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  1. 13 3月, 2014 2 次提交
    • R
      virtio: fail adding buffer on broken queues. · 70670444
      由 Rusty Russell 提交于 
      Heinz points out that adding buffers to a broken virtqueue (which
should "never happen") still works.  Failing allows drivers to detect
and complain about broken devices.

Now drivers are robust, we can add this extra check.
Reported-by: NHeinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      70670444
    • J
      tools/virtio: fix missing kmemleak_ignore symbol · 6abb2dd9
      由 Joel Stanley 提交于 
      In commit bb478d8b virtio_ring: plug kmemleak false positive,
kmemleak_ignore was introduced. This broke compilation of virtio_test:

  cc -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign
    -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD
    -U_FORTIFY_SOURCE   -c -o virtio_ring.o ../../drivers/virtio/virtio_ring.c
  ../../drivers/virtio/virtio_ring.c: In function ‘vring_add_indirect’:
  ../../drivers/virtio/virtio_ring.c:177:2: warning: implicit declaration
  of function ‘kmemleak_ignore’ [-Wimplicit-function-declaration]
    kmemleak_ignore(desc);
    ^
  cc   virtio_test.o virtio_ring.o   -o virtio_test
  virtio_ring.o: In function `vring_add_indirect':
  tools/virtio/../../drivers/virtio/virtio_ring.c:177:
  undefined reference to `kmemleak_ignore'

Add a dummy header for tools/virtio, and add #incldue <linux/kmemleak.h>
to drivers/virtio/virtio_ring.c so it is picked up by the userspace
tools.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      6abb2dd9
  3. 05 11月, 2013 1 次提交
  5. 29 10月, 2013 3 次提交
  7. 17 10月, 2013 1 次提交
    • R
      virtio_ring: plug kmemleak false positive. · bb478d8b
      由 Rusty Russell 提交于 
      unreferenced object 0xffff88003d467e20 (size 32):
  comm "softirq", pid 0, jiffies 4295197765 (age 6.364s)
  hex dump (first 32 bytes):
    28 19 bf 3d 00 00 00 00 0c 00 00 00 01 00 01 00  (..=............
    02 dc 51 3c 00 00 00 00 56 00 00 00 00 00 00 00  ..Q<....V.......
  backtrace:
    [<ffffffff8152db19>] kmemleak_alloc+0x59/0xc0
    [<ffffffff81102e93>] __kmalloc+0xf3/0x180
    [<ffffffff812db5d6>] vring_add_indirect+0x36/0x280
    [<ffffffff812dc59f>] virtqueue_add_outbuf+0xbf/0x4e0
    [<ffffffff813a8b30>] start_xmit+0x1a0/0x3b0
    [<ffffffff81445861>] dev_hard_start_xmit+0x2d1/0x4d0
    [<ffffffff81460052>] sch_direct_xmit+0xf2/0x1c0
    [<ffffffff81445c28>] dev_queue_xmit+0x1c8/0x460
    [<ffffffff814e3187>] ip6_finish_output2+0x1d7/0x470
    [<ffffffff814e34b0>] ip6_finish_output+0x90/0xb0
    [<ffffffff814e3507>] ip6_output+0x37/0xb0
    [<ffffffff815021eb>] igmp6_send+0x2db/0x470
    [<ffffffff81502645>] igmp6_timer_handler+0x95/0xa0
    [<ffffffff8104b57c>] call_timer_fn+0x2c/0x90
    [<ffffffff8104b7ba>] run_timer_softirq+0x1da/0x1f0
    [<ffffffff81045721>] __do_softirq+0xd1/0x1b0

Address gets embedded in a descriptor via virt_to_phys().  See detach_buf,
which frees it:

	if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT)
		kfree(phys_to_virt(vq->vring.desc[i].addr));
Reported-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Fix-suggested-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Typing-done-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      bb478d8b
  9. 10 7月, 2013 1 次提交
  11. 20 5月, 2013 1 次提交
  13. 20 3月, 2013 3 次提交
  15. 18 12月, 2012 2 次提交
  17. 22 10月, 2012 1 次提交
    • W
      virtio: force vring descriptors to be allocated from lowmem · b92b1b89
      由 Will Deacon 提交于 
      Virtio devices may attempt to add descriptors to a virtqueue from atomic
context using GFP_ATOMIC allocation. This is problematic because such
allocations can fall outside of the lowmem mapping, causing virt_to_phys
to report bogus physical addresses which are subsequently passed to
userspace via the buffers for the virtual device.

