Merge pull request #7799 from UiPath/clh-directio-support

clh: Direct IO support for block devices

src/runtime/config/configuration-clh.toml.in

@@ -176,6 +176,15 @@ virtio_fs_cache = "@DEFVIRTIOFSCACHE@"
 # rootfs is backed by a block device. This is virtio-blk.
 block_device_driver = "virtio-blk"
 
+# Specifies cache-related options will be set to block devices or not.
+# Default false
+#block_device_cache_set = true
+
+# Specifies cache-related options for block devices.
+# Denotes whether use of O_DIRECT (bypass the host page cache) is enabled.
+# Default false
+#block_device_cache_direct = true
+
 # Enable huge pages for VM RAM, default false
 # Enabling this will result in the VM memory
 # being allocated using huge pages.

src/runtime/config/configuration-fc.toml.in

@@ -126,11 +126,6 @@ block_device_driver = "@DEFBLOCKSTORAGEDRIVER_FC@"
 # Default false
 #block_device_cache_set = true
 
-# Specifies cache-related options for block devices.
-# Denotes whether use of O_DIRECT (bypass the host page cache) is enabled.
-# Default false
-#block_device_cache_direct = true
-
 # Specifies cache-related options for block devices.
 # Denotes whether flush requests for the device are ignored.
 # Default false

src/runtime/pkg/katautils/config.go

@@ -1082,7 +1082,6 @@ func newClhHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		BlockDeviceDriver:              blockDriver,
 		BlockDeviceCacheSet:            h.BlockDeviceCacheSet,
 		BlockDeviceCacheDirect:         h.BlockDeviceCacheDirect,
-		BlockDeviceCacheNoflush:        h.BlockDeviceCacheNoflush,
 		EnableIOThreads:                h.EnableIOThreads,
 		Msize9p:                        h.msize9p(),
 		ColdPlugVFIO:                   h.coldPlugVFIO(),

src/runtime/virtcontainers/clh.go

@@ -851,6 +851,9 @@ func (clh *cloudHypervisor) hotplugAddBlockDevice(drive *config.BlockDrive) erro
 	clhDisk := *chclient.NewDiskConfig(drive.File)
 	clhDisk.Readonly = &drive.ReadOnly
 	clhDisk.VhostUser = func(b bool) *bool { return &b }(false)
+	if clh.config.BlockDeviceCacheSet {
+		clhDisk.Direct = &clh.config.BlockDeviceCacheDirect
+	}
 
 	queues := int32(clh.config.NumVCPUs)
 	queueSize := int32(1024)

src/runtime/virtcontainers/fc.go

@@ -835,6 +835,17 @@ func (fc *firecracker) createDiskPool(ctx context.Context) error {
 			PathOnHost:   &jailedDrive,
 		}
 
+		if fc.config.BlockDeviceCacheSet {
+			var cacheOption string
+			if fc.config.BlockDeviceCacheNoflush {
+				cacheOption = models.DriveCacheTypeUnsafe
+			} else {
+				cacheOption = models.DriveCacheTypeWriteback
+			}
+
+			drive.CacheType = &cacheOption
+		}
+
 		fc.fcConfig.Drives = append(fc.fcConfig.Drives, drive)
 	}