Commit Graph

82 Commits

Author SHA1 Message Date
Asias He 6ac1afbf61 vhost: Make vhost a separate module
Currently, vhost-net and vhost-scsi are sharing the vhost core code.
However, vhost-scsi shares the code by including the vhost.c file
directly.

Making vhost a separate module makes it is easier to share code with
other vhost devices.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-07-07 17:33:44 +03:00
Asias He 6d5e6aa860 vhost: Simplify dev->vqs[i] access
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-07-07 14:38:26 +03:00
Michael S. Tsirkin 05c0535194 vhost: check owner before we overwrite ubuf_info
If device has an owner, we shouldn't touch ubuf_info
since it might be in use.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-11 02:46:21 -07:00
Michael S. Tsirkin 7542a6b0d2 vhost: drop virtio_net.h dependency
There's no net specific code in vhost.c anymore,
don't include the virtio_net.h header.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-06 14:04:06 +03:00
Asias He 54db63c2ca vhost: Export vhost_dev_set_owner
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-06 12:57:54 +03:00
Michael S. Tsirkin 150b9e51ae vhost: fix error handling in RESET_OWNER ioctl
RESET_OWNER ioctl would leave the fd in a bad state if
memory allocation failed: device is stopped
but owner is not reset. Make state changes
after allocating memory, such that a failed
ioctl has no effect.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01 10:02:54 +03:00
Michael S. Tsirkin 81f95a5580 vhost: move per-vq net specific fields out to net
This will remove the need for vhost scsi to pull
in virtio-net.h.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01 10:02:53 +03:00
Asias He 2839400f8f vhost: move vhost-net zerocopy fields to net.c
On top of 'vhost: Allow device specific fields per vq', we can move device
specific fields to device virt queue from vhost virt queue.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01 10:02:52 +03:00
Asias He 3ab2e420ec vhost: Allow device specific fields per vq
This is useful for any device who wants device specific fields per vq.
For example, tcm_vhost wants a per vq field to track requests which are
in flight on the vq. Also, on top of this we can add patches to move
things like ubufs from vhost.h out to net.c.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01 10:02:45 +03:00
Jason Wang 70181d5120 vhost_net: remove tx polling state
After commit 2b8b328b61 (vhost_net: handle polling
errors when setting backend), we in fact track the polling state through
poll->wqh, so there's no need to duplicate the work with an extra
vhost_net_polling_state. So this patch removes this and make the code simpler.

This patch also removes the all tx starting/stopping code in tx path according
to Michael's suggestion.

Netperf test shows almost the same result in stream test, but gets improvements
on TCP_RR tests (both zerocopy or copy) especially on low load cases.

Tested between multiqueue kvm guest and external host with two direct
connected 82599s.

zerocopy disabled:

sessions|transaction rates|normalize|
before/after/+improvements
1 | 9510.24/11727.29/+23.3%    | 693.54/887.68/+28.0%   |
25| 192931.50/241729.87/+25.3% | 2376.80/2771.70/+16.6% |
50| 277634.64/291905.76/+5%    | 3118.36/3230.11/+3.6%  |

zerocopy enabled:

sessions|transaction rates|normalize|
before/after/+improvements
1 | 7318.33/11929.76/+63.0%    | 521.86/843.30/+61.6%   |
25| 167264.88/242422.15/+44.9% | 2181.60/2788.16/+27.8% |
50| 272181.02/294347.04/+8.1%  | 3071.56/3257.85/+6.1%  |

Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-11 16:16:22 -04:00
Jason Wang 2b8b328b61 vhost_net: handle polling errors when setting backend
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 <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-29 15:43:03 -05:00
Michael S. Tsirkin 935cdee7ee vhost: avoid backend flush on vring ops
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 <mst@redhat.com>
2012-12-06 17:09:18 +02:00
David S. Miller 8a2cf062b2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-29 12:51:17 -05:00
Michael S. Tsirkin bd97120fc3 vhost: fix length for cross region descriptor
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 <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-28 11:27:01 -05:00
Michael S. Tsirkin b211616d71 vhost: move -net specific code out
Zerocopy handling code is vhost-net specific.
Move it from vhost.c/vhost.h out to net.c

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02 21:29:58 -04:00
Michael S. Tsirkin c4fcb586c3 vhost: track zero copy failures using DMA length
This will be used to disable zerocopy when error rate
is high.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02 21:29:57 -04:00
Michael S. Tsirkin 70e4cb9aaf vhost-net: cleanup macros for DMA status tracking
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 <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02 21:29:57 -04:00
Michael S. Tsirkin e19d6763cc skb: report completion status for zero copy skbs
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 <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02 21:29:57 -04:00
Al Viro cecb46f194 vhost_set_vring(): turn pollstart/pollstop into bool
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:12 -04:00
Stefan Hajnoczi 163049aefd vhost: make vhost work queue visible
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 <stefanha@linux.vnet.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-07-22 01:22:23 +03:00
Jens Freimann d7ffde35e3 vhost: use USER_DS in vhost_worker thread
On some architectures address spaces are set up in a way that this is
not necessary to work properly but on some others (like s390) it is.
Make sure we operate on the user address space to allow copy_xxx_user()
from the vhost_worker() thread by setting it explicitly before calling
use_mm() and revert it after unuse_mm().

