Set application category (#940)

Was looking into performance and was wondering about Game Mode on Sonoma.

This change is unrelated. Just found they have a category for tools like Tart.

.ci/set-version.sh

@@ -4,4 +4,4 @@ TMPFILE=$(mktemp)
 envsubst < Sources/tart/CI/CI.swift > $TMPFILE
 mv $TMPFILE Sources/tart/CI/CI.swift
 
-/usr/libexec/PlistBuddy -c "Add :CFBundleShortVersionString string ${CIRRUS_TAG}" Info.plist
+/usr/libexec/PlistBuddy -c "Add :CFBundleShortVersionString string ${CIRRUS_TAG}" Resources/Info.plist

PROFILING.md

@@ -0,0 +1,64 @@
+# Profiling Tart
+
+## Using `time(1)`
+
+Perhaps, the easiest, but not the most comprehensive way to tell what's going on with Tart is to use the [`time(1)`](https://ss64.com/mac/time.html) command.
+
+In the example below, you will run `tart pull` via `time(1)` to gather generalized CPU, I/O and memory usage metrics:
+
+```shell
+/usr/bin/time -l tart pull ghcr.io/cirruslabs/macos-sequoia-base:latest
+```
+
+**Note:** you need to specify a full path to `time(1)` binary, otherwise the shell's built-in `time` command will be invoked, which doesn't have the `-l` command-line argument.
+
+**Note:** The `-l` command-line argument makes `time(1)` return much more useful information, for example, maximum memory usage.
+
+When running the command above, you'll see the `tart pull` output first as it pulls the image, and then the `time(1)` output, which will be printed once the Tart process finishes:
+
+```
+      172.17 real        10.29 user         8.36 sys
+           353796096  maximum resident set size
+                   0  average shared memory size
+                   0  average unshared data size
+                   0  average unshared stack size
+               23838  page reclaims
+                  35  page faults
+                   0  swaps
+                   0  block input operations
+                   0  block output operations
+                   8  messages sent
+                   8  messages received
+                   0  signals received
+                 146  voluntary context switches
+              222950  involuntary context switches
+         39683070975  instructions retired
+         27562035252  cycles elapsed
+           170920448  peak memory footprint
+```
+
+From the output above, you can tell that `tart pull` spent nearly 90% of time off-CPU (`real` > `user` + `sys`), which means that Tart was mostly waiting for the I/O (be it a network or disk), instead of decompressing disk layers or doing other useful computations.
+
+## Using `xctrace(1)`
+
+[`xctrace(1)`](https://keith.github.io/xcode-man-pages/xctrace.1.html) is a `.trace` format recorder for the [Instruments](https://en.wikipedia.org/wiki/Instruments_(software)) app, which yields much more powerful insights compared to `time(1)`. For example, it can tell which Tart functions spent the most time on the CPU, thus allowing the Tart developers to further optimize these functions.
+
+To use it, make sure that [Xcode](https://developer.apple.com/xcode/resources/) is installed. If you're installing Xcode for the first time on the machine, you'll need to launch it once and click the blue "Install" button. There's no need to choose any platforms except for the macOS.
+
+Once done, you can create a CPU profile of `tart pull`:
+
+```shell
+xctrace record --template "CPU Profiler" --target-stdout - --launch -- /opt/homebrew/bin/tart pull ghcr.io/cirruslabs/macos-sequoia-base:latest
+```
+
+Now that `xctrace(1)` is running, you'll see the `tart pull`-related output first, and once finished, the following line will appear:
+
+```
+Output file saved as: Launch_[...].trace
+```
+
+To view this trace in the Instruments app, simply find this directory in Finder and double-click it. Instruments app will appear:
+
+![](Resources/Instruments.png)
+
+To send this trace, right-click its directory in Finder and choose "Compress [...]". This will result in a similarly named file with a `.zip` at the end, which can now be conveniently sent via email or uploaded.

