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2018-04-06Merge tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds4-41/+348
Pull VFIO updates from Alex Williamson: - Adopt iommu_unmap_fast() interface to type1 backend (Suravee Suthikulpanit) - mdev sample driver fixup (Shunyong Yang) - More efficient PFN mapping handling in type1 backend (Jason Cai) - VFIO device ioeventfd interface (Alex Williamson) - Tag new vfio-platform sub-maintainer (Alex Williamson) * tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfio: MAINTAINERS: vfio/platform: Update sub-maintainer vfio/pci: Add ioeventfd support vfio/pci: Use endian neutral helpers vfio/pci: Pull BAR mapping setup from read-write path vfio/type1: Improve memory pinning process for raw PFN mapping vfio-mdev/samples: change RDI interrupt condition vfio/type1: Adopt fast IOTLB flush interface when unmap IOVAs
2018-03-26vfio/pci: Add ioeventfd supportAlex Williamson3-0/+165
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>
2018-03-26vfio/pci: Use endian neutral helpersAlex Williamson1-8/+26
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>
2018-03-26vfio/pci: Pull BAR mapping setup from read-write pathAlex Williamson1-12/+27
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>
2018-03-22vfio/type1: Improve memory pinning process for raw PFN mappingJason Cai (Xiang Feng)1-10/+15
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>
2018-03-21Revert: "vfio-pci: Mask INTx if a device is not capabable of enabling it"Alex Williamson1-3/+0
This reverts commit 2170dd04316e0754cbbfa4892a25aead39d225f7 The intent of commit 2170dd04316e ("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: 2170dd04316e ("vfio-pci: Mask INTx if a device is not capabable of enabling it") Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-03-21vfio/type1: Adopt fast IOTLB flush interface when unmap IOVAsSuravee Suthikulpanit1-11/+115
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>
2018-03-02vfio: disable filesystem-dax page pinningDan Williams1-3/+15
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: d475c6346a38 ("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>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-4/+4
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>
2018-02-01Merge tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds3-110/+23
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
2018-01-09vfio: mdev: make a couple of functions and structure vfio_mdev_driver staticXiongwei Song1-3/+3
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>
2017-12-20vfio-pci: Allow mapping MSIX BARAlexey Kardashevskiy1-56/+8
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>
2017-12-20vfio: Simplify capability helperAlex Williamson2-54/+12
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>
2017-12-20vfio-pci: Mask INTx if a device is not capabable of enabling itAlexey Kardashevskiy1-0/+3
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>
2017-11-27annotate poll-related wait keysAl Viro1-1/+1
__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>
2017-11-27anntotate the places where ->poll() return values goAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-14Merge tag 'vfio-v4.15-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds6-3/+156
Pull VFIO updates from Alex Williamson: - Virtualize PCI MPS and MRRS registers - Avoid soft lockups on SPAPR when clearing TCE - Broadcom FlexRM platform device support - Samples driver cleanup & type1 integer overflow fix * tag 'vfio-v4.15-rc1' of git://github.com/awilliam/linux-vfio: vfio: platform: reset: Add Broadcom FlexRM reset module vfio/type1: silence integer overflow warning vfio-mdev/samples: make mdev_fops const and static vfio/spapr: Add cond_resched() for huge updates vfio/pci: Virtualize Maximum Read Request Size vfio/pci: Virtualize Maximum Payload Size
2017-11-13Merge branches 'vfio/fixes' and 'vfio/platform' into vfio-next-20171113.0Alex Williamson3-0/+123
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar3-0/+3
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman3-0/+3
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>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland1-1/+1
to READ_ONCE()/WRITE_ONCE() 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>
2017-10-20vfio: platform: reset: Add Broadcom FlexRM reset moduleAnup Patel3-0/+123
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>
2017-10-20vfio/type1: silence integer overflow warningDan Carpenter1-0/+3
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>
2017-10-02vfio/spapr: Add cond_resched() for huge updatesAlexey Kardashevskiy1-0/+2
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>
2017-10-02vfio/pci: Virtualize Maximum Read Request SizeAlex Williamson1-3/+26
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>
2017-10-02vfio/pci: Virtualize Maximum Payload SizeAlex Williamson1-2/+4
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>
2017-08-30vfio: platform: constify amba_idArvind Yadav1-1/+1
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>
2017-08-30vfio: Stall vfio_del_group_dev() for container group detachAlex Williamson1-0/+20
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>
2017-08-30vfio: fix noiommu vfio_iommu_group_get reference countEric Auger1-2/+3
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>
2017-08-10vfio/type1: Give hardware MSI regions precedenceRobin Murphy1-2/+10
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>
2017-08-10vfio/type1: Cope with hardware MSI reserved regionsRobin Murphy1-2/+2
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>
2017-07-27vfio/pci: Fix handling of RC integrated endpoint PCIe capability sizeAlex Williamson1-4/+9
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>
2017-07-26vfio/pci: Use pci_try_reset_function() on initial openAlex Williamson1-1/+8
