From KVM
Revision as of 10:37, 2 September 2010 by Amit (Talk | contribs)

Guest API

Function Linux guest Windows guest
Port discovery symlinks from /dev/virtio-port/<portname> to /dev/vportNpn
Opening port open(2). Returns >= 0 on success. Only one open allowed at a time for a port.
Reading read(2). Blocking as well as non-blocking reads available. Return 0 if host is not connected. Block or -EINTR otherwise. Return -ENODEV if port or device get hot-unplugged
Writing write(2). Blocking as well as non-blocking. If host is not connected, write blocks or returns -EINTR. Return -ENODEV if port or device get hot-unplugged.
Poll poll(). POLLIN, POLLOUT with usual meaning. POLLHUP when host is not connected or when port or device got unplugged
Signals From kernel 2.6.37, SIGIO will be sent to guest apps that set O_ASYNC flag on the fd. SIGIO will be sent on host connection up, down and port unplug events.

Host API