| From 02e38e24676d48d8a792ab6631a903ae1faa6271 Mon Sep 17 00:00:00 2001 |
| From: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> |
| Date: Mon, 15 Aug 2022 15:12:49 +0100 |
| Subject: [PATCH 09/38] FF-A v15: arm_ffa: efi: introduce FF-A MM communication |
| |
| Add MM communication support using FF-A transport |
| |
| This feature allows accessing MM partitions services through |
| EFI MM communication protocol. MM partitions such as StandAlonneMM |
| or smm-gateway secure partitions which reside in secure world. |
| |
| An MM shared buffer and a door bell event are used to exchange |
| the data. |
| |
| The data is used by EFI services such as GetVariable()/SetVariable() |
| and copied from the communication buffer to the MM shared buffer. |
| |
| The secure partition is notified about availability of data in the |
| MM shared buffer by an FF-A message (door bell). |
| |
| On such event, MM SP can read the data and updates the MM shared |
| buffer with the response data. |
| |
| The response data is copied back to the communication buffer and |
| consumed by the EFI subsystem. |
| |
| MM communication protocol supports FF-A 64-bit direct messaging. |
| |
| Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> |
| Tested-by: Gowtham Suresh Kumar <gowtham.sureshkumar@arm.com> |
| Reviewed-by: Simon Glass <sjg@chromium.org> |
| Cc: Tom Rini <trini@konsulko.com> |
| Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org> |
| Cc: Jens Wiklander <jens.wiklander@linaro.org> |
| Upstream-Status: Submitted [cover letter: https://lore.kernel.org/all/20230713132847.176000-1-abdellatif.elkhlifi@arm.com/] |
| --- |
| include/mm_communication.h | 13 ++ |
| lib/efi_loader/Kconfig | 46 +++++- |
| lib/efi_loader/efi_variable_tee.c | 257 +++++++++++++++++++++++++++++- |
| 3 files changed, 309 insertions(+), 7 deletions(-) |
| |
| diff --git a/include/mm_communication.h b/include/mm_communication.h |
| index e65fbde60d..f17847583b 100644 |
| --- a/include/mm_communication.h |
| +++ b/include/mm_communication.h |
| @@ -6,6 +6,9 @@ |
| * 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> |
| + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com> |
| + * Authors: |
| + * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> |
| */ |
| |
| #ifndef _MM_COMMUNICATION_H_ |
| @@ -13,6 +16,9 @@ |
| |
| #include <part_efi.h> |
| |
| +/* MM service UUID string (big-endian format). This UUID is common across all MM SPs */ |
| +#define MM_SP_UUID "33d532ed-e699-0942-c09c-a798d9cd722d" |
| + |
| /* |
| * Interface to the pseudo Trusted Application (TA), which provides a |
| * communication channel with the Standalone MM (Management Mode) |
| @@ -248,4 +254,11 @@ struct smm_variable_var_check_property { |
| u16 name[]; |
| }; |
| |
| +/* supported MM transports */ |
| +enum mm_comms_select { |
| + MM_COMMS_UNDEFINED, |
| + MM_COMMS_FFA, |
| + MM_COMMS_OPTEE |
| +}; |
| + |
| #endif /* _MM_COMMUNICATION_H_ */ |
| diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig |
| index c5835e6ef6..553e6a30a2 100644 |
| --- a/lib/efi_loader/Kconfig |
| +++ b/lib/efi_loader/Kconfig |
| @@ -55,13 +55,55 @@ config EFI_VARIABLE_FILE_STORE |
| stored as file /ubootefi.var on the EFI system partition. |
| |
| config EFI_MM_COMM_TEE |
| - bool "UEFI variables storage service via OP-TEE" |
| - depends on OPTEE |
| + bool "UEFI variables storage service via the trusted world" |
| + select ARM_FFA_TRANSPORT |
| + select TEE |
| + select OPTEE |
| help |
| + Allowing access to the MM SP services (SPs such as StandAlonneMM, smm-gateway). |
| + When using the u-boot OP-TEE driver, StandAlonneMM is supported. |
| + When using the u-boot FF-A driver any MM SP is supported. |
