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2019-09-25vfio/type1: untag user pointers in vaddr_get_pfnAndrey Konovalov1-0/+2
This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. vaddr_get_pfn() uses provided user pointers for vma lookups, which can only by done with untagged pointers. Untag user pointers in this function. Link: http://lkml.kernel.org/r/87422b4d72116a975896f2b19b00f38acbd28f33.1563904656.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jens Wiklander <jens.wiklander@linaro.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-20Merge tag 'vfio-v5.4-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-12/+506
Pull VFIO updates from Alex Williamson: - Fix spapr iommu error case case (Alexey Kardashevskiy) - Consolidate region type definitions (Cornelia Huck) - Restore saved original PCI state on release (hexin) - Simplify mtty sample driver interrupt path (Parav Pandit) - Support for reporting valid IOVA regions to user (Shameer Kolothum) * tag 'vfio-v5.4-rc1' of git://github.com/awilliam/linux-vfio: vfio_pci: Restore original state on release vfio/type1: remove duplicate retrieval of reserved regions vfio/type1: Add IOVA range capability support vfio/type1: check dma map request is within a valid iova range vfio/spapr_tce: Fix incorrect tce_iommu_group memory free vfio-mdev/mtty: Simplify interrupt generation vfio: re-arrange vfio region definitions vfio/type1: Update iova list on detach vfio/type1: Check reserved region conflict and update iova list vfio/type1: Introduce iova list and add iommu aperture validity check
2019-08-19vfio/type1: remove duplicate retrieval of reserved regionsShameer Kolothum1-9/+6
As we now already have the reserved regions list, just pass that into vfio_iommu_has_sw_msi() fn. Signed-off-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>
2019-08-19vfio/type1: Add IOVA range capability supportShameer Kolothum1-0/+101
This allows the user-space to retrieve the supported IOVA range(s), excluding any non-relaxable reserved regions. The implementation is based on capability chains, added to VFIO_IOMMU_GET_INFO ioctl. Signed-off-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>
2019-08-19vfio/type1: check dma map request is within a valid iova rangeShameer Kolothum1-0/+26
This checks and rejects any dma map request outside valid iova range. Signed-off-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>
2019-08-19vfio/type1: Update iova list on detachShameer Kolothum1-0/+94
Get a copy of iova list on _group_detach and try to update the list. On success replace the current one with the copy. Leave the list as it is if update fails. Signed-off-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>
2019-08-19vfio/type1: Check reserved region conflict and update iova listShameer Kolothum1-0/+98
This retrieves the reserved regions associated with dev group and checks for conflicts with any existing dma mappings. Also update the iova list excluding the reserved regions. Reserved regions with type IOMMU_RESV_DIRECT_RELAXABLE are excluded from above checks as they are considered as directly mapped regions which are known to be relaxable. Signed-off-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>
2019-08-19vfio/type1: Introduce iova list and add iommu aperture validity checkShameer Kolothum1-3/+181
This introduces an iova list that is valid for dma mappings. Make sure the new iommu aperture window doesn't conflict with the current one or with any existing dma mappings during attach. Signed-off-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>
2019-07-24iommu: Introduce struct iommu_iotlb_gather for batching TLB flushesWill Deacon1-9/+17
To permit batching of TLB flushes across multiple calls to the IOMMU driver's ->unmap() implementation, introduce a new structure for tracking the address range to be flushed and the granularity at which the flushing is required. This is hooked into the IOMMU API and its caller are updated to make use of the new structure. Subsequent patches will plumb this into the IOMMU drivers as well, but for now the gathering information is ignored. Signed-off-by: Will Deacon <will@kernel.org>
2019-07-24iommu: Remove empty iommu_tlb_range_add() callback from iommu_opsWill Deacon1-1/+0
Commit add02cfdc9bc ("iommu: Introduce Interface for IOMMU TLB Flushing") added three new TLB flushing operations to the IOMMU API so that the underlying driver operations can be batched when unmapping large regions of IO virtual address space. However, the ->iotlb_range_add() callback has not been implemented by any IOMMU drivers (amd_iommu.c implements it as an empty function, which incurs the overhead of an indirect branch). Instead, drivers either flush the entire IOTLB in the ->iotlb_sync() callback or perform the necessary invalidation during ->unmap(). Attempting to implement ->iotlb_range_add() for arm-smmu-v3.c revealed two major issues: 1. The page size used to map the region in the page-table is not known, and so it is not generally possible to issue TLB flushes in the most efficient manner. 2. The only mutable state passed to the callback is a pointer to the iommu_domain, which can be accessed concurrently and therefore requires expensive synchronisation to keep track of the outstanding flushes. Remove the callback entirely in preparation for extending ->unmap() and ->iotlb_sync() to update a token on the caller's stack. Signed-off-by: Will Deacon <will@kernel.org>
