instead of continuations directly from shm callbacks or interrupt
handlers. The whole CPS design remains but is adapted to cope with
a thread model.
This patch allows scheduling away I/O requests of domains that behave
abnormally, or even destroy them if there is a need to (without thrashing
dom0 with lots of error messages at IPL_BIO).
I took this opportunity to make the driver MPSAFE, so multiple instances
can run concurrently. Moved from home-grown pool(9) queues to
pool_cache(9), and rework the callback mechanism so that it delegates
I/O processing to thread instead of handling it itself through the
continuation trampoline.
This one fixes the potential DoS many have seen in a dom0 when trying to
suspend a NetBSD domU with a corrupted I/O ring.
Benchmarks (build.sh release runs and bonnie++) do not show any
performance regression, the "new" driver is on-par with the "old" one.
ok bouyer@.
54f95b1441