tree 793c1f8763350012caa521a55c5778b1c633b7e5
parent 15045275c32bf6d15d32c2eca8157be9c0ba6e45
author Rusty Russell <rusty@rustcorp.com.au> 1193016261 +1000
committer Rusty Russell <rusty@rustcorp.com.au> 1193118596 +1000

Lguest support for Virtio

This makes lguest able to use the virtio devices.

We change the device descriptor page from a simple array to a variable
length "type, config_len, status, config data..." format, and
implement virtio_config_ops to read from that config data.

We use the virtio ring implementation for an efficient Guest <-> Host
virtqueue mechanism, and the new LHCALL_NOTIFY hypercall to kick the
host when it changes.

We also use LHCALL_NOTIFY on kernel addresses for very very early
console output.  We could have another hypercall, but this hack works
quite well.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>