2019-07-16mm: add account_locked_vm utility functionDaniel Jordan1-15/+2
locked_vm accounting is done roughly the same way in five places, so unify them in a helper. Include the helper's caller in the debug print to distinguish between callsites. Error codes stay the same, so user-visible behavior does too. The one exception is that the -EPERM case in tce_account_locked_vm is removed because Alexey has never seen it triggered. [daniel.m.jordan@oracle.com: v3] Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@oracle.com [sfr@canb.auug.org.au: fix mm/util.c] Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@oracle.com Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Cc: Alan Tull <atull@kernel.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Lameter <cl@linux.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Moritz Fischer <mdf@kernel.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Steve Sistare <steven.sistare@oracle.com> Cc: Wu Hao <hao.wu@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERMIra Weiny1-1/+2
Pach series "Add FOLL_LONGTERM to GUP fast and use it". HFI1, qib, and mthca, use get_user_pages_fast() due to its performance advantages. These pages can be held for a significant time. But get_user_pages_fast() does not protect against mapping FS DAX pages. Introduce FOLL_LONGTERM and use this flag in get_user_pages_fast() which retains the performance while also adding the FS DAX checks. XDP has also shown interest in using this functionality.[1] In addition we change get_user_pages() to use the new FOLL_LONGTERM flag and remove the specialized get_user_pages_longterm call. [1] https://lkml.org/lkml/2019/3/19/939 "longterm" is a relative thing and at this point is probably a misnomer. This is really flagging a pin which is going to be given to hardware and can't move. I've thought of a couple of alternative names but I think we have to settle on if we are going to use FL_LAYOUT or something else to solve the "longterm" problem. Then I think we can change the flag to a better name. Secondly, it depends on how often you are registering memory. I have spoken with some RDMA users who consider MR in the performance path... For the overall application performance. I don't have the numbers as the tests for HFI1 were done a long time ago. But there was a significant advantage. Some of which is probably due to the fact that you don't have to hold mmap_sem. Finally, architecturally I think it would be good for everyone to use *_fast. There are patches submitted to the RDMA list which would allow the use of *_fast (they reworking the use of mmap_sem) and as soon as they are accepted I'll submit a patch to convert the RDMA core as well. Also to this point others are looking to use *_fast. As an aside, Jasons pointed out in my previous submission that *_fast and *_unlocked look very much the same. I agree and I think further cleanup will be coming. But I'm focused on getting the final solution for DAX at the moment. This patch (of 7): This patch starts a series which aims to support FOLL_LONGTERM in get_user_pages_fast(). Some callers who would like to do a longterm (user controlled pin) of pages with the fast variant of GUP for performance purposes. Rather than have a separate get_user_pages_longterm() call, introduce FOLL_LONGTERM and change the longterm callers to use it. This patch does not change any functionality. In the short term "longterm" or user controlled pins are unsafe for Filesystems and FS DAX in particular has been blocked. However, callers of get_user_pages_fast() were not "protected". FOLL_LONGTERM can _only_ be supported with get_user_pages[_fast]() as it requires vmas to determine if DAX is in use. NOTE: In merging with the CMA changes we opt to change the get_user_pages() call in check_and_migrate_cma_pages() to a call of __get_user_pages_locked() on the newly migrated pages. This makes the code read better in that we are calling __get_user_pages_locked() on the pages before and after a potential migration. As a side affect some of the interfaces are cleaned up but this is not the primary purpose of the series. In review[1] it was asked: <quote> > This I don't get - if you do lock down long term mappings performance > of the actual get_user_pages call shouldn't matter to start with. > > What do I miss? A couple of points. First "longterm" is a relative thing and at this point is probably a misnomer. This is really flagging a pin which is going to be given to hardware and can't move. I've thought of a couple of alternative names but I think we have to settle on if we are going to use FL_LAYOUT or something else to solve the "longterm" problem. Then I think we can change the flag to a better name. Second, It depends on how often you are registering memory. I have spoken with some RDMA users who consider MR in the performance path... For the overall application performance. I don't have the numbers as the tests for HFI1 were done a long time ago. But