Re: [PATCH v5 03/19] arm64: rsi: Add RSI definitions
From: Steven Price
Date: Mon Sep 09 2024 - 05:12:45 EST
On 09/09/2024 06:10, Gavin Shan wrote:
> On 8/19/24 11:19 PM, Steven Price wrote:
>> From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
>>
>> The RMM (Realm Management Monitor) provides functionality that can be
>> accessed by a realm guest through SMC (Realm Services Interface) calls.
>>
>> The SMC definitions are based on DEN0137[1] version 1.0-rel0-rc1.
>>
>> [1]
>> https://developer.arm.com/-/cdn-downloads/permalink/PDF/Architectures/DEN0137_1.0-rel0-rc1_rmm-arch_external.pdf
>>
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
>> Signed-off-by: Steven Price <steven.price@xxxxxxx>
>> ---
>> Changes since v4:
>> * Update to match the latest RMM spec version 1.0-rel0-rc1.
>> * Make use of the ARM_SMCCC_CALL_VAL macro.
>> * Cast using (_UL macro) various values to unsigned long.
>> Changes since v3:
>> * Drop invoke_rsi_fn_smc_with_res() function and call arm_smccc_smc()
>> directly instead.
>> * Rename header guard in rsi_smc.h to be consistent.
>> Changes since v2:
>> * Rename rsi_get_version() to rsi_request_version()
>> * Fix size/alignment of struct realm_config
>> ---
>> arch/arm64/include/asm/rsi_cmds.h | 136 +++++++++++++++++++++
>> arch/arm64/include/asm/rsi_smc.h | 189 ++++++++++++++++++++++++++++++
>> 2 files changed, 325 insertions(+)
>> create mode 100644 arch/arm64/include/asm/rsi_cmds.h
>> create mode 100644 arch/arm64/include/asm/rsi_smc.h
>>
>
> With the following minor comments addressed:
>
> Reviewed-by: Gavin Shan <gshan@xxxxxxxxx>
Thanks for the review!
>> diff --git a/arch/arm64/include/asm/rsi_cmds.h
>> b/arch/arm64/include/asm/rsi_cmds.h
>> new file mode 100644
>> index 000000000000..968b03f4e703
>> --- /dev/null
>> +++ b/arch/arm64/include/asm/rsi_cmds.h
>> @@ -0,0 +1,136 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2023 ARM Ltd.
>> + */
>> +
>> +#ifndef __ASM_RSI_CMDS_H
>> +#define __ASM_RSI_CMDS_H
>> +
>> +#include <linux/arm-smccc.h>
>> +
>> +#include <asm/rsi_smc.h>
>> +
>> +#define RSI_GRANULE_SHIFT 12
>> +#define RSI_GRANULE_SIZE (_AC(1, UL) << RSI_GRANULE_SHIFT)
>> +
>> +enum ripas {
>> + RSI_RIPAS_EMPTY = 0,
>> + RSI_RIPAS_RAM = 1,
>> + RSI_RIPAS_DESTROYED = 2,
>> + RSI_RIPAS_IO = 3,
>> +};
>> +
>
> The 'RSI_RIPAS_IO' corresponds to 'RIPAS_DEV' defined in
> tf-rmm/lib/s2tt/include/ripas.h.
> Shall we rename it to RSI_RIPAS_DEV so that the name is matched with
> that defined in
> tf-rmm?
Yes it should be renamed. This was posted based on the v1.0-rel0-rc1
spec and follows the naming there. But shortly after that spec was
released the decision to rename to RIPAS_DEV was made (as it's really
specifying that it's a device not that I/O is happening at an address).
I kept the naming to match the spec, but the next release of the spec
should have the RIPAS_DEV so I'll update to match that.
> ---> tf-rmm/lib/s2tt/include/ripas.h
>
> /*
> * The RmmRipas enumeration represents realm IPA state.
> *
> * Map RmmRipas to RmiRipas to simplify code/decode operations.
