Pull vfio updates from Alex Williamson:
 "Largely hugepage support for vfio/type1 iommu and surrounding cleanups
  and fixes"

* tag 'vfio-v3.11' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Fix leak on error path
  vfio: Limit group opens
  vfio/type1: Fix missed frees and zero sized removes
  vfio: fix documentation
  vfio: Provide module option to disable vfio_iommu_type1 hugepage support
  vfio: hugepage support for vfio_iommu_type1
  vfio: Convert type1 iommu to use rbtree

Pull powerpc updates from Ben Herrenschmidt:
 "This is the powerpc changes for the 3.11 merge window.  In addition to
  the usual bug fixes and small updates, the main highlights are:

   - Support for transparent huge pages by Aneesh Kumar for 64-bit
     server processors.  This allows the use of 16M pages as transparent
     huge pages on kernels compiled with a 64K base page size.

   - Base VFIO support for KVM on power by Alexey Kardashevskiy

   - Wiring up of our nvram to the pstore infrastructure, including
     putting compressed oopses in there by Aruna Balakrishnaiah

   - Move, rework and improve our "EEH" (basically PCI error handling
     and recovery) infrastructure.  It is no longer specific to pseries
     but is now usable by the new "powernv" platform as well (no
     hypervisor) by Gavin Shan.

   - I fixed some bugs in our math-emu instruction decoding and made it
     usable to emulate some optional FP instructions on processors with
     hard FP that lack them (such as fsqrt on Freescale embedded
     processors).

   - Support for Power8 "Event Based Branch" facility by Michael
     Ellerman.  This facility allows what is basically "userspace
     interrupts" for performance monitor events.

   - A bunch of Transactional Memory vs.  Signals bug fixes and HW
     breakpoint/watchpoint fixes by Michael Neuling.

  And more ...  I appologize in advance if I've failed to highlight
  something that somebody deemed worth it."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  pstore: Add hsize argument in write_buf call of pstore_ftrace_call
  powerpc/fsl: add MPIC timer wakeup support
  powerpc/mpic: create mpic subsystem object
  powerpc/mpic: add global timer support
  powerpc/mpic: add irq_set_wake support
  powerpc/85xx: enable coreint for all the 64bit boards
  powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx
  powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig
  powerpc/mpic: Add get_version API both for internal and external use
  powerpc: Handle both new style and old style reserve maps
  powerpc/hw_brk: Fix off by one error when validating DAWR region end
  powerpc/pseries: Support compression of oops text via pstore
  powerpc/pseries: Re-organise the oops compression code
  pstore: Pass header size in the pstore write callback
  powerpc/powernv: Fix iommu initialization again
  powerpc/pseries: Inform the hypervisor we are using EBB regs
  powerpc/perf: Add power8 EBB support
  powerpc/perf: Core EBB support for 64-bit book3s
  powerpc/perf: Drop MMCRA from thread_struct
  powerpc/perf: Don't enable if we have zero events
  ...

We also don't handle unpinning zero pages as an error on other exits
so we can fix that inconsistency by rolling in the next conditional
return.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

vfio_group_fops_open attempts to limit concurrent sessions by
disallowing opens once group->container is set.  This really doesn't
do what we want and allow for inconsistent behavior, for instance a
group can be opened twice, then a container set giving the user two
file descriptors to the group.  But then it won't allow more to be
opened.  There's not much reason to have the group opened multiple
times since most access is through devices or the container, so
complete what the original code intended and only allow a single
instance.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

With hugepage support we can only properly aligned and sized ranges.
We only guarantee that we can unmap the same ranges mapped and not
arbitrary sub-ranges.  This means we might not free anything or might
free more than requested.  The vfio unmap interface started storing
the unmapped size to return to userspace to handle this.  This patch
fixes a few places where we don't properly handle those cases, moves
a memory allocation to a place where failure is an option and checks
our loops to make sure we don't get into an infinite loop trying to
remove an overlap.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Add a module option to vfio_iommu_type1 to disable IOMMU hugepage
support.  This causes iommu_map to only be called with single page
mappings, disabling the IOMMU driver's ability to use hugepages.
This option can be enabled by loading vfio_iommu_type1 with
disable_hugepages=1 or dynamically through sysfs.  If enabled
dynamically, only new mappings are restricted.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

We currently send all mappings to the iommu in PAGE_SIZE chunks,
which prevents the iommu from enabling support for larger page sizes.
We still need to pin pages, which means we step through them in
PAGE_SIZE chunks, but we can batch up contiguous physical memory
chunks to allow the iommu the opportunity to use larger pages.  The
approach here is a bit different that the one currently used for
legacy KVM device assignment.  Rather than looking at the vma page
size and using that as the maximum size to pass to the iommu, we
instead simply look at whether the next page is physically
contiguous.  This means we might ask the iommu to map a 4MB region,
while legacy KVM might limit itself to a maximum of 2MB.

Splitting our mapping path also allows us to be smarter about locked
memory because we can more easily unwind if the user attempts to
exceed the limit.  Therefore, rather than assuming that a mapping
will result in locked memory, we test each page as it is pinned to
determine whether it locks RAM vs an mmap'd MMIO region.  This should
result in better locking granularity and less locked page fudge
factors in userspace.

The unmap path uses the same algorithm as legacy KVM.  We don't want
to track the pfn for each mapping ourselves, but we need the pfn in
order to unpin pages.  We therefore ask the iommu for the iova to
physical address translation, ask it to unpin a page, and see how many
pages were actually unpinned.  iommus supporting large pages will
often return something bigger than a page here, which we know will be
physically contiguous and we can unpin a batch of pfns.  iommus not
supporting large mappings won't see an improvement in batching here as
they only unmap a page at a time.

With this change, we also make a clarification to the API for mapping
and unmapping DMA.  We can only guarantee unmaps at the same
granularity as used for the original mapping.  In other words,
unmapping a subregion of a previous mapping is not guaranteed and may
result in a larger or smaller unmapping than requested.  The size
field in the unmapping structure is updated to reflect this.
Previously this was unmodified on mapping, always returning the the
requested unmap size.  This is now updated to return the actual unmap
size on success, allowing userspace to appropriately track mappings.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

We need to keep track of all the DMA mappings of an iommu container so
that it can be automatically unmapped when the user releases the file
descriptor.  We currently do this using a simple list, where we merge
entries with contiguous iovas and virtual addresses.  Using a tree for
this is a bit more efficient and allows us to use common code instead
of inventing our own.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

The enables VFIO on the pSeries platform, enabling user space
programs to access PCI devices directly.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>