[PATCH v12 00/46] arm64: Support for Arm CCA in KVM

@@ -10,6 +10,8 @@
 #include <linux/kvm_host.h>
 #include <uapi/linux/psci.h>
 
+#include <asm/kvm_emulate.h>
+
 #define KVM_ARM_PSCI_0_1	PSCI_VERSION(0, 1)
 #define KVM_ARM_PSCI_0_2	PSCI_VERSION(0, 2)
 #define KVM_ARM_PSCI_1_0	PSCI_VERSION(1, 0)

@@ -858,6 +858,22 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr,
 	return 0;
 }
 
+static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+	const struct fault_info *inf = esr_to_fault_info(esr);
+
+	die_kernel_fault(inf->name, far, esr, regs);
+	return 0;
+}
+
+static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+	if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr))
+		return 0;
+
+	return 1;
+}
+
 static const struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"ttbr address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level 1 address size fault"	},

@@ -894,12 +910,12 @@ static const struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 32"			},
 	{ do_alignment_fault,	SIGBUS,  BUS_ADRALN,	"alignment fault"		},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 34"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 35"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 36"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 37"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 38"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 39"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 40"			},
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"Granule Protection Fault at level -1" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"Granule Protection Fault at level 0" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"Granule Protection Fault at level 1" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"Granule Protection Fault at level 2" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"Granule Protection Fault at level 3" },
+	{ do_gpf,		SIGBUS,  SI_KERNEL,	"Granule Protection Fault not on table walk" },
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level -1 address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 42"			},
 	{ do_translation_fault,	SIGSEGV, SEGV_MAPERR,	"level -1 translation fault"	},

