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2020-01-27vfio/mdev: Fix aborting mdev child device removal if one failsParav Pandit
[ Upstream commit 6093e348a5e2475c5bb2e571346460f939998670 ] device_for_each_child() stops executing callback function for remaining child devices, if callback hits an error. Each child mdev device is independent of each other. While unregistering parent device, mdev core must remove all child mdev devices. Therefore, mdev_device_remove_cb() always returns success so that device_for_each_child doesn't abort if one child removal hits error. While at it, improve remove and unregister functions for below simplicity. There isn't need to pass forced flag pointer during mdev parent removal which invokes mdev_device_remove(). So simplify the flow. mdev_device_remove() is called from two paths. 1. mdev_unregister_driver() mdev_device_remove_cb() mdev_device_remove() 2. remove_store() mdev_device_remove() Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27vfio/mdev: Avoid release parent reference during error pathParav Pandit
[ Upstream commit 60e7f2c3fe9919cee9534b422865eed49f4efb15 ] During mdev parent registration in mdev_register_device(), if parent device is duplicate, it releases the reference of existing parent device. This is incorrect. Existing parent device should not be touched. Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27vfio_pci: Enable memory accesses before calling pci_map_romEric Auger
[ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ] pci_map_rom/pci_get_rom_size() performs memory access in the ROM. In case the Memory Space accesses were disabled, readw() is likely to trigger a synchronous external abort on some platforms. In case memory accesses were disabled, re-enable them before the call and disable them back again just after. Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Eric Auger <eric.auger@redhat.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-21vfio/pci: call irq_bypass_unregister_producer() before freeing irqJiang Yi
commit d567fb8819162099035e546b11a736e29c2af0ea upstream. Since irq_bypass_register_producer() is called after request_irq(), we should do tear-down in reverse order: irq_bypass_unregister_producer() then free_irq(). Specifically free_irq() may release resources required by the irqbypass del_producer() callback. Notably an example provided by Marc Zyngier on arm64 with GICv4 that he indicates has the potential to wedge the hardware: free_irq(irq) __free_irq(irq) irq_domain_deactivate_irq(irq) its_irq_domain_deactivate() [unmap the VLPI from the ITS] kvm_arch_irq_bypass_del_producer(cons, prod) kvm_vgic_v4_unset_forwarding(kvm, irq, ...) its_unmap_vlpi(irq) [Unmap the VLPI from the ITS (again), remap the original LPI] Signed-off-by: Jiang Yi <giangyi@amazon.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 6d7425f109d26 ("vfio: Register/unregister irq_bypass_producer") Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> [aw: commit log] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05vfio/spapr_tce: Get rid of possible infinite loopAlexey Kardashevskiy
[ Upstream commit 517ad4ae8aa93dccdb9a88c27257ecb421c9e848 ] As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered memory. If there is a bug in memory release, the loop in tce_iommu_release() becomes infinite; this actually happened to me. This makes the loop finite and prints a warning on every failure to make the code more bug prone. Signed-off-by: Alexey Kardashevskiy <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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20vfio/pci: Mask buggy SR-IOV VF INTx supportAlex Williamson
[ Upstream commit db04264fe9bc0f2b62e036629f9afb530324b693 ] The SR-IOV spec requires that VFs must report zero for the INTx pin register as VFs are precluded from INTx support. It's much easier for the host kernel to understand whether a device is a VF and therefore whether a non-zero pin register value is bogus than it is to do the same in userspace. Override the INTx count for such devices and virtualize the pin register to provide a consistent view of the device to the user. As this is clearly a spec violation, warn about it to support hardware validation, but also provide a known whitelist as it doesn't do much good to continue complaining if the hardware vendor doesn't plan to fix it. Known devices with this issue: 8086:270c Tested-by: Gage Eads <gage.eads@intel.com> Reviewed-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20vfio/pci: Fix potential memory leak in vfio_msi_cap_lenLi Qiang
[ Upstream commit 30ea32ab1951c80c6113f300fce2c70cd12659e4 ] Free allocated vdev->msi_perm in error path. Signed-off-by: Li Qiang <liq3ea@gmail.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-07vfio_pci: Restore original state on releasehexin