| + |
| 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. |
| |
| + When ARM_FFA_TRANSPORT is used, dispatch all UEFI variable related |
| + operations to the MM SP running in the secure world. |
| + A door bell mechanism is used to notify the SP when there is data in the shared |
| + MM buffer. The data is copied by u-boot to the shared buffer before issuing |
| + the door bell event. |
| + |
| +config FFA_SHARED_MM_BUF_SIZE |
| + int "Memory size of the shared MM communication buffer" |
| + default 0 |
| + depends on EFI_MM_COMM_TEE |
| + help |
| + This defines the size in bytes of the memory area reserved for the shared |
| + buffer used for communication between the MM feature in U-Boot and |
| + the MM SP in secure world. |
| + The size of the memory region must be a multiple of the size of the maximum |
| + translation granule size that is specified in the ID_AA64MMFR0_EL1 System register. |
| + It is assumed that the MM SP knows the size of the shared MM communication buffer. |
| + |
| +config FFA_SHARED_MM_BUF_OFFSET |
| + int "Data offset in the shared MM communication buffer" |
| + default 0 |
| + depends on EFI_MM_COMM_TEE |
| + help |
| + This defines the offset in bytes of the data read or written to in the shared |
| + buffer by the MM SP. |
| + |
| +config FFA_SHARED_MM_BUF_ADDR |
| + hex "Define the address of the shared MM communication buffer" |
| + default 0x0 |
| + depends on EFI_MM_COMM_TEE |
| + help |
| + This defines the address of the shared MM communication buffer |
| + used for communication between the MM feature in U-Boot and |
| + the MM SP in secure world. |
| + It is assumed that the MM SP knows the address of the shared MM communication buffer. |
| + |
| config EFI_VARIABLE_NO_STORE |
| bool "Don't persist non-volatile UEFI variables" |
| help |
| diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c |
| index dfef18435d..5137b871ea 100644 |
| --- a/lib/efi_loader/efi_variable_tee.c |
| +++ b/lib/efi_loader/efi_variable_tee.c |
| @@ -4,17 +4,34 @@ |
| * |
| * Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org> |
| * Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org> |
| + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com> |
| + * |
| + * Authors: |
| + * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> |
| */ |
| |
| #include <common.h> |
| +#include <arm_ffa.h> |
| +#include <cpu_func.h> |
| +#include <dm.h> |
| #include <efi.h> |
| #include <efi_api.h> |
| #include <efi_loader.h> |
| #include <efi_variable.h> |
| -#include <tee.h> |
| #include <malloc.h> |
| +#include <mapmem.h> |
| #include <mm_communication.h> |
| +#include <tee.h> |
| + |
| +/* MM return codes */ |
| +#define MM_SUCCESS (0) |
| +#define MM_NOT_SUPPORTED (-1) |
| +#define MM_INVALID_PARAMETER (-2) |
| +#define MM_DENIED (-3) |
| +#define MM_NO_MEMORY (-5) |
| |
| +static const char *mm_sp_svc_uuid = MM_SP_UUID; |
| +static u16 mm_sp_id; |
| extern struct efi_var_file __efi_runtime_data *efi_var_buf; |
| static efi_uintn_t max_buffer_size; /* comm + var + func + data */ |
| static efi_uintn_t max_payload_size; /* func + data */ |
| @@ -145,16 +162,241 @@ static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize) |
| } |
| |
| /** |
| - * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send |
| + * ffa_notify_mm_sp() - Announce there is data in the shared buffer |
| + * |
| + * Notify the MM partition in the trusted world that |
| + * data is available in the shared buffer. |
| + * This is a blocking call during which trusted world has exclusive access |
| + * to the MM shared buffer. |
| + * |
| + * Return: |
| + * |
| + * 0 on success |
| + */ |
| +static int ffa_notify_mm_sp(void) |
