linux-stable.git/drivers/vfio, branch linux-3.17.y

vfio-pci: Fix remove path locking

2014-10-30T16:43:13+00:00

commit 93899a679fd6b2534b5c297d9316bae039ebcbe1 upstream.

Locking both the remove() and release() path results in a deadlock
that should have been obvious.  To fix this we can get and hold the
vfio_device reference as we evaluate whether to do a bus/slot reset.
This will automatically block any remove() calls, allowing us to
remove the explict lock.  Fixes 61d792562b53.

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

drivers/vfio: Enable VFIO if EEH is not supported

2014-08-08T16:39:16+00:00

The existing vfio_pci_open() fails upon error returned from
vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
support which this patch brings back.

The patch fixes the issue by dropping the return value of
vfio_spapr_pci_eeh_open().

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Gavin Shan 
Signed-off-by: Alex Williamson

drivers/vfio: Allow EEH to be built as module

2014-08-08T16:37:51+00:00

This adds necessary declarations to the SPAPR VFIO EEH module,
otherwise multiple dynamic linker errors reported:

vfio_spapr_eeh: Unknown symbol eeh_pe_set_option (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_configure (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_reset (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_get_state (err 0)
vfio_spapr_eeh: Unknown symbol eeh_iommu_group_to_pe (err 0)
vfio_spapr_eeh: Unknown symbol eeh_dev_open (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_set_option (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_configure (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_reset (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_get_state (err 0)
vfio_spapr_eeh: Unknown symbol eeh_iommu_group_to_pe (err 0)
vfio_spapr_eeh: Unknown symbol eeh_dev_open (err 0)

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Gavin Shan 
Signed-off-by: Alex Williamson

drivers/vfio: Fix EEH build error

2014-08-08T16:36:20+00:00

The VFIO related components could be built as dynamic modules.
Unfortunately, CONFIG_EEH can't be configured to "m". The patch
fixes the build errors when configuring VFIO related components
as dynamic modules as follows:

  CC [M]  drivers/vfio/vfio_iommu_spapr_tce.o
In file included from drivers/vfio/vfio.c:33:0:
include/linux/vfio.h:101:43: warning: ‘struct pci_dev’ declared \
inside parameter list [enabled by default]
   :
  WRAP    arch/powerpc/boot/zImage.pseries
  WRAP    arch/powerpc/boot/zImage.maple
  WRAP    arch/powerpc/boot/zImage.pmac
  WRAP    arch/powerpc/boot/zImage.epapr
  MODPOST 1818 modules
ERROR: ".vfio_spapr_iommu_eeh_ioctl" [drivers/vfio/vfio_iommu_spapr_tce.ko]\
undefined!
ERROR: ".vfio_spapr_pci_eeh_open" [drivers/vfio/pci/vfio-pci.ko] undefined!
ERROR: ".vfio_spapr_pci_eeh_release" [drivers/vfio/pci/vfio-pci.ko] undefined!

Reported-by: Alexey Kardashevskiy 
Signed-off-by: Gavin Shan 
Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Alex Williamson

vfio-pci: Attempt bus/slot reset on release

2014-08-07T17:12:07+00:00

Each time a device is released, mark whether a local reset was
successful or whether a bus/slot reset is needed.  If a reset is
needed and all of the affected devices are bound to vfio-pci and
unused, allow the reset.  This is most useful when the userspace
driver is killed and releases all the devices in an unclean state,
such as when a QEMU VM quits.

Signed-off-by: Alex Williamson

vfio-pci: Use mutex around open, release, and remove

2014-08-07T17:12:04+00:00

Serializing open/release allows us to fix a refcnt error if we fail
to enable the device and lets us prevent devices from being unbound
or opened, giving us an opportunity to do bus resets on release.  No
restriction added to serialize binding devices to vfio-pci while the
mutex is held though.

Signed-off-by: Alex Williamson

vfio-pci: Release devices with BusMaster disabled

2014-08-07T17:12:02+00:00

Our current open/release path looks like this:

vfio_pci_open
  vfio_pci_enable
    pci_enable_device
    pci_save_state
    pci_store_saved_state

vfio_pci_release
  vfio_pci_disable
    pci_disable_device
    pci_restore_state

pci_enable_device() doesn't modify PCI_COMMAND_MASTER, so if a device
comes to us with it enabled, it persists through the open and gets
stored as part of the device saved state.  We then restore that saved
state when released, which can allow the device to attempt to continue
to do DMA.  When the group is disconnected from the domain, this will
get caught by the IOMMU, but if there are other devices in the group,
the device may continue running and interfere with the user.  Even in
the former case, IOMMUs don't necessarily behave well and a stream of
blocked DMA can result in unpleasant behavior on the host.

Explicitly disable Bus Master as we're enabling the device and
slightly re-work release to make sure that pci_disable_device() is
the last thing that touches the device.

Signed-off-by: Alex Williamson

drivers/vfio: EEH support for VFIO PCI device

2014-08-05T05:28:48+00:00

The patch adds new IOCTL commands for sPAPR VFIO container device
to support EEH functionality for PCI devices, which have been passed
through from host to somebody else via VFIO.

Signed-off-by: Gavin Shan 
Acked-by: Alexander Graf 
Acked-by: Alex Williamson 
Signed-off-by: Benjamin Herrenschmidt

Merge tag 'vfio-v3.16-rc1' of git://github.com/awilliam/linux-vfio into next

2014-06-08T03:12:15+00:00

Pull VFIO updates from Alex Williamson:
 "A handful of VFIO bug fixes for v3.16"

* tag 'vfio-v3.16-rc1' of git://github.com/awilliam/linux-vfio:
  drivers/vfio/pci: Fix wrong MSI interrupt count
  drivers/vfio: Rework offsetofend()
  vfio/iommu_type1: Avoid overflow
  vfio/pci: Fix unchecked return value
  vfio/pci: Fix sizing of DPA and THP express capabilities

drivers/vfio/pci: Fix wrong MSI interrupt count

2014-05-30T17:35:54+00:00

According PCI local bus specification, the register of Message
Control for MSI (offset: 2, length: 2) has bit#0 to enable or
disable MSI logic and it shouldn't be part contributing to the
calculation of MSI interrupt count. The patch fixes the issue.

Signed-off-by: Gavin Shan 
Signed-off-by: Alex Williamson