> */
> enum ripas {
> RIPAS_EMPTY = RMI_EMPTY, /* Unused IPA for Realm */
> RIPAS_RAM = RMI_RAM, /* IPA used for Code/Data by
> Realm */
> RIPAS_DESTROYED = RMI_DESTROYED,/* IPA is inaccessible to the
> Realm */
> RIPAS_DEV /* Address where memory of an
> assigned
> Realm device is mapped */
> };
>
>> +static inline unsigned long rsi_request_version(unsigned long req,
>> + unsigned long *out_lower,
>> + unsigned long *out_higher)
>> +{
>> + struct arm_smccc_res res;
>> +
>> + arm_smccc_smc(SMC_RSI_ABI_VERSION, req, 0, 0, 0, 0, 0, 0, &res);
>> +
>> + if (out_lower)
>> + *out_lower = res.a1;
>> + if (out_higher)
>> + *out_higher = res.a2;
>> +
>> + return res.a0;
>> +}
>> +
>> +static inline unsigned long rsi_get_realm_config(struct realm_config
>> *cfg)
>> +{
>> + struct arm_smccc_res res;
>> +
>> + arm_smccc_smc(SMC_RSI_REALM_CONFIG, virt_to_phys(cfg),
>> + 0, 0, 0, 0, 0, 0, &res);
>> + return res.a0;
>> +}
>> +
>> +static inline unsigned long rsi_set_addr_range_state(phys_addr_t start,
>> + phys_addr_t end,
>> + enum ripas state,
>> + unsigned long flags,
>> + phys_addr_t *top)
>> +{
>> + struct arm_smccc_res res;
>> +
>> + arm_smccc_smc(SMC_RSI_IPA_STATE_SET, start, end, state,
>> + flags, 0, 0, 0, &res);
>> +
>> + if (top)
>> + *top = res.a1;
>> +
>> + return res.a0;
>> +}
>> +
>> +/**
>> + * rsi_attestation_token_init - Initialise the operation to retrieve an
>> + * attestation token.
>> + *
>> + * @challenge: The challenge data to be used in the attestation token
>> + * generation.
>> + * @size: Size of the challenge data in bytes.
>> + *
>> + * Initialises the attestation token generation and returns an upper
>> bound
>> + * on the attestation token size that can be used to allocate an
>> adequate
>> + * buffer. The caller is expected to subsequently call
>> + * rsi_attestation_token_continue() to retrieve the attestation token
>> data on
>> + * the same CPU.
>> + *
>> + * Returns:
>> + * On success, returns the upper limit of the attestation report size.
>> + * Otherwise, -EINVAL
>> + */
>> +static inline unsigned long
>> +rsi_attestation_token_init(const u8 *challenge, unsigned long size)
>> +{
>> + struct arm_smccc_1_2_regs regs = { 0 };
>> +
>> + /* The challenge must be at least 32bytes and at most 64bytes */
>> + if (!challenge || size < 32 || size > 64)
>> + return -EINVAL;
>> +
>> + regs.a0 = SMC_RSI_ATTESTATION_TOKEN_INIT;
>> + memcpy(®s.a1, challenge, size);
>> + arm_smccc_1_2_smc(®s, ®s);
>> +
>> + if (regs.a0 == RSI_SUCCESS)
>> + return regs.a1;
>> +
>> + return -EINVAL;
>> +}
>> +
>
> The type of the return value would be 'long' instead of 'unsigned long'
> since
> '-EINVAL' can be returned.
Good spot! The call site is casting back to long, so it "should work",
but clearly this is the wrong type.
>> +/**
>> + * rsi_attestation_token_continue - Continue the operation to
>> retrieve an
>> + * attestation token.
>> + *
>> + * @granule: {I}PA of the Granule to which the token will be written.
>> + * @offset: Offset within Granule to start of buffer in bytes.
>> + * @size: The size of the buffer.
>> + * @len: The number of bytes written to the buffer.
>> + *
>> + * Retrieves up to a RSI_GRANULE_SIZE worth of token data per call.
>> The caller
>> + * is expected to call rsi_attestation_token_init() before calling this
>> + * function to retrieve the attestation token.
>> + *
>> + * Return:
>> + * * %RSI_SUCCESS - Attestation token retrieved successfully.
>> + * * %RSI_INCOMPLETE - Token generation is not complete.
>> + * * %RSI_ERROR_INPUT - A parameter was not valid.
>> + * * %RSI_ERROR_STATE - Attestation not in progress.
>> + */
>> +static inline int rsi_attestation_token_continue(phys_addr_t granule,
>> + unsigned long offset,
>> + unsigned long size,
>> + unsigned long *len)
>> +{
>> + struct arm_smccc_res res;
>> +
>> + arm_smccc_1_1_invoke(SMC_RSI_ATTESTATION_TOKEN_CONTINUE,
>> + granule, offset, size, 0, &res);
>> +
>> + if (len)
>> + *len = res.a1;
>> + return res.a0;
>> +}
>> +
>> +#endif /* __ASM_RSI_CMDS_H */
>> diff --git a/arch/arm64/include/asm/rsi_smc.h
>> b/arch/arm64/include/asm/rsi_smc.h
>> new file mode 100644
>> index 000000000000..b76b03a8fea8
>> --- /dev/null
>> +++ b/arch/arm64/include/asm/rsi_smc.h
>> @@ -0,0 +1,189 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2023 ARM Ltd.
