chore: import upstream snapshot with attribution

Sources/Containerization/VZVirtualMachineManager.swift

@@ -0,0 +1,84 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2025-2026 Apple Inc. and the Containerization project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+#if os(macOS)
+import ContainerizationError
+import ContainerizationOCI
+import Foundation
+import Logging
+import NIOCore
+
+/// A virtualization.framework backed `VirtualMachineManager` implementation.
+public struct VZVirtualMachineManager: VirtualMachineManager {
+    private let kernel: Kernel
+    private let initialFilesystem: Mount
+    private let rosetta: Bool
+    private let nestedVirtualization: Bool
+    private let group: EventLoopGroup?
+    private let logger: Logger?
+
+    public init(
+        kernel: Kernel,
+        initialFilesystem: Mount,
+        rosetta: Bool = false,
+        nestedVirtualization: Bool = false,
+        group: EventLoopGroup? = nil,
+        logger: Logger? = nil
+    ) {
+        self.kernel = kernel
+        self.initialFilesystem = initialFilesystem
+        self.rosetta = rosetta
+        self.nestedVirtualization = nestedVirtualization
+        self.group = group
+        self.logger = logger
+    }
+
+    public func create(config: some VMCreationConfig) throws -> any VirtualMachineInstance {
+        let vmConfig = config.configuration
+
+        // Use nested virtualization if requested in config or set as default in manager
+        let useNestedVirtualization = vmConfig.nestedVirtualization || self.nestedVirtualization
+
+        // Clamp to system RAM as Virtualization.framework bounds us to this.
+        let memoryInBytes = min(vmConfig.memoryInBytes, ProcessInfo.processInfo.physicalMemory)
+
+        // Clamp to system CPU count as Virtualization.framework bounds us to this.
+        let cpus = min(vmConfig.cpus, ProcessInfo.processInfo.activeProcessorCount)
+
+        return try VZVirtualMachineInstance(
+            group: self.group,
+            logger: self.logger,
+            with: { instanceConfig in
+                instanceConfig.cpus = cpus
+                instanceConfig.memoryInBytes = memoryInBytes
+
+                instanceConfig.kernel = self.kernel
+                instanceConfig.initialFilesystem = self.initialFilesystem
+
+                if let bootLog = vmConfig.bootLog {
+                    instanceConfig.bootLog = bootLog
+                }
+
+                instanceConfig.interfaces = vmConfig.interfaces
+                instanceConfig.rosetta = self.rosetta
+                instanceConfig.nestedVirtualization = useNestedVirtualization
+
+                instanceConfig.mountsByID = vmConfig.mountsByID
+                instanceConfig.extensions = vmConfig.extensions
+            })
+    }
+}
+#endif