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2019-01-23vfio-pci/nvlink2: Fix ancient gcc warningsAlexey Kardashevskiy
Using the {0} construct as a generic initializer is perfectly fine in C, however due to a bug in old gcc there is a warning: + /kisskb/src/drivers/vfio/pci/vfio_pci_nvlink2.c: warning: (near initialization for 'cap.header') [-Wmissing-braces]: => 181:9 Since for whatever reason we still want to compile the modern kernel with such an old gcc without warnings, this changes the capabilities initialization. The gcc bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119 Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-22vfio/pci: Cleanup license messThomas Gleixner
The recently added nvlink2 VFIO driver introduced a license conflict in two files. In both cases the SPDX license identifier is: SPDX-License-Identifier: GPL-2.0+ but the files contain also the following license boiler plate text: * 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 The latter is GPL-2.9-only and not GPL-2.0=. Looking deeper. The nvlink source file is derived from vfio_pci_igd.c which is also licensed under GPL-2.0-only and it can be assumed that the file was copied and modified. As the original file is licensed GPL-2.0-only it's not possible to relicense derivative work to GPL-2.0-or-later. Fix the SPDX identifier and remove the boiler plate as it is redundant. Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: kvm@vger.kernel.org Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-08vfio/type1: Fix unmap overflow off-by-oneAlex Williamson
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>
2019-01-08vfio/pci: set TRACE_INCLUDE_PATH to fix the build errorMasahiro Yamada
drivers/vfio/pci/vfio_pci_nvlink2.c cannot be compiled for in-tree building. CC drivers/vfio/pci/vfio_pci_nvlink2.o In file included from drivers/vfio/pci/trace.h:102, from drivers/vfio/pci/vfio_pci_nvlink2.c:29: ./include/trace/define_trace.h:89:42: fatal error: ./trace.h: No such file or directory #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) ^ compilation terminated. make[1]: *** [scripts/Makefile.build;277: drivers/vfio/pci/vfio_pci_nvlink2.o] Error 1 To fix the build error, let's tell include/trace/define_trace.h the location of drivers/vfio/pci/trace.h Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Reported-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-01-01Merge tag 'iommu-updates-v4.21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU updates from Joerg Roedel: - Page table code for AMD IOMMU now supports large pages where smaller page-sizes were mapped before. VFIO had to work around that in the past and I included a patch to remove it (acked by Alex Williamson) - Patches to unmodularize a couple of IOMMU drivers that would never work as modules anyway. - Work to unify the the iommu-related pointers in 'struct device' into one pointer. This work is not finished yet, but will probably be in the next cycle. - NUMA aware allocation in iommu-dma code - Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver - Scalable mode support for the Intel VT-d driver - PM runtime improvements for the ARM-SMMU driver - Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom - Various smaller fixes and improvements * tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (78 commits) iommu: Check for iommu_ops == NULL in iommu_probe_device() ACPI/IORT: Don't call iommu_ops->add_device directly iommu/of: Don't call iommu_ops->add_device directly iommu: Consolitate ->add/remove_device() calls iommu/sysfs: Rename iommu_release_device() dmaengine: sh: rcar-dmac: Use device_iommu_mapped() xhci: Use device_iommu_mapped() powerpc/iommu: Use device_iommu_mapped() ACPI/IORT: Use device_iommu_mapped() iommu/of: Use device_iommu_mapped() driver core: Introduce device_iommu_mapped() function iommu/tegra: Use helper functions to access dev->iommu_fwspec iommu/qcom: Use helper functions to access dev->iommu_fwspec iommu/of: Use helper functions to access dev->iommu_fwspec iommu/mediatek: Use helper functions to access dev->iommu_fwspec iommu/ipmmu-vmsa: Use helper functions to access dev->iommu_fwspec iommu/dma: Use helper functions to access dev->iommu_fwspec iommu/arm-smmu: Use helper functions to access dev->iommu_fwspec ACPI/IORT: Use helper functions to access dev->iommu_fwspec iommu: Introduce wrappers around dev->iommu_fwspec ...