there was a significant advantage. Some of which is probably due to the fact that you don't have to hold mmap_sem. Finally, architecturally I think it would be good for everyone to use *_fast. There are patches submitted to the RDMA list which would allow the use of *_fast (they reworking the use of mmap_sem) and as soon as they are accepted I'll submit a patch to convert the RDMA core as well. Also to this point others are looking to use *_fast. As an asside, Jasons pointed out in my previous submission that *_fast and *_unlocked look very much the same. I agree and I think further cleanup will be coming. But I'm focused on getting the final solution for DAX at the moment. </quote> [1] https://lore.kernel.org/lkml/20190220180255.GA12020@iweiny-DESK2.sc.intel.com/T/#md6abad2569f3bf6c1f03686c8097ab6563e94965 [ira.weiny@intel.com: v3] Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-2-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Marshall <hubcap@omnibond.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-12vfio/type1: Handle different mdev isolation typeLu Baolu1-13/+42
This adds the support to determine the isolation type of a mediated device group by checking whether it has an iommu device. If an iommu device exists, an iommu domain will be allocated and then attached to the iommu device. Otherwise, keep the same behavior as it is. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com> Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-04-12vfio/type1: Add domain at(de)taching group helpersLu Baolu1-7/+77
This adds helpers to attach or detach a domain to a group. This will replace iommu_attach_group() which only works for non-mdev devices. If a domain is attaching to a group which includes the mediated devices, it should attach to the iommu device (a pci device which represents the mdev in iommu scope) instead. The added helper supports attaching domain to groups for both pci and mdev devices. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com> Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-04-03vfio/type1: Limit DMA mappings per containerAlex Williamson1-0/+14
Memory backed DMA mappings are accounted against a user's locked memory limit, including multiple mappings of the same memory. This accounting bounds the number of such mappings that a user can create. However, DMA mappings that are not backed by memory, such as DMA mappings of device MMIO via mmaps, do not make use of page pinning and therefore do not count against the user's locked memory limit. These mappings still consume memory, but the memory is not well associated to the process for the purpose of oom killing a task. To add bounding on this use case, we introduce a limit to the total number of concurrent DMA mappings that a user is allowed to create. This limit is exposed as a tunable module option where the default value of 64K is expected to be well in excess of any reasonable use case (a large virtual machine configuration would typically only make use of tens of concurrent mappings). This fixes CVE-2019-3882. Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-08vfio/type1: Fix unmap overflow off-by-oneAlex Williamson1-1/+1
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 <pezhang@redhat.com> Debugged-by: Peter Xu <peterx@redhat.com> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Peter Xu <peterx@redhat.com> Tested-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-11-15vfio/type1: Remove map_try_harder() code pathJoerg Roedel1-31/+2
The AMD IOMMU driver can now map a huge-page where smaller mappings existed before, so this code-path is no longer triggered. Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-08-06vfio: Mark expected switch fall-throughsGustavo A. R. Silva1-0/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-30vfio: Use get_user_pages_longterm correctlyJason Gunthorpe1-9/+7
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: 94db151dc892 ("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>
2018-06-08vfio/type1: Fix task tracking for QEMU vCPU hotplugAlex Williamson1-26/+47
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>
2018-06-02Revert "vfio/type1: Improve memory pinning process for raw PFN mapping"Alex Williamson1-15/+10
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: 356e88ebe447 ("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>
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>
2018-03-21vfio/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>
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>
2017-08-10vfio/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>
2017-04-18vfio/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>
2017-03-22iommu: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>Ingo Molnar1-1/+1
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>Ingo Molnar1-0/+1
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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>
2017-02-10vfio/type1: Fix error return code in vfio_iommu_type1_attach_group()Wei Yongjun1-2/+5
Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: 5d704992189f ("vfio/type1: Allow transparent MSI IOVA allocation") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-01-30Merge branch 'iommu/guest-msi' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into arm/coreJoerg Roedel1-2/+35
