Disable offloading for krunkit

Future krunkit provides unixgram socket option supporting offloading
argument to enable of disable offloading. This is a quick and dirty
change to test the new option.

To complete this change we need to remove the "auto" feature for
offloading since we never want to enable it automatically. It can be
nice to keep it for testing krunkit with offloading, since it does
increase performance for vm-to-host traffic.

Requires krunkit PR:
containers/krunkit#63

And installing local libkrun-efi from main.

Author: nirs

example

@@ -22,9 +22,7 @@ CONNECTION_AUTO = {
 
 VMNET_OFFLOAD_AUTO = {
     "vfkit": "off",
-    # libkrun enables offloading features by default, so we must enable vmnet
-    # offloading.  See https://github.com/containers/libkrun/issues/264
-    "krunkit": "on",
+    "krunkit": "off",
     "qemu": "off",
 }
 

vmnet/vm.py

@@ -42,6 +42,7 @@ def __init__(self, args, mac_address, fd=None, socket=None, client=None):
         self.memory = args.memory
         self.distro = args.distro
         self.serial = store.vm_path(self.vm_name, "serial.log")
+        self.vmnet_offload = args.vmnet_offload
 
         # Running info
         self.disk = None
@@ -174,14 +175,15 @@ def krunkit_command(self):
             raise ValueError("fd connection not supported for krunkit driver")
         if self.socket is None:
             raise ValueError("socket connection required")
+        offloading = "true" if self.vment_offload == "on" else "false"
         return [
             self.driver_command or "krunkit",
             f"--memory={self.memory}",
             f"--cpus={self.cpus}",
             f"--restful-uri=none://",
             f"--device=virtio-blk,path={self.disk['image']}",
             f"--device=virtio-blk,path={self.cidata}",
-            f"--device=virtio-net,unixSocketPath={self.socket},mac={self.mac_address}",
+            f"--device=virtio-net,unixgram={self.socket},mac={self.mac_address},offloading={offloading}",
             f"--device=virtio-serial,logFilePath={self.serial}",
             "--krun-log-level=3",
         ]