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2021-02-22KVM: x86/mmu: Consider the hva in mmu_notifier retryDavid Stevens1-4/+25
Track the range being invalidated by mmu_notifier and skip page fault retries if the fault address is not affected by the in-progress invalidation. Handle concurrent invalidations by finding the minimal range which includes all ranges being invalidated. Although the combined range may include unrelated addresses and cannot be shrunk as individual invalidation operations complete, it is unlikely the marginal gains of proper range tracking are worth the additional complexity. The primary benefit of this change is the reduction in the likelihood of extreme latency when handing a page fault due to another thread having been preempted while modifying host virtual addresses. Signed-off-by: David Stevens <stevensd@chromium.org> Message-Id: <20210222024522.1751719-3-stevensd@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped()Sean Christopherson1-1/+1
Use kvm_pfn_t, a.k.a. u64, for the local 'pfn' variable when retrieving a so called "remapped" hva/pfn pair. In theory, the hva could resolve to a pfn in high memory on a 32-bit kernel. This bug was inadvertantly exposed by commit bd2fae8da794 ("KVM: do not assume PTE is writable after follow_pfn"), which added an error PFN value to the mix, causing gcc to comlain about overflowing the unsigned long. arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function ‘hva_to_pfn_remapped’: include/linux/kvm_host.h:89:30: error: conversion from ‘long long unsigned int’ to ‘long unsigned int’ changes value from ‘9218868437227405314’ to ‘2’ [-Werror=overflow] 89 | #define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2) | ^ virt/kvm/kvm_main.c:1935:9: note: in expansion of macro ‘KVM_PFN_ERR_RO_FAULT’ Cc: stable@vger.kernel.org Fixes: add6a0cd1c5b ("KVM: MMU: try to fix up page faults before giving up") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210208201940.1258328-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09mm: provide a saner PTE walking API for modulesPaolo Bonzini1-2/+2
Currently, the follow_pfn function is exported for modules but follow_pte is not. However, follow_pfn is very easy to misuse, because it does not provide protections (so most of its callers assume the page is writable!) and because it returns after having already unlocked the page table lock. Provide instead a simplified version of follow_pte that does not have the pmdpp and range arguments. The older version survives as follow_invalidate_pte() for use by fs/dax.c. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86/mmu: Use an rwlock for the x86 MMUBen Gardon3-19/+46
Add a read / write lock to be used in place of the MMU spinlock on x86. The rwlock will enable the TDP MMU to handle page faults, and other operations in parallel in future commits. Reviewed-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210202185734.1680553-19-bgardon@google.com> [Introduce virt/kvm/mmu_lock.h - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: X86: use vzalloc() instead of vmalloc/memsetTian Tao1-2/+1
fixed the following warning： /virt/kvm/dirty_ring.c:70:20-27: WARNING: vzalloc should be used for ring -> dirty_gfns, instead of vmalloc/memset. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Message-Id: <1611547045-13669-1-git-send-email-tiantao6@hisilicon.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: do not assume PTE is writable after follow_pfnPaolo Bonzini1-3/+12
In order to convert an HVA to a PFN, KVM usually tries to use the get_user_pages family of functinso. This however is not possible for VM_IO vmas; in that case, KVM instead uses follow_pfn. In doing this however KVM loses the information on whether the PFN is writable. That is usually not a problem because the main use of VM_IO vmas with KVM is for BARs in PCI device assignment, however it is a bug. To fix it, use follow_pte and check pte_write while under the protection of the PTE lock. The information can be used to fail hva_to_pfn_remapped or passed back to the caller via *writable. Usage of follow_pfn was introduced in commit add6a0cd1c5b ("KVM: MMU: try to fix up page faults before giving up", 2016-07-05); however, even older version have the same issue, all the way back to commit 2e2e3738af33 ("KVM: Handle vma regions with no backing page", 2008-07-20), as they also did not check whether the PFN was writable. Fixes: 2e2e3738af33 ("KVM: Handle vma regions with no backing page") Reported-by: David Stevens <stevensd@google.com> Cc: 3pvd@google.com Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-25Merge tag 'kvmarm-fixes-5.11-2' of ↵Paolo Bonzini1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.11, take #2 - Don't allow tagged pointers to point to memslots - Filter out ARMv8.1+ PMU events on v8.0 hardware - Hide PMU registers from userspace when no PMU is configured - More PMU cleanups - Don't try to handle broken PSCI firmware - More sys_reg() to reg_to_encoding() conversions
2021-01-21KVM: Forbid the use of tagged userspace addresses for memslotsMarc Zyngier1-0/+1
