[PATCH v5 28/43] arm64: rme: support RSI_HOST_CALL

[Steven Price <steven.price@arm.com>]

From: Joey Gouly <joey.gouly@arm.com>

Forward RSI_HOST_CALLS to KVM's HVC handler.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v4:
 * Setting GPRS is now done by kvm_rec_enter() rather than
   rec_exit_host_call() (see previous patch - arm64: RME: Handle realm
   enter/exit). This fixes a bug where the registers set by user space
   were being ignored.
---
 arch/arm64/kvm/rme-exit.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/arm64/kvm/rme-exit.c b/arch/arm64/kvm/rme-exit.c
index 1ddbff123149..06ec0d7867d0 100644
--- a/arch/arm64/kvm/rme-exit.c
+++ b/arch/arm64/kvm/rme-exit.c
@@ -115,6 +115,26 @@ static int rec_exit_ripas_change(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static int rec_exit_host_call(struct kvm_vcpu *vcpu)
+{
+	int ret, i;
+	struct realm_rec *rec = &vcpu->arch.rec;
+
+	vcpu->stat.hvc_exit_stat++;
+
+	for (i = 0; i < REC_RUN_GPRS; i++)
+		vcpu_set_reg(vcpu, i, rec->run->exit.gprs[i]);
+
+	ret = kvm_smccc_call_handler(vcpu);
+
+	if (ret < 0) {
+		vcpu_set_reg(vcpu, 0, ~0UL);
+		ret = 1;
+	}
+
+	return ret;
+}
+
 static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu)
 {
 	struct realm_rec *rec = &vcpu->arch.rec;
@@ -176,6 +196,8 @@ int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
 		return rec_exit_psci(vcpu);
 	case RMI_EXIT_RIPAS_CHANGE:
 		return rec_exit_ripas_change(vcpu);
+	case RMI_EXIT_HOST_CALL:
+		return rec_exit_host_call(vcpu);
 	}
 
 	kvm_pr_unimpl("Unsupported exit reason: %u\n",
-- 
2.34.1