2018-12-28Merge tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Replace global vfio-pci lock with per bus lock to allow concurrent open and release (Alex Williamson) - Declare mdev function as static (Paolo Cretaro) - Convert char to u8 in mdev/mtty sample driver (Nathan Chancellor) * tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio: vfio-mdev/samples: Use u8 instead of char for handle functions vfio/mdev: add static modifier to add_mdev_supported_type vfio/pci: Parallelize device open and release
2018-12-21vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriverAlexey Kardashevskiy
POWER9 Witherspoon machines come with 4 or 6 V100 GPUs which are not pluggable PCIe devices but still have PCIe links which are used for config space and MMIO. In addition to that the GPUs have 6 NVLinks which are connected to other GPUs and the POWER9 CPU. POWER9 chips have a special unit on a die called an NPU which is an NVLink2 host bus adapter with p2p connections to 2 to 3 GPUs, 3 or 2 NVLinks to each. These systems also support ATS (address translation services) which is a part of the NVLink2 protocol. Such GPUs also share on-board RAM (16GB or 32GB) to the system via the same NVLink2 so a CPU has cache-coherent access to a GPU RAM. This exports GPU RAM to the userspace as a new VFIO device region. This preregisters the new memory as device memory as it might be used for DMA. This inserts pfns from the fault handler as the GPU memory is not onlined until the vendor driver is loaded and trained the NVLinks so doing this earlier causes low level errors which we fence in the firmware so it does not hurt the host system but still better be avoided; for the same reason this does not map GPU RAM into the host kernel (usual thing for emulated access otherwise). This exports an ATSD (Address Translation Shootdown) register of NPU which allows TLB invalidations inside GPU for an operating system. The register conveniently occupies a single 64k page. It is also presented to the userspace as a new VFIO device region. One NPU has 8 ATSD registers, each of them can be used for TLB invalidation in a GPU linked to this NPU. This allocates one ATSD register per an NVLink bridge allowing passing up to 6 registers. Due to the host firmware bug (just recently fixed), only 1 ATSD register per NPU was actually advertised to the host system so this passes that alone register via the first NVLink bridge device in the group which is still enough as QEMU collects them all back and presents to the guest via vPHB to mimic the emulated NPU PHB on the host. In order to provide the userspace with the information about GPU-to-NVLink connections, this exports an additional capability called "tgt" (which is an abbreviated host system bus address). The "tgt" property tells the GPU its own system address and allows the guest driver to conglomerate the routing information so each GPU knows how to get directly to the other GPUs. For ATS to work, the nest MMU (an NVIDIA block in a P9 CPU) needs to know LPID (a logical partition ID or a KVM guest hardware ID in other words) and PID (a memory context ID of a userspace process, not to be confused with a linux pid). This assigns a GPU to LPID in the NPU and this is why this adds a listener for KVM on an IOMMU group. A PID comes via NVLink from a GPU and NPU uses a PID wildcard to pass it through. This requires coherent memory and ATSD to be available on the host as the GPU vendor only supports configurations with both features enabled and other configurations are known not to work. Because of this and because of the ways the features are advertised to the host system (which is a device tree with very platform specific properties), this requires enabled POWERNV platform. The V100 GPUs do not advertise any of these capabilities via the config space and there are more than just one device ID so this relies on the platform to tell whether these GPUs have special abilities such as NVLinks. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21vfio_pci: Allow regions to add own capabilitiesAlexey Kardashevskiy
VFIO regions already support region capabilities with a limited set of fields. However the subdriver might have to report to the userspace additional bits. This adds an add_capability() hook to vfio_pci_regops. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21vfio_pci: Allow mapping extra regionsAlexey Kardashevskiy
