Model memory usage in VMs

15 files changed, 124 insertions, 46 deletions

diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/ServerFlavor.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Flavor.kt
index d57dadf9..ff5060de 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/ServerFlavor.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Flavor.kt
@@ -25,18 +25,17 @@
 package com.atlarge.opendc.compute.core
 
 /**
- * (Virtual) hardware configuration of a server.
+ * Flavors define the compute and memory capacity of [Server] instance. o put it simply, a flavor is an available
+ * hardware configuration for a server. It defines the size of a virtual server that can be launched.
  */
-public data class ServerFlavor(
+public data class Flavor(
     /**
-     * The processing units of this machine.
+     * The number of (virtual) processing cores to use.
      */
-    public val cpus: List<ProcessingUnit>,
+    public val cpuCount: Int,
 
     /**
-     * Key and value pairs that can be used to describe the specification of the server which is more than just about
-     * CPU, disk and RAM. For example, it can be used to indicate that the server created by this flavor has PCI
-     * devices, etc.
+     * The amount of RAM available to the server (in MB).
      */
-    public val details: Map<String, Any> = emptyMap()
+    public val memorySize: Long
 )
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/MemoryUnit.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/MemoryUnit.kt
new file mode 100644
index 00000000..ce57fc72
--- /dev/null
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/MemoryUnit.kt
@@ -0,0 +1,40 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.compute.core
+
+/**
+ * A memory unit of a compute resource, either virtual or physical.
+ *
+ * @property vendor The vendor string of the memory.
+ * @property modelName The name of the memory model.
+ * @property speed The access speed of the memory in MHz.
+ * @property size The size of the memory unit in MBs.
+ */
+public data class MemoryUnit(
+    public val vendor: String,
+    public val modelName: String,
+    public val speed: Double,
+    public val size: Long
+)
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Server.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Server.kt
index cb11cfc7..86ec9a5b 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Server.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/Server.kt
@@ -53,7 +53,7 @@ public data class Server(
     /**
      * The hardware configuration of the server.
      */
-    public val flavor: ServerFlavor,
+    public val flavor: Flavor,
 
     /**
      * The image running on the server.
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/FlopsApplicationImage.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/FlopsApplicationImage.kt
index f09adc84..3576b488 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/FlopsApplicationImage.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/FlopsApplicationImage.kt
@@ -60,7 +60,7 @@ class FlopsApplicationImage(
      * Execute the runtime behavior based on a number of floating point operations to execute.
      */
     override suspend fun invoke(ctx: ServerContext) {
-        val cores = min(this.cores, ctx.server.flavor.cpus.sumBy { it.cores })
+        val cores = min(this.cores, ctx.server.flavor.cpuCount)
         val req = flops / cores
 
         coroutineScope {
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/VmImage.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/VmImage.kt
index b7eacd88..257b6149 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/VmImage.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/core/image/VmImage.kt
@@ -13,7 +13,8 @@ class VmImage(
     public override val name: String,
     public override val tags: TagContainer,
     public val flopsHistory: List<FlopsHistoryFragment>,
-    public val cores: Int
+    public val cores: Int,
+    public val requiredMemory: Long
 ) : Image {
 
     override suspend fun invoke(ctx: ServerContext) {
@@ -21,7 +22,7 @@ class VmImage(
             if (fragment.flops == 0L) {
                 delay(fragment.duration)
             } else {
-                val cores = min(this.cores, ctx.server.flavor.cpus.sumBy { it.cores })
+                val cores = min(this.cores, ctx.server.flavor.cpuCount)
                 val req = fragment.flops / cores
 
                 coroutineScope {
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
index 29573007..202c30e9 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
@@ -28,7 +28,8 @@ import com.atlarge.odcsim.ProcessContext
 import com.atlarge.odcsim.processContext
 import com.atlarge.opendc.compute.core.ProcessingUnit
 import com.atlarge.opendc.compute.core.Server
-import com.atlarge.opendc.compute.core.ServerFlavor
+import com.atlarge.opendc.compute.core.Flavor
+import com.atlarge.opendc.compute.core.MemoryUnit
 import com.atlarge.opendc.compute.core.ServerState
 import com.atlarge.opendc.compute.core.execution.ProcessorContext
 import com.atlarge.opendc.compute.core.execution.ServerManagementContext
@@ -49,12 +50,13 @@ import kotlin.math.min
  *
  * @param uid The unique identifier of the machine.
  * @param name An optional name of the machine.
- * @param flavor The hardware configuration of the machine.
+ * @param cpuNodes The CPU nodes/packages available to the bare metal machine.
  */
 public class SimpleBareMetalDriver(
     uid: UUID,
     name: String,
-    private val flavor: ServerFlavor
+    val cpuNodes: List<ProcessingUnit>,
+    val memoryUnits: List<MemoryUnit>
 ) : BareMetalDriver {
     /**
      * The monitor to use.
@@ -66,6 +68,11 @@ public class SimpleBareMetalDriver(
      */
     private var node: Node = Node(uid, name, PowerState.POWER_OFF, EmptyImage, null)
 
