linux-stable.git/drivers/vhost/vhost.h, branch linux-3.9.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

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: 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

vhost: Separate vhost-net features from vhost features

2012-07-21T22:21:53+00:00

In order for other vhost devices to use the VHOST_FEATURES bits the
vhost-net specific bits need to be moved to their own VHOST_NET_FEATURES
constant.

(Asias: Update drivers/vhost/test.c to use VHOST_NET_FEATURES)

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

skbuff: struct ubuf_info callback type safety

2012-04-13T17:09:19+00:00

The skb struct ubuf_info callback gets passed struct ubuf_info
itself, not the arg value as the field name and the function signature
seem to imply. Rename the arg field to ctx to match usage,
add documentation and change the callback argument type
to make usage clear and to have compiler check correctness.

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

vhost: fix release path lockdep checks

2012-02-28T07:13:22+00:00

We shouldn't hold any locks on release path. Pass a flag to
vhost_dev_cleanup to use the lockdep info correctly.

Signed-off-by: Michael S. Tsirkin 
Tested-by: Sasha Levin