>> + */
>> +
>> +#ifndef __ASM_RSI_SMC_H_
>> +#define __ASM_RSI_SMC_H_
>> +
>> +#include <linux/arm-smccc.h>
>> +
>> +/*
>> + * This file describes the Realm Services Interface (RSI) Application
>> Binary
>> + * Interface (ABI) for SMC calls made from within the Realm to the
>> RMM and
>> + * serviced by the RMM.
>> + */
>> +
>> +/*
>> + * The major version number of the RSI implementation. This is
>> increased when
>> + * the binary format or semantics of the SMC calls change.
>> + */
>> +#define RSI_ABI_VERSION_MAJOR UL(1)
>> +
>> +/*
>> + * The minor version number of the RSI implementation. This is
>> increased when
>> + * a bug is fixed, or a feature is added without breaking binary
>> compatibility.
>> + */
>> +#define RSI_ABI_VERSION_MINOR UL(0)
>> +
>> +#define RSI_ABI_VERSION ((RSI_ABI_VERSION_MAJOR << 16) | \
>> + RSI_ABI_VERSION_MINOR)
>> +
>> +#define RSI_ABI_VERSION_GET_MAJOR(_version) ((_version) >> 16)
>> +#define RSI_ABI_VERSION_GET_MINOR(_version) ((_version) & 0xFFFF)
>> +
>> +#define RSI_SUCCESS UL(0)
>> +#define RSI_ERROR_INPUT UL(1)
>> +#define RSI_ERROR_STATE UL(2)
>> +#define RSI_INCOMPLETE UL(3)
>> +#define RSI_ERROR_UNKNOWN UL(4)
>> +
>> +#define SMC_RSI_FID(n)
>> ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
>> + ARM_SMCCC_SMC_64, \
>> + ARM_SMCCC_OWNER_STANDARD, \
>> + n)
>> +
>> +/*
>> + * Returns RSI version.
>> + *
>> + * arg1 == Requested interface revision
>> + * ret0 == Status /error
>> + * ret1 == Lower implemented interface revision
>> + * ret2 == Higher implemented interface revision
>> + */
>> +#define SMC_RSI_ABI_VERSION SMC_RSI_FID(0x190)
>> +
>> +/*
>> + * Read feature register.
>> + *
>> + * arg1 == Feature register index
>> + * ret0 == Status /error
> ^^^^^^^^^^^^^
> Status / error
Ack
>> + * ret1 == Feature register value
>> + */
>> +#define SMC_RSI_FEATURES SMC_RSI_FID(0x191)
>> +
>> +/*
>> + * Read measurement for the current Realm.
>> + *
>> + * arg1 == Index, which measurements slot to read
>> + * ret0 == Status / error
>> + * ret1 == Measurement value, bytes: 0 - 7
>> + * ret2 == Measurement value, bytes: 7 - 15
> ^^^^^^
> 8 - 15
>
>> + * ret3 == Measurement value, bytes: 16 - 23
>> + * ret4 == Measurement value, bytes: 24 - 31
>> + * ret5 == Measurement value, bytes: 32 - 39
>> + * ret6 == Measurement value, bytes: 40 - 47
>> + * ret7 == Measurement value, bytes: 48 - 55
>> + * ret8 == Measurement value, bytes: 56 - 63
>> + */
>> +#define SMC_RSI_MEASUREMENT_READ SMC_RSI_FID(0x192)
>> +
>> +/*
>> + * Extend Realm Extensible Measurement (REM) value.
>> + *
>> + * arg1 == Index, which measurements slot to extend
>> + * arg2 == Size of realm measurement in bytes, max 64 bytes
>> + * arg3 == Measurement value, bytes: 0 - 7
>> + * arg4 == Measurement value, bytes: 7 - 15
> ^^^^^^
> 8 - 15
>
>> + * arg5 == Measurement value, bytes: 16 - 23
>> + * arg6 == Measurement value, bytes: 24 - 31
>> + * arg7 == Measurement value, bytes: 32 - 39
>> + * arg8 == Measurement value, bytes: 40 - 47
>> + * arg9 == Measurement value, bytes: 48 - 55
>> + * arg10 == Measurement value, bytes: 56 - 63
>> + * ret0 == Status / error
>> + */
>> +#define SMC_RSI_MEASUREMENT_EXTEND SMC_RSI_FID(0x193)
>> +
>> +/*
>> + * Initialize the operation to retrieve an attestation token.
