hvm: introduce HVM_PARAM_BUFIOREQ_EVTCHN
Introduce an event channel for buffered io event notifications,
advertise the port number using an hvm param. This way the device
model is not forced to check the buffered io page for data several
times a second for the entire life of the VM (buffered io is mostly
used for stdvga emulation in Xen that is switched off after the guest
goes into graphical mode).
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
projects / xen.git / commit