The patch noted in the fixes below converted get_user_pages_fast() to
get_user_pages_longterm(), however the two calls differ in a few ways.
First _fast() is documented to not require the mmap_sem, while _longterm()
is documented to need it. Hold the mmap sem as required.
Second, _fast accepts an 'int write' while _longterm uses 'unsigned int
gup_flags', so the expression '!!(prot & IOMMU_WRITE)' is only working by
luck as FOLL_WRITE is currently == 0x1. Use the expected FOLL_WRITE
constant instead.
Fixes: 94db151dc8 ("vfio: disable filesystem-dax page pinning")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Allow the code which provides extensions to support direct assignment
of Intel IGD (GVT-d) to be compiled out of the kernel if desired. The
config option for this was previously automatically enabled on X86,
therefore the default remains Y. This simply provides the option to
disable it even for X86.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If a device is part of a PM Domain (e.g. power and/or clock domain), its
power state is managed using Runtime PM. Without Runtime PM, the device
may not be powered up or clocked, causing subtle failures, crashes, or
system lock-ups when the device is accessed by the guest.
Fix this by adding Runtime PM support, powering the device when the VFIO
device is opened by the guest.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
match_string() returns the index of an array for a matching string,
which can be used intead of open coded variant.
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There exists a gap at the end of mdev_device_create() where the device
is visible to userspace, but we're not yet ready to handle removal, as
triggered through the 'remove' attribute. We handle this properly in
mdev_device_remove() with an -EAGAIN return, but we can marginally
reduce this gap by adding this attribute as a final step of our sysfs
setup.
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When we create an mdev device, we check for duplicates against the
parent device and return -EEXIST if found, but the mdev device
namespace is global since we'll link all devices from the bus. We do
catch this later in sysfs_do_create_link_sd() to return -EEXIST, but
with it comes a kernel warning and stack trace for trying to create
duplicate sysfs links, which makes it an undesirable response.
Therefore we should really be looking for duplicates across all mdev
parent devices, or as implemented here, against our mdev device list.
Using mdev_list to prevent duplicates means that we can remove
mdev_parent.lock, but in order not to serialize mdev device creation
and removal globally, we add mdev_device.active which allows UUIDs to
be reserved such that we can drop the mdev_list_lock before the mdev
device is fully in place.
Two behavioral notes; first, mdev_parent.lock had the side-effect of
serializing mdev create and remove ops per parent device. This was
an implementation detail, not an intentional guarantee provided to
the mdev vendor drivers. Vendor drivers can trivially provide this
serialization internally if necessary. Second, review comments note
the new -EAGAIN behavior when the device, and in particular the remove
attribute, becomes visible in sysfs. If a remove is triggered prior
to completion of mdev_device_create() the user will see a -EAGAIN
error. While the errno is different, receiving an error during this
period is not, the previous implementation returned -ENODEV for the
same condition. Furthermore, the consistency to the user is improved
in the case where mdev_device_remove_ops() returns error. Previously
concurrent calls to mdev_device_remove() could see the device
disappear with -ENODEV and return in the case of error. Now a user
would see -EAGAIN while the device is in this transitory state.
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Capitalize the first word of error messages,
- Unwrap statements that fit on a single line,
- Use "VFIO" instead of "vfio" as the error message prefix.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If the IOMMU group setup fails, the reset module is not released.
Fixes: b5add544d6 ("vfio, platform: make reset driver a requirement by default")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
MAP_DMA ioctls might be called from various threads within a process,
for example when using QEMU, the vCPU threads are often generating
these calls and we therefore take a reference to that vCPU task.
However, QEMU also supports vCPU hotplug on some machines and the task
that called MAP_DMA may have exited by the time UNMAP_DMA is called,
resulting in the mm_struct pointer being NULL and thus a failure to
match against the existing mapping.
To resolve this, we instead take a reference to the thread
group_leader, which has the same mm_struct and resource limits, but
is less likely exit, at least in the QEMU case. A difficulty here is
guaranteeing that the capabilities of the group_leader match that of
the calling thread, which we resolve by tracking CAP_IPC_LOCK at the
time of calling rather than at an indeterminate time in the future.
Potentially this also results in better efficiency as this is now
recorded once per MAP_DMA ioctl.
Reported-by: Xu Yandong <xuyandong2@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Pull aio updates from Al Viro:
"Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly.
The only thing I'm holding back for a day or so is Adam's aio ioprio -
his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case),
but let it sit in -next for decency sake..."
