clh: Add memory hotplug

Request memory to resize memory to hypervisor.

Depends-on: github.com/kata-containers/tests#2413

Fixes: #2526

Signed-off-by: Jose Carlos Venegas Munoz <[email protected]>

virtcontainers/clh.go

@@ -217,6 +217,13 @@ func (clh *cloudHypervisor) createSandbox(ctx context.Context, id string, networ
 	// Convert to int64 openApiClient only support int64
 	clh.vmconfig.Memory.Size = int64((utils.MemUnit(clh.config.MemorySize) * utils.MiB).ToBytes())
 	clh.vmconfig.Memory.File = "/dev/shm"
+	hostMemKb, err := getHostMemorySizeKb(procMemInfo)
+	if err != nil {
+		return nil
+	}
+
+	// OpenAPI only supports int64 values
+	clh.vmconfig.Memory.HotplugSize = int64((utils.MemUnit(hostMemKb) * utils.KiB).ToBytes())
 	// Set initial amount of cpu's for the virtual machine
 	clh.vmconfig.Cpus = chclient.CpusConfig{
 		// cast to int32, as openAPI has a limitation that it does not support unsigned values
@@ -425,8 +432,68 @@ func (clh *cloudHypervisor) hypervisorConfig() HypervisorConfig {
 }
 
 func (clh *cloudHypervisor) resizeMemory(reqMemMB uint32, memoryBlockSizeMB uint32, probe bool) (uint32, memoryDevice, error) {
-	clh.Logger().WithField("function", "resizeMemory").Warn("not supported")
-	return 0, memoryDevice{}, nil
+
+	// TODO: Add support for virtio-mem
+
+	if probe {
+		return 0, memoryDevice{}, errors.New("probe memory is not supported for cloud-hypervisor")
+	}
+
+	if reqMemMB == 0 {
+		// This is a corner case if requested to resize to 0 means something went really wrong.
+		return 0, memoryDevice{}, errors.New("Can not resize memory to 0")
+	}
+
+	info, err := clh.vmInfo()
+	if err != nil {
+		return 0, memoryDevice{}, err
+	}
+
+	currentMem := utils.MemUnit(info.Config.Memory.Size) * utils.Byte
+	newMem := utils.MemUnit(reqMemMB) * utils.MiB
+
+	// Early check to verify if boot memory is the same as requested
+	if currentMem == newMem {
+		clh.Logger().WithField("memory", reqMemMB).Debugf("VM already has requested memory")
+		return uint32(currentMem.ToMiB()), memoryDevice{}, nil
+	}
+
+	if currentMem > newMem {
+		clh.Logger().Warn("Remove memory is not supported, nothing to do")
+		return uint32(currentMem.ToMiB()), memoryDevice{}, nil
+	}
+
+	blockSize := utils.MemUnit(memoryBlockSizeMB) * utils.MiB
+	hotplugSize := (newMem - currentMem).AlignMem(blockSize)
+
+	// Update memory request to increase memory aligned block
+	alignedRequest := currentMem + hotplugSize
+	if newMem != alignedRequest {
+		clh.Logger().WithFields(log.Fields{"request": newMem, "aligned-request": alignedRequest}).Debug("aligning VM memory request")
+		newMem = alignedRequest
+	}
+
+	// Check if memory is the same as requested, a second check is done
+	// to consider the memory request now that is updated to be memory aligned
+	if currentMem == newMem {
+		clh.Logger().WithFields(log.Fields{"current-memory": currentMem, "new-memory": newMem}).Debug("VM already has requested memory(after alignment)")
+		return uint32(currentMem.ToMiB()), memoryDevice{}, nil
+	}
+
+	cl := clh.client()
+	ctx, cancelResize := context.WithTimeout(context.Background(), clhAPITimeout*time.Second)
+	defer cancelResize()
+
+	// OpenApi does not support uint64, convert to int64
+	resize := chclient.VmResize{DesiredRam: int64(newMem.ToBytes())}
+	clh.Logger().WithFields(log.Fields{"current-memory": currentMem, "new-memory": newMem}).Debug("updating VM memory")
+	if _, err = cl.VmResizePut(ctx, resize); err != nil {
+		clh.Logger().WithFields(log.Fields{"current-memory": currentMem, "new-memory": newMem}).Warnf("failed to update memory %s", openAPIClientError(err))
+		err = fmt.Errorf("Failed to resize memory from %d to %d: %s", currentMem, newMem, openAPIClientError(err))
+		return uint32(currentMem.ToMiB()), memoryDevice{}, openAPIClientError(err)
+	}
+
+	return uint32(newMem.ToMiB()), memoryDevice{sizeMB: int(hotplugSize.ToMiB())}, nil
 }
 
