linux-stable.git/drivers/vhost/vhost.c, branch linux-5.8.y

vhost: Use vhost_get_used_size() in vhost_vring_set_addr()

2020-10-14T09:55:46+00:00

commit 71878fa46c7e3b40fa7b3f1b6e4ba3f92f1ac359 upstream.

The open-coded computation of the used size doesn't take the event
into account when the VIRTIO_RING_F_EVENT_IDX feature is present.
Fix that by using vhost_get_used_size().

Fixes: 8ea8cf89e19a ("vhost: support event index")
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kurz 
Link: https://lore.kernel.org/r/160171932300.284610.11846106312938909461.stgit@bahia.lan
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

vhost: Don't call access_ok() when using IOTLB

2020-10-14T09:55:46+00:00

commit 0210a8db2aeca393fb3067e234967877e3146266 upstream.

When the IOTLB device is enabled, the vring addresses we get
from userspace are GIOVAs. It is thus wrong to pass them down
to access_ok() which only takes HVAs.

Access validation is done at prefetch time with IOTLB. Teach
vq_access_ok() about that by moving the (vq->iotlb) check
from vhost_vq_access_ok() to vq_access_ok(). This prevents
vhost_vring_set_addr() to fail when verifying the accesses.
No behavior change for vhost_vq_access_ok().

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1883084
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Cc: jasowang@redhat.com
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Greg Kurz 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/160171931213.284610.2052489816407219136.stgit@bahia.lan
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'akpm' (patches from Andrew)

2020-06-11T20:25:53+00:00

Merge some more updates from Andrew Morton:

 - various hotfixes and minor things

 - hch's use_mm/unuse_mm clearnups

Subsystems affected by this patch series: mm/hugetlb, scripts, kcov,
lib, nilfs, checkpatch, lib, mm/debug, ocfs2, lib, misc.

* emailed patches from Andrew Morton :
  kernel: set USER_DS in kthread_use_mm
  kernel: better document the use_mm/unuse_mm API contract
  kernel: move use_mm/unuse_mm to kthread.c
  kernel: move use_mm/unuse_mm to kthread.c
  stacktrace: cleanup inconsistent variable type
  lib: test get_count_order/long in test_bitops.c
  mm: add comments on pglist_data zones
  ocfs2: fix spelling mistake and grammar
  mm/debug_vm_pgtable: fix kernel crash by checking for THP support
  lib: fix bitmap_parse() on 64-bit big endian archs
  checkpatch: correct check for kernel parameters doc
  nilfs2: fix null pointer dereference at nilfs_segctor_do_construct()
  lib/lz4/lz4_decompress.c: document deliberate use of `&'
  kcov: check kcov_softirq in kcov_remote_stop()
  scripts/spelling: add a few more typos
  khugepaged: selftests: fix timeout condition in wait_for_scan()

kernel: set USER_DS in kthread_use_mm

2020-06-11T02:14:18+00:00

Some architectures like arm64 and s390 require USER_DS to be set for
kernel threads to access user address space, which is the whole purpose of
kthread_use_mm, but other like x86 don't.  That has lead to a huge mess
where some callers are fixed up once they are tested on said
architectures, while others linger around and yet other like io_uring try
to do "clever" optimizations for what usually is just a trivial asignment
to a member in the thread_struct for most architectures.

Make kthread_use_mm set USER_DS, and kthread_unuse_mm restore to the
previous value instead.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Michael S. Tsirkin 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Felix Kuehling 
Cc: Jason Wang 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Cc: Greg Kroah-Hartman 
Link: http://lkml.kernel.org/r/20200404094101.672954-7-hch@lst.de
Signed-off-by: Linus Torvalds

kernel: better document the use_mm/unuse_mm API contract

2020-06-11T02:14:18+00:00

Switch the function documentation to kerneldoc comments, and add
WARN_ON_ONCE asserts that the calling thread is a kernel thread and does
not have ->mm set (or has ->mm set in the case of unuse_mm).

Also give the functions a kthread_ prefix to better document the use case.

[hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio]
  Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de
[sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename]
  Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au

Signed-off-by: Christoph Hellwig 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Felix Kuehling 
Acked-by: Greg Kroah-Hartman  [usb]
Acked-by: Haren Myneni 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Jason Wang 
Cc: "Michael S. Tsirkin" 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de
Signed-off-by: Linus Torvalds

kernel: move use_mm/unuse_mm to kthread.c

2020-06-11T02:14:18+00:00

Patch series "improve use_mm / unuse_mm", v2.

This series improves the use_mm / unuse_mm interface by better documenting
the assumptions, and my taking the set_fs manipulations spread over the
callers into the core API.

This patch (of 3):

Use the proper API instead.

Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de

These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward.  Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Felix Kuehling 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Jason Wang 
Cc: "Michael S. Tsirkin" 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Cc: Greg Kroah-Hartman 
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.de
Signed-off-by: Linus Torvalds

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2020-06-10T20:42:09+00:00

Pull virtio updates from Michael Tsirkin:

 - virtio-mem: paravirtualized memory hotplug

 - support doorbell mapping for vdpa

 - config interrupt support in ifc

 - fixes all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits)
  vhost/test: fix up after API change
  virtio_mem: convert device block size into 64bit
  virtio-mem: drop unnecessary initialization
  ifcvf: implement config interrupt in IFCVF
  vhost: replace -1 with VHOST_FILE_UNBIND in ioctls
  vhost_vdpa: Support config interrupt in vdpa
  ifcvf: ignore continuous setting same status value
  virtio-mem: Don't rely on implicit compiler padding for requests
  virtio-mem: Try to unplug the complete online memory block first
  virtio-mem: Use -ETXTBSY as error code if the device is busy
  virtio-mem: Unplug subblocks right-to-left
  virtio-mem: Drop manual check for already present memory
  virtio-mem: Add parent resource for all added "System RAM"
  virtio-mem: Better retry handling
  virtio-mem: Offline and remove completely unplugged memory blocks
  mm/memory_hotplug: Introduce offline_and_remove_memory()
  virtio-mem: Allow to offline partially unplugged memory blocks
  mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE
  virtio-mem: Paravirtualized memory hotunplug part 2
  virtio-mem: Paravirtualized memory hotunplug part 1
  ...

vhost: convert get_user_pages() --> pin_user_pages()

2020-06-08T18:05:57+00:00

This code was using get_user_pages*(), in approximately a "Case 5"
scenario (accessing the data within a page), using the categorization
from [1].  That means that it's time to convert the get_user_pages*() +
put_page() calls to pin_user_pages*() + unpin_user_pages() calls.

There is some helpful background in [2]: basically, this is a small part
of fixing a long-standing disconnect between pinning pages, and file
systems' use of those pages.

[1] Documentation/core-api/pin_user_pages.rst

[2] "Explicit pinning of user-space pages":
    https://lwn.net/Articles/807108/

Signed-off-by: John Hubbard 
Signed-off-by: Andrew Morton 
Reviewed-by: Jan Kara 
Acked-by: Michael S. Tsirkin 
Acked-by: Pankaj Gupta 
Cc: Jason Wang 
Cc: Dave Chinner 
Cc: Jérôme Glisse 
Cc: Jonathan Corbet 
Cc: Souptick Joarder 
Cc: Vlastimil Babka 
Link: http://lkml.kernel.org/r/20200529234309.484480-3-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds

vhost: replace -1 with VHOST_FILE_UNBIND in ioctls

2020-06-06T20:26:27+00:00

This commit replaces -1 with VHOST_FILE_UNBIND in ioctls since
we have added such a macro in the uapi header for vdpa_host.

Signed-off-by: Zhu Lingshan 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/1591352835-22441-5-git-send-email-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin

vhost: (cosmetic) remove a superfluous variable initialisation

2020-06-04T19:36:51+00:00

Even the compiler is able to figure out that in this case the
initialisation is superfluous.

Signed-off-by: Guennadi Liakhovetski 
Link: https://lore.kernel.org/r/20200527180541.5570-3-guennadi.liakhovetski@linux.intel.com
Signed-off-by: Michael S. Tsirkin