linux-stable.git/drivers/vfio, branch linux-3.14.y

vfio-pci: Fix the check on pci device type in vfio_pci_probe()

2015-01-27T16:18:56+00:00

commit 7c2e211f3c95b91912a92a8c6736343690042e2e upstream.

Current vfio-pci just supports normal pci device, so vfio_pci_probe() will
return if the pci device is not a normal device. While current code makes a
mistake. PCI_HEADER_TYPE is the offset in configuration space of the device
type, but we use this value to mask the type value.

This patch fixs this by do the check directly on the pci_dev->hdr_type.

Signed-off-by: Wei Yang 
Signed-off-by: Alex Williamson 
Signed-off-by: Greg Kroah-Hartman

mm: close PageTail race

2014-03-04T15:55:47+00:00

Commit bf6bddf1924e ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes 
Cc: Holger Kiehl 
Cc: Christoph Lameter 
Cc: Rafael Aquini 
Cc: Vlastimil Babka 
Cc: Michal Hocko 
Cc: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: Rik van Riel 
Cc: "Kirill A. Shutemov" 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2014-01-28T05:11:26+00:00

Pull powerpc updates from Ben Herrenschmidt:
 "So here's my next branch for powerpc.  A bit late as I was on vacation
  last week.  It's mostly the same stuff that was in next already, I
  just added two patches today which are the wiring up of lockref for
  powerpc, which for some reason fell through the cracks last time and
  is trivial.

  The highlights are, in addition to a bunch of bug fixes:

   - Reworked Machine Check handling on kernels running without a
     hypervisor (or acting as a hypervisor).  Provides hooks to handle
     some errors in real mode such as TLB errors, handle SLB errors,
     etc...

   - Support for retrieving memory error information from the service
     processor on IBM servers running without a hypervisor and routing
     them to the memory poison infrastructure.

   - _PAGE_NUMA support on server processors

   - 32-bit BookE relocatable kernel support

   - FSL e6500 hardware tablewalk support

   - A bunch of new/revived board support

   - FSL e6500 deeper idle states and altivec powerdown support

  You'll notice a generic mm change here, it has been acked by the
  relevant authorities and is a pre-req for our _PAGE_NUMA support"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (121 commits)
  powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked()
  powerpc: Add support for the optimised lockref implementation
  powerpc/powernv: Call OPAL sync before kexec'ing
  powerpc/eeh: Escalate error on non-existing PE
  powerpc/eeh: Handle multiple EEH errors
  powerpc: Fix transactional FP/VMX/VSX unavailable handlers
  powerpc: Don't corrupt transactional state when using FP/VMX in kernel
  powerpc: Reclaim two unused thread_info flag bits
  powerpc: Fix races with irq_work
  Move precessing of MCE queued event out from syscall exit path.
  pseries/cpuidle: Remove redundant call to ppc64_runlatch_off() in cpu idle routines
  powerpc: Make add_system_ram_resources() __init
  powerpc: add SATA_MV to ppc64_defconfig
  powerpc/powernv: Increase candidate fw image size
  powerpc: Add debug checks to catch invalid cpu-to-node mappings
  powerpc: Fix the setup of CPU-to-Node mappings during CPU online
  powerpc/iommu: Don't detach device without IOMMU group
  powerpc/eeh: Hotplug improvement
  powerpc/eeh: Call opal_pci_reinit() on powernv for restoring config space
  powerpc/eeh: Add restore_config operation
  ...

Merge tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio

2014-01-25T01:42:31+00:00

Pull vfio update from Alex Williamson:
 - convert to misc driver to support module auto loading
 - remove unnecessary and dangerous use of device_lock

* tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Don't use device_lock around AER interrupt setup
  vfio: Convert control interface to misc driver
  misc: Reserve minor for VFIO

vfio-pci: Use pci "try" reset interface

2014-01-15T17:43:17+00:00

PCI resets will attempt to take the device_lock for any device to be
reset.  This is a problem if that lock is already held, for instance
in the device remove path.  It's not sufficient to simply kill the
user process or skip the reset if called after .remove as a race could
result in the same deadlock.  Instead, we handle all resets as "best
effort" using the PCI "try" reset interfaces.  This prevents the user
from being able to induce a deadlock by triggering a reset.

Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas

vfio-pci: Don't use device_lock around AER interrupt setup

2014-01-14T23:12:55+00:00

device_lock is much too prone to lockups.  For instance if we have a
pending .remove then device_lock is already held.  If userspace
attempts to modify AER signaling after that point, a deadlock occurs.
eventfd setup/teardown is already protected in vfio with the igate
mutex.  AER is not a high performance interrupt, so we can also use
the same mutex to protect signaling versus setup races.

Signed-off-by: Alex Williamson

powerpc/iommu: Update constant names to reflect their hardcoded page size

2013-12-30T03:17:06+00:00

The powerpc iommu uses a hardcoded page size of 4K. This patch changes
the name of the IOMMU_PAGE_* macros to reflect the hardcoded values. A
future patch will use the existing names to support dynamic page
sizes.

Signed-off-by: Alistair Popple 
Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Benjamin Herrenschmidt

vfio: Convert control interface to misc driver

2013-12-19T17:17:13+00:00

This change allows us to support module auto loading using devname
support in userspace tools.  With this, /dev/vfio/vfio will always
be present and opening it will cause the vfio module to load.  This
should avoid needing to configure the system to statically load
vfio in order to get libvirt to correctly detect support for it.

Suggested-by: Paolo Bonzini 
Signed-off-by: Alex Williamson

PCI: Rename PCI_VC_PORT_REG1/2 to PCI_VC_PORT_CAP1/2

2013-12-18T00:49:39+00:00

These are set of two capability registers, it's pretty much given that
they're registers, so reflect their purpose in the name.

Suggested-by: Bjorn Helgaas 
Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas

VFIO: vfio_iommu_type1: fix bug caused by break in nested loop

2013-10-11T16:40:46+00:00

In vfio_iommu_type1.c there is a bug in vfio_dma_do_map, when checking
that pages are not already mapped. Since the check is being done in a
for loop nested within the main loop, breaking out of it does not create
the intended behavior. If the underlying IOMMU driver returns a non-NULL
value, this will be ignored and mapping the DMA range will be attempted
anyway, leading to unpredictable behavior.

This interracts badly with the ARM SMMU driver issue fixed in the patch
that was submitted with the title:
"[PATCH 2/2] ARM: SMMU: return NULL on error in arm_smmu_iova_to_phys"
Both fixes are required in order to use the vfio_iommu_type1 driver
with an ARM SMMU.

This patch refactors the function slightly, in order to also make this
kind of bug less likely.

Signed-off-by: Antonios Motakis 
Signed-off-by: Alex Williamson