runtime: Define default values for QEMU riscv

Provide default values while invoking QEMU as the hypervisor for Go
runtime on riscv64 platform.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

src/runtime/virtcontainers/qemu_riscv64.go

@@ -0,0 +1,65 @@
+// Copyright (c) 2024 Institute of Software, CAS.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package virtcontainers
+
+import (
+	"fmt"
+	"time"
+
+	govmmQemu "github.com/kata-containers/kata-containers/src/runtime/pkg/govmm/qemu"
+)
+
+type qemuRiscv64 struct {
+	// inherit from qemuArchBase, overwrite methods if needed
+	qemuArchBase
+}
+
+const defaultQemuPath = "/usr/bin/qemu-system-riscv64"
+
+const defaultQemuMachineType = QemuVirt
+
+const qmpMigrationWaitTimeout = 10 * time.Second
+
+const defaultQemuMachineOptions = "accel=kvm,usb=off"
+
+var kernelParams = []Param{
+	{"numa", "off"},
+}
+
+var supportedQemuMachine = govmmQemu.Machine{
+	Type:    QemuVirt,
+	Options: defaultQemuMachineOptions,
+}
+
+func newQemuArch(config HypervisorConfig) (qemuArch, error) {
+	machineType := config.HypervisorMachineType
+	if machineType == "" {
+		machineType = defaultQemuMachineType
+	}
+
+	if machineType != defaultQemuMachineType {
+		return nil, fmt.Errorf("unrecognised machinetype: %v", machineType)
+	}
+
+	q := &qemuRiscv64{
+		qemuArchBase{
+			qemuMachine:          supportedQemuMachine,
+			qemuExePath:          defaultQemuPath,
+			memoryOffset:         config.MemOffset,
+			kernelParamsNonDebug: kernelParamsNonDebug,
+			kernelParamsDebug:    kernelParamsDebug,
+			kernelParams:         kernelParams,
+		},
+	}
+
+	q.handleImagePath(config)
+
+	return q, nil
+}
+
+func (q *qemuRiscv64) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error) {
+	return devices, fmt.Errorf("riscv64 does not support appending a vIOMMU")
+}