2017-01-23vfio/type1: Check MSI remapping at irq domain levelEric Auger1-3/+6
In case the IOMMU translates MSI transactions (typical case on ARM), we check MSI remapping capability at IRQ domain level. Otherwise it is checked at IOMMU level. At this stage the arm-smmu-(v3) still advertise the IOMMU_CAP_INTR_REMAP capability at IOMMU level. This will be removed in subsequent patches. Signed-off-by: Eric Auger <eric.auger@redhat.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-23vfio/type1: Allow transparent MSI IOVA allocationEric Auger1-0/+30
When attaching a group to the container, check the group's reserved regions and test whether the IOMMU translates MSI transactions. If yes, we initialize an IOVA allocator through the iommu_get_msi_cookie API. This will allow the MSI IOVAs to be transparently allocated on MSI controller's compose(). Signed-off-by: Eric Auger <eric.auger@redhat.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-13vfio/type1: Remove pid_namespace.h includeAlex Williamson1-1/+0
Using has_capability() rather than ns_capable(), we're no longer using this header. Cc: Jike Song <jike.song@intel.com> Cc: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-01-12vfio iommu type1: fix the testing of capability for remote taskJike Song1-2/+1
Before the mdev enhancement type1 iommu used capable() to test the capability of current task; in the course of mdev development a new requirement, testing for another task other than current, was raised. ns_capable() was used for this purpose, however it still tests current, the only difference is, in a specified namespace. Fix it by using has_capability() instead, which tests the cap for specified task in init_user_ns, the same namespace as capable(). Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Jike Song <jike.song@intel.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-30vfio/type1: Restore mapping performance with mdev supportAlex Williamson1-47/+51
As part of the mdev support, type1 now gets a task reference per vfio_dma and uses that to get an mm reference for the task while working on accounting. That's correct, but it's not fast. For some paths, like vfio_pin_pages_remote(), we know we're only called from user context, so we can restore the lighter weight calls. In other cases, we're effectively already testing whether we're in the stored task context elsewhere, extend this vfio_lock_acct() as well. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
2016-12-14mm: add locked parameter to get_user_pages_remote()Lorenzo Stoakes1-1/+1
Patch series "mm: unexport __get_user_pages_unlocked()". This patch series continues the cleanup of get_user_pages*() functions taking advantage of the fact we can now pass gup_flags as we please. It firstly adds an additional 'locked' parameter to get_user_pages_remote() to allow for its callers to utilise VM_FAULT_RETRY functionality. This is necessary as the invocation of __get_user_pages_unlocked() in process_vm_rw_single_vec() makes use of this and no other existing higher level function would allow it to do so. Secondly existing callers of __get_user_pages_unlocked() are replaced with the appropriate higher-level replacement - get_user_pages_unlocked() if the current task and memory descriptor are referenced, or get_user_pages_remote() if other task/memory descriptors are referenced (having acquiring mmap_sem.) This patch (of 2): Add a int *locked parameter to get_user_pages_remote() to allow VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked(). Taking into account the previous adjustments to get_user_pages*() functions allowing for the passing of gup_flags, we are now in a position where __get_user_pages_unlocked() need only be exported for his ability to allow VM_FAULT_RETRY behaviour, this adjustment allows us to subsequently unexport __get_user_pages_unlocked() as well as allowing for future flexibility in the use of get_user_pages_remote(). [sfr@canb.auug.org.au: merge fix for get_user_pages_remote API change] Link: http://lkml.kernel.org/r/20161122210511.024ec341@canb.auug.org.au Link: http://lkml.kernel.org/r/20161027095141.2569-2-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-06vfio iommu type1: Fix size argument to vfio_find_dma() in pin_pages/unpin_pagesKirti Wankhede1-3/+3
Passing zero for the size to vfio_find_dma() isn't compatible with matching the start address of an existing vfio_dma. Doing so triggers a corner case. In vfio_find_dma(), when the start address is equal to dma->iova and size is 0, check for the end of search range makes it to take wrong side of RB-tree. That fails the search even though the address is present in mapped dma ranges. In functions pin_pages and unpin_pages, the iova which is being searched is base address of page to be pinned or unpinned. So here size should be set to PAGE_SIZE, as argument to vfio_find_dma(). Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-06vfio iommu type1: Fix size argument to vfio_find_dma() during DMA UNMAP.Kirti Wankhede1-1/+1
