Commit Graph

438 Commits

Author SHA1 Message Date
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Parav Pandit 5715c4dd66 vfio/mdev: Synchronize device create/remove with parent removal
In following sequences, child devices created while removing mdev parent
device can be left out, or it may lead to race of removing half
initialized child mdev devices.

issue-1:
--------
       cpu-0                         cpu-1
       -----                         -----
                                  mdev_unregister_device()
                                    device_for_each_child()
                                      mdev_device_remove_cb()
                                        mdev_device_remove()
create_store()
  mdev_device_create()                   [...]
    device_add()
                                  parent_remove_sysfs_files()

/* BUG: device added by cpu-0
 * whose parent is getting removed
 * and it won't process this mdev.
 */

issue-2:
--------
Below crash is observed when user initiated remove is in progress
and mdev_unregister_driver() completes parent unregistration.

       cpu-0                         cpu-1
       -----                         -----
remove_store()
   mdev_device_remove()
   active = false;
                                  mdev_unregister_device()
                                  parent device removed.
   [...]
   parents->ops->remove()
 /*
  * BUG: Accessing invalid parent.
  */

This is similar race like create() racing with mdev_unregister_device().

BUG: unable to handle kernel paging request at ffffffffc0585668
PGD e8f618067 P4D e8f618067 PUD e8f61a067 PMD 85adca067 PTE 0
Oops: 0000 [#1] SMP PTI
CPU: 41 PID: 37403 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
RIP: 0010:mdev_device_remove+0xfa/0x140 [mdev]
Call Trace:
 remove_store+0x71/0x90 [mdev]
 kernfs_fop_write+0x113/0x1a0
 vfs_write+0xad/0x1b0
 ksys_write+0x5a/0xe0
 do_syscall_64+0x5a/0x210
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Therefore, mdev core is improved as below to overcome above issues.

Wait for any ongoing mdev create() and remove() to finish before
unregistering parent device.
This continues to allow multiple create and remove to progress in
parallel for different mdev devices as most common case.
At the same time guard parent removal while parent is being accessed by
create() and remove() callbacks.
create()/remove() and unregister_device() are synchronized by the rwsem.

Refactor device removal code to mdev_device_remove_common() to avoid
acquiring unreg_sem of the parent.

Fixes: 7b96953bc6 ("vfio: Mediated device Core driver")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-06-06 12:32:37 -06:00
Parav Pandit 26c9e3988e vfio/mdev: Avoid creating sysfs remove file on stale device removal
If device is removal is initiated by two threads as below, mdev core
attempts to create a syfs remove file on stale device.
During this flow, below [1] call trace is observed.

     cpu-0                                    cpu-1
     -----                                    -----
  mdev_unregister_device()
    device_for_each_child
       mdev_device_remove_cb
          mdev_device_remove
                                       user_syscall
                                         remove_store()
                                           mdev_device_remove()
                                        [..]
   unregister device();
                                       /* not found in list or
                                        * active=false.
                                        */
                                          sysfs_create_file()
                                          ..Call trace

Now that mdev core follows correct device removal sequence of the linux
bus model, remove shouldn't fail in normal cases. If it fails, there is
no point of creating a stale file or checking for specific error status.

kernel: WARNING: CPU: 2 PID: 9348 at fs/sysfs/file.c:327
sysfs_create_file_ns+0x7f/0x90
kernel: CPU: 2 PID: 9348 Comm: bash Kdump: loaded Not tainted
5.1.0-rc6-vdevbus+ #6
kernel: Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b
08/09/2016
kernel: RIP: 0010:sysfs_create_file_ns+0x7f/0x90
kernel: Call Trace:
kernel: remove_store+0xdc/0x100 [mdev]
kernel: kernfs_fop_write+0x113/0x1a0
kernel: vfs_write+0xad/0x1b0
kernel: ksys_write+0x5a/0xe0
kernel: do_syscall_64+0x5a/0x210
kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-06-06 12:32:37 -06:00
Parav Pandit 522ecce08a vfio/mdev: Improve the create/remove sequence
This patch addresses below two issues and prepares the code to address
3rd issue listed below.

1. mdev device is placed on the mdev bus before it is created in the
vendor driver. Once a device is placed on the mdev bus without creating
its supporting underlying vendor device, mdev driver's probe() gets
triggered.  However there isn't a stable mdev available to work on.

   create_store()
     mdev_create_device()
       device_register()
          ...
         vfio_mdev_probe()
        [...]
        parent->ops->create()
          vfio_ap_mdev_create()
            mdev_set_drvdata(mdev, matrix_mdev);
            /* Valid pointer set above */

Due to this way of initialization, mdev driver who wants to use the mdev,
doesn't have a valid mdev to work on.

2. Current creation sequence is,
   parent->ops_create()
   groups_register()

Remove sequence is,
   parent->ops->remove()
   groups_unregister()

However, remove sequence should be exact mirror of creation sequence.
Once this is achieved, all users of the mdev will be terminated first
before removing underlying vendor device.
(Follow standard linux driver model).
At that point vendor's remove() ops shouldn't fail because taking the
device off the bus should terminate any usage.

3. When remove operation fails, mdev sysfs removal attempts to add the
file back on already removed device. Following call trace [1] is observed.

[1] call trace:
kernel: WARNING: CPU: 2 PID: 9348 at fs/sysfs/file.c:327 sysfs_create_file_ns+0x7f/0x90
kernel: CPU: 2 PID: 9348 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
kernel: Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
kernel: RIP: 0010:sysfs_create_file_ns+0x7f/0x90
kernel: Call Trace:
kernel: remove_store+0xdc/0x100 [mdev]
kernel: kernfs_fop_write+0x113/0x1a0
kernel: vfs_write+0xad/0x1b0
kernel: ksys_write+0x5a/0xe0
kernel: do_syscall_64+0x5a/0x210
kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe

Therefore, mdev core is improved in following ways.

1. Split the device registration/deregistration sequence so that some
things can be done between initialization of the device and hooking it
up to the bus respectively after deregistering it from the bus but
before giving up our final reference.
In particular, this means invoking the ->create() and ->remove()
callbacks in those new windows. This gives the vendor driver an
initialized mdev device to work with during creation.
At the same time, a bus driver who wish to bind to mdev driver also
gets initialized mdev device.

This follows standard Linux kernel bus and device model.

2. During remove flow, first remove the device from the bus. This
ensures that any bus specific devices are removed.
Once device is taken off the mdev bus, invoke remove() of mdev
from the vendor driver.

