virtcontainers: x86: Support microvm machine type

[ port from runtime commit 6aff077901021d9a0075c446dfe281b2487e1487 ]

With the addition of support to govmm for multiple transports (intel/govmm#111)
and microvm (intel/govmm#121) we can now enable support for the 'microvm'
machine type in kata-runtime.

Signed-off-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Peng Tao <bergwolf@hyper.sh>

src/runtime/pkg/katautils/config.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"github.com/BurntSushi/toml"
+	govmmQemu "github.com/intel/govmm/qemu"
 	vc "github.com/kata-containers/kata-containers/src/runtime/virtcontainers"
 	"github.com/kata-containers/kata-containers/src/runtime/virtcontainers/device/config"
 	exp "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/experimental"
@@ -626,6 +627,14 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 	kernelParams := h.kernelParams()
 	machineType := h.machineType()
 
+	// The "microvm" machine type doesn't support NVDIMM so override the
+	// config setting to explicitly disable it (i.e. don't require the
+	// user to add 'disable_image_nvdimm = true' in the .toml file).
+	if machineType == govmmQemu.MachineTypeMicrovm && !h.DisableImageNvdimm {
+		h.DisableImageNvdimm = true
+		kataUtilsLogger.Info("Setting 'disable_image_nvdimm = true' as microvm does not support NVDIMM")
+	}
+
 	blockDriver, err := h.blockDeviceDriver()
 	if err != nil {
 		return vc.HypervisorConfig{}, err

src/runtime/virtcontainers/qemu_amd64.go

@@ -35,6 +35,7 @@ var qemuPaths = map[string]string{
 	QemuPCLite:  "/usr/bin/qemu-lite-system-x86_64",
 	QemuPC:      defaultQemuPath,
 	QemuQ35:     defaultQemuPath,
+	QemuMicrovm: defaultQemuPath,
 }
 
 var kernelParams = []Param{
@@ -71,6 +72,10 @@ var supportedQemuMachines = []govmmQemu.Machine{
 		Type:    QemuVirt,
 		Options: defaultQemuMachineOptions,
 	},
+	{
+		Type:    QemuMicrovm,
+		Options: defaultQemuMachineOptions,
+	},
 }
 
 // MaxQemuVCPUs returns the maximum number of vCPUs supported
@@ -171,6 +176,12 @@ func (q *qemuAmd64) memoryTopology(memoryMb, hostMemoryMb uint64, slots uint8) g
 	return genericMemoryTopology(memoryMb, hostMemoryMb, slots, q.memoryOffset)
 }
 
+// Is Memory Hotplug supported by this architecture/machine type combination?
+func (q *qemuAmd64) supportGuestMemoryHotplug() bool {
+	// true for all amd64 machine types except for microvm.
+	return q.qemuMachine.Type != govmmQemu.MachineTypeMicrovm
+}
+
 func (q *qemuAmd64) appendImage(devices []govmmQemu.Device, path string) ([]govmmQemu.Device, error) {
 	if !q.disableNvdimm {
 		return q.appendNvdimmImage(devices, path)

src/runtime/virtcontainers/qemu_amd64_test.go

@@ -47,6 +47,10 @@ func TestQemuAmd64Capabilities(t *testing.T) {
 	amd64 = newTestQemu(assert, QemuQ35)
 	caps = amd64.capabilities()
 	assert.True(caps.IsBlockDeviceHotplugSupported())
+
+	amd64 = newTestQemu(assert, QemuMicrovm)
+	caps = amd64.capabilities()
+	assert.False(caps.IsBlockDeviceHotplugSupported())
 }
 
 func TestQemuAmd64Bridges(t *testing.T) {
@@ -65,6 +69,11 @@ func TestQemuAmd64Bridges(t *testing.T) {
 		assert.NotNil(b.Devices)
 	}
 
+	amd64 = newTestQemu(assert, QemuMicrovm)
+	amd64.bridges(uint32(len))
+	bridges = amd64.getBridges()
+	assert.Nil(bridges)
+
 	amd64 = newTestQemu(assert, QemuQ35)
 	amd64.bridges(uint32(len))
 	bridges = amd64.getBridges()
@@ -256,3 +265,18 @@ func TestQemuAmd64Iommu(t *testing.T) {
 	m := qemu.machine()
 	assert.Contains(m.Options, "kernel_irqchip=split")
 }
+
+func TestQemuAmd64Microvm(t *testing.T) {
+	assert := assert.New(t)
+
+	cfg := qemuConfig(QemuMicrovm)
+	amd64, err := newQemuArch(cfg)
+	assert.NoError(err)
+	assert.False(cfg.DisableImageNvdimm)
+
+	for _, m := range supportedQemuMachines {
+		assert.NotContains(m.Options, qemuNvdimmOption)
+	}
+
+	assert.False(amd64.supportGuestMemoryHotplug())
+}

src/runtime/virtcontainers/qemu_arch_base.go

@@ -177,6 +177,9 @@ const (
 	// QemuQ35 is the QEMU Q35 machine type for amd64
 	QemuQ35 = "q35"
 
+	// QemuMicrovm is the QEMU microvm machine type for amd64
+	QemuMicrovm = "microvm"
+
 	// QemuVirt is the QEMU virt machine type for aarch64 or amd64
 	QemuVirt = "virt"