Resources/Info.plist

@@ -10,8 +10,8 @@
 	<string>org.cirruslabs.tart</string>
 	<key>CFBundleExecutable</key>
 	<string>tart</string>
-	<key>LSBackgroundOnly</key>
-	<string>1</string>
+  <key>LSApplicationCategoryType</key>
+  <string>public.app-category.developer-tools</string>
 	<key>CFBundleIconFiles</key>
 	<array>
 		<string>AppIcon.png</string>

Sources/tart/Commands/Run.swift

@@ -156,6 +156,9 @@ struct Run: AsyncParsableCommand {
   """, valueName: "[name:]path[:options]"))
   var dir: [String] = []
 
+  @Flag(help: ArgumentHelp("Enable nested virtualization if possible"))
+  var nested: Bool = false
+
   @Option(help: ArgumentHelp("""
   Use bridged networking instead of the default shared (NAT) networking \n(e.g. --net-bridged=en0 or --net-bridged=\"Wi-Fi\")
   """, discussion: """
@@ -221,6 +224,14 @@ struct Run: AsyncParsableCommand {
       throw ValidationError("--captures-system-keys can only be used with the default VM view")
     }
 
+    if nested {
+      if #unavailable(macOS 15) {
+        throw ValidationError("Nested virtualization is supported on hosts starting with macOS 15 (Sequia), and later.")
+      } else if !VZGenericPlatformConfiguration.isNestedVirtualizationSupported {
+        throw ValidationError("Nested virtualization is available for Mac with the M3 chip, and later.")
+      }
+    }
+
     let localStorage = VMStorageLocal()
     let vmDir = try localStorage.open(name)
     if try vmDir.state() == .Suspended {
@@ -294,6 +305,7 @@ struct Run: AsyncParsableCommand {
       directorySharingDevices: directoryShares() + rosettaDirectoryShare(),
       serialPorts: serialPorts,
       suspendable: suspendable,
+      nested: nested,
       audio: !noAudio,
       clipboard: !noClipboard,
       sync: VZDiskImageSynchronizationMode(diskOptions.syncModeRaw)
@@ -460,8 +472,10 @@ struct Run: AsyncParsableCommand {
 
     let useVNCWithoutGraphics = (vnc || vncExperimental) && !graphics
     if noGraphics || useVNCWithoutGraphics {
-      // enter the main even loop, without bringing up any UI,
-      // and just wait for the VM to exit.
+      // Enter the main event loop without bringing up any UI,
+      // waiting for the VM to exit.
+      NSApplication.shared.setActivationPolicy(.prohibited)
+
       NSApplication.shared.run()
     } else {
       runUI(suspendable, captureSystemKeys)

Sources/tart/Platform/Darwin.swift

@@ -58,7 +58,11 @@ struct UnsupportedHostOSError: Error, CustomStringConvertible {
       VZMacOSBootLoader()
     }
 
-    func platform(nvramURL: URL) throws -> VZPlatformConfiguration {
+    func platform(nvramURL: URL, needsNestedVirtualization: Bool) throws -> VZPlatformConfiguration {
+      if needsNestedVirtualization {
+        throw RuntimeError.VMConfigurationError("macOS virtual machines do not support nested virtualization")
+      }
+
       let result = VZMacPlatformConfiguration()
 
       result.machineIdentifier = ecid

Sources/tart/Platform/Linux.swift

@@ -14,8 +14,12 @@ struct Linux: Platform {
     return result
   }
 
-  func platform(nvramURL: URL) throws -> VZPlatformConfiguration {
-    VZGenericPlatformConfiguration()
+  func platform(nvramURL: URL, needsNestedVirtualization: Bool) throws -> VZPlatformConfiguration {
+    let config = VZGenericPlatformConfiguration()
+    if #available(macOS 15, *) {
+      config.isNestedVirtualizationEnabled = needsNestedVirtualization
+    }
+    return config
   }
 
   func graphicsDevice(vmConfig: VMConfig) -> VZGraphicsDeviceConfiguration {

Sources/tart/Platform/Platform.swift

@@ -3,7 +3,7 @@ import Virtualization
 protocol Platform: Codable {
   func os() -> OS
   func bootLoader(nvramURL: URL) throws -> VZBootLoader
-  func platform(nvramURL: URL) throws -> VZPlatformConfiguration
+  func platform(nvramURL: URL, needsNestedVirtualization: Bool) throws -> VZPlatformConfiguration
   func graphicsDevice(vmConfig: VMConfig) -> VZGraphicsDeviceConfiguration
   func keyboards() -> [VZKeyboardConfiguration]
   func pointingDevices() -> [VZPointingDeviceConfiguration]