[ Upstream commit 92c8026854c25093946e0d7fe536fd9eac440f06 ] vfio_pci_enable() saves the device's initial configuration information with the intent that it is restored in vfio_pci_disable(). However, the commit referenced in Fixes: below replaced the call to __pci_reset_function_locked(), which is not wrapped in a state save and restore, with pci_try_reset_function(), which overwrites the restored device state with the current state before applying it to the device. Reinstate use of __pci_reset_function_locked() to return to the desired behavior. Fixes: 890ed578df82 ("vfio-pci: Use pci "try" reset interface") Signed-off-by: hexin <hexin15@baidu.com> Signed-off-by: Liu Qi <liuqi16@baidu.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-15vfio: Fix WARNING "do not call blocking ops when !TASK_RUNNING"Farhan Ali
[ Upstream commit 41be3e2618174fdf3361e49e64f2bf530f40c6b0 ] vfio_dev_present() which is the condition to wait_event_interruptible_timeout(), will call vfio_group_get_device and try to acquire the mutex group->device_lock. wait_event_interruptible_timeout() will set the state of the current task to TASK_INTERRUPTIBLE, before doing the condition check. This means that we will try to acquire the mutex while already in a sleeping state. The scheduler warns us by giving the following warning: [ 4050.264464] ------------[ cut here ]------------ [ 4050.264508] do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000b33c00e2>] prepare_to_wait_event+0x14a/0x188 [ 4050.264529] WARNING: CPU: 12 PID: 35924 at kernel/sched/core.c:6112 __might_sleep+0x76/0x90 .... 4050.264756] Call Trace: [ 4050.264765] ([<000000000017bbaa>] __might_sleep+0x72/0x90) [ 4050.264774] [<0000000000b97edc>] __mutex_lock+0x44/0x8c0 [ 4050.264782] [<0000000000b9878a>] mutex_lock_nested+0x32/0x40 [ 4050.264793] [<000003ff800d7abe>] vfio_group_get_device+0x36/0xa8 [vfio] [ 4050.264803] [<000003ff800d87c0>] vfio_del_group_dev+0x238/0x378 [vfio] [ 4050.264813] [<000003ff8015f67c>] mdev_remove+0x3c/0x68 [mdev] [ 4050.264825] [<00000000008e01b0>] device_release_driver_internal+0x168/0x268 [ 4050.264834] [<00000000008de692>] bus_remove_device+0x162/0x190 [ 4050.264843] [<00000000008daf42>] device_del+0x1e2/0x368 [ 4050.264851] [<00000000008db12c>] device_unregister+0x64/0x88 [ 4050.264862] [<000003ff8015ed84>] mdev_device_remove+0xec/0x130 [mdev] [ 4050.264872] [<000003ff8015f074>] remove_store+0x6c/0xa8 [mdev] [ 4050.264881] [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8 [ 4050.264890] [<00000000003c1530>] __vfs_write+0x38/0x1a8 [ 4050.264899] [<00000000003c187c>] vfs_write+0xb4/0x198 [ 4050.264908] [<00000000003c1af2>] ksys_write+0x5a/0xb0 [ 4050.264916] [<0000000000b9e270>] system_call+0xdc/0x2d8 [ 4050.264925] 4 locks held by sh/35924: [ 4050.264933] #0: 000000001ef90325 (sb_writers#4){.+.+}, at: vfs_write+0x9e/0x198 [ 4050.264948] #1: 000000005c1ab0b3 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1cc/0x1f8 [ 4050.264963] #2: 0000000034831ab8 (kn->count#297){++++}, at: kernfs_remove_self+0x12e/0x150 [ 4050.264979] #3: 00000000e152484f (&dev->mutex){....}, at: device_release_driver_internal+0x5c/0x268 [ 4050.264993] Last Breaking-Event-Address: [ 4050.265002] [<000000000017bbaa>] __might_sleep+0x72/0x90 [ 4050.265010] irq event stamp: 7039 [ 4050.265020] hardirqs last enabled at (7047): [<00000000001cee7a>] console_unlock+0x6d2/0x740 [ 4050.265029] hardirqs last disabled at (7054): [<00000000001ce87e>] console_unlock+0xd6/0x740 [ 4050.265040] softirqs last enabled at (6416): [<0000000000b8fe26>] __udelay+0xb6/0x100 [ 4050.265049] softirqs last disabled at (6415): [<0000000000b8fe06>] __udelay+0x96/0x100 [ 4050.265057] ---[ end trace d04a07d39d99a9f9 ]--- Let's fix this as described in the article https://lwn.net/Articles/628628/. Signed-off-by: Farhan Ali <alifm@linux.ibm.com> [remove now redundant vfio_dev_present()] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-08vfio/pci: use correct format charactersLouis Taylor
[ Upstream commit 426b046b748d1f47e096e05bdcc6fb4172791307 ] When compiling with -Wformat, clang emits the following warnings: drivers/vfio/pci/vfio_pci.c:1601:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1601:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ The types of these arguments are unconditionally defined, so this patch updates the format character to the correct ones for unsigned ints. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Signed-off-by: Louis Taylor <louis@kragniz.eu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-02vfio/type1: Limit DMA mappings per containerAlex Williamson
commit 492855939bdb59c6f947b0b5b44af9ad82b7e38c upstream. Memory backed DMA mappings are accounted against a user's locked memory limit, including multiple mappings of the same memory. This accounting bounds the number of such mappings that a user can create. However, DMA mappings that are not backed by memory, such as DMA mappings of device MMIO via mmaps, do not make use of page pinning and therefore do not count against the user's locked memory limit. These mappings still consume memory, but the memory is not well associated to the process for the purpose of oom killing a task. To add bounding on this use case, we introduce a limit to the total number of concurrent DMA mappings that a user is allowed to create. This limit is exposed as a tunable module option where the default value of 64K is expected to be well in excess of any reasonable use case (a large virtual machine configuration would typically only make use of tens of concurrent mappings). This fixes CVE-2019-3882. Reviewed-by: Eric Auger <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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03vfio/type1: Fix task tracking for QEMU vCPU hotplugAlex Williamson