+    /**
+     * The flavor that corresponds to this machine.
+     */
+    private val flavor = Flavor(cpuNodes.sumBy { it.cores }, memoryUnits.map { it.size }.sum())
+
     override suspend fun init(monitor: ServerMonitor): Node {
         this.monitor = monitor
         return node
@@ -141,7 +148,7 @@ public class SimpleBareMetalDriver(
         private var initialized: Boolean = false
         private lateinit var ctx: ProcessContext
 
-        override val cpus: List<ProcessorContextImpl> = flavor.cpus
+        override val cpus: List<ProcessorContextImpl> = cpuNodes
             .asSequence()
             .flatMap { cpu ->
                 generateSequence { ProcessorContextImpl(cpu) }.take(cpu.cores)
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/VirtDriver.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/VirtDriver.kt
index 3541b414..68b8e541 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/VirtDriver.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/VirtDriver.kt
@@ -25,7 +25,7 @@
 package com.atlarge.opendc.compute.virt.driver
 
 import com.atlarge.opendc.compute.core.Server
-import com.atlarge.opendc.compute.core.ServerFlavor
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.image.Image
 import com.atlarge.opendc.compute.core.monitor.ServerMonitor
 import com.atlarge.opendc.core.services.AbstractServiceKey
@@ -44,7 +44,7 @@ public interface VirtDriver {
      * @param flavor The flavor of the server which this driver is controlling.
      * @return The virtual server spawned by this method.
      */
-    public suspend fun spawn(image: Image, monitor: ServerMonitor, flavor: ServerFlavor): Server
+    public suspend fun spawn(image: Image, monitor: ServerMonitor, flavor: Flavor): Server
 
     /**
      * Returns the number of spawned images on the server managed by this driver.
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorImage.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorImage.kt
index fc7322db..b7848cf3 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorImage.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorImage.kt
@@ -43,7 +43,7 @@ class HypervisorImage(
     override val tags: TagContainer = emptyMap()
 
     override suspend fun invoke(ctx: ServerContext) {
-        val driver = HypervisorVirtDriver(VmSchedulerImpl(ctx, hypervisorMonitor))
+        val driver = HypervisorVirtDriver(ctx, VmSchedulerImpl(ctx, hypervisorMonitor))
 
         ctx.publishService(VirtDriver.Key, driver)
 
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorVirtDriver.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorVirtDriver.kt
index 9ae71f14..65ec75a2 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorVirtDriver.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/HypervisorVirtDriver.kt
@@ -27,9 +27,10 @@ package com.atlarge.opendc.compute.virt.driver.hypervisor
 import com.atlarge.odcsim.ProcessContext
 import com.atlarge.odcsim.processContext
 import com.atlarge.opendc.compute.core.Server
-import com.atlarge.opendc.compute.core.ServerFlavor
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.ServerState
 import com.atlarge.opendc.compute.core.execution.ProcessorContext
+import com.atlarge.opendc.compute.core.execution.ServerContext
 import com.atlarge.opendc.compute.core.execution.ServerManagementContext
 import com.atlarge.opendc.compute.core.image.Image
 import com.atlarge.opendc.compute.core.monitor.ServerMonitor
@@ -41,15 +42,29 @@ import java.util.UUID
 /**
  * A [VirtDriver] that is backed by a simple hypervisor implementation.
  */
-class HypervisorVirtDriver(private val scheduler: VmScheduler) : VirtDriver {
+class HypervisorVirtDriver(
+    private val hostContext: ServerContext,
+    private val scheduler: VmScheduler
+) : VirtDriver {
     /**
      * A set for tracking the VM context objects.
      */
     internal val vms: MutableSet<VmServerContext> = mutableSetOf()
 
-    override suspend fun spawn(image: Image, monitor: ServerMonitor, flavor: ServerFlavor): Server {
+    /**
+     * Current total memory use of the images on this hypervisor.
+     */
+    private var memoryAvailable: Long = hostContext.server.flavor.memorySize
+
+    override suspend fun spawn(image: Image, monitor: ServerMonitor, flavor: Flavor): Server {
+        val requiredMemory = flavor.memorySize
+        if (memoryAvailable - requiredMemory < 0) {
+            throw InsufficientMemoryOnServerException()
+        }
+
         val server = Server(UUID.randomUUID(), "<unnamed>", emptyMap(), flavor, image, ServerState.BUILD)
-        vms.add(VmServerContext(server, monitor, flavor, processContext))
+        memoryAvailable -= requiredMemory
+        vms.add(VmServerContext(server, monitor, processContext))
         return server
     }
 