@@ -0,0 +1,269 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2024 ARM Ltd.
+ *
+ * The values and structures in this file are from the Realm Management Monitor
+ * specification (DEN0137) version 1.0-rel0:
+ * https://developer.arm.com/documentation/den0137/1-0rel0/
+ */
+
+#ifndef __ASM_RMI_SMC_H
+#define __ASM_RMI_SMC_H
+
+#include <linux/arm-smccc.h>
+
+#define SMC_RMI_CALL(func)				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+			   ARM_SMCCC_SMC_64,		\
+			   ARM_SMCCC_OWNER_STANDARD,	\
+			   (func))
+
+#define SMC_RMI_VERSION			SMC_RMI_CALL(0x0150)
+#define SMC_RMI_GRANULE_DELEGATE	SMC_RMI_CALL(0x0151)
+#define SMC_RMI_GRANULE_UNDELEGATE	SMC_RMI_CALL(0x0152)
+#define SMC_RMI_DATA_CREATE		SMC_RMI_CALL(0x0153)
+#define SMC_RMI_DATA_CREATE_UNKNOWN	SMC_RMI_CALL(0x0154)
+#define SMC_RMI_DATA_DESTROY		SMC_RMI_CALL(0x0155)
+
+#define SMC_RMI_REALM_ACTIVATE		SMC_RMI_CALL(0x0157)
+#define SMC_RMI_REALM_CREATE		SMC_RMI_CALL(0x0158)
+#define SMC_RMI_REALM_DESTROY		SMC_RMI_CALL(0x0159)
+#define SMC_RMI_REC_CREATE		SMC_RMI_CALL(0x015a)
+#define SMC_RMI_REC_DESTROY		SMC_RMI_CALL(0x015b)
+#define SMC_RMI_REC_ENTER		SMC_RMI_CALL(0x015c)
+#define SMC_RMI_RTT_CREATE		SMC_RMI_CALL(0x015d)
+#define SMC_RMI_RTT_DESTROY		SMC_RMI_CALL(0x015e)
+#define SMC_RMI_RTT_MAP_UNPROTECTED	SMC_RMI_CALL(0x015f)
+
+#define SMC_RMI_RTT_READ_ENTRY		SMC_RMI_CALL(0x0161)
+#define SMC_RMI_RTT_UNMAP_UNPROTECTED	SMC_RMI_CALL(0x0162)
+
+#define SMC_RMI_PSCI_COMPLETE		SMC_RMI_CALL(0x0164)
+#define SMC_RMI_FEATURES		SMC_RMI_CALL(0x0165)
+#define SMC_RMI_RTT_FOLD		SMC_RMI_CALL(0x0166)
+#define SMC_RMI_REC_AUX_COUNT		SMC_RMI_CALL(0x0167)
+#define SMC_RMI_RTT_INIT_RIPAS		SMC_RMI_CALL(0x0168)
+#define SMC_RMI_RTT_SET_RIPAS		SMC_RMI_CALL(0x0169)
+
+#define RMI_ABI_MAJOR_VERSION	1
+#define RMI_ABI_MINOR_VERSION	0
+
+#define RMI_ABI_VERSION_GET_MAJOR(version) ((version) >> 16)
+#define RMI_ABI_VERSION_GET_MINOR(version) ((version) & 0xFFFF)
+#define RMI_ABI_VERSION(major, minor)      (((major) << 16) | (minor))
+
+#define RMI_UNASSIGNED			0
+#define RMI_ASSIGNED			1
+#define RMI_TABLE			2
+
+#define RMI_RETURN_STATUS(ret)		((ret) & 0xFF)
+#define RMI_RETURN_INDEX(ret)		(((ret) >> 8) & 0xFF)
+
+#define RMI_SUCCESS		0
+#define RMI_ERROR_INPUT		1
+#define RMI_ERROR_REALM		2
+#define RMI_ERROR_REC		3
+#define RMI_ERROR_RTT		4
+
+enum rmi_ripas {
+	RMI_EMPTY = 0,
+	RMI_RAM = 1,
+	RMI_DESTROYED = 2,
+};
+
+#define RMI_NO_MEASURE_CONTENT	0
+#define RMI_MEASURE_CONTENT	1
+
+#define RMI_FEATURE_REGISTER_0_S2SZ		GENMASK(7, 0)
+#define RMI_FEATURE_REGISTER_0_LPA2		BIT(8)
+#define RMI_FEATURE_REGISTER_0_SVE_EN		BIT(9)
+#define RMI_FEATURE_REGISTER_0_SVE_VL		GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_0_NUM_BPS		GENMASK(19, 14)
+#define RMI_FEATURE_REGISTER_0_NUM_WPS		GENMASK(25, 20)
+#define RMI_FEATURE_REGISTER_0_PMU_EN		BIT(26)
+#define RMI_FEATURE_REGISTER_0_PMU_NUM_CTRS	GENMASK(31, 27)
+#define RMI_FEATURE_REGISTER_0_HASH_SHA_256	BIT(32)
+#define RMI_FEATURE_REGISTER_0_HASH_SHA_512	BIT(33)
+#define RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS	GENMASK(37, 34)
+#define RMI_FEATURE_REGISTER_0_MAX_RECS_ORDER	GENMASK(41, 38)
+#define RMI_FEATURE_REGISTER_0_Reserved		GENMASK(63, 42)
+
+#define RMI_REALM_PARAM_FLAG_LPA2		BIT(0)
+#define RMI_REALM_PARAM_FLAG_SVE		BIT(1)