[ Upstream commit 48d8476b41eed63567dd2f0ad125c895b9ac648a ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03vfio/mdev: Check globally for duplicate devicesAlex Williamson
[ Upstream commit 002fe996f67f4f46d8917b14cfb6e4313c20685a ] When we create an mdev device, we check for duplicates against the parent device and return -EEXIST if found, but the mdev device namespace is global since we'll link all devices from the bus. We do catch this later in sysfs_do_create_link_sd() to return -EEXIST, but with it comes a kernel warning and stack trace for trying to create duplicate sysfs links, which makes it an undesirable response. Therefore we should really be looking for duplicates across all mdev parent devices, or as implemented here, against our mdev device list. Using mdev_list to prevent duplicates means that we can remove mdev_parent.lock, but in order not to serialize mdev device creation and removal globally, we add mdev_device.active which allows UUIDs to be reserved such that we can drop the mdev_list_lock before the mdev device is fully in place. Two behavioral notes; first, mdev_parent.lock had the side-effect of serializing mdev create and remove ops per parent device. This was an implementation detail, not an intentional guarantee provided to the mdev vendor drivers. Vendor drivers can trivially provide this serialization internally if necessary. Second, review comments note the new -EAGAIN behavior when the device, and in particular the remove attribute, becomes visible in sysfs. If a remove is triggered prior to completion of mdev_device_create() the user will see a -EAGAIN error. While the errno is different, receiving an error during this period is not, the previous implementation returned -ENODEV for the same condition. Furthermore, the consistency to the user is improved in the case where mdev_device_remove_ops() returns error. Previously concurrent calls to mdev_device_remove() could see the device disappear with -ENODEV and return in the case of error. Now a user would see -EAGAIN while the device is in this transitory state. Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03vfio: platform: Fix reset module leak in error pathGeert Uytterhoeven
[ Upstream commit 28a68387888997e8a7fa57940ea5d55f2e16b594 ] If the IOMMU group setup fails, the reset module is not released. Fixes: b5add544d677d363 ("vfio, platform: make reset driver a requirement by default") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28KVM: PPC: Check if IOMMU page is contained in the pinned physical pageAlexey Kardashevskiy
commit 76fa4975f3ed12d15762bc979ca44078598ed8ee upstream. A VM which has: - a DMA capable device passed through to it (eg. network card); - running a malicious kernel that ignores H_PUT_TCE failure; - capability of using IOMMU pages bigger that physical pages can create an IOMMU mapping that exposes (for example) 16MB of the host physical memory to the device when only 64K was allocated to the VM. The remaining 16MB - 64K will be some other content of host memory, possibly including pages of the VM, but also pages of host kernel memory, host programs or other VMs. The attacking VM does not control the location of the page it can map, and is only allowed to map as many pages as it has pages of RAM. We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that an IOMMU page is contained in the physical page so the PCI hardware won't get access to unassigned host memory; however this check is missing in the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and did not hit this yet as the very first time when the mapping happens we do not have tbl::it_userspace allocated yet and fall back to the userspace which in turn calls VFIO IOMMU driver, this fails and the guest does not retry, This stores the smallest preregistered page size in the preregistered region descriptor and changes the mm_iommu_xxx API to check this against the IOMMU page size. This calculates maximum page size as a minimum of the natural region alignment and compound page size. For the page shift this uses the shift returned by find_linux_pte() which indicates how the page is mapped to the current userspace - if the page is huge and this is not a zero, then it is a leaf pte and the page is mapped within the range. Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25vfio/spapr: Use IOMMU pageshift rather than pagesizeAlexey Kardashevskiy
commit 1463edca6734d42ab4406fa2896e20b45478ea36 upstream. The size is always equal to 1 page so let's use this. Later on this will be used for other checks which use page shifts to check the granularity of access. This should cause no behavioral change. Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25vfio/pci: Fix potential Spectre v1Gustavo A. R. Silva
