In order to prepare for the support of multithreaded multiqueues, the
structure VhostUserNetThread is simplified to hold only one RX queue,
one TX queue, and one TAP interface.
Following this change, VhostUserNetBackend now holds a list of threads
instead of going through each thread to handle multiqueues.
These changes decouple neatly the abstraction between the backend and
each thread. This allows for a lot of simplification since we now know
all threads are identical, hence the handling of events becomes very
straightforward.
One important point is that each thread can be locked when in use,
without causing any contention with other threads since the backend
doesn't need to be locked anymore.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that multiple worker threads can be run from the backend crate, it
is important that each backend implementation can access every worker
thread.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
By changing the mutability of this function, after adapting all
backends, we should be able to implement multithreads with
multiqueues support without hitting a bottleneck on the backend
locking.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Both blk, net and fs backends have been updated to avoid the requirement
of having handle_event(&mut self). This will allow the backend crate to
avoid taking a write lock onto the backend object, which will remove the
potential contention point when multiple threads will be handling
multiqueues.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Add helpers to Vring and VhostUserSlaveReqHandler for EVENT_IDX, so
consumers of this crate can make use of this feature.
Signed-off-by: Sergio Lopez <slp@redhat.com>
Implement the exit_event() method on the VhostUserBackend trait. It is
necessary to specify a custom exit event id in this case as the loop is
also used for handling activity on the tap file descriptors.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Split the basic launching functionality into its own function in the
newly added vhost_user_net crate.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Extract the majority of the code that provides the vhost-user-net
backend into its own crate and port the binary to use it.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