| +{ |
| + struct ffa_send_direct_data msg = {0}; |
| + int ret; |
| + int sp_event_ret; |
| + struct udevice *dev; |
| + |
| + ret = uclass_first_device_err(UCLASS_FFA, &dev); |
| + if (ret) { |
| + log_err("EFI: Cannot find FF-A bus device, notify MM SP failure\n"); |
| + return ret; |
| + } |
| + |
| + msg.data0 = CONFIG_FFA_SHARED_MM_BUF_OFFSET; /* x3 */ |
| + |
| + ret = ffa_sync_send_receive(dev, mm_sp_id, &msg, 1); |
| + if (ret) |
| + return ret; |
| + |
| + sp_event_ret = msg.data0; /* x3 */ |
| + |
| + switch (sp_event_ret) { |
| + case MM_SUCCESS: |
| + ret = 0; |
| + break; |
| + case MM_NOT_SUPPORTED: |
| + ret = -EINVAL; |
| + break; |
| + case MM_INVALID_PARAMETER: |
| + ret = -EPERM; |
| + break; |
| + case MM_DENIED: |
| + ret = -EACCES; |
| + break; |
| + case MM_NO_MEMORY: |
| + ret = -EBUSY; |
| + break; |
| + default: |
| + ret = -EACCES; |
| + } |
| + |
| + return ret; |
| +} |
| + |
| +/** |
| + * ffa_discover_mm_sp_id() - Query the MM partition ID |
| + * |
| + * Use the FF-A driver to get the MM partition ID. |
| + * If multiple partitions are found, use the first one. |
| + * This is a boot time function. |
| + * |
| + * Return: |
| + * |
| + * 0 on success |
| + */ |
| +static int ffa_discover_mm_sp_id(void) |
| +{ |
| + u32 count = 0; |
| + int ret; |
| + struct ffa_partition_desc *descs; |
| + struct udevice *dev; |
| + |
| + ret = uclass_first_device_err(UCLASS_FFA, &dev); |
| + if (ret) { |
| + log_err("EFI: Cannot find FF-A bus device, MM SP discovery failure\n"); |
| + return ret; |
| + } |
| + |
| + /* Ask the driver to fill the buffer with the SPs info */ |
| + ret = ffa_partition_info_get(dev, mm_sp_svc_uuid, &count, &descs); |
| + if (ret) { |
| + log_err("EFI: Failure in querying SPs info (%d), MM SP discovery failure\n", ret); |
| + return ret; |
| + } |
| + |
| + /* MM SPs found , use the first one */ |
| + |
| + mm_sp_id = descs[0].info.id; |
| + |
| + log_info("EFI: MM partition ID 0x%x\n", mm_sp_id); |
| + |
| + return 0; |
| +} |
| + |
| +/** |
| + * ffa_mm_communicate() - Exchange EFI services data with the MM partition using FF-A |
| + * @comm_buf: locally allocated communication buffer used for rx/tx |
| + * @dsize: communication buffer size |
| + * |
| + * Issue a door bell event to notify the MM partition (SP) running in OP-TEE |
| + * that there is data to read from the shared buffer. |
| + * Communication with the MM SP is performed using FF-A transport. |
| + * On the event, MM SP can read the data from the buffer and |
| + * update the MM shared buffer with response data. |
| + * The response data is copied back to the communication buffer. |
| + * |
| + * Return: |
| + * |
| + * EFI status code |
| + */ |
| +static efi_status_t ffa_mm_communicate(void *comm_buf, ulong comm_buf_size) |
| +{ |
| + ulong tx_data_size; |
| + int ffa_ret; |
| + efi_status_t efi_ret; |
| + struct efi_mm_communicate_header *mm_hdr; |
| + void *virt_shared_buf; |
| + |
| + if (!comm_buf) |
| + return EFI_INVALID_PARAMETER; |
| + |
| + /* Discover MM partition ID at boot time */ |
| + if (!mm_sp_id && ffa_discover_mm_sp_id()) { |
| + log_err("EFI: Failure to discover MM SP ID at boot time, FF-A MM comms failure\n"); |
| + return EFI_UNSUPPORTED; |
| + } |
| + |
| + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; |
| + tx_data_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t); |
| + |
| + if (comm_buf_size != tx_data_size || tx_data_size > CONFIG_FFA_SHARED_MM_BUF_SIZE) |
| + return EFI_INVALID_PARAMETER; |
| + |
| + /* Copy the data to the shared buffer */ |
| + |
| + virt_shared_buf = map_sysmem((phys_addr_t)CONFIG_FFA_SHARED_MM_BUF_ADDR, 0); |
