Different RSI calls related to DA result in REC exits. Add a facility to
register handlers for handling these REC exits.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 arch/arm64/include/asm/kvm_rme.h |  3 ++
 arch/arm64/include/asm/rmi_smc.h | 14 +++++++-
 arch/arm64/kvm/rme-exit.c        | 60 ++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index e954bb95dc86..370d056222e8 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -136,4 +136,7 @@ static inline bool kvm_realm_is_private_address(struct realm *realm,
 	return !(addr & BIT(realm->ia_bits - 1));
 }
 
+extern int (*realm_exit_vdev_req_handler)(struct realm_rec *rec);
+extern int (*realm_exit_vdev_comm_handler)(struct realm_rec *rec);
+extern int (*realm_exit_dev_mem_map_handler)(struct realm_rec *rec);
 #endif /* __ASM_KVM_RME_H */
diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
index c6e16ab608e1..a5ef68b62bc0 100644
--- a/arch/arm64/include/asm/rmi_smc.h
+++ b/arch/arm64/include/asm/rmi_smc.h
@@ -219,6 +219,9 @@ struct rec_enter {
 #define RMI_EXIT_RIPAS_CHANGE		0x04
 #define RMI_EXIT_HOST_CALL		0x05
 #define RMI_EXIT_SERROR			0x06
+#define RMI_EXIT_VDEV_REQUEST		0x08
+#define RMI_EXIT_VDEV_COMM		0x09
+#define RMI_EXIT_DEV_MEM_MAP		0x0a
 
 struct rec_exit {
 	union { /* 0x000 */
@@ -264,7 +267,16 @@ struct rec_exit {
 		u8 padding5[0x100];
 	};
 	union { /* 0x600 */
-		u16 imm;
+		struct {
+			u16 imm;
+			u8 padding[6];
+			u64 plane;
+			u64 vdev;
+			u64 vdev_action;
+			u64 dev_mem_base;
+			u64 dev_mem_top;
+			u64 dev_mem_pa;
+		};
 		u8 padding6[0x100];
 	};
 	union { /* 0x700 */
diff --git a/arch/arm64/kvm/rme-exit.c b/arch/arm64/kvm/rme-exit.c
index 1a8ca7526863..25948207fc5b 100644
--- a/arch/arm64/kvm/rme-exit.c
+++ b/arch/arm64/kvm/rme-exit.c
@@ -129,6 +129,60 @@ static int rec_exit_host_call(struct kvm_vcpu *vcpu)
 	return kvm_smccc_call_handler(vcpu);
 }
 
+int (*realm_exit_vdev_req_handler)(struct realm_rec *rec);
+EXPORT_SYMBOL_GPL(realm_exit_vdev_req_handler);
+static int rec_exit_vdev_request(struct kvm_vcpu *vcpu)
+{
+	int ret;
+	struct realm_rec *rec = &vcpu->arch.rec;
+
+	if (realm_exit_vdev_req_handler) {
+		ret = (*realm_exit_vdev_req_handler)(rec);
+	} else {
+		kvm_pr_unimpl("Unsupported exit reason: %u\n",
+			      rec->run->exit.exit_reason);
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = 0;
+	}
+	return ret;
+}
+
+int (*realm_exit_vdev_comm_handler)(struct realm_rec *rec);
+EXPORT_SYMBOL_GPL(realm_exit_vdev_comm_handler);
+static int rec_exit_vdev_communication(struct kvm_vcpu *vcpu)
+{
+	int ret;
+	struct realm_rec *rec = &vcpu->arch.rec;
+
+	if (realm_exit_vdev_comm_handler) {
+		ret = (*realm_exit_vdev_comm_handler)(rec);
+	} else {
+		kvm_pr_unimpl("Unsupported exit reason: %u\n",
+			      rec->run->exit.exit_reason);
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = 0;
+	}
+	return ret;
+}
+
+int (*realm_exit_dev_mem_map_handler)(struct realm_rec *rec);
+EXPORT_SYMBOL_GPL(realm_exit_dev_mem_map_handler);
+static int rec_exit_dev_mem_map(struct kvm_vcpu *vcpu)
+{
+	int ret;
+	struct realm_rec *rec = &vcpu->arch.rec;
+
+	if (realm_exit_dev_mem_map_handler) {
+		ret = (*realm_exit_dev_mem_map_handler)(rec);
+	} else {
+		kvm_pr_unimpl("Unsupported exit reason: %u\n",
+			      rec->run->exit.exit_reason);
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = 0;
+	}
+	return ret;
+}
+
 static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu)
 {
 	struct realm_rec *rec = &vcpu->arch.rec;
@@ -198,6 +252,12 @@ int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
 		return rec_exit_ripas_change(vcpu);
 	case RMI_EXIT_HOST_CALL:
 		return rec_exit_host_call(vcpu);
+	case RMI_EXIT_VDEV_REQUEST:
+		return rec_exit_vdev_request(vcpu);
+	case RMI_EXIT_VDEV_COMM:
+		return rec_exit_vdev_communication(vcpu);
+	case RMI_EXIT_DEV_MEM_MAP:
+		return rec_exit_dev_mem_map(vcpu);
 	}
 
 	kvm_pr_unimpl("Unsupported exit reason: %u\n",
-- 
2.43.0

On Mon, 28 Jul 2025 19:22:03 +0530
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> wrote:

> Different RSI calls related to DA result in REC exits. Add a facility to
> register handlers for handling these REC exits.
> 
> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>


> diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
> index c6e16ab608e1..a5ef68b62bc0 100644
> --- a/arch/arm64/include/asm/rmi_smc.h
> +++ b/arch/arm64/include/asm/rmi_smc.h

> diff --git a/arch/arm64/kvm/rme-exit.c b/arch/arm64/kvm/rme-exit.c
> index 1a8ca7526863..25948207fc5b 100644
> --- a/arch/arm64/kvm/rme-exit.c
> +++ b/arch/arm64/kvm/rme-exit.c


> +static int rec_exit_dev_mem_map(struct kvm_vcpu *vcpu)
> +{
> +	int ret;
> +	struct realm_rec *rec = &vcpu->arch.rec;
> +
> +	if (realm_exit_dev_mem_map_handler) {
> +		ret = (*realm_exit_dev_mem_map_handler)(rec);
> +	} else {
> +		kvm_pr_unimpl("Unsupported exit reason: %u\n",
> +			      rec->run->exit.exit_reason);
> +		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> +		ret = 0;

I guess maybe this gets more complex later, but right now
		return 0;

And maybe return in the if branch as well.
Same for other similar code in this patch.

> +	}
> +	return ret;
> +}
> +
>  static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu)
>  {
>  	struct realm_rec *rec = &vcpu->arch.rec;
> @@ -198,6 +252,12 @@ int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
>  		return rec_exit_ripas_change(vcpu);
>  	case RMI_EXIT_HOST_CALL:
>  		return rec_exit_host_call(vcpu);
> +	case RMI_EXIT_VDEV_REQUEST:
> +		return rec_exit_vdev_request(vcpu);
> +	case RMI_EXIT_VDEV_COMM:
> +		return rec_exit_vdev_communication(vcpu);
> +	case RMI_EXIT_DEV_MEM_MAP:
> +		return rec_exit_dev_mem_map(vcpu);
>  	}
>  
>  	kvm_pr_unimpl("Unsupported exit reason: %u\n",