + * @variable_name_size:	size of variable_name buffer in byte
> + * @variable_name:	name of uefi variable's name in u16
> + * @guid:		vendor's guid
> + * Return:              status code
> + */
> +static efi_status_t __efi_runtime EFIAPI
> +efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
> +				   u16 *variable_name, efi_guid_t *guid)
> +{
> +	return EFI_UNSUPPORTED;
> +}
> +
> +/**
> + * efi_query_variable_info() - get information about EFI variables
> + *
> + * This function implements the QueryVariableInfo() runtime service.
> + *
> + * See the Unified Extensible Firmware Interface (UEFI) specification for
> + * details.
> + *
> + * @attributes:				bitmask to select variables to be
> + *					queried
> + * @maximum_variable_storage_size:	maximum size of storage area for the
> + *					selected variable types
> + * @remaining_variable_storage_size:	remaining size of storage are for the
> + *					selected variable types
> + * @maximum_variable_size:		maximum size of a variable of the
> + *					selected type
> + * Return:				status code
> + */
> +efi_status_t EFIAPI __efi_runtime
> +efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size,
> +				u64 *remain_variable_storage_size,
> +				u64 *max_variable_size)
> +{
> +	return EFI_UNSUPPORTED;
> +}
> +
> +/**
> + * efi_set_variable_runtime() - runtime implementation of SetVariable()
> + *
> + * @variable_name:	name of the variable
> + * @guid:		vendor GUID
> + * @attributes:		attributes of the variable
> + * @data_size:		size of the buffer with the variable value
> + * @data:		buffer with the variable value
> + * Return:		status code
> + */
> +static efi_status_t __efi_runtime EFIAPI
> +efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
> +			 u32 attributes, efi_uintn_t data_size,
> +			 const void *data)
> +{
> +	return EFI_UNSUPPORTED;
> +}
> +
> +/**
> + * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
> + */
> +void efi_variables_boot_exit_notify(void)
> +{
> +	u8 *comm_buf;
> +	efi_status_t ret;
> +
> +	comm_buf = setup_mm_hdr(NULL, 0,
> +				SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret);
> +	if (comm_buf)
> +		ret = mm_communicate(comm_buf, 0);
> +	else
> +		ret = EFI_NOT_FOUND;
> +
> +	if (ret != EFI_SUCCESS)
> +		log_err("Unable to notify StMM for ExitBootServices\n");
> +	free(comm_buf);
> +
> +	/* Update runtime service table */
> +	efi_runtime_services.query_variable_info =
> +			efi_query_variable_info_runtime;
> +	efi_runtime_services.get_variable = efi_get_variable_runtime;
> +	efi_runtime_services.get_next_variable_name =
> +			efi_get_next_variable_name_runtime;
> +	efi_runtime_services.set_variable = efi_set_variable_runtime;
> +	efi_update_table_header_crc32(&efi_runtime_services.hdr);
> +}
> +
> +/**
> + * efi_init_variables() - initialize variable services
> + *
> + * Return:	status code
> + */
> +efi_status_t efi_init_variables(void)
> +{
> +	efi_status_t ret;
> +
> +	ret = get_max_payload(&max_payload_size);
> +	if (ret != EFI_SUCCESS)
> +		return ret;
> +
> +	max_buffer_size = MM_COMMUNICATE_HEADER_SIZE +
> +			  MM_VARIABLE_COMMUNICATE_SIZE +
> +			  max_payload_size;
> +
> +	return EFI_SUCCESS;
> +}
>

[PATCH 2/5 v2] efi_loader: Implement EFI variable handling via OP-TEE

[Ilias Apalodimas]

On Wed, May 13, 2020 at 08:14:19AM +0200, Heinrich Schuchardt wrote:
> On 5/11/20 8:14 PM, Ilias Apalodimas wrote:
> > In OP-TEE we can run EDK2's StandAloneMM on a secure partition.
> > StandAloneMM is responsible for the UEFI variable support. In
> > +

[...]

> > +	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, guid);
> > +
> > +	if (!variable_name_size || !variable_name || !guid)
> > +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> > +
> > +	out_name_size = *variable_name_size;
> > +	in_name_size = u16_strsize(variable_name);
> 
> The UEFI spec requires that EFI_INVALID_PARAMETER should be returned if
> there is no '\0' character in the first *variable_name_size words of
> variable_name. I think we should add this test here instead of using
> max(out_name_size, in_name_size) later in the code.

Ok I'll have a look 

> 
> You are currently calling EFI_EXIT() in many places. Depending on the
> level of code optimizations done by the compiler and the debug settings
> this may need to unnecessary code size. I suggest to use a single exit
> point in each of the functions, e.g.
> 
> 	if (out_name_size > in_name_size) {
> 		ret = EFI_INVALID_PARAMETER;
> 		goto out;
> 	}
> ...
> out:
> 	EFI_EXIT(ret);

Fair enough, most of U-Boot is coded that way anyway, might as well have a
common approach.