3. The driver core device model provides way to register and auto
unregister the device sysfs attribute groups at dev->groups.
Make use of dev->groups to let core create the groups and eliminate
code to avoid explicit groups creation and removal.

To ensure, that new sequence is solid, a below stack dump of a
process is taken who attempts to remove the device while device is in
use by vfio driver and user application.
This stack dump validates that vfio driver guards against such device
removal when device is in use.

 cat /proc/21962/stack
[<0>] vfio_del_group_dev+0x216/0x3c0 [vfio]
[<0>] mdev_remove+0x21/0x40 [mdev]
[<0>] device_release_driver_internal+0xe8/0x1b0
[<0>] bus_remove_device+0xf9/0x170
[<0>] device_del+0x168/0x350
[<0>] mdev_device_remove_common+0x1d/0x50 [mdev]
[<0>] mdev_device_remove+0x8c/0xd0 [mdev]
[<0>] remove_store+0x71/0x90 [mdev]
[<0>] kernfs_fop_write+0x113/0x1a0
[<0>] vfs_write+0xad/0x1b0
[<0>] ksys_write+0x5a/0xe0
[<0>] do_syscall_64+0x5a/0x210
[<0>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<0>] 0xffffffffffffffff

This prepares the code to eliminate calling device_create_file() in
subsequent patch.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-06-06 10:52:32 -06:00
Thomas Gleixner 9952f6918d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:52 -07:00
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00
Thomas Gleixner ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Ira Weiny 73b0140bf0 mm/gup: change GUP fast to use flags rather than a write 'bool'
To facilitate additional options to get_user_pages_fast() change the
singular write parameter to be gup_flags.

This patch does not change any functionality.  New functionality will
follow in subsequent patches.

Some of the get_user_pages_fast() call sites were unchanged because they
already passed FOLL_WRITE or 0 for the write parameter.

NOTE: It was suggested to change the ordering of the get_user_pages_fast()
arguments to ensure that callers were converted.  This breaks the current
GUP call site convention of having the returned pages be the final
parameter.  So the suggestion was rejected.

Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marshall <hubcap@omnibond.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:46 -07:00
Ira Weiny 932f4a630a mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM
Pach series "Add FOLL_LONGTERM to GUP fast and use it".

HFI1, qib, and mthca, use get_user_pages_fast() due to its performance
advantages.  These pages can be held for a significant time.  But
get_user_pages_fast() does not protect against mapping FS DAX pages.

Introduce FOLL_LONGTERM and use this flag in get_user_pages_fast() which
retains the performance while also adding the FS DAX checks.  XDP has also
shown interest in using this functionality.[1]

In addition we change get_user_pages() to use the new FOLL_LONGTERM flag
and remove the specialized get_user_pages_longterm call.

[1] https://lkml.org/lkml/2019/3/19/939

"longterm" is a relative thing and at this point is probably a misnomer.
This is really flagging a pin which is going to be given to hardware and
can't move.  I've thought of a couple of alternative names but I think we
have to settle on if we are going to use FL_LAYOUT or something else to
solve the "longterm" problem.  Then I think we can change the flag to a
better name.

Secondly, it depends on how often you are registering memory.  I have
spoken with some RDMA users who consider MR in the performance path...
For the overall application performance.  I don't have the numbers as the
tests for HFI1 were done a long time ago.  But there was a significant
advantage.  Some of which is probably due to the fact that you don't have
to hold mmap_sem.

Finally, architecturally I think it would be good for everyone to use
*_fast.  There are patches submitted to the RDMA list which would allow
the use of *_fast (they reworking the use of mmap_sem) and as soon as they
are accepted I'll submit a patch to convert the RDMA core as well.  Also
to this point others are looking to use *_fast.

As an aside, Jasons pointed out in my previous submission that *_fast and
*_unlocked look very much the same.  I agree and I think further cleanup
will be coming.  But I'm focused on getting the final solution for DAX at
the moment.

This patch (of 7):

This patch starts a series which aims to support FOLL_LONGTERM in
get_user_pages_fast().  Some callers who would like to do a longterm (user
controlled pin) of pages with the fast variant of GUP for performance
purposes.

Rather than have a separate get_user_pages_longterm() call, introduce
FOLL_LONGTERM and change the longterm callers to use it.

This patch does not change any functionality.  In the short term
"longterm" or user controlled pins are unsafe for Filesystems and FS DAX
in particular has been blocked.  However, callers of get_user_pages_fast()
were not "protected".

FOLL_LONGTERM can _only_ be supported with get_user_pages[_fast]() as it
requires vmas to determine if DAX is in use.

NOTE: In merging with the CMA changes we opt to change the
get_user_pages() call in check_and_migrate_cma_pages() to a call of
__get_user_pages_locked() on the newly migrated pages.  This makes the
code read better in that we are calling __get_user_pages_locked() on the
pages before and after a potential migration.

As a side affect some of the interfaces are cleaned up but this is not the
primary purpose of the series.

In review[1] it was asked:

<quote>
> This I don't get - if you do lock down long term mappings performance
> of the actual get_user_pages call shouldn't matter to start with.
>
> What do I miss?

A couple of points.

First "longterm" is a relative thing and at this point is probably a
misnomer.  This is really flagging a pin which is going to be given to
hardware and can't move.  I've thought of a couple of alternative names
but I think we have to settle on if we are going to use FL_LAYOUT or
something else to solve the "longterm" problem.  Then I think we can
change the flag to a better name.

Second, It depends on how often you are registering memory.  I have spoken
with some RDMA users who consider MR in the performance path...  For the
overall application performance.  I don't have the numbers as the tests
for HFI1 were done a long time ago.  But there was a significant
advantage.  Some of which is probably due to the fact that you don't have
to hold mmap_sem.

Finally, architecturally I think it would be good for everyone to use
*_fast.  There are patches submitted to the RDMA list which would allow
the use of *_fast (they reworking the use of mmap_sem) and as soon as they
are accepted I'll submit a patch to convert the RDMA core as well.  Also
to this point others are looking to use *_fast.

As an asside, Jasons pointed out in my previous submission that *_fast and
*_unlocked look very much the same.  I agree and I think further cleanup
will be coming.  But I'm focused on getting the final solution for DAX at
the moment.

