linux.git/drivers/vfio, branch v5.0-rc2

vfio/type1: Fix unmap overflow off-by-one

2019-01-08T16:31:28+00:00

The below referenced commit adds a test for integer overflow, but in
doing so prevents the unmap ioctl from ever including the last page of
the address space.  Subtract one to compare to the last address of the
unmap to avoid the overflow and wrap-around.

Fixes: 71a7d3d78e3c ("vfio/type1: silence integer overflow warning")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1662291
Cc: stable@vger.kernel.org # v4.15+
Reported-by: Pei Zhang 
Debugged-by: Peter Xu 
Reviewed-by: Dan Carpenter 
Reviewed-by: Peter Xu 
Tested-by: Peter Xu 
Reviewed-by: Cornelia Huck 
Signed-off-by: Alex Williamson

vfio/pci: set TRACE_INCLUDE_PATH to fix the build error

2019-01-08T16:08:30+00:00

drivers/vfio/pci/vfio_pci_nvlink2.c cannot be compiled for in-tree
building.

    CC      drivers/vfio/pci/vfio_pci_nvlink2.o
  In file included from drivers/vfio/pci/trace.h:102,
                   from drivers/vfio/pci/vfio_pci_nvlink2.c:29:
  ./include/trace/define_trace.h:89:42: fatal error: ./trace.h: No such file or directory
   #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
                                          ^
  compilation terminated.
  make[1]: *** [scripts/Makefile.build;277: drivers/vfio/pci/vfio_pci_nvlink2.o] Error 1

To fix the build error, let's tell include/trace/define_trace.h the
location of drivers/vfio/pci/trace.h

Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Reported-by: Laura Abbott 
Signed-off-by: Masahiro Yamada 
Reviewed-by: Cornelia Huck 
Signed-off-by: Alex Williamson

Merge tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2019-01-01T23:55:29+00:00

Pull IOMMU updates from Joerg Roedel:

 - Page table code for AMD IOMMU now supports large pages where smaller
   page-sizes were mapped before. VFIO had to work around that in the
   past and I included a patch to remove it (acked by Alex Williamson)

 - Patches to unmodularize a couple of IOMMU drivers that would never
   work as modules anyway.

 - Work to unify the the iommu-related pointers in 'struct device' into
   one pointer. This work is not finished yet, but will probably be in
   the next cycle.

 - NUMA aware allocation in iommu-dma code

 - Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver

 - Scalable mode support for the Intel VT-d driver

 - PM runtime improvements for the ARM-SMMU driver

 - Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom

 - Various smaller fixes and improvements

* tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (78 commits)
  iommu: Check for iommu_ops == NULL in iommu_probe_device()
  ACPI/IORT: Don't call iommu_ops->add_device directly
  iommu/of: Don't call iommu_ops->add_device directly
  iommu: Consolitate ->add/remove_device() calls
  iommu/sysfs: Rename iommu_release_device()
  dmaengine: sh: rcar-dmac: Use device_iommu_mapped()
  xhci: Use device_iommu_mapped()
  powerpc/iommu: Use device_iommu_mapped()
  ACPI/IORT: Use device_iommu_mapped()
  iommu/of: Use device_iommu_mapped()
  driver core: Introduce device_iommu_mapped() function
  iommu/tegra: Use helper functions to access dev->iommu_fwspec
  iommu/qcom: Use helper functions to access dev->iommu_fwspec
  iommu/of: Use helper functions to access dev->iommu_fwspec
  iommu/mediatek: Use helper functions to access dev->iommu_fwspec
  iommu/ipmmu-vmsa: Use helper functions to access dev->iommu_fwspec
  iommu/dma: Use helper functions to access dev->iommu_fwspec
  iommu/arm-smmu: Use helper functions to access dev->iommu_fwspec
  ACPI/IORT: Use helper functions to access dev->iommu_fwspec
  iommu: Introduce wrappers around dev->iommu_fwspec
  ...

Merge tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio

2018-12-29T03:41:58+00:00

Pull VFIO updates from Alex Williamson:

 - Replace global vfio-pci lock with per bus lock to allow concurrent
   open and release (Alex Williamson)

 - Declare mdev function as static (Paolo Cretaro)

 - Convert char to u8 in mdev/mtty sample driver (Nathan Chancellor)

* tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-mdev/samples: Use u8 instead of char for handle functions
  vfio/mdev: add static modifier to add_mdev_supported_type
  vfio/pci: Parallelize device open and release

vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver

2018-12-21T05:20:47+00:00

POWER9 Witherspoon machines come with 4 or 6 V100 GPUs which are not
pluggable PCIe devices but still have PCIe links which are used
for config space and MMIO. In addition to that the GPUs have 6 NVLinks
which are connected to other GPUs and the POWER9 CPU. POWER9 chips
have a special unit on a die called an NPU which is an NVLink2 host bus
adapter with p2p connections to 2 to 3 GPUs, 3 or 2 NVLinks to each.
These systems also support ATS (address translation services) which is
a part of the NVLink2 protocol. Such GPUs also share on-board RAM
(16GB or 32GB) to the system via the same NVLink2 so a CPU has
cache-coherent access to a GPU RAM.