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26 21:10:56 -07:00
Jason Wang c70aa540c7 vhost: zerocopy: poll vq in zerocopy callback
We add used and signal guest in worker thread but did not poll the virtqueue
during the zero copy callback. This may lead the missing of adding and
signalling during zerocopy. Solve this by polling the virtqueue and let it
wakeup the worker during callback.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-05-02 18:22:25 +03:00
Michael S. Tsirkin ca8f4fb21d skbuff: struct ubuf_info callback type safety
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 <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 13:09:19 -04:00
David S. Miller f1e84eb3bb Merge branch 'vhost-net' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 2012-03-23 14:46:48 -04:00
Cong Wang c6daa7ffa8 vhost: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:21 +08:00
Michael S. Tsirkin ea5d404655 vhost: fix release path lockdep checks
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 <mst@redhat.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
2012-02-28 09:13:22 +02:00
Nadav Har'El d550dda192 vhost: don't forget to schedule()
This is a tiny, but important, patch to vhost.

Vhost's worker thread only called schedule() when it had no work to do, and
it wanted to go to sleep. But if there's always work to do, e.g., the guest
is running a network-intensive program like netperf with small message sizes,
schedule() was *never* called. This had several negative implications (on
non-preemptive kernels):

 1. Passing time was not properly accounted to the "vhost" process (ps and
    top would wrongly show it using zero CPU time).

 2. Sometimes error messages about RCU timeouts would be printed, if the
    core running the vhost thread didn't schedule() for a very long time.

 3. Worst of all, a vhost thread would "hog" the core. If several vhost
    threads need to share the same core, typically one would get most of the
    CPU time (and its associated guest most of the performance), while the
    others hardly get any work done.

The trivial solution is to add

	if (need_resched())
		schedule();

After doing every piece of work. This will not do the heavy schedule() all
the time, just when the timer interrupt decided a reschedule is warranted
(so need_resched returns true).

Thanks to Abel Gordon for this patch.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-02-28 09:13:19 +02:00
Michael S. Tsirkin b834226b04 vhost: optimize interrupt enable/disable
As we now only update used ring after enabling
the backend, we can write flags with __put_user:
as that's done on data path, it matters.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-19 17:17:28 +03:00
Michael S. Tsirkin 75fd9edc10 vhost: fix zcopy reference counting
Fix get/put refcount imbalance with zero copy,
which caused qemu to hang forever on guest driver unload.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-19 13:28:34 +03:00
Jason Wang 2723feaa8e vhost: set log when updating used flags or avail event
We need to log writes when updating used flags and avail event
fields.  Otherwise the guest may see a stale value after migration and
miss notifying the host.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-19 13:28:34 +03:00
Jason Wang f59281dafb vhost: init used ring after backend was set
Move the used ring initialization after backend was set. This
makes it possible to disable the backend and tweak the used ring,
then restart. This will also make it possible to log the used ring
write correctly.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-19 13:28:34 +03:00
Michael S. Tsirkin bab632d69e vhost: vhost TX zero-copy support
>From: Shirley Ma <mashirle@us.ibm.com>

This adds experimental zero copy support in vhost-net,
disabled by default. To enable, set
experimental_zcopytx module option to 1.

This patch maintains the outstanding userspace buffers in the
sequence it is delivered to vhost. The outstanding userspace buffers
will be marked as done once the lower device buffers DMA has finished.
This is monitored through last reference of kfree_skb callback. Two
buffer indices are used for this purpose.

The vhost-net device passes the userspace buffers info to lower device
skb through message control. DMA done status check and guest
notification are handled by handle_tx: in the worst case is all buffers
in the vq are in pending/done status, so we need to notify guest to
release DMA done buffers first before we get any new buffers from the
vq.

One known problem is that if the guest stops submitting
buffers, buffers might never get used until some
further action, e.g. device reset. This does not
seem to affect linux guests.

Signed-off-by: Shirley <xma@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-18 10:42:32 -07:00
Michael S. Tsirkin 8ea8cf89e1 vhost: support event index
Support the new event index feature. When acked,
utilize it to reduce the # of interrupts sent to the guest.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-30 11:14:15 +09:30
Rob Landley 6151658751 Correct occurrences of
- Documentation/kvm/ to Documentation/virtual/kvm
- Documentation/uml/ to Documentation/virtual/uml
- Documentation/lguest/ to Documentation/virtual/lguest
throughout the kernel source tree.

Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
2011-05-06 09:27:55 -07:00
Michael S. Tsirkin fcc042a280 vhost: copy_from_user -> __copy_from_user
copy_from_user is pretty high on perf top profile,
replacing it with __copy_from_user helps.
It's also safe because we do access_ok checks during setup.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-03-08 18:03:05 +02:00
Krishna Kumar d47effe1be vhost: Cleanup vhost.c and net.c
Minor cleanup of vhost.c and net.c to match coding style.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-03-08 18:02:47 +02:00
Michael S. Tsirkin 0174b0c30a vhost: fix signed/unsigned comparison
To detect that a sequence number is done, we are doing math on unsigned
integers so the result is unsigned too. Not what was intended for the <=
comparison. The result is user stuck forever in flush call.
Convert to int to fix this.

Further, get rid of ({}) to make code clearer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-01-10 10:03:39 +02:00
Michael S. Tsirkin 28831ee60b vhost: better variable name in logging
We really store a page offset in write_address,
so rename it write_page to avoid confusion.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-09 16:00:10 +02:00
Michael S. Tsirkin 3bf9be40ff vhost: correctly set bits of dirty pages
Fix two bugs in dirty page logging:
When counting pages we should increase address by 1 instead of
VHOST_PAGE_SIZE. Make log_write() correctly process requests
that cross pages with write_address not starting at page boundary.

Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-09 15:39:17 +02:00
Michael S. Tsirkin bf5e0bd27f vhost: remove unused include
vhost.c does not need to know about sockets,
don't include sock.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-09 15:39:13 +02:00
Michael S. Tsirkin 8b7347aab6 vhost: get/put_user -> __get/__put_user
We do access_ok checks on all ring values on an ioctl,
so we don't need to redo them on each access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-04 13:22:12 +02:00
Michael S. Tsirkin dfe5ac5b18 vhost: copy_to_user -> __copy_to_user
We do access_ok checks at setup time, so we don't need to
redo them on each access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-04 13:22:11 +02:00
Michael S. Tsirkin 64e1c80748 vhost-net: batch use/unuse mm
Move use/unuse mm to vhost.c which makes it possible to batch these
operations.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-04 13:22:11 +02:00
Michael S. Tsirkin 533a19b4b8 vhost: put mm after thread stop
makes it possible to batch use/unuse mm

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-04 13:22:10 +02:00
Julia Lawall 3fcedec752 drivers/vhost/vhost.c: delete double assignment
Delete successive assignments to the same location.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression i;
@@

*i = ...;
 i = ...;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-10-26 20:39:30 +02:00
Linus Torvalds 5f05647dd8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1699 commits)
  bnx2/bnx2x: Unsupported Ethtool operations should return -EINVAL.
  vlan: Calling vlan_hwaccel_do_receive() is always valid.
  tproxy: use the interface primary IP address as a default value for --on-ip
  tproxy: added IPv6 support to the socket match
  cxgb3: function namespace cleanup
  tproxy: added IPv6 support to the TPROXY target
  tproxy: added IPv6 socket lookup function to nf_tproxy_core
  be2net: Changes to use only priority codes allowed by f/w
  tproxy: allow non-local binds of IPv6 sockets if IP_TRANSPARENT is enabled
  tproxy: added tproxy sockopt interface in the IPV6 layer
  tproxy: added udp6_lib_lookup function
  tproxy: added const specifiers to udp lookup functions
  tproxy: split off ipv6 defragmentation to a separate module
  l2tp: small cleanup
  nf_nat: restrict ICMP translation for embedded header
  can: mcp251x: fix generation of error frames
  can: mcp251x: fix endless loop in interrupt handler if CANINTF_MERRF is set
  can-raw: add msg_flags to distinguish local traffic
  9p: client code cleanup
  rds: make local functions/variables static
  ...

Fix up conflicts in net/core/dev.c, drivers/net/pcmcia/smc91c92_cs.c and
drivers/net/wireless/ath/ath9k/debug.c as per David
2010-10-23 11:47:02 -07:00
David S. Miller 2198a10b50 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/core/dev.c
2010-10-21 08:43:05 -07:00
Dan Carpenter 6d97e55f71 vhost: fix return code for log_access_ok()
access_ok() returns 1 if it's OK otherwise it should return 0.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-10-12 14:32:28 +02:00
Ingo Molnar 556ef63255 Merge commit 'v2.6.36-rc7' into core/rcu
Merge reason: Update from -rc3 to -rc7.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-07 09:43:45 +02:00
Ingo Molnar d4f8f217b8 Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu 2010-10-07 09:43:11 +02:00