The use of a tagged address could be pretty confusing for the whole memslot infrastructure as well as the MMU notifiers. Forbid it altogether, as it never quite worked the first place. Cc: stable@vger.kernel.org Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-01-08Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-2/+1
Pull kvm fixes from Paolo Bonzini: "x86: - Fixes for the new scalable MMU - Fixes for migration of nested hypervisors on AMD - Fix for clang integrated assembler - Fix for left shift by 64 (UBSAN) - Small cleanups - Straggler SEV-ES patch ARM: - VM init cleanups - PSCI relay cleanups - Kill CONFIG_KVM_ARM_PMU - Fixup __init annotations - Fixup reg_to_encoding() - Fix spurious PMCR_EL0 access Misc: - selftests cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (38 commits) KVM: x86: __kvm_vcpu_halt can be static KVM: SVM: Add support for booting APs in an SEV-ES guest KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexit KVM: nSVM: mark vmcb as dirty when forcingly leaving the guest mode KVM: nSVM: correctly restore nested_run_pending on migration KVM: x86/mmu: Clarify TDP MMU page list invariants KVM: x86/mmu: Ensure TDP MMU roots are freed after yield kvm: check tlbs_dirty directly KVM: x86: change in pv_eoi_get_pending() to make code more readable MAINTAINERS: Really update email address for Sean Christopherson KVM: x86: fix shift out of bounds reported by UBSAN KVM: selftests: Implement perf_test_util more conventionally KVM: selftests: Use vm_create_with_vcpus in create_vm KVM: selftests: Factor out guest mode code KVM/SVM: Remove leftover __svm_vcpu_run prototype from svm.c KVM: SVM: Add register operand to vmsave call in sev_es_vcpu_load KVM: x86/mmu: Optimize not-present/MMIO SPTE check in get_mmio_spte() KVM: x86/mmu: Use raw level to index into MMIO walks' sptes array KVM: x86/mmu: Get root level from walkers when retrieving MMIO SPTE KVM: x86/mmu: Use -1 to flag an undefined spte in get_mmio_spte() ...
2021-01-07kvm: check tlbs_dirty directlyLai Jiangshan1-2/+1
In kvm_mmu_notifier_invalidate_range_start(), tlbs_dirty is used as: need_tlb_flush |= kvm->tlbs_dirty; with need_tlb_flush's type being int and tlbs_dirty's type being long. It means that tlbs_dirty is always used as int and the higher 32 bits is useless. We need to check tlbs_dirty in a correct way and this change checks it directly without propagating it to need_tlb_flush. Note: it's _extremely_ unlikely this neglecting of higher 32 bits can cause problems in practice. It would require encountering tlbs_dirty on a 4 billion count boundary, and KVM would need to be using shadow paging or be running a nested guest. Cc: stable@vger.kernel.org Fixes: a4ee1ca4a36e ("KVM: MMU: delay flush all tlbs on sync_page path") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20201217154118.16497-1-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-20Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-27/+346
Pull KVM updates from Paolo Bonzini: "Much x86 work was pushed out to 5.12, but ARM more than made up for it. ARM: - PSCI relay at EL2 when "protected KVM" is enabled - New exception injection code - Simplification of AArch32 system register handling - Fix PMU accesses when no PMU is enabled - Expose CSV3 on non-Meltdown hosts - Cache hierarchy discovery fixes - PV steal-time cleanups - Allow function pointers at EL2 - Various host EL2 entry cleanups - Simplification of the EL2 vector allocation s390: - memcg accouting for s390 specific parts of kvm and gmap - selftest for diag318 - new kvm_stat for when async_pf falls back to sync x86: - Tracepoints for the new pagetable code from 5.10 - Catch VFIO and KVM irqfd events before userspace - Reporting dirty pages to userspace with a ring buffer - SEV-ES host support - Nested VMX support for wait-for-SIPI activity state - New feature flag (AVX512 FP16) - New system ioctl to report Hyper-V-compatible paravirtualization features Generic: - Selftest improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits) KVM: SVM: fix 32-bit compilation KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting KVM: SVM: Provide support to launch and run an SEV-ES guest KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests KVM: SVM: Provide support for SEV-ES vCPU loading KVM: SVM: Provide support for SEV-ES vCPU creation/loading KVM: SVM: Update ASID allocation to support SEV-ES guests KVM: SVM: Set the encryption mask for the SVM host save area KVM: SVM: Add NMI support for an SEV-ES guest KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest KVM: SVM: Do not report support for SMM for an SEV-ES guest KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES KVM: SVM: Add support for CR8 write traps for an SEV-ES guest KVM: SVM: Add support for CR4 write traps for an SEV-ES guest KVM: SVM: Add support for CR0 write traps for an SEV-ES guest KVM: SVM: Add support for EFER write traps for an SEV-ES guest KVM: SVM: Support string IO operations for an SEV-ES guest KVM: SVM: Support MMIO for an SEV-ES guest KVM: SVM: Create trace events for VMGEXIT MSR protocol processing KVM: SVM: Create trace events for VMGEXIT processing ...