</quote>

[1] https://lore.kernel.org/lkml/20190220180255.GA12020@iweiny-DESK2.sc.intel.com/T/#md6abad2569f3bf6c1f03686c8097ab6563e94965

[ira.weiny@intel.com: v3]
  Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-2-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:45 -07:00
Linus Torvalds a13f065550 IOMMU Updates for Linux v5.2
Including:
 
 	- ATS support for ARM-SMMU-v3.
 
 	- AUX domain support in the IOMMU-API and the Intel VT-d driver.
 	  This adds support for multiple DMA address spaces per
 	  (PCI-)device. The use-case is to multiplex devices between
 	  host and KVM guests in a more flexible way than supported by
 	  SR-IOV.
 
 	- The Rest are smaller cleanups and fixes, two of which needed
 	  to be reverted after testing in linux-next.
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Merge tag 'iommu-updates-v5.2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:

 - ATS support for ARM-SMMU-v3.

 - AUX domain support in the IOMMU-API and the Intel VT-d driver. This
   adds support for multiple DMA address spaces per (PCI-)device. The
   use-case is to multiplex devices between host and KVM guests in a
   more flexible way than supported by SR-IOV.

 - the rest are smaller cleanups and fixes, two of which needed to be
   reverted after testing in linux-next.

* tag 'iommu-updates-v5.2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (45 commits)
  Revert "iommu/amd: Flush not present cache in iommu_map_page"
  Revert "iommu/amd: Remove the leftover of bypass support"
  iommu/vt-d: Fix leak in intel_pasid_alloc_table on error path
  iommu/vt-d: Make kernel parameter igfx_off work with vIOMMU
  iommu/vt-d: Set intel_iommu_gfx_mapped correctly
  iommu/amd: Flush not present cache in iommu_map_page
  iommu/vt-d: Cleanup: no spaces at the start of a line
  iommu/vt-d: Don't request page request irq under dmar_global_lock
  iommu/vt-d: Use struct_size() helper
  iommu/mediatek: Fix leaked of_node references
  iommu/amd: Remove amd_iommu_pd_list
  iommu/arm-smmu: Log CBFRSYNRA register on context fault
  iommu/arm-smmu-v3: Don't disable SMMU in kdump kernel
  iommu/arm-smmu-v3: Disable tagged pointers
  iommu/arm-smmu-v3: Add support for PCI ATS
  iommu/arm-smmu-v3: Link domains and devices
  iommu/arm-smmu-v3: Add a master->domain pointer
  iommu/arm-smmu-v3: Store SteamIDs in master
  iommu/arm-smmu-v3: Rename arm_smmu_master_data to arm_smmu_master
  ACPI/IORT: Check ATS capability in root complex nodes
  ...
2019-05-13 09:23:18 -04:00
Linus Torvalds 6fe567df04 VFIO updates for v5.2-rc1
- Improve dev_printk() usage (Bjorn Helgaas)
 
  - Fix issue with blocking in !TASK_RUNNING state while waiting for
    userspace to release devices (Farhan Ali)
 
  - Fix error path cleanup in nvlink setup (Greg Kurz)
 
  - mdev-core cleanups and fixes in preparation for more use cases
    (Parav Pandit)
 
  - Cornelia has volunteered as an official vfio reviewer (Cornelia Huck)
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Merge tag 'vfio-v5.2-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Improve dev_printk() usage (Bjorn Helgaas)

 - Fix issue with blocking in !TASK_RUNNING state while waiting for
   userspace to release devices (Farhan Ali)

 - Fix error path cleanup in nvlink setup (Greg Kurz)

 - mdev-core cleanups and fixes in preparation for more use cases (Parav
   Pandit)

 - Cornelia has volunteered as an official vfio reviewer (Cornelia Huck)

* tag 'vfio-v5.2-rc1' of git://github.com/awilliam/linux-vfio:
  vfio: Add Cornelia Huck as reviewer
  vfio/mdev: Avoid inline get and put parent helpers
  vfio/mdev: Fix aborting mdev child device removal if one fails
  vfio/mdev: Follow correct remove sequence
  vfio/mdev: Avoid masking error code to EBUSY
  vfio/mdev: Drop redundant extern for exported symbols
  vfio/mdev: Removed unused kref
  vfio/mdev: Avoid release parent reference during error path
  vfio-pci/nvlink2: Fix potential VMA leak
  vfio: Fix WARNING "do not call blocking ops when !TASK_RUNNING"
  vfio: Use dev_printk() when possible
2019-05-11 10:47:46 -04:00
Parav Pandit 405ecbf72f vfio/mdev: Avoid inline get and put parent helpers
As section 15 of Documentation/process/coding-style.rst clearly
describes that compiler will be able to optimize code.

Hence drop inline for get and put helpers for parent.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Parav Pandit 6093e348a5 vfio/mdev: Fix aborting mdev child device removal if one fails
device_for_each_child() stops executing callback function for remaining
child devices, if callback hits an error.
Each child mdev device is independent of each other.
While unregistering parent device, mdev core must remove all child mdev
devices.
Therefore, mdev_device_remove_cb() always returns success so that
device_for_each_child doesn't abort if one child removal hits error.

While at it, improve remove and unregister functions for below simplicity.

There isn't need to pass forced flag pointer during mdev parent
removal which invokes mdev_device_remove(). So simplify the flow.

mdev_device_remove() is called from two paths.
1. mdev_unregister_driver()
     mdev_device_remove_cb()
       mdev_device_remove()
2. remove_store()
     mdev_device_remove()

Fixes: 7b96953bc6 ("vfio: Mediated device Core driver")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Parav Pandit a6d6f4f160 vfio/mdev: Follow correct remove sequence
mdev_remove_sysfs_files() should follow exact mirror sequence of a
create, similar to what is followed in error unwinding path of
mdev_create_sysfs_files().

Fixes: 6a62c1dfb5 ("vfio/mdev: Re-order sysfs attribute creation")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Parav Pandit d300046350 vfio/mdev: Avoid masking error code to EBUSY
Instead of masking return error to -EBUSY, return actual error
returned by the driver.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Parav Pandit f707d837b6 vfio/mdev: Removed unused kref
Remove unused kref from the mdev_device structure.

Fixes: 7b96953bc6 ("vfio: Mediated device Core driver")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Parav Pandit 60e7f2c3fe vfio/mdev: Avoid release parent reference during error path
During mdev parent registration in mdev_register_device(),
if parent device is duplicate, it releases the reference of existing
parent device.
This is incorrect. Existing parent device should not be touched.