So far we only allowed mapping of MMIO BARs to the userspace. However there are GPUs with on-board coherent RAM accessible via side channels which we also want to map to the userspace. The first client for this is NVIDIA V100 GPU with NVLink2 direct links to a POWER9 NPU-enabled CPU; such GPUs have 16GB RAM which is coherently mapped to the system address space, we are going to export these as an extra PCI region. We already support extra PCI regions and this adds support for mapping them to the userspace. Signed-off-by: Alexey Kardashevskiy <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>
2018-12-21powerpc/vfio/iommu/kvm: Do not pin device memoryAlexey Kardashevskiy
This new memory does not have page structs as it is not plugged to the host so gup() will fail anyway. This adds 2 helpers: - mm_iommu_newdev() to preregister the "memory device" memory so the rest of API can still be used; - mm_iommu_is_devmem() to know if the physical address is one of thise new regions which we must avoid unpinning of. This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test if the memory is device memory to avoid pfn_to_page(). This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which does delayed pages dirtying. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a regionAlexey Kardashevskiy
Normally mm_iommu_get() should add a reference and mm_iommu_put() should remove it. However historically mm_iommu_find() does the referencing and mm_iommu_get() is doing allocation and referencing. We are going to add another helper to preregister device memory so instead of having mm_iommu_new() (which pre-registers the normal memory and references the region), we need separate helpers for pre-registering and referencing. This renames: - mm_iommu_get to mm_iommu_new; - mm_iommu_find to mm_iommu_get. This changes mm_iommu_get() to reference the region so the name now reflects what it does. This removes the check for exact match from mm_iommu_new() as we want it to fail on existing regions; mm_iommu_get() should be used instead. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20vfio/spapr_tce: Get rid of possible infinite loopAlexey Kardashevskiy
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>
2018-12-12vfio/mdev: add static modifier to add_mdev_supported_typePaolo Cretaro
Set add_mdev_supported_type as static since it is only used within mdev_sysfs.c. This fixes -Wmissing-prototypes gcc warning. Signed-off-by: Paolo Cretaro <paolocretaro@gmail.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-12-12vfio/pci: Parallelize device open and releaseAlex Williamson
In commit 61d792562b53 ("vfio-pci: Use mutex around open, release, and remove") a mutex was added to freeze the refcnt for a device so that we can handle errors and perform bus resets on final close. However, bus resets can be rather slow and a global mutex here is undesirable. Evaluating the potential locking granularity, a per-device mutex provides the best resolution but with multiple devices on a bus all released concurrently, they'll race to acquire each other's mutex, likely resulting in no reset at all if we use trylock. We therefore lock at the granularity of the bus/slot reset as we're only attempting a single reset for this group of devices anyway. This allows much greater scaling as we're bounded in the number of devices protected by a single reflck object. Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Reviewed-by: Eric Auger <eric.auger@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 Roedel
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>
2018-10-31Merge tag 'vfio-v4.20-rc1.v2' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - EDID interfaces for vfio devices supporting display extensions (Gerd Hoffmann) - Generically select Type-1 IOMMU model support on ARM/ARM64 (Geert Uytterhoeven) - Quirk for VFs reporting INTx pin (Alex Williamson) - Fix error path memory leak in MSI support (Li Qiang) * tag 'vfio-v4.20-rc1.v2' of git://github.com/awilliam/linux-vfio: vfio: add edid support to mbochs sample driver vfio: add edid api for display (vgpu) devices. drivers/vfio: Allow type-1 IOMMU instantiation with all ARM/ARM64 IOMMUs vfio/pci: Mask buggy SR-IOV VF INTx support vfio/pci: Fix potential memory leak in vfio_msi_cap_len
2018-10-20KVM: PPC: Optimize clearing TCEs for sparse tablesAlexey Kardashevskiy