This patch masks out __GFP_HIGH and __GFP_HIGHMEM from the requested
flags when allocating descriptors for a virtqueue. If an atomic
allocation is requested and later fails, we will return -ENOSPC which
will be handled by the driver.

Cc: stable@kernel.org
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      b92b1b89
  19. 28 9月, 2012 1 次提交
  21. 28 1月, 2012 2 次提交
  23. 12 1月, 2012 7 次提交
  25. 01 11月, 2011 1 次提交
  27. 24 10月, 2011 1 次提交
  29. 30 5月, 2011 2 次提交
    • M
      virtio: add api for delayed callbacks · 7ab358c2
      由 Michael S. Tsirkin 提交于 
      Add an API that tells the other side that callbacks
should be delayed until a lot of work has been done.
Implement using the new event_idx feature.

Note: it might seem advantageous to let the drivers
ask for a callback after a specific capacity has
been reached. However, as a single head can
free many entries in the descriptor table,
we don't really have a clue about capacity
until get_buf is called. The API is the simplest
to implement at the moment, we'll see what kind of
hints drivers can pass when there's more than one
user of the feature.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      7ab358c2
    • M
      virtio_ring: support event idx feature · a5c262c5
      由 Michael S. Tsirkin 提交于 
      Support for the new event idx feature:
1. When enabling interrupts, publish the current avail index
   value to the host to get interrupts on the next update.
2. Use the new avail_event feature to reduce the number
   of exits from the guest.

Simple test with the simulator:

[virtio]# time ./virtio_test
spurious wakeus: 0x7

real    0m0.169s
user    0m0.140s
sys     0m0.019s
[virtio]# time ./virtio_test --no-event-idx
spurious wakeus: 0x11

real    0m0.649s
user    0m0.295s
sys     0m0.335s
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      a5c262c5
  31. 21 4月, 2011 1 次提交
  33. 24 11月, 2010 1 次提交
  35. 26 7月, 2010 1 次提交
  37. 23 6月, 2010 1 次提交
  39. 19 5月, 2010 2 次提交
  41. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  43. 24 2月, 2010 4 次提交
    • A
      virtio: Initialize vq->data entries to NULL · 3b870624
      由 Amit Shah 提交于 
      vq operations depend on vq->data[i] being NULL to figure out if the vq
entry is in use (since the previous patch).

We have to initialize them to NULL to ensure we don't work with junk
data and trigger false BUG_ONs.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Shirley Ma <xma@us.ibm.com>
      3b870624
    • S
      virtio: Add ability to detach unused buffers from vrings · c021eac4
      由 Shirley Ma 提交于 
      There's currently no way for a virtio driver to ask for unused
buffers, so it has to keep a list itself to reclaim them at shutdown.
This is redundant, since virtio_ring stores that information.  So
add a new hook to do this.
Signed-off-by: NShirley Ma <xma@us.ibm.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      c021eac4
    • M
      virtio: use smp_XX barriers on SMP · d57ed95d
      由 Michael S. Tsirkin 提交于 
      virtio is communicating with a virtual "device" that actually runs on
another host processor. Thus SMP barriers can be used to control
memory access ordering.

Where possible, we should use SMP barriers which are more lightweight than
mandatory barriers, because mandatory barriers also control MMIO effects on
accesses through relaxed memory I/O windows (which virtio does not use)
(compare specifically smp_rmb and rmb on x86_64).

We can't just use smp_mb and friends though, because
we must force memory ordering even if guest is UP since host could be
running on another CPU, but SMP barriers are defined to barrier() in
that configuration. So, for UP fall back to mandatory barriers instead.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      d57ed95d
    • R
      virtio: remove bogus barriers from DEBUG version of virtio_ring.c · 97a545ab
      由 Rusty Russell 提交于 
      With DEBUG defined, we add an ->in_use flag to detect if the caller
invokes two virtio methods in parallel.  The barriers attempt to ensure
timely update of the ->in_use flag.

But they're voodoo: if we need these barriers it implies that the
calling code doesn't have sufficient synchronization to ensure the
code paths aren't invoked at the same time anyway, and we want to
detect it.

Also, adding barriers changes timing, so turning on debug has more
chance of hiding real problems.

Thanks to MST for drawing my attention to this code...

CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      97a545ab