[PATCH v4 1/6] arm64: rsi: Add RSI host call structure and helper function
flat view
COOLING9d
REVIEWED: 1 (0M)
From: Kameron Carr <hidden>
Date: 2026-10-01 22:06:59
Also in:
linux-arch, linux-arm-kernel, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Revision v4 of 5 in this series; 1 review trailer.
Revisions (5)
Add struct rsi_host_call to rsi_smc.h, which represents the host call data structure used by the Realm Management Monitor (RMM) for the RSI_HOST_CALL interface. The structure contains a 16-bit immediate field and 31 general-purpose register values, aligned to 256 bytes as required by the CCA RMM specification. Add rsi_host_call() static inline wrapper in rsi_cmds.h that invokes SMC_RSI_HOST_CALL with the physical address of the host call structure. This will be used by Hyper-V guest code to route hypercalls through the RSI interface when running inside an Arm CCA Realm. Reviewed-by: Michael Kelley <redacted> Signed-off-by: Kameron Carr <redacted> --- include/linux/arm-rsi-cmds.h | 22 ++++++++++++++++++++++ include/linux/arm-smccc-rsi.h | 7 +++++++ 2 files changed, 29 insertions(+)
diff --git a/include/linux/arm-rsi-cmds.h b/include/linux/arm-rsi-cmds.h
index 3f7a6a8..01d292e 100644
--- a/include/linux/arm-rsi-cmds.h
+++ b/include/linux/arm-rsi-cmds.h@@ -236,4 +236,26 @@ static inline unsigned long rsi_attestation_token_continue(phys_addr_t granule, return res.a0; } +/** + * rsi_host_call - Make a Host call. + * @host_call_struct: IPA of host call structure + * + * This call will fail if the IPA of the host call structure: + * * is not aligned to 256 bytes, + * * is not protected / encrypted, + * * is RIPAS_EMPTY + * + * Returns: + * On success, returns RSI_SUCCESS. + * Otherwise, returns an error code. + */ +static inline unsigned long rsi_host_call(phys_addr_t host_call_struct) +{ + struct arm_smccc_res res; + + arm_smccc_smc(SMC_RSI_HOST_CALL, host_call_struct, 0, 0, 0, 0, 0, 0, + &res); + return res.a0; +} + #endif /* __LINUX_ARM_RSI_CMDS_H_ */
diff --git a/include/linux/arm-smccc-rsi.h b/include/linux/arm-smccc-rsi.h
index fddb779..4c8530b 100644
--- a/include/linux/arm-smccc-rsi.h
+++ b/include/linux/arm-smccc-rsi.h@@ -142,6 +142,13 @@ struct realm_config { */ } __aligned(0x1000); +struct rsi_host_call { + u16 immediate; + u8 _padding[6]; + u64 gprs[31]; +} __aligned(256); +static_assert(sizeof(struct rsi_host_call) == 256); + #endif /* __ASSEMBLER__ */ /*
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