linux-stable.git/drivers/vhost/vhost.c, branch linux-3.8.y

vhost_net: handle polling errors when setting backend

2013-01-29T20:43:03+00:00

Currently, the polling errors were ignored, which can lead following issues:

- vhost remove itself unconditionally from waitqueue when stopping the poll,
  this may crash the kernel since the previous attempt of starting may fail to
  add itself to the waitqueue
- userspace may think the backend were successfully set even when the polling
  failed.

Solve this by:

- check poll->wqh before trying to remove from waitqueue
- report polling errors in vhost_poll_start(), tx_poll_start(), the return value
  will be checked and returned when userspace want to set the backend

After this fix, there still could be a polling failure after backend is set, it
will addressed by the next patch.

Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost: avoid backend flush on vring ops

2012-12-06T15:09:18+00:00

vring changes already do a flush internally where appropriate, so we do
not need a second flush.

It's currently not very expensive but a follow-up patch makes flush more
heavy-weight, so remove the extra flush here to avoid regressing
performance if call or kick fds are changed on data path.

Signed-off-by: Michael S. Tsirkin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2012-11-29T17:51:17+00:00

Signed-off-by: David S. Miller

vhost: fix length for cross region descriptor

2012-11-28T16:27:01+00:00

If a single descriptor crosses a region, the
second chunk length should be decremented
by size translated so far, instead it includes
the full descriptor length.

Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang 
Signed-off-by: David S. Miller

vhost: move -net specific code out

2012-11-03T01:29:58+00:00

Zerocopy handling code is vhost-net specific.
Move it from vhost.c/vhost.h out to net.c

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost: track zero copy failures using DMA length

2012-11-03T01:29:57+00:00

This will be used to disable zerocopy when error rate
is high.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost-net: cleanup macros for DMA status tracking

2012-11-03T01:29:57+00:00

Better document macros for DMA tracking. Add an
explicit one for DMA in progress instead of
relying on user supplying len != 1.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

skb: report completion status for zero copy skbs

2012-11-03T01:29:57+00:00

Even if skb is marked for zero copy, net core might still decide
to copy it later which is somewhat slower than a copy in user context:
besides copying the data we need to pin/unpin the pages.

Add a parameter reporting such cases through zero copy callback:
if this happens a lot, device can take this into account
and switch to copying in user context.

This patch updates all users but ignores the passed value for now:
it will be used by follow-up patches.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost_set_vring(): turn pollstart/pollstop into bool

2012-09-27T01:10:12+00:00

Signed-off-by: Al Viro

vhost: make vhost work queue visible

2012-07-21T22:22:23+00:00

The vhost work queue allows processing to be done in vhost worker thread
context, which uses the owner process mm.  Access to the vring and guest
memory is typically only possible from vhost worker context so it is
useful to allow work to be queued directly by users.

Currently vhost_net only uses the poll wrappers which do not expose the
work queue functions.  However, for tcm_vhost (vhost_scsi) it will be
necessary to queue custom work.

Signed-off-by: Stefan Hajnoczi 
Cc: Zhi Yong Wu 
Cc: Michael S. Tsirkin 
Cc: Paolo Bonzini 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Michael S. Tsirkin