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

From: Steven Price
Date: Fri Oct 04 2024 - 11:38:01 EST


From: Joey Gouly <joey.gouly@xxxxxxx>

Forward RSI_HOST_CALLS to KVM's HVC handler.

Signed-off-by: Joey Gouly <joey.gouly@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
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