* 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
aio: sanitize the limit checking in io_submit(2)
aio: fold do_io_submit() into callers
aio: shift copyin of iocb into io_submit_one()
aio_read_events_ring(): make a bit more readable
aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way
aio: take list removal to (some) callers of aio_complete()
aio: add missing break for the IOCB_CMD_FDSYNC case
random: convert to ->poll_mask
timerfd: convert to ->poll_mask
eventfd: switch to ->poll_mask
pipe: convert to ->poll_mask
crypto: af_alg: convert to ->poll_mask
net/rxrpc: convert to ->poll_mask
net/iucv: convert to ->poll_mask
net/phonet: convert to ->poll_mask
net/nfc: convert to ->poll_mask
net/caif: convert to ->poll_mask
net/bluetooth: convert to ->poll_mask
net/sctp: convert to ->poll_mask
net/tipc: convert to ->poll_mask
...
Bisection by Amadeusz Sławiński implicates this commit leading to bad
page state issues after VM shutdown, likely due to unbalanced page
references. The original commit was intended only as a performance
improvement, therefore revert for offline rework.
Link: https://lkml.org/lkml/2018/6/2/97
Fixes: 356e88ebe4 ("vfio/type1: Improve memory pinning process for raw PFN mapping")
Cc: Jason Cai (Xiang Feng) <jason.cai@linux.alibaba.com>
Reported-by: Amadeusz Sławiński <amade@asmblr.net>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
These abstract out calls to the poll method in preparation for changes
in how we poll.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
The ioeventfd here is actually irqfd handling of an ioeventfd such as
supported in KVM. A user is able to pre-program a device write to
occur when the eventfd triggers. This is yet another instance of
eventfd-irqfd triggering between KVM and vfio. The impetus for this
is high frequency writes to pages which are virtualized in QEMU.
Enabling this near-direct write path for selected registers within
the virtualized page can improve performance and reduce overhead.
Specifically this is initially targeted at NVIDIA graphics cards where
the driver issues a write to an MMIO register within a virtualized
region in order to allow the MSI interrupt to re-trigger.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The iowriteXX/ioreadXX functions assume little endian hardware and
convert to little endian on a write and from little endian on a read.
We currently do our own explicit conversion to negate this. Instead,
add some endian dependent defines to avoid all byte swaps. There
should be no functional change other than big endian systems aren't
penalized with wasted swaps.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This creates a common helper that we'll use for ioeventfd setup.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When using vfio to pass through a PCIe device (e.g. a GPU card) that
has a huge BAR (e.g. 16GB), a lot of cycles are wasted on memory
pinning because PFNs of PCI BAR are not backed by struct page, and
the corresponding VMA has flag VM_PFNMAP.
With this change, when pinning a region which is a raw PFN mapping,
it can skip unnecessary user memory pinning process, and thus, can
significantly improve VM's boot up time when passing through devices
via VFIO. In my test on a Xeon E5 2.6GHz, the time mapping a 16GB
BAR was reduced from about 0.4s to 1.5us.
Signed-off-by: Jason Cai (Xiang Feng) <jason.cai@linux.alibaba.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This reverts commit 2170dd0431
The intent of commit 2170dd0431 ("vfio-pci: Mask INTx if a device is
not capabable of enabling it") was to disallow the user from seeing
that the device supports INTx if the platform is incapable of enabling
it. The detection of this case however incorrectly includes devices
which natively do not support INTx, such as SR-IOV VFs, and further
discussions reveal gaps even for the target use case.
Reported-by: Arjun Vynipadath <arjun@chelsio.com>
Fixes: 2170dd0431 ("vfio-pci: Mask INTx if a device is not capabable of enabling it")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
VFIO IOMMU type1 currently upmaps IOVA pages synchronously, which requires
IOTLB flushing for every unmapping. This results in large IOTLB flushing
overhead when handling pass-through devices has a large number of mapped
IOVAs. This can be avoided by using the new IOTLB flushing interface.
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
[aw - use LIST_HEAD]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Filesystem-DAX is incompatible with 'longterm' page pinning. Without
page cache indirection a DAX mapping maps filesystem blocks directly.
This means that the filesystem must not modify a file's block map while
any page in a mapping is pinned. In order to prevent the situation of
userspace holding of filesystem operations indefinitely, disallow
'longterm' Filesystem-DAX mappings.
RDMA has the same conflict and the plan there is to add a 'with lease'
mechanism to allow the kernel to notify userspace that the mapping is
being torn down for block-map maintenance. Perhaps something similar can
be put in place for vfio.
Note that xfs and ext4 still report:
"DAX enabled. Warning: EXPERIMENTAL, use at your own risk"
...at mount time, and resolving the dax-dma-vs-truncate problem is one
of the last hurdles to remove that designation.
