linux-stable.git/drivers/vfio, branch v4.4.201

vfio_pci: Restore original state on release

2019-10-07T19:01:00+00:00

[ Upstream commit 92c8026854c25093946e0d7fe536fd9eac440f06 ]

vfio_pci_enable() saves the device's initial configuration information
with the intent that it is restored in vfio_pci_disable().  However,
the commit referenced in Fixes: below replaced the call to
__pci_reset_function_locked(), which is not wrapped in a state save
and restore, with pci_try_reset_function(), which overwrites the
restored device state with the current state before applying it to the
device.  Reinstate use of __pci_reset_function_locked() to return to
the desired behavior.

Fixes: 890ed578df82 ("vfio-pci: Use pci "try" reset interface")
Signed-off-by: hexin 
Signed-off-by: Liu Qi 
Signed-off-by: Zhang Yu 
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin

vfio/pci: use correct format characters

2019-05-16T17:45:01+00:00

[ Upstream commit 426b046b748d1f47e096e05bdcc6fb4172791307 ]

When compiling with -Wformat, clang emits the following warnings:

drivers/vfio/pci/vfio_pci.c:1601:5: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                ^~~~~~

drivers/vfio/pci/vfio_pci.c:1601:13: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                        ^~~~~~

drivers/vfio/pci/vfio_pci.c:1601:21: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1601:32: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                           ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1605:5: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                ^~~~~~

drivers/vfio/pci/vfio_pci.c:1605:13: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                        ^~~~~~

drivers/vfio/pci/vfio_pci.c:1605:21: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                ^~~~~~~~~

drivers/vfio/pci/vfio_pci.c:1605:32: warning: format specifies type
      'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                                vendor, device, subvendor, subdevice,
                                                           ^~~~~~~~~
The types of these arguments are unconditionally defined, so this patch
updates the format character to the correct ones for unsigned ints.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Louis Taylor 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin

vfio/type1: Limit DMA mappings per container

2019-05-16T17:44:59+00:00

commit 492855939bdb59c6f947b0b5b44af9ad82b7e38c upstream.

Memory backed DMA mappings are accounted against a user's locked
memory limit, including multiple mappings of the same memory.  This
accounting bounds the number of such mappings that a user can create.
However, DMA mappings that are not backed by memory, such as DMA
mappings of device MMIO via mmaps, do not make use of page pinning
and therefore do not count against the user's locked memory limit.
These mappings still consume memory, but the memory is not well
associated to the process for the purpose of oom killing a task.

To add bounding on this use case, we introduce a limit to the total
number of concurrent DMA mappings that a user is allowed to create.
This limit is exposed as a tunable module option where the default
value of 64K is expected to be well in excess of any reasonable use
case (a large virtual machine configuration would typically only make
use of tens of concurrent mappings).

This fixes CVE-2019-3882.

Reviewed-by: Eric Auger 
Tested-by: Eric Auger 
Reviewed-by: Peter Xu 
Reviewed-by: Cornelia Huck 
Signed-off-by: Alex Williamson 
[groeck: Adjust for missing upstream commit]
Signed-off-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

vfio/pci: Virtualize Maximum Read Request Size

2018-04-24T07:32:09+00:00

commit cf0d53ba4947aad6e471491d5b20a567cbe92e56 upstream.

MRRS defines the maximum read request size a device is allowed to
make.  Drivers will often increase this to allow more data transfer
with a single request.  Completions to this request are bound by the
MPS setting for the bus.  Aside from device quirks (none known), it
doesn't seem to make sense to set an MRRS value less than MPS, yet
this is a likely scenario given that user drivers do not have a
system-wide view of the PCI topology.  Virtualize MRRS such that the
user can set MRRS >= MPS, but use MPS as the floor value that we'll
write to hardware.

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

vfio/pci: Virtualize Maximum Payload Size

2018-04-24T07:32:09+00:00

commit 523184972b282cd9ca17a76f6ca4742394856818 upstream.