+#define RMI_REALM_PARAM_FLAG_PMU		BIT(2)
+
+/*
+ * Note many of these fields are smaller than u64 but all fields have u64
+ * alignment, so use u64 to ensure correct alignment.
+ */
+struct realm_params {
+	union { /* 0x0 */
+		struct {
+			u64 flags;
+			u64 s2sz;
+			u64 sve_vl;
+			u64 num_bps;
+			u64 num_wps;
+			u64 pmu_num_ctrs;
+			u64 hash_algo;
+		};
+		u8 padding0[0x400];
+	};
+	union { /* 0x400 */
+		u8 rpv[64];
+		u8 padding1[0x400];
+	};
+	union { /* 0x800 */
+		struct {
+			u64 vmid;
+			u64 rtt_base;
+			s64 rtt_level_start;
+			u64 rtt_num_start;
+		};
+		u8 padding2[0x800];
+	};
+};
+
+/*
+ * The number of GPRs (starting from X0) that are
+ * configured by the host when a REC is created.
+ */
+#define REC_CREATE_NR_GPRS		8
+
+#define REC_PARAMS_FLAG_RUNNABLE	BIT_ULL(0)
+
+#define REC_PARAMS_AUX_GRANULES		16
+
+struct rec_params {
+	union { /* 0x0 */
+		u64 flags;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		u64 mpidr;
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 pc;
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		u64 gprs[REC_CREATE_NR_GPRS];
+		u8 padding3[0x500];
+	};
+	union { /* 0x800 */
+		struct {
+			u64 num_rec_aux;
+			u64 aux[REC_PARAMS_AUX_GRANULES];
+		};
+		u8 padding4[0x800];
+	};
+};
+
+#define REC_ENTER_FLAG_EMULATED_MMIO	BIT(0)
+#define REC_ENTER_FLAG_INJECT_SEA	BIT(1)
+#define REC_ENTER_FLAG_TRAP_WFI		BIT(2)
+#define REC_ENTER_FLAG_TRAP_WFE		BIT(3)
+#define REC_ENTER_FLAG_RIPAS_RESPONSE	BIT(4)
+
+#define REC_RUN_GPRS			31
+#define REC_MAX_GIC_NUM_LRS		16
+
+#define RMI_PERMITTED_GICV3_HCR_BITS	(ICH_HCR_EL2_UIE |		\
+					 ICH_HCR_EL2_LRENPIE |		\
+					 ICH_HCR_EL2_NPIE |		\
+					 ICH_HCR_EL2_VGrp0EIE |		\
+					 ICH_HCR_EL2_VGrp0DIE |		\
+					 ICH_HCR_EL2_VGrp1EIE |		\
+					 ICH_HCR_EL2_VGrp1DIE |		\
+					 ICH_HCR_EL2_TDIR)
+
+struct rec_enter {
+	union { /* 0x000 */
+		u64 flags;
+		u8 padding0[0x200];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding1[0x100];
+	};
+	union { /* 0x300 */
+		struct {
+			u64 gicv3_hcr;
+			u64 gicv3_lrs[REC_MAX_GIC_NUM_LRS];
+		};
+		u8 padding2[0x100];
+	};
+	u8 padding3[0x400];
+};
+
+#define RMI_EXIT_SYNC			0x00
+#define RMI_EXIT_IRQ			0x01
+#define RMI_EXIT_FIQ			0x02
+#define RMI_EXIT_PSCI			0x03
+#define RMI_EXIT_RIPAS_CHANGE		0x04
+#define RMI_EXIT_HOST_CALL		0x05
+#define RMI_EXIT_SERROR			0x06
+
+struct rec_exit {
+	union { /* 0x000 */
+		u8 exit_reason;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		struct {
+			u64 esr;
+			u64 far;
+			u64 hpfar;
+		};
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		struct {
+			u64 gicv3_hcr;
+			u64 gicv3_lrs[REC_MAX_GIC_NUM_LRS];
+			u64 gicv3_misr;
+			u64 gicv3_vmcr;
+		};
+		u8 padding3[0x100];
+	};
+	union { /* 0x400 */
+		struct {
+			u64 cntp_ctl;
+			u64 cntp_cval;
+			u64 cntv_ctl;
+			u64 cntv_cval;
+		};
+		u8 padding4[0x100];
+	};
+	union { /* 0x500 */
+		struct {
+			u64 ripas_base;
+			u64 ripas_top;
+			u8 ripas_value;
+			u8 padding8[7];
+		};
+		u8 padding5[0x100];
+	};
+	union { /* 0x600 */
+		u16 imm;
+		u8 padding6[0x100];
+	};
+	union { /* 0x700 */
+		struct {
+			u8 pmu_ovf_status;
+		};
+		u8 padding7[0x100];
+	};
+};
+
+struct rec_run {
+	struct rec_enter enter;
+	struct rec_exit exit;
+};
+
+#endif /* __ASM_RMI_SMC_H */