The powernv platform maintains 2 TCE tables for VFIO - a hardware TCE table and a table with userspace addresses. These tables are radix trees, we allocate indirect levels when they are written to. Since the memory allocation is problematic in real mode, we have 2 accessors to the entries: - for virtual mode: it allocates the memory and it is always expected to return non-NULL; - fr real mode: it does not allocate and can return NULL. Also, DMA windows can span to up to 55 bits of the address space and since we never have this much RAM, such windows are sparse. However currently the SPAPR TCE IOMMU driver walks through all TCEs to unpin DMA memory. Since we maintain a userspace addresses table for VFIO which is a mirror of the hardware table, we can use it to know which parts of the DMA window have not been mapped and skip these so does this patch. The bare metal systems do not have this problem as they use a bypass mode of a PHB which maps RAM directly. This helps a lot with sparse DMA windows, reducing the shutdown time from about 3 minutes per 1 billion TCEs to a few seconds for 32GB sparse guest. Just skipping the last level seems to be good enough. As non-allocating accessor is used now in virtual mode as well, rename it from IOMMU_TABLE_USERSPACE_ENTRY_RM (real mode) to _RO (read only). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-09-25drivers/vfio: Allow type-1 IOMMU instantiation with all ARM/ARM64 IOMMUsGeert Uytterhoeven
Currently the type-1 IOMMU instantiation depends on "ARM_SMMU || ARM_SMMU_V3", while it applies to other ARM/ARM64 platforms with an IOMMU (e.g. Renesas VMSA-compatible IPMMUs). Instead of extending the list of IOMMU types on ARM platforms, replace the list by "ARM || ARM64", like other architectures do. The feature is still restricted to ARM/ARM64 platforms with an IOMMU by the dependency on IOMMU_API. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-09-25vfio/pci: Mask buggy SR-IOV VF INTx supportAlex Williamson
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>
2018-09-25vfio/pci: Fix potential memory leak in vfio_msi_cap_lenLi Qiang
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>
2018-08-17Merge tag 'powerpc-4.19-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - A fix for a bug in our page table fragment allocator, where a page table page could be freed and reallocated for something else while still in use, leading to memory corruption etc. The fix reuses pt_mm in struct page (x86 only) for a powerpc only refcount. - Fixes to our pkey support. Several are user-visible changes, but bring us in to line with x86 behaviour and/or fix outright bugs. Thanks to Florian Weimer for reporting many of these. - A series to improve the hvc driver & related OPAL console code, which have been seen to cause hardlockups at times. The hvc driver changes in particular have been in linux-next for ~month. - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y. - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in use anywhere other than as a paper weight. - An optimised memcmp implementation using Power7-or-later VMX instructions - Support for barrier_nospec on some NXP CPUs. - Support for flushing the count cache on context switch on some IBM CPUs (controlled by firmware), as a Spectre v2 mitigation. - A series to enhance the information we print on unhandled signals to bring it into line with other arches, including showing the offending VMA and dumping the instructions around the fault. Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski, Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng, Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand, Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues, Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha, Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood, Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat Rao, zhong jiang" * tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits) powerpc/mm/book3s/radix: Add mapping statistics powerpc/uaccess: Enable get_user(u64, *p) on 32-bit powerpc/mm/hash: Remove unnecessary do { } while(0) loop powerpc/64s: move machine check SLB flushing to mm/slb.c powerpc/powernv/idle: Fix build error powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range powerpc/mm: remove warning about ‘type’ being set powerpc/32: Include setup.h header file to fix warnings powerpc: Move `path` variable inside DEBUG_PROM powerpc/powermac: Make some functions static powerpc/powermac: Remove variable x that's never read cxl: remove a dead branch powerpc/powermac: Add missing include of header pmac.h powerpc/kexec: Use common error handling code in setup_new_fdt() powerpc/xmon: Add address lookup for percpu symbols powerpc/mm: remove huge_pte_offset_and_shift() prototype powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled powerpc/pseries: Fix endianness while restoring of r3 in MCE handler. powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements powerpc/fadump: handle crash memory ranges array index overflow ...