commit 0e714d27786ce1fb3efa9aac58abc096e68b1c2a upstream. info.index can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/vfio/pci/vfio_pci.c:734 vfio_pci_ioctl() warn: potential spectre issue 'vdev->region' Fix this by sanitizing info.index before indirectly using it to index vdev->region Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11vfio: Use get_user_pages_longterm correctlyJason Gunthorpe
commit bb94b55af3461e26b32f0e23d455abeae0cfca5d upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-24vfio/pci: Virtualize Maximum Read Request SizeAlex Williamson
commit cf0d53ba4947aad6e471491d5b20a567cbe92e56 upstream. MRRS defines the maximum read request size a device is allowed to make. Drivers will often increase this to allow more data transfer with a single request. Completions to this request are bound by the MPS setting for the bus. Aside from device quirks (none known), it doesn't seem to make sense to set an MRRS value less than MPS, yet this is a likely scenario given that user drivers do not have a system-wide view of the PCI topology. Virtualize MRRS such that the user can set MRRS >= MPS, but use MPS as the floor value that we'll write to hardware. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-08vfio: disable filesystem-dax page pinningDan Williams
commit 94db151dc89262bfa82922c44e8320cea2334667 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-25vfio/pci: Virtualize Maximum Payload SizeAlex Williamson
[ Upstream commit 523184972b282cd9ca17a76f6ca4742394856818 ] 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> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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>
2017-08-30vfio: platform: constify amba_idArvind Yadav
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 Williamson
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 Auger
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 Murphy
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 Murphy
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 Williamson
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 Williamson
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 Torvalds
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 Williamson
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 Williamson
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 Williamson
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 Molnar
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 Carpenter
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 Williamson
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 Torvalds
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 Williamson
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 Williamson
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 Williamson
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 Kardashevskiy
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 Kardashevskiy
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 Kardashevskiy
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 Kardashevskiy
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 Torvalds
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 Murphy
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>
2017-03-21vfio: Rework group release notifier warningAlex Williamson
The intent of the original warning is make sure that the mdev vendor driver has removed any group notifiers at the point where the group is closed by the user. Theoretically this would be through an orderly shutdown where any devices are release prior to the group release. We can't always count on an orderly shutdown, the user can close the group before the notifier can be removed or the user task might be killed. We'd like to add this sanity test when the group is idle and the only references are from the devices within the group themselves, but we don't have a good way to do that. Instead check both when the group itself is removed and when the group is opened. A bit later than we'd prefer, but better than the current over aggressive approach. Fixes: ccd46dbae77d ("vfio: support notifier chain in vfio_group") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: <stable@vger.kernel.org> # v4.10 Cc: Jike Song <jike.song@intel.com>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/signal.h> 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 ↵Ingo Molnar
<linux/sched/mm.h> 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>
2017-02-23Merge tag 'vfio-v4.11-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Kconfig fixes for SPAPR_TCE_IOMMU=n (Michael Ellerman) - Module softdep rather than request_module to simplify usage from initrd (Alex Williamson) - Comment typo fix (Changbin Du) * tag 'vfio-v4.11-rc1' of git://github.com/awilliam/linux-vfio: vfio: fix a typo in comment of function vfio_pin_pages vfio: Replace module request with softdep vfio/mdev: Use a module softdep for vfio_mdev vfio: Fix build break when SPAPR_TCE_IOMMU=n