Fixes: 7b96953bc6 ("vfio: Mediated device Core driver")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-07 11:23:13 -06:00
Greg Kurz 2c85f2bd51 vfio-pci/nvlink2: Fix potential VMA leak
If vfio_pci_register_dev_region() fails then we should rollback
previous changes, ie. unmap the ATSD registers.

Fixes: 7f92891778 ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-05-01 13:31:41 -06:00
Farhan Ali 41be3e2618 vfio: Fix WARNING "do not call blocking ops when !TASK_RUNNING"
vfio_dev_present() which is the condition to
wait_event_interruptible_timeout(), will call vfio_group_get_device
and try to acquire the mutex group->device_lock.

wait_event_interruptible_timeout() will set the state of the current
task to TASK_INTERRUPTIBLE, before doing the condition check. This
means that we will try to acquire the mutex while already in a
sleeping state. The scheduler warns us by giving the following
warning:

[ 4050.264464] ------------[ cut here ]------------
[ 4050.264508] do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000b33c00e2>] prepare_to_wait_event+0x14a/0x188
[ 4050.264529] WARNING: CPU: 12 PID: 35924 at kernel/sched/core.c:6112 __might_sleep+0x76/0x90
....

 4050.264756] Call Trace:
[ 4050.264765] ([<000000000017bbaa>] __might_sleep+0x72/0x90)
[ 4050.264774]  [<0000000000b97edc>] __mutex_lock+0x44/0x8c0
[ 4050.264782]  [<0000000000b9878a>] mutex_lock_nested+0x32/0x40
[ 4050.264793]  [<000003ff800d7abe>] vfio_group_get_device+0x36/0xa8 [vfio]
[ 4050.264803]  [<000003ff800d87c0>] vfio_del_group_dev+0x238/0x378 [vfio]
[ 4050.264813]  [<000003ff8015f67c>] mdev_remove+0x3c/0x68 [mdev]
[ 4050.264825]  [<00000000008e01b0>] device_release_driver_internal+0x168/0x268
[ 4050.264834]  [<00000000008de692>] bus_remove_device+0x162/0x190
[ 4050.264843]  [<00000000008daf42>] device_del+0x1e2/0x368
[ 4050.264851]  [<00000000008db12c>] device_unregister+0x64/0x88
[ 4050.264862]  [<000003ff8015ed84>] mdev_device_remove+0xec/0x130 [mdev]
[ 4050.264872]  [<000003ff8015f074>] remove_store+0x6c/0xa8 [mdev]
[ 4050.264881]  [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8
[ 4050.264890]  [<00000000003c1530>] __vfs_write+0x38/0x1a8
[ 4050.264899]  [<00000000003c187c>] vfs_write+0xb4/0x198
[ 4050.264908]  [<00000000003c1af2>] ksys_write+0x5a/0xb0
[ 4050.264916]  [<0000000000b9e270>] system_call+0xdc/0x2d8
[ 4050.264925] 4 locks held by sh/35924:
[ 4050.264933]  #0: 000000001ef90325 (sb_writers#4){.+.+}, at: vfs_write+0x9e/0x198
[ 4050.264948]  #1: 000000005c1ab0b3 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1cc/0x1f8
[ 4050.264963]  #2: 0000000034831ab8 (kn->count#297){++++}, at: kernfs_remove_self+0x12e/0x150
[ 4050.264979]  #3: 00000000e152484f (&dev->mutex){....}, at: device_release_driver_internal+0x5c/0x268
[ 4050.264993] Last Breaking-Event-Address:
[ 4050.265002]  [<000000000017bbaa>] __might_sleep+0x72/0x90
[ 4050.265010] irq event stamp: 7039
[ 4050.265020] hardirqs last  enabled at (7047): [<00000000001cee7a>] console_unlock+0x6d2/0x740
[ 4050.265029] hardirqs last disabled at (7054): [<00000000001ce87e>] console_unlock+0xd6/0x740
[ 4050.265040] softirqs last  enabled at (6416): [<0000000000b8fe26>] __udelay+0xb6/0x100
[ 4050.265049] softirqs last disabled at (6415): [<0000000000b8fe06>] __udelay+0x96/0x100
[ 4050.265057] ---[ end trace d04a07d39d99a9f9 ]---

Let's fix this as described in the article
https://lwn.net/Articles/628628/.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
[remove now redundant vfio_dev_present()]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-23 11:30:46 -06:00
Bjorn Helgaas a88a7b3eb0 vfio: Use dev_printk() when possible
Use dev_printk() when possible to make messages consistent with other
device-related messages.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-22 11:45:42 -06:00
David Howells 5dd50aaeb1
Make anon_inodes unconditional
Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[christian@brauner.io: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner <christian@brauner.io>
2019-04-19 14:03:11 +02:00
Lu Baolu be068fa236 vfio/type1: Handle different mdev isolation type
This adds the support to determine the isolation type
of a mediated device group by checking whether it has
an iommu device. If an iommu device exists, an iommu
domain will be allocated and then attached to the iommu
device. Otherwise, keep the same behavior as it is.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-04-12 13:00:37 +02:00
Lu Baolu 7bd50f0cd2 vfio/type1: Add domain at(de)taching group helpers
This adds helpers to attach or detach a domain to a
group. This will replace iommu_attach_group() which
only works for non-mdev devices.

If a domain is attaching to a group which includes the
mediated devices, it should attach to the iommu device
(a pci device which represents the mdev in iommu scope)
instead. The added helper supports attaching domain to
groups for both pci and mdev devices.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-04-12 13:00:37 +02:00
Lu Baolu 8ac13175cb vfio/mdev: Add iommu related member in mdev_device
A parent device might create different types of mediated
devices. For example, a mediated device could be created
by the parent device with full isolation and protection
provided by the IOMMU. One usage case could be found on
Intel platforms where a mediated device is an assignable
subset of a PCI, the DMA requests on behalf of it are all
tagged with a PASID. Since IOMMU supports PASID-granular
translations (scalable mode in VT-d 3.0), this mediated
device could be individually protected and isolated by an
IOMMU.

This patch adds a new member in the struct mdev_device to
indicate that the mediated device represented by mdev could
be isolated and protected by attaching a domain to a device
represented by mdev->iommu_device. It also adds a helper to
add or set the iommu device.

* mdev_device->iommu_device
  - This, if set, indicates that the mediated device could
    be fully isolated and protected by IOMMU via attaching
    an iommu domain to this device. If empty, it indicates
    using vendor defined isolation, hence bypass IOMMU.