@@ -60,7 +75,6 @@ class HypervisorVirtDriver(private val scheduler: VmScheduler) : VirtDriver {
     internal inner class VmServerContext(
         override var server: Server,
         val monitor: ServerMonitor,
-        flavor: ServerFlavor,
         ctx: ProcessContext
     ) : ServerManagementContext {
         private var initialized: Boolean = false
@@ -75,7 +89,7 @@ class HypervisorVirtDriver(private val scheduler: VmScheduler) : VirtDriver {
             }
         }
 
-        override val cpus: List<ProcessorContext> = scheduler.createVirtualCpus(flavor)
+        override val cpus: List<ProcessorContext> = scheduler.createVirtualCpus(server.flavor)
 
         override suspend fun init() {
             if (initialized) {
@@ -92,6 +106,7 @@ class HypervisorVirtDriver(private val scheduler: VmScheduler) : VirtDriver {
             val previousState = server.state
             val state = if (cause == null) ServerState.SHUTOFF else ServerState.ERROR
             server = server.copy(state = state)
+            memoryAvailable += server.flavor.memorySize
             monitor.onUpdate(server, previousState)
             initialized = false
         }
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/InsufficientMemoryOnServerException.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/InsufficientMemoryOnServerException.kt
new file mode 100644
index 00000000..926234b5
--- /dev/null
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/InsufficientMemoryOnServerException.kt
@@ -0,0 +1,3 @@
+package com.atlarge.opendc.compute.virt.driver.hypervisor
+
+public class InsufficientMemoryOnServerException : IllegalStateException("Insufficient memory left on server.")
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmScheduler.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmScheduler.kt
index f02ac2b3..7b00d99c 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmScheduler.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmScheduler.kt
@@ -24,7 +24,7 @@
 
 package com.atlarge.opendc.compute.virt.driver.hypervisor
 
-import com.atlarge.opendc.compute.core.ServerFlavor
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.execution.ProcessorContext
 
 /**
@@ -34,5 +34,5 @@ public interface VmScheduler {
     /**
      * Create the virtual CPUs for the specified [flavor].
      */
-    fun createVirtualCpus(flavor: ServerFlavor): List<ProcessorContext>
+    fun createVirtualCpus(flavor: Flavor): List<ProcessorContext>
 }
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmSchedulerImpl.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmSchedulerImpl.kt
index b6be935e..dfed3d58 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmSchedulerImpl.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/driver/hypervisor/VmSchedulerImpl.kt
@@ -26,7 +26,7 @@ package com.atlarge.opendc.compute.virt.driver.hypervisor
 
 import com.atlarge.odcsim.processContext
 import com.atlarge.opendc.compute.core.ProcessingUnit
-import com.atlarge.opendc.compute.core.ServerFlavor
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.execution.ProcessorContext
 import com.atlarge.opendc.compute.core.execution.ServerContext
 import com.atlarge.opendc.compute.virt.monitor.HypervisorMonitor
@@ -53,9 +53,10 @@ public class VmSchedulerImpl(
      */
     private val cpus = hostContext.cpus.map { HostProcessorContext(it, hostContext, hypervisorMonitor) }
 
-    override fun createVirtualCpus(flavor: ServerFlavor): List<ProcessorContext> {
+    override fun createVirtualCpus(flavor: Flavor): List<ProcessorContext> {
+        // TODO At the moment, the first N cores get filled the first. Distribute over all cores instead
         return cpus.asSequence()
-            .take(flavor.cpus.sumBy { it.cores })
+            .take(flavor.cpuCount)
             .map { VirtualProcessorContext(it) }
             .toList()
     }
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/monitor/HypervisorMonitor.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/monitor/HypervisorMonitor.kt
index d4d71aaa..e259a3c0 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/monitor/HypervisorMonitor.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/monitor/HypervisorMonitor.kt
@@ -10,15 +10,15 @@ interface HypervisorMonitor {
      * Invoked after a scheduling slice has finished processed.
      *
      * @param time The current time (in ms).
-     * @param totalRequestedBurst The total requested CPU time (can be above capacity).
-     * @param totalGrantedBurst The actual total granted capacity.
+     * @param requestedBurst The total requested CPU time (can be above capacity).
+     * @param grantedBurst The actual total granted capacity.
      * @param numberOfDeployedImages The number of images deployed on this hypervisor.
      * @param hostServer The server hosting this hypervisor.
      */
     fun onSliceFinish(
         time: Long,
-        totalRequestedBurst: Long,
-        totalGrantedBurst: Long,
+        requestedBurst: Long,
+        grantedBurst: Long,
         numberOfDeployedImages: Int,
         hostServer: Server
     )
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/SimpleVirtProvisioningService.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/SimpleVirtProvisioningService.kt
index baf3f9ef..ef1528d9 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/SimpleVirtProvisioningService.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/SimpleVirtProvisioningService.kt
@@ -1,14 +1,16 @@
 package com.atlarge.opendc.compute.virt.service
 
