linux-stable.git/drivers/vhost/net.c, branch linux-4.13.y Linux kernel stable tree vhost_net: correctly check tx avail during rx busy polling 2017-09-20T06:27:46+00:00 Jason Wang jasowang@redhat.com 2017-09-05T01:22:05+00:00 b076d2518599fb5ea8ade23be2e04f326fa85a57 [ Upstream commit 8b949bef9172ca69d918e93509a4ecb03d0355e0 ] We check tx avail through vhost_enable_notify() in the past which is wrong since it only checks whether or not guest has filled more available buffer since last avail idx synchronization which was just done by vhost_vq_avail_empty() before. What we really want is checking pending buffers in the avail ring. Fix this by calling vhost_vq_avail_empty() instead. This issue could be noticed by doing netperf TCP_RR benchmark as client from guest (but not host). With this fix, TCP_RR from guest to localhost restores from 1375.91 trans per sec to 55235.28 trans per sec on my laptop (Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz). Fixes: 030881372460 ("vhost_net: basic polling support") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 8b949bef9172ca69d918e93509a4ecb03d0355e0 ]

We check tx avail through vhost_enable_notify() in the past which is
wrong since it only checks whether or not guest has filled more
available buffer since last avail idx synchronization which was just
done by vhost_vq_avail_empty() before. What we really want is checking
pending buffers in the avail ring. Fix this by calling
vhost_vq_avail_empty() instead.

This issue could be noticed by doing netperf TCP_RR benchmark as
client from guest (but not host). With this fix, TCP_RR from guest to
localhost restores from 1375.91 trans per sec to 55235.28 trans per
sec on my laptop (Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz).

Fixes: 030881372460 ("vhost_net: basic polling support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic 2017-07-12T23:26:03+00:00 Michal Hocko mhocko@suse.com 2017-07-12T21:36:45+00:00 dcda9b04713c3f6ff0875652924844fae28286ea __GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator.  This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER.  It has been always
ignored for smaller sizes.  This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.

Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic.  Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success.  This will work independent of the order and overrides the
default allocator behavior.  Page allocator users have several levels of
guarantee vs.  cost options (take GFP_KERNEL as an example)

 - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
   attempt to free memory at all. The most light weight mode which even
   doesn't kick the background reclaim. Should be used carefully because
   it might deplete the memory and the next user might hit the more
   aggressive reclaim

 - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
   allocation without any attempt to free memory from the current
   context but can wake kswapd to reclaim memory if the zone is below
   the low watermark. Can be used from either atomic contexts or when
   the request is a performance optimization and there is another
   fallback for a slow path.

 - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
   non sleeping allocation with an expensive fallback so it can access
   some portion of memory reserves. Usually used from interrupt/bh
   context with an expensive slow path fallback.

 - GFP_KERNEL - both background and direct reclaim are allowed and the
   _default_ page allocator behavior is used. That means that !costly
   allocation requests are basically nofail but there is no guarantee of
   that behavior so failures have to be checked properly by callers
   (e.g. OOM killer victim is allowed to fail currently).

 - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
   and all allocation requests fail early rather than cause disruptive
   reclaim (one round of reclaim in this implementation). The OOM killer
   is not invoked.

 - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
   behavior and all allocation requests try really hard. The request
   will fail if the reclaim cannot make any progress. The OOM killer
   won't be triggered.

 - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
   and all allocation requests will loop endlessly until they succeed.
   This might be really dangerous especially for larger orders.

Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic.  No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.

This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.