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org>
Reported-by: Haozhong Zhang <haozhong.zhang@intel.com>
Tested-by: Haozhong Zhang <haozhong.zhang@intel.com>
Fixes: d475c6346a ("dax,ext2: replace XIP read and write with DAX I/O")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Mask INTx from user if pdev->irq is zero (Alexey Kardashevskiy)
- Capability helper cleanup (Alex Williamson)
- Allow mmaps overlapping MSI-X vector table with region capability
exposing this feature (Alexey Kardashevskiy)
- mdev static cleanups (Xiongwei Song)
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Merge tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Mask INTx from user if pdev->irq is zero (Alexey Kardashevskiy)
- Capability helper cleanup (Alex Williamson)
- Allow mmaps overlapping MSI-X vector table with region capability
exposing this feature (Alexey Kardashevskiy)
- mdev static cleanups (Xiongwei Song)
* tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfio:
vfio: mdev: make a couple of functions and structure vfio_mdev_driver static
vfio-pci: Allow mapping MSIX BAR
vfio: Simplify capability helper
vfio-pci: Mask INTx if a device is not capabable of enabling it
The functions vfio_mdev_probe, vfio_mdev_remove and the structure
vfio_mdev_driver are only used in this file, so make them static.
Clean up sparse warnings:
drivers/vfio/mdev/vfio_mdev.c:114:5: warning: no previous prototype
for 'vfio_mdev_probe' [-Wmissing-prototypes]
drivers/vfio/mdev/vfio_mdev.c:121:6: warning: no previous prototype
for 'vfio_mdev_remove' [-Wmissing-prototypes]
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Reviewed-by: Quan Xu <quan.xu0@gmail.com>
Reviewed-by: Liu, Yi L <yi.l.liu@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
By default VFIO disables mapping of MSIX BAR to the userspace as
the userspace may program it in a way allowing spurious interrupts;
instead the userspace uses the VFIO_DEVICE_SET_IRQS ioctl.
In order to eliminate guessing from the userspace about what is
mmapable, VFIO also advertises a sparse list of regions allowed to mmap.
This works fine as long as the system page size equals to the MSIX
alignment requirement which is 4KB. However with a bigger page size
the existing code prohibits mapping non-MSIX parts of a page with MSIX
structures so these parts have to be emulated via slow reads/writes on
a VFIO device fd. If these emulated bits are accessed often, this has
serious impact on performance.
This allows mmap of the entire BAR containing MSIX vector table.
This removes the sparse capability for PCI devices as it becomes useless.
As the userspace needs to know for sure whether mmapping of the MSIX
vector containing data can succeed, this adds a new capability -
VFIO_REGION_INFO_CAP_MSIX_MAPPABLE - which explicitly tells the userspace
that the entire BAR can be mmapped.
This does not touch the MSIX mangling in the BAR read/write handlers as
we are doing this just to enable direct access to non MSIX registers.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw - fixup whitespace, trim function name]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The vfio_info_add_capability() helper requires the caller to pass a
capability ID, which it then uses to fill in header fields, assuming
hard coded versions. This makes for an awkward and rigid interface.
The only thing we want this helper to do is allocate sufficient
space in the caps buffer and chain this capability into the list.
Reduce it to that simple task.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
At the moment VFIO rightfully assumes that INTx is supported if
the interrupt pin is not set to zero in the device config space.
However if that is not the case (the pin is not zero but pdev->irq is),
vfio_intx_enable() fails.
In order to prevent the userspace from trying to enable INTx when we know
that it cannot work, let's mask the PCI_INTERRUPT_PIN register.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
__poll_t is also used as wait key in some waitqueues.
Verify that wait_..._poll() gets __poll_t as key and
provide a helper for wakeup functions to get back to
that __poll_t value.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.
However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:
----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()
// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds Broadcom FlexRM low-level reset for
VFIO platform.
It will do the following:
1. Disable/Deactivate each FlexRM ring
2. Flush each FlexRM ring
The cleanup sequence for FlexRM rings is adapted from
Broadcom FlexRM mailbox driver.
Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Oza Oza <oza.oza@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
I get a static checker warning about the potential integer overflow if
we add "unmap->iova + unmap->size". The integer overflow isn't really
harmful, but we may as well fix it. Also unmap->size gets truncated to
size_t when we pass it to vfio_find_dma() so we could check for too high
values of that as well.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Clearing very big IOMMU tables can trigger soft lockups. This adds
cond_resched() to allow the scheduler to do context switching when
it decides to.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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 <alex.williamson@redhat.com>
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 <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
amba_id are not supposed to change at runtime. All functions
working with const amba_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When the user unbinds the last device of a group from a vfio bus
driver, the devices within that group should be available for other
purposes. We currently have a race that makes this generally, but
not always true. The device can be unbound from the vfio bus driver,
but remaining IOMMU context of the group attached to the container
can result in errors as the next driver configures DMA for the device.