* mdev_set/get_iommu_device(dev, iommu_device)
  - Set or get the iommu device which represents this mdev
    in IOMMU's device scope. Drivers don't need to set the
    iommu device if it uses vendor defined isolation.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-04-12 13:00:37 +02:00
Alex Williamson 492855939b vfio/type1: Limit DMA mappings per container
Memory backed DMA mappings are accounted against a user's locked
memory limit, including multiple mappings of the same memory.  This
accounting bounds the number of such mappings that a user can create.
However, DMA mappings that are not backed by memory, such as DMA
mappings of device MMIO via mmaps, do not make use of page pinning
and therefore do not count against the user's locked memory limit.
These mappings still consume memory, but the memory is not well
associated to the process for the purpose of oom killing a task.

To add bounding on this use case, we introduce a limit to the total
number of concurrent DMA mappings that a user is allowed to create.
This limit is exposed as a tunable module option where the default
value of 64K is expected to be well in excess of any reasonable use
case (a large virtual machine configuration would typically only make
use of tens of concurrent mappings).

This fixes CVE-2019-3882.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-03 12:43:05 -06:00
Wang Hai e39dd513d5 vfio/spapr_tce: Make symbol 'tce_iommu_driver_ops' static
Fixes the following sparse warning:

drivers/vfio/vfio_iommu_spapr_tce.c:1401:36: warning:
 symbol 'tce_iommu_driver_ops' was not declared. Should it be static?

Fixes: 5ffd229c02 ("powerpc/vfio: Implement IOMMU driver for VFIO")
Signed-off-by: Wang Hai <wanghai26@huawei.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-03 12:42:02 -06:00
Louis Taylor 426b046b74 vfio/pci: use correct format characters
When compiling with -Wformat, clang emits the following warnings:

drivers/vfio/pci/vfio_pci.c:1601:5: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                ^~~~~~

drivers/vfio/pci/vfio_pci.c:1601:13: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                        ^~~~~~

drivers/vfio/pci/vfio_pci.c:1601:21: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1601:32: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                           ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1605:5: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                ^~~~~~

drivers/vfio/pci/vfio_pci.c:1605:13: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                        ^~~~~~

drivers/vfio/pci/vfio_pci.c:1605:21: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1605:32: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                           ^~~~~~~~~
The types of these arguments are unconditionally defined, so this patch
updates the format character to the correct ones for unsigned ints.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Louis Taylor <louis@kragniz.eu>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-03 12:36:20 -06:00
Linus Torvalds 6c3ac11343 powerpc updates for 5.1
Notable changes:
 
  - Enable THREAD_INFO_IN_TASK to move thread_info off the stack.
 
  - A big series from Christoph reworking our DMA code to use more of the generic
    infrastructure, as he said:
    "This series switches the powerpc port to use the generic swiotlb and
     noncoherent dma ops, and to use more generic code for the coherent direct
     mapping, as well as removing a lot of dead code."
 
  - Increase our vmalloc space to 512T with the Hash MMU on modern CPUs, allowing
    us to support machines with larger amounts of total RAM or distance between
    nodes.
 
  - Two series from Christophe, one to optimise TLB miss handlers on 6xx, and
    another to optimise the way STRICT_KERNEL_RWX is implemented on some 32-bit
    CPUs.
 
  - Support for KCOV coverage instrumentation which means we can run syzkaller
    and discover even more bugs in our code.
 
 And as always many clean-ups, reworks and minor fixes etc.
 
 Thanks to:
  Alan Modra, Alexey Kardashevskiy, Alistair Popple, Andrea Arcangeli, Andrew
  Donnellan, Aneesh Kumar K.V, Aravinda Prasad, Balbir Singh, Brajeswar Ghosh,
  Breno Leitao, Christian Lamparter, Christian Zigotzky, Christophe Leroy,
  Christoph Hellwig, Corentin Labbe, Daniel Axtens, David Gibson, Diana Craciun,
  Firoz Khan, Gustavo A. R. Silva, Igor Stoppa, Joe Lawrence, Joel Stanley,
  Jonathan Neuschäfer, Jordan Niethe, Laurent Dufour, Madhavan Srinivasan, Mahesh
  Salgaonkar, Mark Cave-Ayland, Masahiro Yamada, Mathieu Malaterre, Matteo Croce,
  Meelis Roos, Michael W. Bringmann, Nathan Chancellor, Nathan Fontenot, Nicholas
  Piggin, Nick Desaulniers, Nicolai Stange, Oliver O'Halloran, Paul Mackerras,
  Peter Xu, PrasannaKumar Muralidharan, Qian Cai, Rashmica Gupta, Reza Arbab,
  Robert P. J. Day, Russell Currey, Sabyasachi Gupta, Sam Bobroff, Sandipan Das,
  Sergey Senozhatsky, Souptick Joarder, Stewart Smith, Tyrel Datwyler, Vaibhav
  Jain, YueHaibing.
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Merge tag 'powerpc-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Enable THREAD_INFO_IN_TASK to move thread_info off the stack.

   - A big series from Christoph reworking our DMA code to use more of
     the generic infrastructure, as he said:
       "This series switches the powerpc port to use the generic swiotlb
        and noncoherent dma ops, and to use more generic code for the
        coherent direct mapping, as well as removing a lot of dead
        code."

   - Increase our vmalloc space to 512T with the Hash MMU on modern
     CPUs, allowing us to support machines with larger amounts of total
     RAM or distance between nodes.

   - Two series from Christophe, one to optimise TLB miss handlers on
     6xx, and another to optimise the way STRICT_KERNEL_RWX is
     implemented on some 32-bit CPUs.

   - Support for KCOV coverage instrumentation which means we can run
     syzkaller and discover even more bugs in our code.

  And as always many clean-ups, reworks and minor fixes etc.