This exports GPU RAM to the userspace as a new VFIO device region. This
preregisters the new memory as device memory as it might be used for DMA.
This inserts pfns from the fault handler as the GPU memory is not onlined
until the vendor driver is loaded and trained the NVLinks so doing this
earlier causes low level errors which we fence in the firmware so
it does not hurt the host system but still better be avoided; for the same
reason this does not map GPU RAM into the host kernel (usual thing for
emulated access otherwise).

This exports an ATSD (Address Translation Shootdown) register of NPU which
allows TLB invalidations inside GPU for an operating system. The register
conveniently occupies a single 64k page. It is also presented to
the userspace as a new VFIO device region. One NPU has 8 ATSD registers,
each of them can be used for TLB invalidation in a GPU linked to this NPU.
This allocates one ATSD register per an NVLink bridge allowing passing
up to 6 registers. Due to the host firmware bug (just recently fixed),
only 1 ATSD register per NPU was actually advertised to the host system
so this passes that alone register via the first NVLink bridge device in
the group which is still enough as QEMU collects them all back and
presents to the guest via vPHB to mimic the emulated NPU PHB on the host.

In order to provide the userspace with the information about GPU-to-NVLink
connections, this exports an additional capability called "tgt"
(which is an abbreviated host system bus address). The "tgt" property
tells the GPU its own system address and allows the guest driver to
conglomerate the routing information so each GPU knows how to get directly
to the other GPUs.

For ATS to work, the nest MMU (an NVIDIA block in a P9 CPU) needs to
know LPID (a logical partition ID or a KVM guest hardware ID in other
words) and PID (a memory context ID of a userspace process, not to be
confused with a linux pid). This assigns a GPU to LPID in the NPU and
this is why this adds a listener for KVM on an IOMMU group. A PID comes
via NVLink from a GPU and NPU uses a PID wildcard to pass it through.

This requires coherent memory and ATSD to be available on the host as
the GPU vendor only supports configurations with both features enabled
and other configurations are known not to work. Because of this and
because of the ways the features are advertised to the host system
(which is a device tree with very platform specific properties),
this requires enabled POWERNV platform.

The V100 GPUs do not advertise any of these capabilities via the config
space and there are more than just one device ID so this relies on
the platform to tell whether these GPUs have special abilities such as
NVLinks.

Signed-off-by: Alexey Kardashevskiy 
Acked-by: Alex Williamson 
Signed-off-by: Michael Ellerman

vfio_pci: Allow regions to add own capabilities

2018-12-21T05:20:47+00:00

VFIO regions already support region capabilities with a limited set of
fields. However the subdriver might have to report to the userspace
additional bits.

This adds an add_capability() hook to vfio_pci_regops.

Signed-off-by: Alexey Kardashevskiy 
Acked-by: Alex Williamson 
Signed-off-by: Michael Ellerman

vfio_pci: Allow mapping extra regions

2018-12-21T05:20:47+00:00

So far we only allowed mapping of MMIO BARs to the userspace. However
there are GPUs with on-board coherent RAM accessible via side
channels which we also want to map to the userspace. The first client
for this is NVIDIA V100 GPU with NVLink2 direct links to a POWER9
NPU-enabled CPU; such GPUs have 16GB RAM which is coherently mapped
to the system address space, we are going to export these as an extra
PCI region.

We already support extra PCI regions and this adds support for mapping
them to the userspace.

Signed-off-by: Alexey Kardashevskiy 
Reviewed-by: David Gibson 
Acked-by: Alex Williamson 
Signed-off-by: Michael Ellerman

powerpc/vfio/iommu/kvm: Do not pin device memory

2018-12-21T05:20:46+00:00

This new memory does not have page structs as it is not plugged to
the host so gup() will fail anyway.

This adds 2 helpers:
- mm_iommu_newdev() to preregister the "memory device" memory so
the rest of API can still be used;
- mm_iommu_is_devmem() to know if the physical address is one of thise
new regions which we must avoid unpinning of.

This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test
if the memory is device memory to avoid pfn_to_page().

This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which
does delayed pages dirtying.

Signed-off-by: Alexey Kardashevskiy 
Reviewed-by: Paul Mackerras 
Signed-off-by: Michael Ellerman

powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a region

2018-12-21T05:20:46+00:00

Normally mm_iommu_get() should add a reference and mm_iommu_put() should
remove it. However historically mm_iommu_find() does the referencing and
mm_iommu_get() is doing allocation and referencing.

We are going to add another helper to preregister device memory so
instead of having mm_iommu_new() (which pre-registers the normal memory
and references the region), we need separate helpers for pre-registering
and referencing.

This renames:
- mm_iommu_get to mm_iommu_new;
- mm_iommu_find to mm_iommu_get.

This changes mm_iommu_get() to reference the region so the name now
reflects what it does.

This removes the check for exact match from mm_iommu_new() as we want it
to fail on existing regions; mm_iommu_get() should be used instead.

Signed-off-by: Alexey Kardashevskiy 
Reviewed-by: David Gibson 
Signed-off-by: Michael Ellerman

vfio/spapr_tce: Get rid of possible infinite loop

2018-12-20T11:59:03+00:00

As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered
memory. If there is a bug in memory release, the loop in
tce_iommu_release() becomes infinite; this actually happened to me.

This makes the loop finite and prints a warning on every failure to make
the code more bug prone.

Signed-off-by: Alexey Kardashevskiy 
Reviewed-by: David Gibson 
Acked-by: Alex Williamson 
Signed-off-by: Michael Ellerman