Sources/tart/URL+AccessDate.swift

@@ -1,4 +1,5 @@
 import Foundation
+import System
 
 extension URL {
   func accessDate() throws -> Date {
@@ -13,7 +14,9 @@ extension URL {
     let times = [accessDate.asTimeval(), modificationDate.asTimeval()]
     let ret = utimes(path, times)
     if ret != 0 {
-      throw RuntimeError.FailedToUpdateAccessDate("utimes(2) failed: \(ret.explanation())")
+      let details = Errno(rawValue: CInt(errno))
+
+      throw RuntimeError.FailedToUpdateAccessDate("utimes(2) failed: \(details)")
     }
   }
 }

Sources/tart/VM.swift

@@ -47,6 +47,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
        directorySharingDevices: [VZDirectorySharingDeviceConfiguration] = [],
        serialPorts: [VZSerialPortConfiguration] = [],
        suspendable: Bool = false,
+       nested: Bool = false,
        audio: Bool = true,
        clipboard: Bool = true,
        sync: VZDiskImageSynchronizationMode = .full
@@ -66,6 +67,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
                                                 directorySharingDevices: directorySharingDevices,
                                                 serialPorts: serialPorts,
                                                 suspendable: suspendable,
+                                                nested: nested,
                                                 audio: audio,
                                                 clipboard: clipboard,
                                                 sync: sync
@@ -295,6 +297,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     directorySharingDevices: [VZDirectorySharingDeviceConfiguration],
     serialPorts: [VZSerialPortConfiguration],
     suspendable: Bool = false,
+    nested: Bool = false,
     audio: Bool = true,
     clipboard: Bool = true,
     sync: VZDiskImageSynchronizationMode = .full
@@ -309,7 +312,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     configuration.memorySize = vmConfig.memorySize
 
     // Platform
-    configuration.platform = try vmConfig.platform.platform(nvramURL: nvramURL)
+    configuration.platform = try vmConfig.platform.platform(nvramURL: nvramURL, needsNestedVirtualization: nested)
 
     // Display
     configuration.graphicsDevices = [vmConfig.platform.graphicsDevice(vmConfig: vmConfig)]
@@ -365,13 +368,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
       try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false, cachingMode: .cached, synchronizationMode: sync) :
       try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false, cachingMode: .automatic, synchronizationMode: sync)
 
-    var device: VZStorageDeviceConfiguration
-    if #available(macOS 14, *), vmConfig.os == .linux {
-      device = VZNVMExpressControllerDeviceConfiguration(attachment: attachment)
-    } else {
-      device = VZVirtioBlockDeviceConfiguration(attachment: attachment)
-    }
-    var devices: [VZStorageDeviceConfiguration] = [device]
+    var devices: [VZStorageDeviceConfiguration] = [VZVirtioBlockDeviceConfiguration(attachment: attachment)]
     devices.append(contentsOf: additionalStorageDevices)
     configuration.storageDevices = devices
 

Sources/tart/VMStorageOCI.swift

@@ -239,6 +239,9 @@ class VMStorageOCI: PrunableStorage {
       // are excluded from garbage collection
       VMDirectory(baseURL: vmURL(name)).markExplicitlyPulled()
     }
+
+    // to explicitly set the image as being accessed so it won't get pruned immediately
+    _ = try VMStorageOCI().open(name)
   }
 
   func linked(from: RemoteName, to: RemoteName) -> Bool {