@@ -0,0 +1,508 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#ifndef __ASM_RMI_CMDS_H
+#define __ASM_RMI_CMDS_H
+
+#include <linux/arm-smccc.h>
+
+#include <asm/rmi_smc.h>
+
+struct rtt_entry {
+	unsigned long walk_level;
+	unsigned long desc;
+	int state;
+	int ripas;
+};
+
+/**
+ * rmi_data_create() - Create a data granule
+ * @rd: PA of the RD
+ * @data: PA of the target granule
+ * @ipa: IPA at which the granule will be mapped in the guest
+ * @src: PA of the source granule
+ * @flags: RMI_MEASURE_CONTENT if the contents should be measured
+ *
+ * Create a new data granule, copying contents from a non-secure granule.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_create(unsigned long rd, unsigned long data,
+				  unsigned long ipa, unsigned long src,
+				  unsigned long flags)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_DATA_CREATE, rd, data, ipa, src,
+			     flags, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_data_create_unknown() - Create a data granule with unknown contents
+ * @rd: PA of the RD
+ * @data: PA of the target granule
+ * @ipa: IPA at which the granule will be mapped in the guest
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_create_unknown(unsigned long rd,
+					  unsigned long data,
+					  unsigned long ipa)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_DATA_CREATE_UNKNOWN, rd, data, ipa, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_data_destroy() - Destroy a data granule
+ * @rd: PA of the RD
+ * @ipa: IPA at which the granule is mapped in the guest
+ * @data_out: PA of the granule which was destroyed
+ * @top_out: Top IPA of non-live RTT entries
+ *
+ * Unmap a protected IPA from stage 2, transitioning it to DESTROYED.
+ * The IPA cannot be used by the guest unless it is transitioned to RAM again
+ * by the realm guest.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_destroy(unsigned long rd, unsigned long ipa,
+				   unsigned long *data_out,
+				   unsigned long *top_out)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_DATA_DESTROY, rd, ipa, &res);
+
+	if (data_out)
+		*data_out = res.a1;
+	if (top_out)
+		*top_out = res.a2;
+
+	return res.a0;
+}
+
+/**
+ * rmi_features() - Read feature register
+ * @index: Feature register index
+ * @out: Feature register value is written to this pointer
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_features(unsigned long index, unsigned long *out)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_FEATURES, index, &res);
+
+	if (out)
+		*out = res.a1;
+	return res.a0;
+}
+
+/**
+ * rmi_granule_delegate() - Delegate a granule
+ * @phys: PA of the granule
+ *
+ * Delegate a granule for use by the realm world.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_granule_delegate(unsigned long phys)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_GRANULE_DELEGATE, phys, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_granule_undelegate() - Undelegate a granule
+ * @phys: PA of the granule
+ *
+ * Undelegate a granule to allow use by the normal world. Will fail if the
+ * granule is in use.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_granule_undelegate(unsigned long phys)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_GRANULE_UNDELEGATE, phys, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_psci_complete() - Complete pending PSCI command
+ * @calling_rec: PA of the calling REC
+ * @target_rec: PA of the target REC
+ * @status: Status of the PSCI request
+ *
+ * Completes a pending PSCI command which was called with an MPIDR argument, by
+ * providing the corresponding REC.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_psci_complete(unsigned long calling_rec,
+				    unsigned long target_rec,
+				    unsigned long status)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_PSCI_COMPLETE, calling_rec, target_rec,
+			     status, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_realm_activate() - Active a realm
+ * @rd: PA of the RD
+ *
+ * Mark a realm as Active signalling that creation is complete and allowing
+ * execution of the realm.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_activate(unsigned long rd)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REALM_ACTIVATE, rd, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_realm_create() - Create a realm
+ * @rd: PA of the RD
+ * @params: PA of realm parameters
+ *
+ * Create a new realm using the given parameters.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_create(unsigned long rd, unsigned long params)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REALM_CREATE, rd, params, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_realm_destroy() - Destroy a realm
+ * @rd: PA of the RD
+ *
+ * Destroys a realm, all objects belonging to the realm must be destroyed first.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_destroy(unsigned long rd)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REALM_DESTROY, rd, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rec_aux_count() - Get number of auxiliary granules required
+ * @rd: PA of the RD
+ * @aux_count: Number of granules written to this pointer
+ *
+ * A REC may require extra auxiliary granules to be delegated for the RMM to
+ * store metadata (not visible to the normal world) in. This function provides
+ * the number of granules that are required.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_aux_count(unsigned long rd, unsigned long *aux_count)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REC_AUX_COUNT, rd, &res);
+
+	if (aux_count)
+		*aux_count = res.a1;
+	return res.a0;
+}
+
+/**
+ * rmi_rec_create() - Create a REC
+ * @rd: PA of the RD
+ * @rec: PA of the target REC
+ * @params: PA of REC parameters
+ *
+ * Create a REC using the parameters specified in the struct rec_params pointed