  Thanks to: Alan Modra, Alexey Kardashevskiy, Alistair Popple, Andrea
  Arcangeli, Andrew Donnellan, Aneesh Kumar K.V, Aravinda Prasad, Balbir
  Singh, Brajeswar Ghosh, Breno Leitao, Christian Lamparter, Christian
  Zigotzky, Christophe Leroy, Christoph Hellwig, Corentin Labbe, Daniel
  Axtens, David Gibson, Diana Craciun, Firoz Khan, Gustavo A. R. Silva,
  Igor Stoppa, Joe Lawrence, Joel Stanley, Jonathan Neuschäfer, Jordan
  Niethe, Laurent Dufour, Madhavan Srinivasan, Mahesh Salgaonkar, Mark
  Cave-Ayland, Masahiro Yamada, Mathieu Malaterre, Matteo Croce, Meelis
  Roos, Michael W. Bringmann, Nathan Chancellor, Nathan Fontenot,
  Nicholas Piggin, Nick Desaulniers, Nicolai Stange, Oliver O'Halloran,
  Paul Mackerras, Peter Xu, PrasannaKumar Muralidharan, Qian Cai,
  Rashmica Gupta, Reza Arbab, Robert P. J. Day, Russell Currey,
  Sabyasachi Gupta, Sam Bobroff, Sandipan Das, Sergey Senozhatsky,
  Souptick Joarder, Stewart Smith, Tyrel Datwyler, Vaibhav Jain,
  YueHaibing"

* tag 'powerpc-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits)
  powerpc/32: Clear on-stack exception marker upon exception return
  powerpc: Remove export of save_stack_trace_tsk_reliable()
  powerpc/mm: fix "section_base" set but not used
  powerpc/mm: Fix "sz" set but not used warning
  powerpc/mm: Check secondary hash page table
  powerpc: remove nargs from __SYSCALL
  powerpc/64s: Fix unrelocated interrupt trampoline address test
  powerpc/powernv/ioda: Fix locked_vm counting for memory used by IOMMU tables
  powerpc/fsl: Fix the flush of branch predictor.
  powerpc/powernv: Make opal log only readable by root
  powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc
  powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to C
  powerpc/64s: Fix data interrupts vs d-side MCE reentrancy
  powerpc/64s: Prepare to handle data interrupts vs d-side MCE reentrancy
  powerpc/64s: system reset interrupt preserve HSRRs
  powerpc/64s: Fix HV NMI vs HV interrupt recoverability test
  powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown search
  powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callback
  selftests/powerpc: Remove duplicate header
  powerpc sstep: Add support for modsd, modud instructions
  ...
2019-03-07 12:56:26 -08:00
Eric Auger 0cfd027be1 vfio_pci: Enable memory accesses before calling pci_map_rom
pci_map_rom/pci_get_rom_size() performs memory access in the ROM.
In case the Memory Space accesses were disabled, readw() is likely
to trigger a synchronous external abort on some platforms.

In case memory accesses were disabled, re-enable them before the
call and disable them back again just after.

Fixes: 89e1f7d4c6 ("vfio: Add PCI device driver")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-18 14:57:50 -07:00
Alex Williamson 51ef3a004b vfio/pci: Restore device state on PM transition
PCI core handles save and restore of device state around reset, but
when using pci_set_power_state() we can unintentionally trigger a soft
reset of the device, where PCI core only restores the BAR state.  If
we're using vfio-pci's idle D3 support to try to put devices into low
power when unused, this might trigger a reset when the device is woken
for use.  Also power state management by the user, or within a guest,
can put the device into D3 power state with potentially limited
ability to restore the device if it should undergo a reset.  The PCI
spec does not define the extent of a soft reset and many devices
reporting soft reset on D3->D0 transition do not undergo a PCI config
space reset.  It's therefore assumed safe to unconditionally restore
the remainder of the state if the device indicates soft reset
support, even on a user initiated wakeup.

Implement a wrapper in vfio-pci to tag devices reporting PM reset
support, save their state on transitions into D3 and restore on
transitions back to D0.

Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-18 14:55:53 -07:00
Alexey Kardashevskiy a390685589 vfio/spapr_tce: Skip unsetting already unset table
VFIO TCE IOMMU v2 owns IOMMU tables. When we detach an IOMMU group from
a container, we need to unset these tables from the group which we do by
calling unset_window(). We also unset tables when removing a DMA window
via the VFIO_IOMMU_SPAPR_TCE_REMOVE ioctl.

The window removal checks if the table actually exists (hidden inside
tce_iommu_find_table()) but the group detaching does not so the user
may see duplicating messages:
pci 0009:03     : [PE# fd] Removing DMA window #0
pci 0009:03     : [PE# fd] Removing DMA window #1
pci 0009:03     : [PE# fd] Removing DMA window #0
pci 0009:03     : [PE# fd] Removing DMA window #1

At the moment this is not a problem as the second invocation
of unset_window() writes zeroes to the HW registers again and exits early
as there is no table.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-13 13:08:12 -07:00
Chengguang Xu 8bcb64a510 vfio: expand minor range when registering chrdev region
Actually, total amount of available minor number
for a single major is MINORMARK + 1. So expand
minor range when registering chrdev region.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-12 13:20:56 -07:00
Masahiro Yamada 3c8d7ef89b vfio: platform: reset: fix up include directives to remove ccflags-y
For the include directive with double-quotes "", the preprocessor
searches the header in the relative path to the current file.

Fix them up, and remove the header search path option.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-05 13:29:30 -07:00
Andy Shevchenko 278bca7f31 vfio-mdev: Switch to use new generic UUID API
There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-05 11:51:56 -07:00
Sam Bobroff 1ef52073fd powerpc/eeh: Improve recovery of passed-through devices
Currently, the EEH recovery process considers passed-through devices
as if they were not EEH-aware, which can cause them to be removed as
part of recovery.  Because device removal requires cooperation from
the guest, this may lead to the process stalling or deadlocking.
Also, if devices are removed on the host side, they will be removed
from their IOMMU group, making recovery in the guest impossible.

Therefore, alter the recovery process so that passed-through devices
are not removed but are instead left frozen (and marked isolated)
until the guest performs it's own recovery.  If firmware thaws a
passed-through PE because it's parent PE has been thawed (because it
was not passed through), re-freeze it.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05 11:55:44 +11:00
Alexey Kardashevskiy 9a71ac7e15 vfio-pci/nvlink2: Fix ancient gcc warnings
Using the {0} construct as a generic initializer is perfectly fine in C,
however due to a bug in old gcc there is a warning:

  + /kisskb/src/drivers/vfio/pci/vfio_pci_nvlink2.c: warning: (near
initialization for 'cap.header') [-Wmissing-braces]:  => 181:9

Since for whatever reason we still want to compile the modern kernel
with such an old gcc without warnings, this changes the capabilities
initialization.