Passing zero for the size to vfio_find_dma() isn't compatible with matching the start address of an existing vfio_dma. Doing so triggers a corner case. In vfio_find_dma(), when the start address is equal to dma->iova and size is 0, check for the end of search range makes it to take wrong side of RB-tree. That fails the search even though the address is present in mapped dma ranges. Due to this, in vfio_dma_do_unmap(), while checking boundary conditions, size should be set to 1 for verifying start address of unmap range. vfio_find_dma() is also used to verify last address in unmap range with size = 0, but in that case address to be searched is calculated with start + size - 1 and so it works correctly. Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> [aw: changelog tweak] Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-05vfio iommu type1: WARN_ON if notifier block is not unregisteredKirti Wankhede1-0/+2
mdev vendor driver should unregister the iommu notifier since the vfio iommu can persist beyond the attachment of the mdev group. WARN_ON will show warning if vendor driver doesn't unregister the notifier and is forced to follow the implementations steps. Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-01vfio: vfio_register_notifier: classify iommu notifierJike Song1-0/+8
Currently vfio_register_notifier assumes that there is only one notifier chain, which is in vfio_iommu. However, the user might also be interested in events other than vfio_iommu, for example, vfio_group. Refactor vfio_{un}register_notifier implementation to make it feasible. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Jike Song <jike.song@intel.com> [aw: merge with commit 816ca69ea9c7 ("vfio: Fix handling of error returned by 'vfio_group_get_from_dev()'"), remove typedef] Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio iommu: Add blocking notifier to notify DMA_UNMAPKirti Wankhede1-13/+61
Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers about DMA_UNMAP. Exported two APIs vfio_register_notifier() and vfio_unregister_notifier(). Notifier should be registered, if external user wants to use vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages. Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate mappings. Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio iommu type1: Add support for mediated devicesKirti Wankhede1-84/+537
VFIO IOMMU drivers are designed for the devices which are IOMMU capable. Mediated device only uses IOMMU APIs, the underlying hardware can be managed by an IOMMU domain. Aim of this change is: - To use most of the code of TYPE1 IOMMU driver for mediated devices - To support direct assigned device and mediated device in single module This change adds pin and unpin support for mediated device to TYPE1 IOMMU backend module. More details: - Domain for external user is tracked separately in vfio_iommu structure. It is allocated when group for first mdev device is attached. - Pages pinned for external domain are tracked in each vfio_dma structure for that iova range. - Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of rb-tree is iova, but it actually aims to track pfns. - On external pin request for an iova, page is pinned once, if iova is already pinned and tracked, ref_count is incremented. - External unpin request unpins pages only when ref_count is 0. - Pinned pages list is used to find pfn from iova and then unpin it. WARN_ON is added if there are entires in pfn_list while detaching the group and releasing the domain. - Page accounting is updated to account in its address space where the pages are pinned/unpinned, i.e dma->task - Accouting for mdev device is only done if there is no iommu capable domain in the container. When there is a direct device assigned to the container and that domain is iommu capable, all pages are already pinned during DMA_MAP. - Page accouting is updated on hot plug and unplug mdev device and pass through device. Tested by assigning below combinations of devices to a single VM: - GPU pass through only - vGPU device only - One GPU pass through and one vGPU device - Linux VM hot plug and unplug vGPU device while GPU pass through device exist - Linux VM hot plug and unplug GPU pass through device while vGPU device exist Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio iommu type1: Add task structure to vfio_dmaKirti Wankhede1-51/+86
Add task structure to vfio_dma structure. Task structure is used for: - During DMA_UNMAP, same task who mapped it or other task who shares same address space is allowed to unmap, otherwise unmap fails. QEMU maps few iova ranges initially, then fork threads and from the child thread calls DMA_UNMAP on previously mapped iova. Since child shares same address space, DMA_UNMAP is successful. - Avoid accessing struct mm while process is exiting by acquiring reference of task's mm during page accounting. - It is also used to get task mlock capability and rlimit for mlock. Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17vfio iommu type1: Add find_iommu_group() functionKirti Wankhede1-24/+33
Add find_iommu_group() Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Neo Jia <cjia@nvidia.com> Reviewed-by: Jike Song <jike.song@intel.com> Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>