[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
  Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
  Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vhost_net: try batch dequing from skb array 2017-05-18T14:07:42+00:00 Jason Wang jasowang@redhat.com 2017-05-17T04:14:45+00:00 c67df11f6e48061e43e9bf9dade83fe268b47d27 We used to dequeue one skb during recvmsg() from skb_array, this could be inefficient because of the bad cache utilization and spinlock touching for each packet. This patch tries to batch them by calling batch dequeuing helpers explicitly on the exported skb array and pass the skb back through msg_control for underlayer socket to finish the userspace copying. Batch dequeuing is also the requirement for more batching improvement on receive path. Tests were done by pktgen on tap with XDP1 in guest. Host is Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz. rx batch | pps 0 2.25Mpps 1 2.33Mpps (+3.56%) 4 2.33Mpps (+3.56%) 16 2.35Mpps (+4.44%) 64 2.42Mpps (+7.56%) <- Default rx batching 128 2.40Mpps (+6.67%) 256 2.38Mpps (+5.78%) Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We used to dequeue one skb during recvmsg() from skb_array, this could
be inefficient because of the bad cache utilization and spinlock
touching for each packet. This patch tries to batch them by calling
batch dequeuing helpers explicitly on the exported skb array and pass
the skb back through msg_control for underlayer socket to finish the
userspace copying. Batch dequeuing is also the requirement for more
batching improvement on receive path.

Tests were done by pktgen on tap with XDP1 in guest. Host is Intel(R)
Xeon(R) CPU E5-2650 0 @ 2.00GHz.

rx batch | pps

0   2.25Mpps
1   2.33Mpps (+3.56%)
4   2.33Mpps (+3.56%)
16  2.35Mpps (+4.44%)
64  2.42Mpps (+7.56%) <- Default rx batching
128 2.40Mpps (+6.67%)
256 2.38Mpps (+5.78%)

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mm: support __GFP_REPEAT in kvmalloc_node for >32kB 2017-05-09T00:15:12+00:00 Michal Hocko mhocko@suse.com 2017-05-08T22:57:15+00:00 6c5ab6511f718c3fb19bcc3f78a90b0e0b601675 vhost code uses __GFP_REPEAT when allocating vhost_virtqueue resp. vhost_vsock because it would really like to prefer kmalloc to the vmalloc fallback - see 23cc5a991c7a ("vhost-net: extend device allocation to vmalloc") for more context. Michael Tsirkin has also noted: "__GFP_REPEAT overhead is during allocation time. Using vmalloc means all accesses are slowed down. Allocation is not on data path, accesses are." The similar applies to other vhost_kvzalloc users. Let's teach kvmalloc_node to handle __GFP_REPEAT properly. There are two things to be careful about. First we should prevent from the OOM killer and so have to involve __GFP_NORETRY by default and secondly override __GFP_REPEAT for !costly order requests as the __GFP_REPEAT is ignored for !costly orders. Supporting __GFP_REPEAT like semantic for !costly request is possible it would require changes in the page allocator. This is out of scope of this patch. This patch shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170306103032.2540-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
vhost code uses __GFP_REPEAT when allocating vhost_virtqueue resp.
vhost_vsock because it would really like to prefer kmalloc to the
vmalloc fallback - see 23cc5a991c7a ("vhost-net: extend device
allocation to vmalloc") for more context.  Michael Tsirkin has also
noted:

 "__GFP_REPEAT overhead is during allocation time. Using vmalloc means
  all accesses are slowed down. Allocation is not on data path, accesses
  are."

The similar applies to other vhost_kvzalloc users.

Let's teach kvmalloc_node to handle __GFP_REPEAT properly.  There are
two things to be careful about.  First we should prevent from the OOM
killer and so have to involve __GFP_NORETRY by default and secondly
override __GFP_REPEAT for !costly order requests as the __GFP_REPEAT is
ignored for !costly orders.

Supporting __GFP_REPEAT like semantic for !costly request is possible it
would require changes in the page allocator.  This is out of scope of
this patch.

This patch shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170306103032.2540-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02T07:42:32+00:00 Ingo Molnar mingo@kernel.org 2017-02-02T18:15:33+00:00 174cd4b1e5fbd0d74c68cf3a74f5bd4923485512 Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02T07:42:27+00:00 Ingo Molnar mingo@kernel.org 2017-02-01T15:36:40+00:00 e601757102cfd3eeae068f53b3bc1234f3a2b2e9 We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.

Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
tap: Renaming tap related APIs, data structures, macros 2017-02-12T01:59:41+00:00 Sainath Grandhi sainath.grandhi@intel.com 2017-02-11T00:03:47+00:00 635b8c8ecdd27142d7fdab0df334b2e9201481cf Renaming tap related APIs, data structures and macros in tap.c from macvtap_.* to tap_.* Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Renaming tap related APIs, data structures and macros in tap.c from macvtap_.* to tap_.*

Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
vhost_net: tx batching 2017-01-18T21:35:30+00:00 Jason Wang jasowang@redhat.com 2017-01-18T07:02:02+00:00 0ed005ce02fa0a88e5e6b7b5f7ff452171881610 This patch tries to utilize tuntap rx batching by peeking the tx virtqueue during transmission, if there's more available buffers in the virtqueue, set MSG_MORE flag for a hint for backend (e.g tuntap) to batch the packets. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> 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> 
This patch tries to utilize tuntap rx batching by peeking the tx
virtqueue during transmission, if there's more available buffers in
the virtqueue, set MSG_MORE flag for a hint for backend (e.g tuntap)
to batch the packets.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
locking/core: Remove cpu_relax_lowlatency() users 2016-11-16T09:15:10+00:00 Christian Borntraeger borntraeger@de.ibm.com 2016-10-25T09:03:14+00:00 f2f09a4cee3507dba0e24b87ba2961a5c377d3a7 With the s390 special case of a yielding cpu_relax() implementation gone, we can now remove all users of cpu_relax_lowlatency() and replace them with cpu_relax(). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Noam Camus <noamc@ezchip.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1477386195-32736-5-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 
With the s390 special case of a yielding cpu_relax() implementation gone,
we can now remove all users of cpu_relax_lowlatency() and replace them
with cpu_relax().

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-5-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 2016-08-06T13:20:13+00:00 Linus Torvalds torvalds@linux-foundation.org 2016-08-06T13:20:13+00:00 0803e04011c2e107b9611660301edde94d7010cc Pull virtio/vhost updates from Michael Tsirkin: - new vsock device support in host and guest - platform IOMMU support in host and guest, including compatibility quirks for legacy systems. - misc fixes and cleanups. * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: VSOCK: Use kvfree() vhost: split out vringh Kconfig vhost: detect 32 bit integer wrap around vhost: new device IOTLB API vhost: drop vringh dependency vhost: convert pre sorted vhost memory array to interval tree vhost: introduce vhost memory accessors VSOCK: Add Makefile and Kconfig VSOCK: Introduce vhost_vsock.ko VSOCK: Introduce virtio_transport.ko VSOCK: Introduce virtio_vsock_common.ko VSOCK: defer sock removal to transports VSOCK: transport-specific vsock_transport functions vhost: drop vringh dependency vop: pull in vhost Kconfig virtio: new feature to detect IOMMU device quirk balloon: check the number of available pages in leak balloon vhost: lockless enqueuing vhost: simplify work flushing 
Pull virtio/vhost updates from Michael Tsirkin:

 - new vsock device support in host and guest

 - platform IOMMU support in host and guest, including compatibility
   quirks for legacy systems.

 - misc fixes and cleanups.

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  VSOCK: Use kvfree()
  vhost: split out vringh Kconfig
  vhost: detect 32 bit integer wrap around
  vhost: new device IOTLB API
  vhost: drop vringh dependency
  vhost: convert pre sorted vhost memory array to interval tree
  vhost: introduce vhost memory accessors
  VSOCK: Add Makefile and Kconfig
  VSOCK: Introduce vhost_vsock.ko
  VSOCK: Introduce virtio_transport.ko
  VSOCK: Introduce virtio_vsock_common.ko
  VSOCK: defer sock removal to transports
  VSOCK: transport-specific vsock_transport functions
  vhost: drop vringh dependency
  vop: pull in vhost Kconfig
  virtio: new feature to detect IOMMU device quirk
  balloon: check the number of available pages in leak balloon
  vhost: lockless enqueuing
  vhost: simplify work flushing