Wait for the group to be detached from the IOMMU backend before
allowing the bus driver remove callback to complete.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In vfio_iommu_group_get() we want to increase the reference
count of the iommu group.
In noiommu case, the group does not exist and is allocated.
iommu_group_add_device() increases the group ref count. However we
then call iommu_group_put() which decrements it.
This leads to a "refcount_t: underflow WARN_ON".
Only decrement the ref count in case of iommu_group_add_device
failure.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If the IOMMU driver advertises 'real' reserved regions for MSIs, but
still includes the software-managed region as well, we are currently
blind to the former and will configure the IOMMU domain to map MSIs into
the latter, which is unlikely to work as expected.
Since it would take a ridiculous hardware topology for both regions to
be valid (which would be rather difficult to support in general), we
should be safe to assume that the presence of any hardware regions makes
the software region irrelevant. However, the IOMMU driver might still
advertise the software region by default, particularly if the hardware
regions are filled in elsewhere by generic code, so it might not be fair
for VFIO to be super-strict about not mixing them. To that end, make
vfio_iommu_has_sw_msi() robust against the presence of both region types
at once, so that we end up doing what is almost certainly right, rather
than what is almost certainly wrong.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
For ARM-based systems with a GICv3 ITS to provide interrupt isolation,
but hardware limitations which are worked around by having MSIs bypass
SMMU translation (e.g. HiSilicon Hip06/Hip07), VFIO neglects to check
for the IRQ_DOMAIN_FLAG_MSI_REMAP capability, (and thus erroneously
demands unsafe_interrupts) if a software-managed MSI region is absent.
Fix this by always checking for isolation capability at both the IRQ
domain and IOMMU domain levels, rather than predicating that on whether
MSIs require an IOMMU mapping (which was always slightly tenuous logic).
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Root complex integrated endpoints do not have a link and therefore may
use a smaller PCIe capability in config space than we expect when
building our config map. Add a case for these to avoid reporting an
erroneous overlap.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Device lock bites again; if a device .remove() callback races a user
calling ioctl(VFIO_GROUP_GET_DEVICE_FD), the unbind request will hold
the device lock, but the user ioctl may have already taken a vfio_device
reference. In the case of a PCI device, the initial open will attempt
to reset the device, which again attempts to get the device lock,
resulting in deadlock. Use the trylock PCI reset interface and return
error on the open path if reset fails due to lock contention.
Link: https://lkml.org/lkml/2017/7/25/381
Reported-by: Wen Congyang <wencongyang2@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Include Intel XXV710 in INTx workaround (Alex Williamson)
- Make use of ERR_CAST() for error return (Dan Carpenter)
- Fix vfio_group release deadlock from iommu notifier (Alex Williamson)
- Unset KVM-VFIO attributes only on group match (Alex Williamson)
- Fix release path group/file matching with KVM-VFIO (Alex Williamson)
- Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)
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Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Include Intel XXV710 in INTx workaround (Alex Williamson)
- Make use of ERR_CAST() for error return (Dan Carpenter)
- Fix vfio_group release deadlock from iommu notifier (Alex Williamson)
- Unset KVM-VFIO attributes only on group match (Alex Williamson)
- Fix release path group/file matching with KVM-VFIO (Alex Williamson)
- Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)
* tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio:
vfio: Remove unnecessary uses of vfio_container.group_lock
vfio: New external user group/file match
kvm-vfio: Decouple only when we match a group
vfio: Fix group release deadlock
vfio: Use ERR_CAST() instead of open coding it
vfio/pci: Add Intel XXV710 to hidden INTx devices
The original intent of vfio_container.group_lock is to protect
vfio_container.group_list, however over time it's become a crutch to
prevent changes in container composition any time we call into the
iommu driver backend. This introduces problems when we start to have
more complex interactions, for example when a user's DMA unmap request
triggers a notification to an mdev vendor driver, who responds by
attempting to unpin mappings within that request, re-entering the
iommu backend. We incorrectly assume that the use of read-locks here
allow for this nested locking behavior, but a poorly timed write-lock
could in fact trigger a deadlock.
The current use of group_lock seems to fall into the trap of locking
code, not data. Correct that by removing uses of group_lock that are
not directly related to group_list. Note that the vfio type1 iommu
backend has its own mutex, vfio_iommu.lock, which it uses to protect
itself for each of these interfaces anyway. The group_lock appears to
be a redundancy for these interfaces and type1 even goes so far as to
release its mutex to allow for exactly the re-entrant code path above.
Reported-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: stable@vger.kernel.org # v4.10+
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 <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Cc: stable@vger.kernel.org
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 <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Cc: stable@vger.kernel.org