+ * to by @params.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_create(unsigned long rd, unsigned long rec,
+				 unsigned long params)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REC_CREATE, rd, rec, params, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rec_destroy() - Destroy a REC
+ * @rec: PA of the target REC
+ *
+ * Destroys a REC. The REC must not be running.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_destroy(unsigned long rec)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REC_DESTROY, rec, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rec_enter() - Enter a REC
+ * @rec: PA of the target REC
+ * @run_ptr: PA of RecRun structure
+ *
+ * Starts (or continues) execution within a REC.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_enter(unsigned long rec, unsigned long run_ptr)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REC_ENTER, rec, run_ptr, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_create() - Creates an RTT
+ * @rd: PA of the RD
+ * @rtt: PA of the target RTT
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ *
+ * Creates an RTT (Realm Translation Table) at the specified level for the
+ * translation of the specified address within the realm.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_create(unsigned long rd, unsigned long rtt,
+				 unsigned long ipa, long level)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_CREATE, rd, rtt, ipa, level, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_destroy() - Destroy an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ * @out_top: Pointer to write the top IPA of non-live RTT entries
+ *
+ * Destroys an RTT. The RTT must be non-live, i.e. none of the entries in the
+ * table are in ASSIGNED or TABLE state.
+ *
+ * Return: RMI return code.
+ */
+static inline int rmi_rtt_destroy(unsigned long rd,
+				  unsigned long ipa,
+				  long level,
+				  unsigned long *out_rtt,
+				  unsigned long *out_top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_DESTROY, rd, ipa, level, &res);
+
+	if (out_rtt)
+		*out_rtt = res.a1;
+	if (out_top)
+		*out_top = res.a2;
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_fold() - Fold an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ *
+ * Folds an RTT. If all entries with the RTT are 'homogeneous' the RTT can be
+ * folded into the parent and the RTT destroyed.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_fold(unsigned long rd, unsigned long ipa,
+			       long level, unsigned long *out_rtt)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_FOLD, rd, ipa, level, &res);
+
+	if (out_rtt)
+		*out_rtt = res.a1;
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_init_ripas() - Set RIPAS for new realm
+ * @rd: PA of the RD
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Top IPA of range whose RIPAS was modified
+ *
+ * Sets the RIPAS of a target IPA range to RAM, for a realm in the NEW state.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_init_ripas(unsigned long rd, unsigned long base,
+				     unsigned long top, unsigned long *out_top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_INIT_RIPAS, rd, base, top, &res);
+
+	if (out_top)
+		*out_top = res.a1;
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_map_unprotected() - Map NS granules into a realm
+ * @rd: PA of the RD
+ * @ipa: Base IPA of the mapping
+ * @level: Depth within the RTT tree
+ * @desc: RTTE descriptor
+ *
+ * Create a mapping from an Unprotected IPA to a Non-secure PA.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_map_unprotected(unsigned long rd,
+					  unsigned long ipa,
+					  long level,
+					  unsigned long desc)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_MAP_UNPROTECTED, rd, ipa, level,
+			     desc, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_read_entry() - Read an RTTE
+ * @rd: PA of the RD
+ * @ipa: IPA for which to read the RTTE
+ * @level: RTT level at which to read the RTTE
+ * @rtt: Output structure describing the RTTE
+ *
+ * Reads a RTTE (Realm Translation Table Entry).
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_read_entry(unsigned long rd, unsigned long ipa,
+				     long level, struct rtt_entry *rtt)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_READ_ENTRY,
+		rd, ipa, level
+	};
+
+	arm_smccc_1_2_invoke(&regs, &regs);
+
+	rtt->walk_level = regs.a1;
+	rtt->state = regs.a2 & 0xFF;
+	rtt->desc = regs.a3;
+	rtt->ripas = regs.a4 & 0xFF;
+
+	return regs.a0;
+}
+
+/**
+ * rmi_rtt_set_ripas() - Set RIPAS for an running realm
+ * @rd: PA of the RD
+ * @rec: PA of the REC making the request
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Pointer to write top IPA of range whose RIPAS was modified
+ *
+ * Completes a request made by the realm to change the RIPAS of a target IPA
+ * range.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_set_ripas(unsigned long rd, unsigned long rec,
+				    unsigned long base, unsigned long top,
+				    unsigned long *out_top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_SET_RIPAS, rd, rec, base, top, &res);
+
+	if (out_top)
+		*out_top = res.a1;
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_unmap_unprotected() - Remove a NS mapping
+ * @rd: PA of the RD
+ * @ipa: Base IPA of the mapping
+ * @level: Depth within the RTT tree
+ * @out_top: Pointer to write top IPA of non-live RTT entries
+ *
+ * Removes a mapping at an Unprotected IPA.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_unmap_unprotected(unsigned long rd,
+					    unsigned long ipa,
+					    long level,
+					    unsigned long *out_top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RTT_UNMAP_UNPROTECTED, rd, ipa,
+			     level, &res);
+
+	if (out_top)
+		*out_top = res.a1;
+
+	return res.a0;
+}
+
+#endif /* __ASM_RMI_CMDS_H */

