There is one (multiplexed) CAP which can be used to create, populate and
then activate the realm.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
 Documentation/virt/kvm/api.rst    |  1 +
 arch/arm64/include/uapi/asm/kvm.h | 49 +++++++++++++++++++++++++++++++
 include/uapi/linux/kvm.h          | 12 ++++++++
 3 files changed, 62 insertions(+)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index e32471977d0a..f10dce8232f6 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -5088,6 +5088,7 @@ Recognised values for feature:
 
   =====      ===========================================
   arm64      KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
+  arm64      KVM_ARM_VCPU_REC (requires KVM_CAP_ARM_RME)
   =====      ===========================================
 
 Finalizes the configuration of the specified vcpu feature.
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 964df31da975..080331008b79 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -108,6 +108,7 @@ struct kvm_regs {
 #define KVM_ARM_VCPU_PTRAUTH_ADDRESS	5 /* VCPU uses address authentication */
 #define KVM_ARM_VCPU_PTRAUTH_GENERIC	6 /* VCPU uses generic authentication */
 #define KVM_ARM_VCPU_HAS_EL2		7 /* Support nested virtualization */
+#define KVM_ARM_VCPU_REC		8 /* VCPU REC state as part of Realm */
 
 struct kvm_vcpu_init {
 	__u32 target;
@@ -418,6 +419,54 @@ enum {
 #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
 #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
 
+/* KVM_CAP_ARM_RME on VM fd */
+#define KVM_CAP_ARM_RME_CONFIG_REALM		0
+#define KVM_CAP_ARM_RME_CREATE_RD		1
+#define KVM_CAP_ARM_RME_INIT_IPA_REALM		2
+#define KVM_CAP_ARM_RME_POPULATE_REALM		3
+#define KVM_CAP_ARM_RME_ACTIVATE_REALM		4
+
+#define KVM_CAP_ARM_RME_MEASUREMENT_ALGO_SHA256		0
+#define KVM_CAP_ARM_RME_MEASUREMENT_ALGO_SHA512		1
+
+#define KVM_CAP_ARM_RME_RPV_SIZE 64
+
+/* List of configuration items accepted for KVM_CAP_ARM_RME_CONFIG_REALM */
+#define KVM_CAP_ARM_RME_CFG_RPV			0
+#define KVM_CAP_ARM_RME_CFG_HASH_ALGO		1
+
+struct kvm_cap_arm_rme_config_item {
+	__u32 cfg;
+	union {
+		/* cfg == KVM_CAP_ARM_RME_CFG_RPV */
+		struct {
+			__u8	rpv[KVM_CAP_ARM_RME_RPV_SIZE];
+		};
+
+		/* cfg == KVM_CAP_ARM_RME_CFG_HASH_ALGO */
+		struct {
+			__u32	hash_algo;
+		};
+
+		/* Fix the size of the union */
+		__u8	reserved[256];
+	};
+};
+
+#define KVM_ARM_RME_POPULATE_FLAGS_MEASURE	BIT(0)
+struct kvm_cap_arm_rme_populate_realm_args {
+	__u64 populate_ipa_base;
+	__u64 populate_ipa_size;
+	__u32 flags;
+	__u32 reserved[3];
+};
+
+struct kvm_cap_arm_rme_init_ipa_args {
+	__u64 init_ipa_base;
+	__u64 init_ipa_size;
+	__u32 reserved[4];
+};
+
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0
 #define   KVM_ARM_VCPU_PMU_V3_IRQ	0
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 637efc055145..b3884757739d 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -934,6 +934,8 @@ struct kvm_enable_cap {
 #define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237
 #define KVM_CAP_X86_GUEST_MODE 238
 
+#define KVM_CAP_ARM_RME 300 /* FIXME: Large number to prevent conflicts */
+
 struct kvm_irq_routing_irqchip {
 	__u32 irqchip;
 	__u32 pin;
@@ -1573,4 +1575,14 @@ struct kvm_pre_fault_memory {
 	__u64 padding[5];
 };
 
+/* Available with KVM_CAP_ARM_RME, only for VMs with KVM_VM_TYPE_ARM_REALM  */
+struct kvm_arm_rmm_psci_complete {
+	__u64 target_mpidr;
+	__u32 psci_status;
+	__u32 padding[3];
+};
+
+/* FIXME: Update nr (0xd2) when merging */
+#define KVM_ARM_VCPU_RMM_PSCI_COMPLETE	_IOW(KVMIO, 0xd2, struct kvm_arm_rmm_psci_complete)
+
 #endif /* __LINUX_KVM_H */
-- 
2.34.1