The log eventfd signalling got put in dead code.
We didn't notice because qemu currently does polling
instead of eventfd select.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

In mergeable buffer case, we use headcount, log_num
and seg as indexes in same-size arrays, and
we know that headcount <= seg and
log_num equals either 0 or seg.

Therefore, the right thing to do is range-check seg,
not headcount as we do now: these will be different
if guest chains s/g descriptors (this does not
happen now, but we can not trust the guest).

Long term, we should add BUG_ON checks to verify
two other indexes are what we think they should be.

Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vhost should set worker to NULL on cgroups attach failure,
so that we won't try to destroy the worker again on close.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Since 2.6.36-rc1, non-root users of vhost-net fail to attach
if they are in any cgroups.

The reason is that when qemu uses vhost, vhost wants to attach
its thread to all cgroups that qemu has.  But we got the API backwards,
so a non-priveledged process (Qemu) tried to control
the priveledged one (vhost), which fails.

Fix this by switching to the new cgroup_attach_task_all,
and running it from the vhost thread.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Its currently illegal to call kthread_stop(NULL)

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits)
  phy/marvell: add 88ec048 support
  igb: Program MDICNFG register prior to PHY init
  e1000e: correct MAC-PHY interconnect register offset for 82579
  hso: Add new product ID
  can: Add driver for esd CAN-USB/2 device
  l2tp: fix export of header file for userspace
  can-raw: Fix skb_orphan_try handling
  Revert "net: remove zap_completion_queue"
  net: cleanup inclusion
  phy/marvell: add 88e1121 interface mode support
  u32: negative offset fix
  net: Fix a typo from "dev" to "ndev"
  igb: Use irq_synchronize per vector when using MSI-X
  ixgbevf: fix null pointer dereference due to filter being set for VLAN 0
  e1000e: Fix irq_synchronize in MSI-X case
  e1000e: register pm_qos request on hardware activation
  ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice
  net: Add getsockopt support for TCP thin-streams
  cxgb4: update driver version
  cxgb4: add new PCI IDs
  ...

Manually fix up conflicts in:
 - drivers/net/e1000e/netdev.c: due to pm_qos registration
   infrastructure changes
 - drivers/net/phy/marvell.c: conflict between adding 88ec048 support
   and cleaning up the IDs
 - drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req
   conflict (registration change vs marking it static)

This adds support for mergeable buffers in vhost-net: this is needed
for older guests without indirect buffer support, as well
as for zero copy with some devices.

Includes changes by Michael S. Tsirkin to make the
patch as low risk as possible (i.e., close to no changes
when feature is disabled).

Signed-off-by: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Apply the cgroup of the owner task to the created vhost worker.

Based on patches from Sridhar Samudrala's and Tejun Heo.
Later we'll need to also apply cpumask and probably priority
of the owner process.

Discussion on the best way to do this is still ongoing.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sridhar Samudrala <samudrala.sridhar@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>

Replace vhost_workqueue with per-vhost kthread.  Other than callback
argument change from struct work_struct * to struct vhost_work *,
there's no visible change to vhost_poll_*() interface.

This conversion is to make each vhost use a dedicated kthread so that
resource control via cgroup can be applied.

Partially based on Sridhar Samudrala's patch.

* Updated to use sub structure vhost_work instead of directly using
  vhost_poll at Michael's suggestion.

* Added flusher wake_up() optimization at Michael's suggestion.

Changes by MST:
* Converted atomics/barrier use to a spinlock.
* Create thread on SET_OWNER
* Fix flushing

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Sridhar Samudrala <samudrala.sridhar@gmail.com>

Reported by Stephen Rothwell.

Signed-off-by: David S. Miller <davem@davemloft.net>