qemu: support appending a vIOMMU device

Add a new function appendIOMMU() to the qemuArch interface
and provide an implementation on amd64 architecture.

Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>

src/runtime/virtcontainers/qemu_arch_base.go

@@ -130,6 +130,9 @@ type qemuArch interface {
 
 	// appendPCIeRootPortDevice appends a pcie-root-port device to pcie.0 bus
 	appendPCIeRootPortDevice(devices []govmmQemu.Device, number uint32) []govmmQemu.Device
+
+	// append vIOMMU device
+	appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error)
 }
 
 type qemuArchBase struct {
@@ -765,4 +768,22 @@ func (q *qemuArchBase) addBridge(b types.Bridge) {
 // appendPCIeRootPortDevice appends to devices the given pcie-root-port
 func (q *qemuArchBase) appendPCIeRootPortDevice(devices []govmmQemu.Device, number uint32) []govmmQemu.Device {
 	return genericAppendPCIeRootPort(devices, number, q.machineType)
+
+}
+
+// appendIOMMU appends a virtual IOMMU device
+func (q *qemuArchBase) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error) {
+	switch q.machineType {
+	case QemuQ35:
+		iommu := govmmQemu.IommuDev{
+			Intremap:    true,
+			DeviceIotlb: true,
+			CachingMode: true,
+		}
+
+		devices = append(devices, iommu)
+		return devices, nil
+	default:
+		return devices, fmt.Errorf("Machine Type %s does not support vIOMMU", q.machineType)
+	}
 }

src/runtime/virtcontainers/qemu_arch_base_test.go

@@ -566,3 +566,27 @@ func TestQemuArchBaseAppendNetwork(t *testing.T) {
 	assert.NoError(err)
 	assert.Equal(expectedOut, devices)
 }
+
+func TestQemuArchBaseAppendIOMMU(t *testing.T) {
+	var devices []govmmQemu.Device
+	var err error
+	assert := assert.New(t)
+	qemuArchBase := newQemuArchBase()
+
+	expectedOut := []govmmQemu.Device{
+		govmmQemu.IommuDev{
+			Intremap:    true,
+			DeviceIotlb: true,
+			CachingMode: true,
+		},
+	}
+	// Test IOMMU is not appended to PC machine type
+	qemuArchBase.machineType = QemuPC
+	devices, err = qemuArchBase.appendIOMMU(devices)
+	assert.Error(err)
+
+	qemuArchBase.machineType = QemuQ35
+	devices, err = qemuArchBase.appendIOMMU(devices)
+	assert.NoError(err)
+	assert.Equal(expectedOut, devices)
+}

src/runtime/virtcontainers/qemu_arm64.go

@@ -7,6 +7,7 @@ package virtcontainers
 
 import (
 	"context"
+	"fmt"
 	"io/ioutil"
 	"runtime"
 	"strings"
@@ -168,3 +169,7 @@ func (q *qemuArm64) setIgnoreSharedMemoryMigrationCaps(_ context.Context, _ *gov
 	// x-ignore-shared not support in arm64 for now
 	return nil
 }
+
+func (q *qemuArm64) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error) {
+	return devices, fmt.Errorf("Arm64 architecture does not support vIOMMU")
+}

src/runtime/virtcontainers/qemu_ppc64le.go

@@ -6,6 +6,7 @@
 package virtcontainers
 
 import (
+	"fmt"
 	"time"
 
 	govmmQemu "github.com/intel/govmm/qemu"
@@ -129,3 +130,7 @@ func (q *qemuPPC64le) memoryTopology(memoryMb, hostMemoryMb uint64, slots uint8)
 func (q *qemuPPC64le) appendBridges(devices []govmmQemu.Device) []govmmQemu.Device {
 	return genericAppendBridges(devices, q.Bridges, q.machineType)
 }
+
+func (q *qemuPPC64le) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error) {
+	return devices, fmt.Errorf("PPC64le does not support appending a vIOMMU")
+}

src/runtime/virtcontainers/qemu_s390x.go

@@ -268,3 +268,7 @@ func (q *qemuS390x) appendVSock(devices []govmmQemu.Device, vsock types.VSock) (
 	return devices, nil
 
 }
+
+func (q *qemuS390x) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device, error) {
+	return devices, fmt.Errorf("S390x does not support appending a vIOMMU")
+}