 import com.atlarge.odcsim.ProcessContext
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.Server
 import com.atlarge.opendc.compute.core.ServerState
 import com.atlarge.opendc.compute.core.image.Image
 import com.atlarge.opendc.compute.core.monitor.ServerMonitor
 import com.atlarge.opendc.compute.metal.Node
 import com.atlarge.opendc.compute.metal.service.ProvisioningService
-import com.atlarge.opendc.compute.virt.driver.hypervisor.HypervisorImage
 import com.atlarge.opendc.compute.virt.driver.VirtDriver
+import com.atlarge.opendc.compute.virt.driver.hypervisor.HypervisorImage
+import com.atlarge.opendc.compute.virt.driver.hypervisor.InsufficientMemoryOnServerException
 import com.atlarge.opendc.compute.virt.monitor.HypervisorMonitor
 import kotlinx.coroutines.launch
 
@@ -63,8 +65,8 @@ class SimpleVirtProvisioningService(
         }
     }
 
-    override suspend fun deploy(image: Image, monitor: ServerMonitor) {
-        val vmInstance = ImageView(image, monitor)
+    override suspend fun deploy(image: Image, monitor: ServerMonitor, flavor: Flavor) {
+        val vmInstance = ImageView(image, monitor, flavor)
         incomingImages += vmInstance
         requestCycle()
     }
@@ -85,16 +87,20 @@ class SimpleVirtProvisioningService(
                 it.server!!.serviceRegistry[VirtDriver.Key].getNumberOfSpawnedImages()
             }
 
-            imageInstance.server = selectedNode?.server!!.serviceRegistry[VirtDriver.Key].spawn(
-                imageInstance.image,
-                imageInstance.monitor,
-                nodes[0].server!!.flavor
-            )
+            try {
+                imageInstance.server = selectedNode?.server!!.serviceRegistry[VirtDriver.Key].spawn(
+                    imageInstance.image,
+                    imageInstance.monitor,
+                    imageInstance.flavor
+                )
+                activeImages += imageInstance
+                imagesByServer.putIfAbsent(imageInstance.server!!, mutableSetOf())
+                imagesByServer[imageInstance.server!!]!!.add(imageInstance)
+            } catch (e: InsufficientMemoryOnServerException) {
+                println("Unable to deploy image due to insufficient memory")
+            }
 
             incomingImages -= imageInstance
-            activeImages += imageInstance
-            imagesByServer.putIfAbsent(imageInstance.server!!, mutableSetOf())
-            imagesByServer[imageInstance.server!!]!!.add(imageInstance)
         }
     }
 
@@ -113,6 +119,7 @@ class SimpleVirtProvisioningService(
     class ImageView(
         val image: Image,
         val monitor: ServerMonitor,
+        val flavor: Flavor,
         var server: Server? = null
     )
 }
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/VirtProvisioningService.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/VirtProvisioningService.kt
index 8e0e1137..fb087f9d 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/VirtProvisioningService.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/virt/service/VirtProvisioningService.kt
@@ -1,5 +1,6 @@
 package com.atlarge.opendc.compute.virt.service
 
+import com.atlarge.opendc.compute.core.Flavor
 import com.atlarge.opendc.compute.core.image.Image
 import com.atlarge.opendc.compute.core.monitor.ServerMonitor
 
@@ -9,6 +10,10 @@ import com.atlarge.opendc.compute.core.monitor.ServerMonitor
 interface VirtProvisioningService {
     /**
      * Submit the specified [Image] to the provisioning service.
+     *
+     * @param image The image to be deployed.
+     * @param monitor The monitor to inform on events.
+     * @param flavor The flavor of the machine instance to run this [image] on.
      */
-    public suspend fun deploy(image: Image, monitor: ServerMonitor)
+    public suspend fun deploy(image: Image, monitor: ServerMonitor, flavor: Flavor)
 }