2018-08-16Merge tag 'vfio-v4.19-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - mark switch fall-through cases (Gustavo A. R. Silva) - disable binding SR-IOV enabled PFs (Alex Williamson) * tag 'vfio-v4.19-rc1' of git://github.com/awilliam/linux-vfio: vfio-pci: Disable binding to PFs with SR-IOV enabled vfio: Mark expected switch fall-throughs
2018-08-16Merge tag 'pci-v4.19-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull pci updates from Bjorn Helgaas: - Decode AER errors with names similar to "lspci" (Tyler Baicar) - Expose AER statistics in sysfs (Rajat Jain) - Clear AER status bits selectively based on the type of recovery (Oza Pawandeep) - Honor "pcie_ports=native" even if HEST sets FIRMWARE_FIRST (Alexandru Gagniuc) - Don't clear AER status bits if we're using the "Firmware-First" strategy where firmware owns the registers (Alexandru Gagniuc) - Use sysfs_match_string() to simplify ASPM sysfs parsing (Andy Shevchenko) - Remove unnecessary includes of <linux/pci-aspm.h> (Bjorn Helgaas) - Defer DPC event handling to work queue (Keith Busch) - Use threaded IRQ for DPC bottom half (Keith Busch) - Print AER status while handling DPC events (Keith Busch) - Work around IDT switch ACS Source Validation erratum (James Puthukattukaran) - Emit diagnostics for all cases of PCIe Link downtraining (Links operating slower than they're capable of) (Alexandru Gagniuc) - Skip VFs when configuring Max Payload Size (Myron Stowe) - Reduce Root Port Max Payload Size if necessary when hot-adding a device below it (Myron Stowe) - Simplify SHPC existence/permission checks (Bjorn Helgaas) - Remove hotplug sample skeleton driver (Lukas Wunner) - Convert pciehp to threaded IRQ handling (Lukas Wunner) - Improve pciehp tolerance of missed events and initially unstable links (Lukas Wunner) - Clear spurious pciehp events on resume (Lukas Wunner) - Add pciehp runtime PM support, including for Thunderbolt controllers (Lukas Wunner) - Support interrupts from pciehp bridges in D3hot (Lukas Wunner) - Mark fall-through switch cases before enabling -Wimplicit-fallthrough (Gustavo A. R. Silva) - Move DMA-debug PCI init from arch code to PCI core (Christoph Hellwig) - Fix pci_request_irq() usage of IRQF_ONESHOT when no handler is supplied (Heiner Kallweit) - Unify PCI and DMA direction #defines (Shunyong Yang) - Add PCI_DEVICE_DATA() macro (Andy Shevchenko) - Check for VPD completion before checking for timeout (Bert Kenward) - Limit Netronome NFP5000 config space size to work around erratum (Jakub Kicinski) - Set IRQCHIP_ONESHOT_SAFE for PCI MSI irqchips (Heiner Kallweit) - Document ACPI description of PCI host bridges (Bjorn Helgaas) - Add "pci=disable_acs_redir=" parameter to disable ACS redirection for peer-to-peer DMA support (we don't have the peer-to-peer support yet; this is just one piece) (Logan Gunthorpe) - Clean up devm_of_pci_get_host_bridge_resources() resource allocation (Jan Kiszka) - Fixup resizable BARs after suspend/resume (Christian König) - Make "pci=earlydump" generic (Sinan Kaya) - Fix ROM BAR access routines to stay in bounds and check for signature correctly (Rex Zhu) - Add DMA alias quirk for Microsemi Switchtec NTB (Doug Meyer) - Expand documentation for pci_add_dma_alias() (Logan Gunthorpe) - To avoid bus errors, enable PASID only if entire path supports End-End TLP prefixes (Sinan Kaya) - Unify slot and bus reset functions and remove hotplug knowledge from callers (Sinan Kaya) - Add Function-Level Reset quirks for Intel and Samsung NVMe devices to fix guest reboot issues (Alex Williamson) - Add function 1 DMA alias quirk for Marvell 88SS9183 PCIe SSD Controller (Bjorn Helgaas) - Remove Xilinx AXI-PCIe host bridge arch dependency (Palmer Dabbelt) - Remove Aardvark outbound window configuration (Evan Wang) - Fix Aardvark bridge window sizing issue (Zachary Zhang) - Convert Aardvark to use pci_host_probe() to reduce code duplication (Thomas Petazzoni) - Correct the Cadence cdns_pcie_writel() signature (Alan Douglas) - Add Cadence support for optional generic PHYs (Alan Douglas) - Add Cadence power management ops (Alan Douglas) - Remove redundant variable from Cadence driver (Colin Ian King) - Add Kirin MSI support (Xiaowei Song) - Drop unnecessary root_bus_nr setting from exynos, imx6, keystone, armada8k, artpec6, designware-plat, histb, qcom, spear13xx (Shawn Guo) - Move link notification settings from DesignWare core to individual drivers (Gustavo Pimentel) - Add endpoint library MSI-X interfaces (Gustavo Pimentel) - Correct signature of endpoint library IRQ interfaces (Gustavo Pimentel) - Add DesignWare endpoint library MSI-X callbacks (Gustavo Pimentel) - Add endpoint library MSI-X test support (Gustavo Pimentel) - Remove