virtio requests are scatter-gather-style descriptors, but no
assumptions should be made about the layout. lguest was lazy here,
but saved by the fact that the network device hands all requests to
tun (which does it correctly) and console and random devices simply
use readv and writev.
Block devices, however, are broken: we convert to iovecs internally,
just make sure we handle the correctly.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We usually got away with ->next on the final entry being NULL, but it
finally bit me.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
This is a better location instead of having it in Documentation.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed compile)
