network,passt: consider overhead when binding all ports

When VMI uses Passt interface and doesn't specify ports, all the
ports are forwarded by Passt process.
Opening all the sockets for forwarding causes kernel to consume
considerable amount of memory.

At the moment, Passt binding can only be used on primary
interface, but since we need to loop over the VMI interfaces
anyway, there's no reason not to be generic and account for
each Passt binding with no specified Ports.

Signed-off-by: Radim Hrazdil <[email protected]>

pkg/virt-controller/services/renderresources.go

@@ -357,6 +357,14 @@ func GetMemoryOverhead(vmi *v1.VirtualMachineInstance, cpuArch string) *resource
 		overhead.Add(resource.MustParse("53Mi"))
 	}
 
+	// Additional overhead for each interface with Passt binding, that forwards all ports.
+	// More information can be found here: https://bugs.passt.top/show_bug.cgi?id=20
+	for _, net := range vmi.Spec.Domain.Devices.Interfaces {
+		if net.Passt != nil && len(net.Ports) == 0 {
+			overhead.Add(resource.MustParse("800Mi"))
+		}
+	}
+
 	return overhead
 }