unnecessary GFP_ATOMIC from Hyper-V "new child" allocation (Jia-Ju Bai) - Add more devices to Broadcom PAXC quirk (Ray Jui) - Work around corrupted Broadcom PAXC config space to enable SMMU and GICv3 ITS (Ray Jui) - Disable MSI parsing to work around broken Broadcom PAXC logic in some devices (Ray Jui) - Hide unconfigured functions to work around a Broadcom PAXC defect (Ray Jui) - Lower iproc log level to reduce console output during boot (Ray Jui) - Fix mobiveil iomem/phys_addr_t type usage (Lorenzo Pieralisi) - Fix mobiveil missing include file (Lorenzo Pieralisi) - Add mobiveil Kconfig/Makefile support (Lorenzo Pieralisi) - Fix mvebu I/O space remapping issues (Thomas Petazzoni) - Use generic pci_host_bridge in mvebu instead of ARM-specific API (Thomas Petazzoni) - Whitelist VMD devices with fast interrupt handlers to avoid sharing vectors with slow handlers (Keith Busch) * tag 'pci-v4.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (153 commits) PCI/AER: Don't clear AER bits if error handling is Firmware-First PCI: Limit config space size for Netronome NFP5000 PCI/MSI: Set IRQCHIP_ONESHOT_SAFE for PCI-MSI irqchips PCI/VPD: Check for VPD access completion before checking for timeout PCI: Add PCI_DEVICE_DATA() macro to fully describe device ID entry PCI: Match Root Port's MPS to endpoint's MPSS as necessary PCI: Skip MPS logic for Virtual Functions (VFs) PCI: Add function 1 DMA alias quirk for Marvell 88SS9183 PCI: Check for PCIe Link downtraining PCI: Add ACS Redirect disable quirk for Intel Sunrise Point PCI: Add device-specific ACS Redirect disable infrastructure PCI: Convert device-specific ACS quirks from NULL termination to ARRAY_SIZE PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support PCI: Allow specifying devices using a base bus and path of devfns PCI: Make specifying PCI devices in kernel parameters reusable PCI: Hide ACS quirk declarations inside PCI core PCI: Delay after FLR of Intel DC P3700 NVMe PCI: Disable Samsung SM961/PM961 NVMe before FLR PCI: Export pcie_has_flr() PCI: mvebu: Drop bogus comment above mvebu_pcie_map_registers() ...
2018-08-13Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch from the 4.18 cycle to resolve some minor conflicts.
2018-08-06vfio-pci: Disable binding to PFs with SR-IOV enabledAlex Williamson
We expect to receive PFs with SR-IOV disabled, however some host drivers leave SR-IOV enabled at unbind. This puts us in a state where we can potentially assign both the PF and the VF, leading to both functionality as well as security concerns due to lack of managing the SR-IOV state as well as vendor dependent isolation from the PF to VF. If we were to attempt to actively disable SR-IOV on driver probe, we risk VF bound drivers blocking, potentially risking live lock scenarios. Therefore simply refuse to bind to PFs with SR-IOV enabled with a warning message indicating the issue. Users can resolve this by re-binding to the host driver and disabling SR-IOV before attempting to use the device with vfio-pci. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-08-06vfio: Mark expected switch fall-throughsGustavo A. R. Silva
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>
2018-07-21Merge tag 'powerpc-4.18-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Two regression fixes, one for xmon disassembly formatting and the other to fix the E500 build. Two commits to fix a potential security issue in the VFIO code under obscure circumstances. And finally a fix to the Power9 idle code to restore SPRG3, which is user visible and used for sched_getcpu(). Thanks to: Alexey Kardashevskiy, David Gibson. Gautham R. Shenoy, James Clarke" * tag 'powerpc-4.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle) powerpc/Makefile: Assemble with -me500 when building for E500 KVM: PPC: Check if IOMMU page is contained in the pinned physical page vfio/spapr: Use IOMMU pageshift rather than pagesize powerpc/xmon: Fix disassembly since printf changes
2018-07-19PCI: Rename pci_try_reset_bus() to pci_reset_bus()Sinan Kaya
Now that the old implementation of pci_reset_bus() is gone, replace pci_try_reset_bus() with pci_reset_bus(). Compared to the old implementation, new code will fail immmediately with -EAGAIN if object lock cannot be obtained. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-07-19PCI: Unify try slot and bus reset APISinan Kaya
Drivers are expected to call pci_try_reset_slot() or pci_try_reset_bus() by querying if a system supports hotplug or not. A survey showed that most drivers don't do this and we are leaking hotplug capability to the user. Hide pci_try_slot_reset() from drivers and embed into pci_try_bus_reset(). Change pci_try_reset_bus() parameter from struct pci_bus to struct pci_dev. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-07-18vfio/pci: Fix potential Spectre v1Gustavo A. R. Silva
