Pull xen fixes from Juergen Gross:

 - a small cleanup

 - a fix for a build error on ARM with some configs

 - a fix of a patch for the Xen gntdev driver

 - three patches for fixing a potential problem in the swiotlb-xen
   driver which Konrad was fine with me carrying them through the Xen
   tree

* tag 'for-linus-5.3a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/swiotlb: remember having called xen_create_contiguous_region()
  xen/swiotlb: simplify range_straddles_page_boundary()
  xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()
  xen: avoid link error on ARM
  xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero()
  xen/pciback: remove set but not used variable 'old_state'

Instead of always calling xen_destroy_contiguous_region() in case the
memory is DMA-able for the used device, do so only in case it has been
made DMA-able via xen_create_contiguous_region() before.

This will avoid a lot of xen_destroy_contiguous_region() calls for
64-bit capable devices.

As the memory in question is owned by swiotlb-xen the PG_owner_priv_1
flag of the first allocated page can be used for remembering.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

range_straddles_page_boundary() is open coding several macros from
include/xen/page.h. Use those instead. Additionally there is no need
to have check_pages_physically_contiguous() as a separate function as
it is used only once, so merge it into range_straddles_page_boundary().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

The condition in xen_swiotlb_free_coherent() for deciding whether to
call xen_destroy_contiguous_region() is wrong: in case the region to
be freed is not contiguous calling xen_destroy_contiguous_region() is
the wrong thing to do: it would result in inconsistent mappings of
multiple PFNs to the same MFN. This will lead to various strange
crashes or data corruption.

Instead of calling xen_destroy_contiguous_region() in that case a
warning should be issued as that situation should never occur.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Building the privcmd code as a loadable module on ARM, we get
a link error due to the private cache management functions:

ERROR: "__sync_icache_dcache" [drivers/xen/xen-privcmd.ko] undefined!

Move the code into a new that is always built in when Xen is enabled,
as suggested by Juergen Gross and Boris Ostrovsky.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>

'commit df9bde015a72 ("xen/gntdev.c: convert to use vm_map_pages()")'
breaks gntdev driver. If vma->vm_pgoff > 0, vm_map_pages()
will:
 - use map->pages starting at vma->vm_pgoff instead of 0
 - verify map->count against vma_pages()+vma->vm_pgoff instead of just
   vma_pages().

In practice, this breaks using a single gntdev FD for mapping multiple
grants.

relevant strace output:
[pid   857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0
[pid   857] mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 7, 0) =
0x777f1211b000
[pid   857] ioctl(7, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, 0x7ffd3407b710) = 0
[pid   857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0
[pid   857] mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 7,
0x1000) = -1 ENXIO (No such device or address)

details here:
https://github.com/QubesOS/qubes-issues/issues/5199

The reason is -> ( copying Marek's word from discussion)

vma->vm_pgoff is used as index passed to gntdev_find_map_index. It's
basically using this parameter for "which grant reference to map".
map struct returned by gntdev_find_map_index() describes just the pages
to be mapped. Specifically map->pages[0] should be mapped at
vma->vm_start, not vma->vm_start+vma->vm_pgoff*PAGE_SIZE.

When trying to map grant with index (aka vma->vm_pgoff) > 1,
__vm_map_pages() will refuse to map it because it will expect map->count
to be at least vma_pages(vma)+vma->vm_pgoff, while it is exactly
vma_pages(vma).

Converting vm_map_pages() to use vm_map_pages_zero() will fix the
problem.

Marek has tested and confirmed the same.

Cc: stable@vger.kernel.org # v5.2+
Fixes: df9bde015a72 ("xen/gntdev.c: convert to use vm_map_pages()")

Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/xen/xen-pciback/conf_space_capability.c: In function pm_ctrl_write:
drivers/xen/xen-pciback/conf_space_capability.c:119:25: warning:
 variable old_state set but not used [-Wunused-but-set-variable]

It is never used so can be removed.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Pull xen updates from Juergen Gross:
 "Fixes and features:

   - A series to introduce a common command line parameter for disabling
     paravirtual extensions when running as a guest in virtualized
     environment

   - A fix for int3 handling in Xen pv guests

   - Removal of the Xen-specific tmem driver as support of tmem in Xen
     has been dropped (and it was experimental only)

   - A security fix for running as Xen dom0 (XSA-300)

   - A fix for IRQ handling when offlining cpus in Xen guests

   - Some small cleanups"

* tag 'for-linus-5.3a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: let alloc_xenballooned_pages() fail if not enough memory free
  xen/pv: Fix a boot up hang revealed by int3 self test
  x86/xen: Add "nopv" support for HVM guest
  x86/paravirt: Remove const mark from x86_hyper_xen_hvm variable
  xen: Map "xen_nopv" parameter to "nopv" and mark it obsolete
  x86: Add "nopv" parameter to disable PV extensions
  x86/xen: Mark xen_hvm_need_lapic() and xen_x2apic_para_available() as __init
  xen: remove tmem driver
  Revert "x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized"
  xen/events: fix binding user event channels to cpus

Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...

Merge yet more updates from Andrew Morton:
 "The rest of MM and a kernel-wide procfs cleanup.

  Summary of the more significant patches:

   - Patch series "mm/memory_hotplug: Factor out memory block
     devicehandling", v3. David Hildenbrand.

     Some spring-cleaning of the memory hotplug code, notably in
     drivers/base/memory.c

   - "mm: thp: fix false negative of shmem vma's THP eligibility". Yang
     Shi.

     Fix /proc/pid/smaps output for THP pages used in shmem.

   - "resource: fix locking in find_next_iomem_res()" + 1. Nadav Amit.

     Bugfix and speedup for kernel/resource.c

   - Patch series "mm: Further memory block device cleanups", David
     Hildenbrand.

     More spring-cleaning of the memory hotplug code.

   - Patch series "mm: Sub-section memory hotplug support". Dan
     Williams.

     Generalise the memory hotplug code so that pmem can use it more
     completely. Then remove the hacks from the libnvdimm code which
     were there to work around the memory-hotplug code's constraints.

   - "proc/sysctl: add shared variables for range check", Matteo Croce.

     We have about 250 instances of

          int zero;
          ...
                  .extra1 = &zero,

     in the tree. This is a tree-wide sweep to make all those private
     "zero"s and "one"s use global variables.

     Alas, it isn't practical to make those two global integers const"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
  proc/sysctl: add shared variables for range check
  mm: migrate: remove unused mode argument
  mm/sparsemem: cleanup 'section number' data types
  libnvdimm/pfn: stop padding pmem namespaces to section alignment
  libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
  mm/devm_memremap_pages: enable sub-section remap
  mm: document ZONE_DEVICE memory-model implications
  mm/sparsemem: support sub-section hotplug
  mm/sparsemem: prepare for sub-section ranges
  mm: kill is_dev_zone() helper
  mm/hotplug: kill is_dev_zone() usage in __remove_pages()
  mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()
  mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal
  mm/sparsemem: add helpers track active portions of a section at boot
  mm/sparsemem: introduce a SECTION_IS_EARLY flag
  mm/sparsemem: introduce struct mem_section_usage
  drivers/base/memory.c: get rid of find_memory_block_hinted()
  mm/memory_hotplug: move and simplify walk_memory_blocks()
  mm/memory_hotplug: rename walk_memory_range() and pass start+size instead of pfns
  mm: make register_mem_sect_under_node() static
  ...