The gcc bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119

Fixes: 7f92891778 ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-23 08:20:43 -07:00
Thomas Gleixner 33e5ee780e vfio/pci: Cleanup license mess
The recently added nvlink2 VFIO driver introduced a license conflict in two
files. In both cases the SPDX license identifier is:

  SPDX-License-Identifier: GPL-2.0+

but the files contain also the following license boiler plate text:

  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation

The latter is GPL-2.9-only and not GPL-2.0=.

Looking deeper. The nvlink source file is derived from vfio_pci_igd.c which
is also licensed under GPL-2.0-only and it can be assumed that the file was
copied and modified. As the original file is licensed GPL-2.0-only it's not
possible to relicense derivative work to GPL-2.0-or-later.

Fix the SPDX identifier and remove the boiler plate as it is redundant.

Fixes: 7f92891778 ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: kvm@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-22 11:06:05 -07:00
Alex Williamson 58fec830fc vfio/type1: Fix unmap overflow off-by-one
The below referenced commit adds a test for integer overflow, but in
doing so prevents the unmap ioctl from ever including the last page of
the address space.  Subtract one to compare to the last address of the
unmap to avoid the overflow and wrap-around.

Fixes: 71a7d3d78e ("vfio/type1: silence integer overflow warning")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1662291
Cc: stable@vger.kernel.org # v4.15+
Reported-by: Pei Zhang <pezhang@redhat.com>
Debugged-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-08 09:31:28 -07:00
Masahiro Yamada d1fc1176c0 vfio/pci: set TRACE_INCLUDE_PATH to fix the build error
drivers/vfio/pci/vfio_pci_nvlink2.c cannot be compiled for in-tree
building.

    CC      drivers/vfio/pci/vfio_pci_nvlink2.o
  In file included from drivers/vfio/pci/trace.h:102,
                   from drivers/vfio/pci/vfio_pci_nvlink2.c:29:
  ./include/trace/define_trace.h:89:42: fatal error: ./trace.h: No such file or directory
   #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
                                          ^
  compilation terminated.
  make[1]: *** [scripts/Makefile.build;277: drivers/vfio/pci/vfio_pci_nvlink2.o] Error 1

To fix the build error, let's tell include/trace/define_trace.h the
location of drivers/vfio/pci/trace.h

Fixes: 7f92891778 ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-08 09:08:30 -07:00
Linus Torvalds 8e143b90e4 IOMMU Updates for Linux v4.21
Including (in no particular order):
 
 	- Page table code for AMD IOMMU now supports large pages where
 	  smaller page-sizes were mapped before. VFIO had to work around
 	  that in the past and I included a patch to remove it (acked by
 	  Alex Williamson)
 
 	- Patches to unmodularize a couple of IOMMU drivers that would
 	  never work as modules anyway.
 
 	- Work to unify the the iommu-related pointers in
 	  'struct device' into one pointer. This work is not finished
 	  yet, but will probably be in the next cycle.
 
 	- NUMA aware allocation in iommu-dma code
 
 	- Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver
 
 	- Scalable mode support for the Intel VT-d driver
 
 	- PM runtime improvements for the ARM-SMMU driver
 
 	- Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom
 
 	- Various smaller fixes and improvements
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Merge tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:

 - Page table code for AMD IOMMU now supports large pages where smaller
   page-sizes were mapped before. VFIO had to work around that in the
   past and I included a patch to remove it (acked by Alex Williamson)

 - Patches to unmodularize a couple of IOMMU drivers that would never
   work as modules anyway.

 - Work to unify the the iommu-related pointers in 'struct device' into
   one pointer. This work is not finished yet, but will probably be in
   the next cycle.

 - NUMA aware allocation in iommu-dma code

 - Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver

 - Scalable mode support for the Intel VT-d driver

 - PM runtime improvements for the ARM-SMMU driver

 - Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom

 - Various smaller fixes and improvements

* tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (78 commits)
  iommu: Check for iommu_ops == NULL in iommu_probe_device()
  ACPI/IORT: Don't call iommu_ops->add_device directly
  iommu/of: Don't call iommu_ops->add_device directly
  iommu: Consolitate ->add/remove_device() calls
  iommu/sysfs: Rename iommu_release_device()
  dmaengine: sh: rcar-dmac: Use device_iommu_mapped()
  xhci: Use device_iommu_mapped()
  powerpc/iommu: Use device_iommu_mapped()
  ACPI/IORT: Use device_iommu_mapped()
  iommu/of: Use device_iommu_mapped()
  driver core: Introduce device_iommu_mapped() function
  iommu/tegra: Use helper functions to access dev->iommu_fwspec
  iommu/qcom: Use helper functions to access dev->iommu_fwspec
  iommu/of: Use helper functions to access dev->iommu_fwspec
  iommu/mediatek: Use helper functions to access dev->iommu_fwspec
  iommu/ipmmu-vmsa: Use helper functions to access dev->iommu_fwspec
  iommu/dma: Use helper functions to access dev->iommu_fwspec
  iommu/arm-smmu: Use helper functions to access dev->iommu_fwspec
  ACPI/IORT: Use helper functions to access dev->iommu_fwspec
  iommu: Introduce wrappers around dev->iommu_fwspec
  ...
2019-01-01 15:55:29 -08:00
Linus Torvalds 1984f65c2f VFIO updates for v4.21
- Replace global vfio-pci lock with per bus lock to allow concurrent
    open and release (Alex Williamson)
 
  - Declare mdev function as static (Paolo Cretaro)
 
  - Convert char to u8 in mdev/mtty sample driver (Nathan Chancellor)
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Merge tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Replace global vfio-pci lock with per bus lock to allow concurrent
   open and release (Alex Williamson)

 - Declare mdev function as static (Paolo Cretaro)

 - Convert char to u8 in mdev/mtty sample driver (Nathan Chancellor)

* tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-mdev/samples: Use u8 instead of char for handle functions
  vfio/mdev: add static modifier to add_mdev_supported_type
  vfio/pci: Parallelize device open and release
2018-12-28 19:41:58 -08:00
Alexey Kardashevskiy 7f92891778 vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver
POWER9 Witherspoon machines come with 4 or 6 V100 GPUs which are not
pluggable PCIe devices but still have PCIe links which are used
for config space and MMIO. In addition to that the GPUs have 6 NVLinks
which are connected to other GPUs and the POWER9 CPU. POWER9 chips
have a special unit on a die called an NPU which is an NVLink2 host bus
adapter with p2p connections to 2 to 3 GPUs, 3 or 2 NVLinks to each.
These systems also support ATS (address translation services) which is
a part of the NVLink2 protocol. Such GPUs also share on-board RAM
(16GB or 32GB) to the system via the same NVLink2 so a CPU has
cache-coherent access to a GPU RAM.