With virtual PCI-Express chipsets, we now see userspace/guest drivers
trying to match the physical MPS setting to a virtual downstream port.
Of course a lone physical device surrounded by virtual interconnects
cannot make a correct decision for a proper MPS setting.  Instead,
let's virtualize the MPS control register so that writes through to
hardware are disallowed.  Userspace drivers like QEMU assume they can
write anything to the device and we'll filter out anything dangerous.
Since mismatched MPS can lead to AER and other faults, let's add it
to the kernel side rather than relying on userspace virtualization to
handle it.

Signed-off-by: Alex Williamson 
Reviewed-by: Eric Auger 
Signed-off-by: Greg Kroah-Hartman

vfio-pci: Virtualize PCIe & AF FLR

2018-04-24T07:32:09+00:00

commit ddf9dc0eb5314d6dac8b19b1cc37c739c6896e7e upstream.

We use a BAR restore trick to try to detect when a user has performed
a device reset, possibly through FLR or other backdoors, to put things
back into a working state.  This is important for backdoor resets, but
we can actually just virtualize the "front door" resets provided via
PCIe and AF FLR.  Set these bits as virtualized + writable, allowing
the default write to set them in vconfig, then we can simply check the
bit, perform an FLR of our own, and clear the bit.  We don't actually
have the granularity in PCI to specify the type of reset we want to
do, but generally devices don't implement both PCIe and AF FLR and
we'll favor these over other types of reset, so we should generally
lineup.  We do test whether the device provides the requested FLR type
to stay consistent with hardware capabilities though.

This seems to fix several instance of devices getting into bad states
with userspace drivers, like dpdk, running inside a VM.

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

vfio-pci: Handle error from pci_iomap

2017-08-07T02:19:46+00:00

[ Upstream commit e19f32da5ded958238eac1bbe001192acef191a2 ]

Here, pci_iomap can fail, handle this case release selected
pci regions and return -ENOMEM.

Signed-off-by: Arvind Yadav 
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

vfio-pci: use 32-bit comparisons for register address for gcc-4.5

2017-08-07T02:19:44+00:00

[ Upstream commit 45e869714489431625c569d21fc952428d761476 ]

Using ancient compilers (gcc-4.5 or older) on ARM, we get a link
failure with the vfio-pci driver:

ERROR: "__aeabi_lcmp" [drivers/vfio/pci/vfio-pci.ko] undefined!

The reason is that the compiler tries to do a comparison of
a 64-bit range. This changes it to convert to a 32-bit number
explicitly first, as newer compilers do for themselves.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

vfio: New external user group/file match

2017-07-27T22:06:07+00:00

commit 5d6dee80a1e94cc284d03e06d930e60e8d3ecf7d upstream.

At the point where the kvm-vfio pseudo device wants to release its
vfio group reference, we can't always acquire a new reference to make
that happen.  The group can be in a state where we wouldn't allow a
new reference to be added.  This new helper function allows a caller
to match a file to a group to facilitate this.  Given a file and
group, report if they match.  Thus the caller needs to already have a
group reference to match to the file.  This allows the deletion of a
group without acquiring a new reference.

Signed-off-by: Alex Williamson 
Reviewed-by: Eric Auger 
Reviewed-by: Paolo Bonzini 
Tested-by: Eric Auger 
Signed-off-by: Greg Kroah-Hartman

vfio: Fix group release deadlock

2017-07-27T22:06:07+00:00

commit 811642d8d8a82c0cce8dc2debfdaf23c5a144839 upstream.

If vfio_iommu_group_notifier() acquires a group reference and that
reference becomes the last reference to the group, then vfio_group_put
introduces a deadlock code path where we're trying to unregister from
the iommu notifier chain from within a callout of that chain.  Use a
work_struct to release this reference asynchronously.

Signed-off-by: Alex Williamson 
Reviewed-by: Eric Auger 
Tested-by: Eric Auger 
Signed-off-by: Greg Kroah-Hartman