>> + *
>> + * arg1 == Challenge value, bytes: 0 - 7
>> + * arg2 == Challenge value, bytes: 7 - 15
> ^^^^^^
> 8 - 15
One mistake and too much copy/pasting :(
>> + * arg3 == Challenge value, bytes: 16 - 23
>> + * arg4 == Challenge value, bytes: 24 - 31
>> + * arg5 == Challenge value, bytes: 32 - 39
>> + * arg6 == Challenge value, bytes: 40 - 47
>> + * arg7 == Challenge value, bytes: 48 - 55
>> + * arg8 == Challenge value, bytes: 56 - 63
>> + * ret0 == Status / error
>> + * ret1 == Upper bound of token size in bytes
>> + */
>> +#define SMC_RSI_ATTESTATION_TOKEN_INIT SMC_RSI_FID(0x194)
>> +
>> +/*
>> + * Continue the operation to retrieve an attestation token.
>> + *
>> + * arg1 == The IPA of token buffer
>> + * arg2 == Offset within the granule of the token buffer
>> + * arg3 == Size of the granule buffer
>> + * ret0 == Status / error
>> + * ret1 == Length of token bytes copied to the granule buffer
>> + */
>> +#define SMC_RSI_ATTESTATION_TOKEN_CONTINUE SMC_RSI_FID(0x195)
>> +
>> +#ifndef __ASSEMBLY__
>> +
>> +struct realm_config {
>> + union {
>> + struct {
>> + unsigned long ipa_bits; /* Width of IPA in bits */
>> + unsigned long hash_algo; /* Hash algorithm */
>> + };
>> + u8 pad[0x200];
>> + };
>> + union {
>> + u8 rpv[64]; /* Realm Personalization Value */
>> + u8 pad2[0xe00];
>> + };
>> + /*
>> + * The RMM requires the configuration structure to be aligned to
>> a 4k
>> + * boundary, ensure this happens by aligning this structure.
>> + */
>> +} __aligned(0x1000);
>> +
>> +#endif /* __ASSEMBLY__ */
>> +
>> +/*
>> + * Read configuration for the current Realm.
>> + *
>> + * arg1 == struct realm_config addr
>> + * ret0 == Status / error
>> + */
>> +#define SMC_RSI_REALM_CONFIG SMC_RSI_FID(0x196)
>> +
>> +/*
>> + * Request RIPAS of a target IPA range to be changed to a specified
>> value.
>> + *
>> + * arg1 == Base IPA address of target region
>> + * arg2 == Top of the region
>> + * arg3 == RIPAS value
>> + * arg4 == flags
>> + * ret0 == Status / error
>> + * ret1 == Top of modified IPA range
>> + */
>> +#define SMC_RSI_IPA_STATE_SET SMC_RSI_FID(0x197)
>> +
>> +#define RSI_NO_CHANGE_DESTROYED UL(0)
>> +#define RSI_CHANGE_DESTROYED UL(1)
>> +
>
> According to the linked specification, the description for the third
> return value
> has been missed here.
>
> ret2 == Whether the host accepted or rejected the request
Worse than just a documentation error - I'd completely forgotten to
check this extra return value in rsi_set_addr_range_state(). Thanks for
spotting this!
Steve
>> +/*
>> + * Get RIPAS of a target IPA range.
>> + *
>> + * arg1 == Base IPA of target region
>> + * arg2 == End of target IPA region
>> + * ret0 == Status / error
>> + * ret1 == Top of IPA region which has the reported RIPAS value
>> + * ret2 == RIPAS value
>> + */
>> +#define SMC_RSI_IPA_STATE_GET SMC_RSI_FID(0x198)
>> +
>> +/*
>> + * Make a Host call.
>> + *
>> + * arg1 == IPA of host call structure
>> + * ret0 == Status / error
>> + */
>> +#define SMC_RSI_HOST_CALL SMC_RSI_FID(0x199)
>> +
>> +#endif /* __ASM_RSI_SMC_H_ */
>
> Thanks,
> Gavin
>