@@ -696,4 +696,22 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
 			vcpu->arch.hcrx_el2 |= HCRX_EL2_SCTLR2En;
 	}
 }
+
+static inline bool kvm_is_realm(struct kvm *kvm)
+{
+	if (static_branch_unlikely(&kvm_rmi_is_available))
+		return kvm->arch.is_realm;
+	return false;
+}
+
+static inline enum realm_state kvm_realm_state(struct kvm *kvm)
+{
+	return READ_ONCE(kvm->arch.realm.state);
+}
+
+static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu)
+{
+	return false;
+}
+
 #endif /* __ARM64_KVM_EMULATE_H__ */

@@ -27,6 +27,7 @@
 #include <asm/fpsimd.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
+#include <asm/kvm_rmi.h>
 #include <asm/vncr_mapping.h>
 
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED

@@ -408,6 +409,9 @@ struct kvm_arch {
 	 * the associated pKVM instance in the hypervisor.
 	 */
 	struct kvm_protected_vm pkvm;
+
+	bool is_realm;
+	struct realm realm;
 };
 
 struct kvm_vcpu_fault_info {

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2025 ARM Ltd.
+ */
+
+#ifndef __ASM_KVM_RMI_H
+#define __ASM_KVM_RMI_H
+
+/**
+ * enum realm_state - State of a Realm
+ */
+enum realm_state {
+	/**
+	 * @REALM_STATE_NONE:
+	 *      Realm has not yet been created. rmi_realm_create() has not
+	 *      yet been called.
+	 */
+	REALM_STATE_NONE,
+	/**
+	 * @REALM_STATE_NEW:
+	 *      Realm is under construction, rmi_realm_create() has been
+	 *      called, but it is not yet activated. Pages may be populated.
+	 */
+	REALM_STATE_NEW,
+	/**
+	 * @REALM_STATE_ACTIVE:
+	 *      Realm has been created and is eligible for execution with
+	 *      rmi_rec_enter(). Pages may no longer be populated with
+	 *      rmi_data_create().
+	 */
+	REALM_STATE_ACTIVE,
+	/**
+	 * @REALM_STATE_DYING:
+	 *      Realm is in the process of being destroyed or has already been
+	 *      destroyed.
+	 */
+	REALM_STATE_DYING,
+	/**
+	 * @REALM_STATE_DEAD:
+	 *      Realm has been destroyed.
+	 */
+	REALM_STATE_DEAD
+};
+
+/**
+ * struct realm - Additional per VM data for a Realm
+ *
+ * @state: The lifetime state machine for the realm
+ */
+struct realm {
+	enum realm_state state;
+};
+
+void kvm_init_rmi(void);
+
+#endif /* __ASM_KVM_RMI_H */