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>
2017-07-13Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds2-42/+48
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
2017-07-07vfio: Remove unnecessary uses of vfio_container.group_lockAlex Williamson1-38/+0
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+
2017-06-28vfio: New external user group/file matchAlex Williamson1-0/+9
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
2017-06-28vfio: Fix group release deadlockAlex Williamson1-1/+36
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
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar1-1/+1
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13vfio: Use ERR_CAST() instead of open coding itDan Carpenter1-1/+1
It's a small cleanup to use ERR_CAST() here. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-06-13vfio/pci: Add Intel XXV710 to hidden INTx devicesAlex Williamson1-2/+2
XXV710 has the same broken INTx behavior as the rest of the X/XL710 series, the interrupt status register is not wired to report pending INTx interrupts, thus we never associate the interrupt to the device. Extend the device IDs to include these so that we hide that the device supports INTx at all to the user. Reported-by: Stefan Assmann <sassmann@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
2017-05-05Merge tag 'powerpc-4.12-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights include: - Larger virtual address space on 64-bit server CPUs. By default we use a 128TB virtual address space, but a process can request access to the full 512TB by passing a hint to mmap(). - Support for the new Power9 "XIVE" interrupt controller. - TLB flushing optimisations for the radix MMU on Power9. - Support for CAPI cards on Power9, using the "Coherent Accelerator Interface Architecture 2.0". - The ability to configure the mmap randomisation limits at build and runtime. - Several small fixes and cleanups to the kprobes code, as well as support for KPROBES_ON_FTRACE. - Major improvements to handling of system reset interrupts, correctly treating them as NMIs, giving them a dedicated stack and using a new hypervisor call to trigger them, all of which should aid debugging and robustness. - Many fixes and other minor enhancements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Ben Hutchings, Benjamin Herrenschmidt, Bhupesh Sharma, Chris Packham, Christian Zigotzky, Christophe Leroy, Christophe Lombard, Daniel Axtens, David Gibson, Gautham R. Shenoy, Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli, Hamish Martin, Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mahesh J Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell Currey, Sukadev Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C. Harding, Tyrel Datwyler, Uma Krishnan, Vaibhav Jain, Vipin K Parashar, Yang Shi" * tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits) powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it powerpc/powernv: Fix TCE kill on NVLink2 powerpc/mm/radix: Drop support for CPUs without lockless tlbie powerpc/book3s/mce: Move add_taint() later in virtual mode powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body powerpc/smp: Document irq enable/disable after migrating IRQs powerpc/mpc52xx: Don't select user-visible RTAS_PROC powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset() powerpc/eeh: Clean up and document event handling functions powerpc/eeh: Avoid use after free in eeh_handle_special_event() cxl: Mask slice error interrupts after first occurrence cxl: Route eeh events to all drivers in cxl_pci_error_detected() cxl: Force context lock during EEH flow powerpc/64: Allow CONFIG_RELOCATABLE if COMPILE_TEST powerpc/xmon: Teach xmon oops about radix vectors powerpc/mm/hash: Fix off-by-one in comment about kernel contexts ids powerpc/pseries: Enable VFIO powerpc/powernv: Fix iommu table size calculation hook for small tables powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc powerpc: Add arch/powerpc/tools directory ...
2017-04-18vfio/type1: Reduce repetitive calls in vfio_pin_pages_remote()Alex Williamson1-6/+11
vfio_pin_pages_remote() is typically called to iterate over a range of memory. Testing CAP_IPC_LOCK is relatively expensive, so it makes sense to push it up to the caller, which can then repeatedly call vfio_pin_pages_remote() using that value. This can show nearly a 20% improvement on the worst case path through VFIO_IOMMU_MAP_DMA with contiguous page mapping disabled. Testing RLIMIT_MEMLOCK is much more lightweight, but we bring it along on the same principle and it does seem to show a marginal improvement. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-04-18vfio/type1: Prune vfio_pin_page_external()Alex Williamson1-27/+8
With vfio_lock_acct() testing the locked memory limit under mmap_sem, it's redundant to do it here for a single page. We can also reorder our tests such that we can avoid testing for reserved pages if we're not doing accounting and let vfio_lock_acct() test the process CAP_IPC_LOCK. Finally, this function oddly returns 1 on success. Update to return zero on success, -errno on error. Since the function only pins a single page, there's no need to return the number of pages pinned. N.B. vfio_pin_pages_remote() can pin a large contiguous range of pages before calling vfio_lock_acct(). If we were to similarly remove the extra test there, a user could temporarily pin far more pages than they're allowed. Suggested-by: Kirti Wankhede <kwankhede@nvidia.com> Suggested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-04-13vfio/type1: Remove locked page accounting workqueueAlex Williamson1-59/+51