I'll post a v3 with the changes, so you can do your testing directly in that 


Regards
/Ilias

[PATCH 2/5 v2] efi_loader: Implement EFI variable handling via OP-TEE

[Heinrich Schuchardt]

On 11.05.20 20:14, Ilias Apalodimas wrote:
> In OP-TEE we can run EDK2's StandAloneMM on a secure partition.
> StandAloneMM is responsible for the UEFI variable support. In
> combination with OP-TEE and it's U-Boot supplicant, variables are
> authenticated/validated in secure world and stored on an RPMB partition.
>
> So let's add a new config option in U-Boot implementing the necessary
> calls to OP-TEE for the variable management.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Signed-off-by: Pipat Methavanitpong <pipat1010@gmail.com>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
>  lib/efi_loader/Kconfig            |   9 +
>  lib/efi_loader/Makefile           |   4 +
>  lib/efi_loader/efi_variable_tee.c | 643 ++++++++++++++++++++++++++++++
>  3 files changed, 656 insertions(+)
>  create mode 100644 lib/efi_loader/efi_variable_tee.c
>
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index 1cfa24ffcf72..e385cd0b9dae 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -164,4 +164,13 @@ config EFI_SECURE_BOOT
>  	  it is signed with a trusted key. To do that, you need to install,
>  	  at least, PK, KEK and db.
>
> +config EFI_MM_COMM_TEE
> +	bool "UEFI variables storage service via OP-TEE"
> +	depends on SUPPORT_EMMC_RPMB
> +	default n
> +	help
> +	  If OP-TEE is present and running StandAloneMM dispatch all UEFI variable
> +	  related operations to that. The application will verify, authenticate and
> +	  store the variables on an RPMB
> +
>  endif

Dear Ilias,

at least CONFIG_TEE=y is needed as dependency. Otherwise compiling fails.

If OP-TEE is not found:

=> bootefi hello
Unable to open OP-TEE session (err=-19)
mm_communicate failed!
Error: Cannot initialize UEFI sub-system, r = 3

I think it could be allowable to boot without variable support unless we
are in secure boot audit mode. So if CONFIG_EFI_SECURE_BOOT=n, maybe we
should be less strict. I guess it will end up in weighing user
friendliness against complexity. What are your ideas?

Best regards

Heinrich

[PATCH 2/5 v2] efi_loader: Implement EFI variable handling via OP-TEE

[Ilias Apalodimas]

On Fri, May 15, 2020 at 01:55:35PM +0200, Heinrich Schuchardt wrote:
> On 11.05.20 20:14, Ilias Apalodimas wrote:
> > In OP-TEE we can run EDK2's StandAloneMM on a secure partition.
> > StandAloneMM is responsible for the UEFI variable support. In
> > combination with OP-TEE and it's U-Boot supplicant, variables are
> > authenticated/validated in secure world and stored on an RPMB partition.
> >
> > So let's add a new config option in U-Boot implementing the necessary
> > calls to OP-TEE for the variable management.
> >
> > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> > Signed-off-by: Pipat Methavanitpong <pipat1010@gmail.com>
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > ---
> >  lib/efi_loader/Kconfig            |   9 +
> >  lib/efi_loader/Makefile           |   4 +
> >  lib/efi_loader/efi_variable_tee.c | 643 ++++++++++++++++++++++++++++++
> >  3 files changed, 656 insertions(+)
> >  create mode 100644 lib/efi_loader/efi_variable_tee.c
> >
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index 1cfa24ffcf72..e385cd0b9dae 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -164,4 +164,13 @@ config EFI_SECURE_BOOT
> >  	  it is signed with a trusted key. To do that, you need to install,
> >  	  at least, PK, KEK and db.
> >
> > +config EFI_MM_COMM_TEE
> > +	bool "UEFI variables storage service via OP-TEE"
> > +	depends on SUPPORT_EMMC_RPMB
> > +	default n
> > +	help
> > +	  If OP-TEE is present and running StandAloneMM dispatch all UEFI variable
> > +	  related operations to that. The application will verify, authenticate and
> > +	  store the variables on an RPMB
> > +
> >  endif
> 
> Dear Ilias,
> 
> at least CONFIG_TEE=y is needed as dependency. Otherwise compiling fails.

Ok I'll add that

> 
> If OP-TEE is not found:
> 
> => bootefi hello
> Unable to open OP-TEE session (err=-19)
> mm_communicate failed!
> Error: Cannot initialize UEFI sub-system, r = 3
> 
> I think it could be allowable to boot without variable support unless we
> are in secure boot audit mode. So if CONFIG_EFI_SECURE_BOOT=n, maybe we
> should be less strict. I guess it will end up in weighing user
> friendliness against complexity. What are your ideas?

I don't have any strong opinions on that tbh. But I think i'd choose the
stricter approach. If it's a UEFI boot/whatever, variables must be initialized
and accessible.

Regards
/Ilias
> 
> Best regards
> 
> Heinrich