while using the virtio-serial device with the number of ports greater than 16, only 16 were seen in the guest. This led to the guest not being able to communicate with the host on the ports beyond the 16th one. This was due to some port instantiation messages getting missed as a result of a small queue size for outstanding requests from the host to guest. The queue size is now increased to 32, enabling more outstanding requests at once. This allows for all of the current maximum 31 ports to be instantiated at once.