 func (clh *cloudHypervisor) resizeVCPUs(reqVCPUs uint32) (currentVCPUs uint32, newVCPUs uint32, err error) {

virtcontainers/clh_test.go

@@ -10,15 +10,22 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"reflect"
 	"testing"
 
 	"github.com/kata-containers/runtime/virtcontainers/device/config"
 	"github.com/kata-containers/runtime/virtcontainers/persist"
 	chclient "github.com/kata-containers/runtime/virtcontainers/pkg/cloud-hypervisor/client"
+	"github.com/kata-containers/runtime/virtcontainers/utils"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 )
 
+const (
+	FAIL = true
+	PASS = !FAIL
+)
+
 func newClhConfig() (HypervisorConfig, error) {
 
 	setupClh()
@@ -255,3 +262,57 @@ func TestClooudHypervisorStartSandbox(t *testing.T) {
 	err = clh.startSandbox(10)
 	assert.NoError(err)
 }
+
+func TestCloudHypervisorResizeMemory(t *testing.T) {
+	assert := assert.New(t)
+	clhConfig, err := newClhConfig()
+	type args struct {
+		reqMemMB          uint32
+		memoryBlockSizeMB uint32
+	}
+	tests := []struct {
+		name           string
+		args           args
+		expectedMemDev memoryDevice
+		wantErr        bool
+	}{
+		{"Resize to zero", args{0, 128}, memoryDevice{probe: false, sizeMB: 0}, FAIL},
+		{"Resize to aligned size", args{clhConfig.MemorySize + 128, 128}, memoryDevice{probe: false, sizeMB: 128}, PASS},
+		{"Resize to aligned size", args{clhConfig.MemorySize + 129, 128}, memoryDevice{probe: false, sizeMB: 256}, PASS},
+		{"Resize to NOT aligned size", args{clhConfig.MemorySize + 125, 128}, memoryDevice{probe: false, sizeMB: 128}, PASS},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.NoError(err)
+			clh := cloudHypervisor{}
+
+			mockClient := &clhClientMock{}
+			mockClient.vmInfo.Config.Memory.Size = int64(utils.MemUnit(clhConfig.MemorySize) * utils.MiB)
+			mockClient.vmInfo.Config.Memory.HotplugSize = int64(40 * utils.GiB.ToBytes())
+
+			clh.APIClient = mockClient
+			clh.config = clhConfig
+
+			newMem, memDev, err := clh.resizeMemory(tt.args.reqMemMB, tt.args.memoryBlockSizeMB, false)
+
+			if (err != nil) != tt.wantErr {
+				t.Errorf("cloudHypervisor.resizeMemory() error = %v, expected to fail = %v", err, tt.wantErr)
+				return
+			}
+
+			if err != nil {
+				return
+			}
+
+			expectedMem := clhConfig.MemorySize + uint32(tt.expectedMemDev.sizeMB)
+
+			if newMem != expectedMem {
+				t.Errorf("cloudHypervisor.resizeMemory() got = %+v, want %+v", newMem, expectedMem)
+			}
+
+			if !reflect.DeepEqual(memDev, tt.expectedMemDev) {
+				t.Errorf("cloudHypervisor.resizeMemory() got = %+v, want %+v", memDev, tt.expectedMemDev)
+			}
+		})
+	}
+}