If the mmap_sem is contented then the vfio type1 IOMMU backend will defer locked page accounting updates to a workqueue task. This has a few problems and depending on which side the user tries to play, they might be over-penalized for unmaps that haven't yet been accounted or race the workqueue to enter more mappings than they're allowed. The original intent of this workqueue mechanism seems to be focused on reducing latency through the ioctl, but we cannot do so at the cost of correctness. Remove this workqueue mechanism and update the callers to allow for failure. We can also now recheck the limit under write lock to make sure we don't exceed it. vfio_pin_pages_remote() also now necessarily includes an unwind path which we can jump to directly if the consecutive page pinning finds that we're exceeding the user's memory limits. This avoids the current lazy approach which does accounting and mapping up to the fault, only to return an error on the next iteration to unwind the entire vfio_dma. Cc: stable@vger.kernel.org Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-04-11vfio/spapr_tce: Check kzalloc() return when preregistering memoryAlexey Kardashevskiy1-0/+5
This adds missing checking for kzalloc() return value. Fixes: 4b6fad7097f8 ("powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown") 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>
2017-04-11vfio/powerpc/spapr_tce: Enforce IOMMU type compatibility checkAlexey Kardashevskiy1-0/+8
The existing SPAPR TCE driver advertises both VFIO_SPAPR_TCE_IOMMU and VFIO_SPAPR_TCE_v2_IOMMU types to the userspace and the userspace usually picks the v2. Normally the userspace would create a container, attach an IOMMU group to it and only then set the IOMMU type (which would normally be v2). However a specific IOMMU group may not support v2, in other words it may not implement set_window/unset_window/take_ownership/ release_ownership and such a group should not be attached to a v2 container. This adds extra checks that a new group can do what the selected IOMMU type suggests. The userspace can then test the return value from ioctl(VFIO_SET_IOMMU, VFIO_SPAPR_TCE_v2_IOMMU) and try VFIO_SPAPR_TCE_IOMMU. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-03-30powerpc/vfio_spapr_tce: Add reference counting to iommu_tableAlexey Kardashevskiy1-1/+1
So far iommu_table obejcts were only used in virtual mode and had a single owner. We are going to change this by implementing in-kernel acceleration of DMA mapping requests. The proposed acceleration will handle requests in real mode and KVM will keep references to tables. This adds a kref to iommu_table and defines new helpers to update it. This replaces iommu_free_table() with iommu_tce_table_put() and makes iommu_free_table() static. iommu_tce_table_get() is not used in this patch but it will be in the following patch. Since this touches prototypes, this also removes @node_name parameter as it has never been really useful on powernv and carrying it for the pseries platform code to iommu_free_table() seems to be quite useless as well. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-30powerpc/iommu/vfio_spapr_tce: Cleanup iommu_table disposalAlexey Kardashevskiy1-1/+1
At the moment iommu_table can be disposed by either calling iommu_table_free() directly or it_ops::free(); the only implementation of free() is in IODA2 - pnv_ioda2_table_free() - and it calls iommu_table_free() anyway. As we are going to have reference counting on tables, we need an unified way of disposing tables. This moves it_ops::free() call into iommu_free_table() and makes use of the latter. The free() callback now handles only platform-specific data. As from now on the iommu_free_table() calls it_ops->free(), we need to have it_ops initialized before calling iommu_free_table() so this moves this initialization in pnv_pci_ioda2_create_table(). This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-24Merge tag 'vfio-v4.11-rc4' of git://github.com/awilliam/linux-vfioLinus Torvalds1-3/+5
Pull VFIO fix from Alex Williamson: "Rework sanity check for mdev driver group notifier de-registration (Alex Williamson)" * tag 'vfio-v4.11-rc4' of git://github.com/awilliam/linux-vfio: vfio: Rework group release notifier warning
2017-03-22iommu: Disambiguate MSI region typesRobin Murphy1-4/+3
The introduction of reserved regions has left a couple of rough edges which we could do with sorting out sooner rather than later. Since we are not yet addressing the potential dynamic aspect of software-managed reservations and presenting them at arbitrary fixed addresses, it is incongruous that we end up displaying hardware vs. software-managed MSI regions to userspace differently, especially since ARM-based systems may actually require one or the other, or even potentially both at once, (which iommu-dma currently has no hope of dealing with at all). Let's resolve the former user-visible inconsistency ASAP before the ABI has been baked into a kernel release, in a way that also lays the groundwork for the latter shortcoming to be addressed by follow-up patches. For clarity, rename the software-managed type to IOMMU_RESV_SW_MSI, use IOMMU_RESV_MSI to describe the hardware type, and document everything a little bit. Since the x86 MSI remapping hardware falls squarely under this meaning of IOMMU_RESV_MSI, apply that type to their regions as well, so that we tell the same story to userspace across all platforms. Secondly, as the various region types require quite different handling, and it really makes little sense to ever try combining them, convert the bitfield-esque #defines to a plain enum in the process before anyone gets the wrong impression. Fixes: d30ddcaa7b02 ("iommu: Add a new type field in iommu_resv_region") Reviewed-by: Eric Auger <eric.auger@redhat.com> CC: Alex Williamson <alex.williamson@redhat.com> CC: David Woodhouse <dwmw2@infradead.org> CC: kvm@vger.kernel.org Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>