1 files changed, 126 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c
new file mode 100644
index 000000000000..f26207f84bab
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_hsm.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/wordpart.h>
+#include <asm/sbi.h>
+#include <asm/kvm_vcpu_sbi.h>
+
+static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+	struct kvm_vcpu *target_vcpu;
+	unsigned long target_vcpuid = cp->a0;
+	int ret = 0;
+
+	target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
+	if (!target_vcpu)
+		return SBI_ERR_INVALID_PARAM;
+
+	spin_lock(&target_vcpu->arch.mp_state_lock);
+
+	if (!kvm_riscv_vcpu_stopped(target_vcpu)) {
+		ret = SBI_ERR_ALREADY_AVAILABLE;
+		goto out;
+	}
+
+	kvm_riscv_vcpu_sbi_request_reset(target_vcpu, cp->a1, cp->a2);
+
+	__kvm_riscv_vcpu_power_on(target_vcpu);
+
+out:
+	spin_unlock(&target_vcpu->arch.mp_state_lock);
+
+	return ret;
+}
+
+static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu)
+{
+	int ret = 0;
+
+	spin_lock(&vcpu->arch.mp_state_lock);
+
+	if (kvm_riscv_vcpu_stopped(vcpu)) {
+		ret = SBI_ERR_FAILURE;
+		goto out;
+	}
+
+	__kvm_riscv_vcpu_power_off(vcpu);
+
+out:
+	spin_unlock(&vcpu->arch.mp_state_lock);
+
+	return ret;
+}
+
+static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+	unsigned long target_vcpuid = cp->a0;
+	struct kvm_vcpu *target_vcpu;
+
+	target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
+	if (!target_vcpu)
+		return SBI_ERR_INVALID_PARAM;
+	if (kvm_riscv_vcpu_stopped(target_vcpu))
+		return SBI_HSM_STATE_STOPPED;
+	else if (target_vcpu->stat.generic.blocking)
+		return SBI_HSM_STATE_SUSPENDED;
+	else
+		return SBI_HSM_STATE_STARTED;
+}
+
+static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+				   struct kvm_vcpu_sbi_return *retdata)
+{
+	int ret = 0;
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+	unsigned long funcid = cp->a6;
+
+	switch (funcid) {
+	case SBI_EXT_HSM_HART_START:
+		ret = kvm_sbi_hsm_vcpu_start(vcpu);
+		break;
+	case SBI_EXT_HSM_HART_STOP:
+		ret = kvm_sbi_hsm_vcpu_stop(vcpu);
+		break;
+	case SBI_EXT_HSM_HART_STATUS:
+		ret = kvm_sbi_hsm_vcpu_get_status(vcpu);
+		if (ret >= 0) {
+			retdata->out_val = ret;
+			retdata->err_val = 0;
+		}
+		return 0;
+	case SBI_EXT_HSM_HART_SUSPEND:
+		switch (lower_32_bits(cp->a0)) {
+		case SBI_HSM_SUSPEND_RET_DEFAULT:
+			kvm_riscv_vcpu_wfi(vcpu);
+			break;
+		case SBI_HSM_SUSPEND_NON_RET_DEFAULT:
+			ret = SBI_ERR_NOT_SUPPORTED;
+			break;
+		default:
+			ret = SBI_ERR_INVALID_PARAM;
+		}
+		break;
+	default:
+		ret = SBI_ERR_NOT_SUPPORTED;
+	}
+
+	retdata->err_val = ret;
+
+	return 0;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = {
+	.extid_start = SBI_EXT_HSM,
+	.extid_end = SBI_EXT_HSM,
+	.handler = kvm_sbi_ext_hsm_handler,
+};