This exports GPU RAM to the userspace as a new VFIO device region. This
preregisters the new memory as device memory as it might be used for DMA.
This inserts pfns from the fault handler as the GPU memory is not onlined
until the vendor driver is loaded and trained the NVLinks so doing this
earlier causes low level errors which we fence in the firmware so
it does not hurt the host system but still better be avoided; for the same
reason this does not map GPU RAM into the host kernel (usual thing for
emulated access otherwise).

This exports an ATSD (Address Translation Shootdown) register of NPU which
allows TLB invalidations inside GPU for an operating system. The register
conveniently occupies a single 64k page. It is also presented to
the userspace as a new VFIO device region. One NPU has 8 ATSD registers,
each of them can be used for TLB invalidation in a GPU linked to this NPU.
This allocates one ATSD register per an NVLink bridge allowing passing
up to 6 registers. Due to the host firmware bug (just recently fixed),
only 1 ATSD register per NPU was actually advertised to the host system
so this passes that alone register via the first NVLink bridge device in
the group which is still enough as QEMU collects them all back and
presents to the guest via vPHB to mimic the emulated NPU PHB on the host.

In order to provide the userspace with the information about GPU-to-NVLink
connections, this exports an additional capability called "tgt"
(which is an abbreviated host system bus address). The "tgt" property
tells the GPU its own system address and allows the guest driver to
conglomerate the routing information so each GPU knows how to get directly
to the other GPUs.

For ATS to work, the nest MMU (an NVIDIA block in a P9 CPU) needs to
know LPID (a logical partition ID or a KVM guest hardware ID in other
words) and PID (a memory context ID of a userspace process, not to be
confused with a linux pid). This assigns a GPU to LPID in the NPU and
this is why this adds a listener for KVM on an IOMMU group. A PID comes
via NVLink from a GPU and NPU uses a PID wildcard to pass it through.

This requires coherent memory and ATSD to be available on the host as
the GPU vendor only supports configurations with both features enabled
and other configurations are known not to work. Because of this and
because of the ways the features are advertised to the host system
(which is a device tree with very platform specific properties),
this requires enabled POWERNV platform.

The V100 GPUs do not advertise any of these capabilities via the config
space and there are more than just one device ID so this relies on
the platform to tell whether these GPUs have special abilities such as
NVLinks.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:47 +11:00
Alexey Kardashevskiy c2c0f1cde0 vfio_pci: Allow regions to add own capabilities
VFIO regions already support region capabilities with a limited set of
fields. However the subdriver might have to report to the userspace
additional bits.

This adds an add_capability() hook to vfio_pci_regops.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:47 +11:00
Alexey Kardashevskiy a15b1883fe vfio_pci: Allow mapping extra regions
So far we only allowed mapping of MMIO BARs to the userspace. However
there are GPUs with on-board coherent RAM accessible via side
channels which we also want to map to the userspace. The first client
for this is NVIDIA V100 GPU with NVLink2 direct links to a POWER9
NPU-enabled CPU; such GPUs have 16GB RAM which is coherently mapped
to the system address space, we are going to export these as an extra
PCI region.

We already support extra PCI regions and this adds support for mapping
them to the userspace.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:47 +11:00
Alexey Kardashevskiy c10c21efa4 powerpc/vfio/iommu/kvm: Do not pin device memory
This new memory does not have page structs as it is not plugged to
the host so gup() will fail anyway.

This adds 2 helpers:
- mm_iommu_newdev() to preregister the "memory device" memory so
the rest of API can still be used;
- mm_iommu_is_devmem() to know if the physical address is one of thise
new regions which we must avoid unpinning of.

This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test
if the memory is device memory to avoid pfn_to_page().

This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which
does delayed pages dirtying.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:46 +11:00
Alexey Kardashevskiy e0bf78b0f9 powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a region
Normally mm_iommu_get() should add a reference and mm_iommu_put() should
remove it. However historically mm_iommu_find() does the referencing and
mm_iommu_get() is doing allocation and referencing.

We are going to add another helper to preregister device memory so
instead of having mm_iommu_new() (which pre-registers the normal memory
and references the region), we need separate helpers for pre-registering
and referencing.

This renames:
- mm_iommu_get to mm_iommu_new;
- mm_iommu_find to mm_iommu_get.

This changes mm_iommu_get() to reference the region so the name now
reflects what it does.

This removes the check for exact match from mm_iommu_new() as we want it
to fail on existing regions; mm_iommu_get() should be used instead.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 16:20:46 +11:00
Alexey Kardashevskiy 517ad4ae8a vfio/spapr_tce: Get rid of possible infinite loop
As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered
memory. If there is a bug in memory release, the loop in
tce_iommu_release() becomes infinite; this actually happened to me.

This makes the loop finite and prints a warning on every failure to make
the code more bug prone.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20 22:59:03 +11:00
Paolo Cretaro 9422f5871d vfio/mdev: add static modifier to add_mdev_supported_type
Set add_mdev_supported_type as static since it is only used within
mdev_sysfs.c.  This fixes -Wmissing-prototypes gcc warning.

Signed-off-by: Paolo Cretaro <paolocretaro@gmail.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-12-12 12:59:48 -07:00
Alex Williamson e309df5b0c vfio/pci: Parallelize device open and release
In commit 61d792562b ("vfio-pci: Use mutex around open, release, and
remove") a mutex was added to freeze the refcnt for a device so that
we can handle errors and perform bus resets on final close.  However,
bus resets can be rather slow and a global mutex here is undesirable.
Evaluating the potential locking granularity, a per-device mutex
provides the best resolution but with multiple devices on a bus all
released concurrently, they'll race to acquire each other's mutex,
likely resulting in no reset at all if we use trylock.  We therefore
lock at the granularity of the bus/slot reset as we're only attempting
a single reset for this group of devices anyway.  This allows much
greater scaling as we're bounded in the number of devices protected by
a single reflck object.

Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-12-12 12:51:07 -07:00
Joerg Roedel 7a30423a95 vfio/type1: Remove map_try_harder() code path
The AMD IOMMU driver can now map a huge-page where smaller
mappings existed before, so this code-path is no longer
triggered.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-11-15 16:40:55 +01:00