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>
2018-07-18KVM: PPC: Check if IOMMU page is contained in the pinned physical pageAlexey Kardashevskiy
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>
2018-07-18vfio/spapr: Use IOMMU pageshift rather than pagesizeAlexey Kardashevskiy
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>
2018-07-16powerpc/powernv/ioda: Allocate indirect TCE levels on demandAlexey Kardashevskiy
At the moment we allocate the entire TCE table, twice (hardware part and userspace translation cache). This normally works as we normally have contigous memory and the guest will map entire RAM for 64bit DMA. However if we have sparse RAM (one example is a memory device), then we will allocate TCEs which will never be used as the guest only maps actual memory for DMA. If it is a single level TCE table, there is nothing we can really do but if it a multilevel table, we can skip allocating TCEs we know we won't need. This adds ability to allocate only first level, saving memory. This changes iommu_table::free() to avoid allocating of an extra level; iommu_table::set() will do this when needed. This adds @alloc parameter to iommu_table::exchange() to tell the callback if it can allocate an extra level; the flag is set to "false" for the realmode KVM handlers of H_PUT_TCE hcalls and the callback returns H_TOO_HARD. This still requires the entire table to be counted in mm::locked_vm. To be conservative, this only does on-demand allocation when the usespace cache table is requested which is the case of VFIO. The example math for a system replicating a powernv setup with NVLink2 in a guest: 16GB RAM mapped at 0x0 128GB GPU RAM window (16GB of actual RAM) mapped at 0x244000000000 the table to cover that all with 64K pages takes: (((0x244000000000 + 0x2000000000) >> 16)*8)>>20 = 4556MB If we allocate only necessary TCE levels, we will only need: (((0x400000000 + 0x400000000) >> 16)*8)>>20 = 4MB (plus some for indirect levels). 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>
2018-07-16powerpc/powernv: Add indirect levels to it_userspaceAlexey Kardashevskiy
We want to support sparse memory and therefore huge chunks of DMA windows do not need to be mapped. If a DMA window big enough to require 2 or more indirect levels, and a DMA window is used to map all RAM (which is a default case for 64bit window), we can actually save some memory by not allocation TCE for regions which we are not going to map anyway. The hardware tables alreary support indirect levels but we also keep host-physical-to-userspace translation array which is allocated by vmalloc() and is a flat array which might use quite some memory. This converts it_userspace from vmalloc'ed array to a multi level table. As the format becomes platform dependend, this replaces the direct access to it_usespace with a iommu_table_ops::useraddrptr hook which returns a pointer to the userspace copy of a TCE; future extension will return NULL if the level was not allocated. This should not change non-KVM handling of TCE tables and it_userspace will not be allocated for non-KVM tables. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-16KVM: PPC: Make iommu_table::it_userspace big endianAlexey Kardashevskiy
We are going to reuse multilevel TCE code for the userspace copy of the TCE table and since it is big endian, let's make the copy big endian too. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-30vfio: Use get_user_pages_longterm correctlyJason Gunthorpe
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>
2018-06-18vfio/pci: Make IGD support a configurable optionAlex Williamson
Allow the code which provides extensions to support direct assignment of Intel IGD (GVT-d) to be compiled out of the kernel if desired. The config option for this was previously automatically enabled on X86, therefore the default remains Y. This simply provides the option to disable it even for X86. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-12Merge tag 'vfio-v4.18-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Bind type1 task tracking to group_leader to facilitate vCPU hotplug in QEMU (Alex Williamson) - Sample mdev display drivers, including region-based host and guest Linux drivers and bochs compatible dmabuf device (Gerd Hoffmann) - Fix vfio-platform reset module leak (Geert Uytterhoeven) - vfio-platform error message consistency (Geert Uytterhoeven) - Global checking for mdev uuid collisions rather than per parent device (Alex Williamson) - Use match_string() helper (Yisheng Xie) - vfio-platform PM domain fixes (Geert Uytterhoeven) - Fix sample mbochs driver build dependency (Arnd Bergmann) * tag 'vfio-v4.18-rc1' of git://github.com/awilliam/linux-vfio: samples: mbochs: add DMA_SHARED_BUFFER dependency vfio: platform: Fix using devices in PM Domains vfio: use match_string() helper vfio/mdev: Re-order sysfs attribute creation vfio/mdev: Check globally for duplicate devices vfio: platform: Make printed error messages more consistent vfio: platform: Fix reset module leak in error path sample: vfio bochs vbe display (host device for bochs-drm) sample: vfio mdev display - guest driver sample: vfio mdev display - host device vfio/type1: Fix task tracking for QEMU vCPU hotplug
