We used to use rte_vhost_driver_session_start() to trigger the vhost-user
session. It takes no argument, thus it's a global trigger. And it could
be problematic.
The issue is, currently, rte_vhost_driver_register(path, flags) actually
tries to put it into the session loop (by fdset_add). However, it needs
a set of APIs to set a vhost-user driver properly:
* rte_vhost_driver_register(path, flags);
* rte_vhost_driver_set_features(path, features);
* rte_vhost_driver_callback_register(path, vhost_device_ops);
If a new vhost-user driver is registered after the trigger (think OVS-DPDK
that could add a port dynamically from cmdline), the current code will
effectively starts the session for the new driver just after the first
API rte_vhost_driver_register() is invoked, leaving later calls taking
no effect at all.
To handle the case properly, this patch introduce a new API,
rte_vhost_driver_start(path), to trigger a specific vhost-user driver.
To do that, the rte_vhost_driver_register(path, flags) is simplified
to create the socket only and let rte_vhost_driver_start(path) to
actually put it into the session loop.
Meanwhile, the rte_vhost_driver_session_start is removed: we could hide
the session thread internally (create the thread if it has not been
created). This would also simplify the application.
NOTE: the API order in prog guide is slightly adjusted for showing the
correct invoke order.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
fdset_add increments pfdset->num, but fdset_del doesn't decrement
pfdset->num, so if we call fdset_add then fdset_del in a loop without
calling fdset_shrink, we can easily exceed MAX_FDS with only a few
number of fds used.
So my solution is simply to call fdset_shrink in fdset_add when it
exceeds MAX_FDS.
Because fdset_shrink and fdset_add locks pfdset->fd_mutex we can't
call fdset_shrink inside fdset_add because that would cause a dead
lock, so this patch split fdset_shrink in two, fdset_shrink and
fdset_shrink_nolock.
Fixes: 59317cef249c ("vhost: allow many vhost-user ports")
Cc: stable@dpdk.org
Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com>
Currently select() is used to monitor file descriptors for vhostuser
ports. This limits the number of ports possible to create since the
fd number is used as index in the fd_set and we have seen fds > 1023.
This patch changes select() to poll(). This way we can keep an
packed (pollfd) array for the fds, e.g. as many fds as the size of
the array.
Also see:
http://dpdk.org/ml/archives/dev/2016-April/037024.html
Reported-by: Patrik Andersson <patrik.r.andersson@ericsson.com>
Signed-off-by: Jan Wickbom <jan.wickbom@ericsson.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
We now have one vhost implementation; no sub source dir is needed.
Remove it by move them to upper dir.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