| + memcpy(virt_shared_buf, comm_buf, tx_data_size); |
| + |
| + /* |
| + * The secure world might have cache disabled for |
| + * the device region used for shared buffer (which is the case for Optee). |
| + * In this case, the secure world reads the data from DRAM. |
| + * Let's flush the cache so the DRAM is updated with the latest data. |
| + */ |
| +#ifdef CONFIG_ARM64 |
| + invalidate_dcache_all(); |
| +#endif |
| + |
| + /* Announce there is data in the shared buffer */ |
| + |
| + ffa_ret = ffa_notify_mm_sp(); |
| + |
| + switch (ffa_ret) { |
| + case 0: { |
| + ulong rx_data_size; |
| + /* Copy the MM SP response from the shared buffer to the communication buffer */ |
| + rx_data_size = ((struct efi_mm_communicate_header *)virt_shared_buf)->message_len + |
| + sizeof(efi_guid_t) + |
| + sizeof(size_t); |
| + |
| + if (rx_data_size > comm_buf_size) { |
| + efi_ret = EFI_OUT_OF_RESOURCES; |
| + break; |
| + } |
| + |
| + memcpy(comm_buf, virt_shared_buf, rx_data_size); |
| + efi_ret = EFI_SUCCESS; |
| + break; |
| + } |
| + case -EINVAL: |
| + efi_ret = EFI_DEVICE_ERROR; |
| + break; |
| + case -EPERM: |
| + efi_ret = EFI_INVALID_PARAMETER; |
| + break; |
| + case -EACCES: |
| + efi_ret = EFI_ACCESS_DENIED; |
| + break; |
| + case -EBUSY: |
| + efi_ret = EFI_OUT_OF_RESOURCES; |
| + break; |
| + default: |
| + efi_ret = EFI_ACCESS_DENIED; |
| + } |
| + |
| + unmap_sysmem(virt_shared_buf); |
| + return efi_ret; |
| +} |
| + |
| +/** |
| + * get_mm_comms() - detect the available MM transport |
| + * |
| + * Make sure the FF-A bus is probed successfully |
| + * which means FF-A communication with secure world works and ready |
| + * for use. |
| + * |
| + * If FF-A bus is not ready, use OPTEE comms. |
| + * |
| + * Return: |
| + * |
| + * MM_COMMS_FFA or MM_COMMS_OPTEE |
| + */ |
| +static enum mm_comms_select get_mm_comms(void) |
| +{ |
| + struct udevice *dev; |
| + int ret; |
| + |
| + ret = uclass_first_device_err(UCLASS_FFA, &dev); |
| + if (ret) { |
| + log_err("EFI: Cannot find FF-A bus device, trying Optee comms\n"); |
| + return MM_COMMS_OPTEE; |
| + } |
| + |
| + return MM_COMMS_FFA; |
| +} |
| + |
| +/** |
| + * mm_communicate() - Adjust the communication buffer to the MM SP and send |
| * it to OP-TEE |
| * |
| - * @comm_buf: locally allocted communcation buffer |
| + * @comm_buf: locally allocated communication buffer |
| * @dsize: buffer size |
| + * |
| + * The SP (also called partition) can be any MM SP such as StandAlonneMM or smm-gateway. |
| + * The comm_buf format is the same for both partitions. |
| + * When using the u-boot OP-TEE driver, StandAlonneMM is supported. |
| + * When using the u-boot FF-A driver, any MM SP is supported. |
| + * |
| * Return: status code |
| */ |
| static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize) |
| { |
| efi_status_t ret; |
| + enum mm_comms_select mm_comms; |
| struct efi_mm_communicate_header *mm_hdr; |
| struct smm_variable_communicate_header *var_hdr; |
| |
| @@ -162,7 +404,12 @@ static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize) |
| 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); |
| + mm_comms = get_mm_comms(); |
| + if (mm_comms == MM_COMMS_FFA) |
| + ret = ffa_mm_communicate(comm_buf, dsize); |
| + else |
| + ret = optee_mm_communicate(comm_buf, dsize); |
| + |
| if (ret != EFI_SUCCESS) { |
| log_err("%s failed!\n", __func__); |
| return ret; |
| @@ -697,7 +944,7 @@ void efi_variables_boot_exit_notify(void) |
| ret = EFI_NOT_FOUND; |
| |
| if (ret != EFI_SUCCESS) |
| - log_err("Unable to notify StMM for ExitBootServices\n"); |
| + log_err("Unable to notify the MM partition for ExitBootServices\n"); |
| free(comm_buf); |
| |
| /* |
| -- |
| 2.25.1 |
| |