2018-06-08vfio: platform: Fix using devices in PM DomainsGeert Uytterhoeven
If a device is part of a PM Domain (e.g. power and/or clock domain), its power state is managed using Runtime PM. Without Runtime PM, the device may not be powered up or clocked, causing subtle failures, crashes, or system lock-ups when the device is accessed by the guest. Fix this by adding Runtime PM support, powering the device when the VFIO device is opened by the guest. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08vfio: use match_string() helperYisheng Xie
match_string() returns the index of an array for a matching string, which can be used intead of open coded variant. Cc: Alex Williamson <alex.williamson@redhat.com> Cc: kvm@vger.kernel.org Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08vfio/mdev: Re-order sysfs attribute creationAlex Williamson
There exists a gap at the end of mdev_device_create() where the device is visible to userspace, but we're not yet ready to handle removal, as triggered through the 'remove' attribute. We handle this properly in mdev_device_remove() with an -EAGAIN return, but we can marginally reduce this gap by adding this attribute as a final step of our sysfs setup. Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08vfio/mdev: Check globally for duplicate devicesAlex Williamson
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>
2018-06-08vfio: platform: Make printed error messages more consistentGeert Uytterhoeven
- Capitalize the first word of error messages, - Unwrap statements that fit on a single line, - Use "VFIO" instead of "vfio" as the error message prefix. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eric Auger <eric.auger@redhat.com> Acked-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08vfio: platform: Fix reset module leak in error pathGeert Uytterhoeven
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>
2018-06-08vfio/type1: Fix task tracking for QEMU vCPU hotplugAlex Williamson
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>
2018-06-04Merge branch 'work.aio-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-06-02Revert "vfio/type1: Improve memory pinning process for raw PFN mapping"Alex Williamson
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>
2018-05-26fs: add new vfs_poll and file_can_poll helpersChristoph Hellwig
These abstract out calls to the poll method in preparation for changes in how we poll. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-04-06Merge tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Adopt iommu_unmap_fast() interface to type1 backend (Suravee Suthikulpanit) - mdev sample driver fixup (Shunyong Yang) - More efficient PFN mapping handling in type1 backend (Jason Cai) - VFIO device ioeventfd interface (Alex Williamson) - Tag new vfio-platform sub-maintainer (Alex Williamson) * tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfio: MAINTAINERS: vfio/platform: Update sub-maintainer vfio/pci: Add ioeventfd support vfio/pci: Use endian neutral helpers vfio/pci: Pull BAR mapping setup from read-write path vfio/type1: Improve memory pinning process for raw PFN mapping vfio-mdev/samples: change RDI interrupt condition vfio/type1: Adopt fast IOTLB flush interface when unmap IOVAs
2018-03-26vfio/pci: Add ioeventfd supportAlex Williamson
The ioeventfd here is actually irqfd handling of an ioeventfd such as supported in KVM. A user is able to pre-program a device write to occur when the eventfd triggers. This is yet another instance of eventfd-irqfd triggering between KVM and vfio. The impetus for this is high frequency writes to pages which are virtualized in QEMU. Enabling this near-direct write path for selected registers within the virtualized page can improve performance and reduce overhead. Specifically this is initially targeted at NVIDIA graphics cards where the driver issues a write to an MMIO register within a virtualized region in order to allow the MSI interrupt to re-trigger. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>