2020-12-19mm, kvm: account kvm_vcpu_mmap to kmemcgShakeel Butt2-2/+2
A VCPU of a VM can allocate couple of pages which can be mmap'ed by the user space application. At the moment this memory is not charged to the memcg of the VMM. On a large machine running large number of VMs or small number of VMs having large number of VCPUs, this unaccounted memory can be very significant. So, charge this memory to the memcg of the VMM. Please note that lifetime of these allocations corresponds to the lifetime of the VMM. Link: https://lkml.kernel.org/r/20201106202923.2087414-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-15KVM: Don't allocate dirty bitmap if dirty ring is enabledPeter Xu1-2/+2
Because kvm dirty rings and kvm dirty log is used in an exclusive way, Let's avoid creating the dirty_bitmap when kvm dirty ring is enabled. At the meantime, since the dirty_bitmap will be conditionally created now, we can't use it as a sign of "whether this memory slot enabled dirty tracking". Change users like that to check against the kvm memory slot flags. Note that there still can be chances where the kvm memory slot got its dirty_bitmap allocated, _if_ the memory slots are created before enabling of the dirty rings and at the same time with the dirty tracking capability enabled, they'll still with the dirty_bitmap. However it should not hurt much (e.g., the bitmaps will always be freed if they are there), and the real users normally won't trigger this because dirty bit tracking flag should in most cases only be applied to kvm slots only before migration starts, that should be far latter than kvm initializes (VM starts). Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012226.5868-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: Make dirty ring exclusive to dirty bitmap logPeter Xu1-0/+12
There's no good reason to use both the dirty bitmap logging and the new dirty ring buffer to track dirty bits. We should be able to even support both of them at the same time, but it could complicate things which could actually help little. Let's simply make it the rule before we enable dirty ring on any arch, that we don't allow these two interfaces to be used together. The big world switch would be KVM_CAP_DIRTY_LOG_RING capability enablement. That's where we'll switch from the default dirty logging way to the dirty ring way. As long as kvm->dirty_ring_size is setup correctly, we'll once and for all switch to the dirty ring buffer mode for the current virtual machine. Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012224.5818-1-peterx@redhat.com> [Change errno from EINVAL to ENXIO. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: X86: Implement ring-based dirty memory trackingPeter Xu2-1/+306
This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: Pass in kvm pointer into mark_page_dirty_in_slot()Peter Xu1-13/+17
The context will be needed to implement the kvm dirty ring. Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012044.5151-5-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: remove kvm_clear_guest_pagePaolo Bonzini1-9/+2
kvm_clear_guest_page is not used anymore after "KVM: X86: Don't track dirty for KVM_SET_[TSS_ADDR|IDENTITY_MAP_ADDR]", except from kvm_clear_guest. We can just inline it in its sole user. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15kvm/eventfd: Drain events from eventfd in irqfd_wakeup()David Woodhouse1-0/+3
Don't allow the events to accumulate in the eventfd counter, drain them as they are handled. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20201027135523.646811-4-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15kvm/eventfd: Use priority waitqueue to catch events before userspaceDavid Woodhouse1-2/+4
As far as I can tell, when we use posted interrupts we silently cut off the events from userspace, if it's listening on the same eventfd that feeds the irqfd. I like that behaviour. Let's do it all the time, even without posted interrupts. It makes it much easier to handle IRQ remapping invalidation without having to constantly add/remove the fd from the userspace poll set. We can just leave userspace polling on it, and the bypass will... well... bypass it. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20201026175325.585623-2-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support dirty logging for the TDP MMUBen Gardon1-4/+2
Dirty logging is a key feature of the KVM MMU and must be supported by the TDP MMU. Add support for both the write protection and PML dirty logging modes. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-16-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21KVM: Cache as_id in kvm_memory_slotPeter Xu1-0/+6
Cache the address space ID just like the slot ID. It will be used in order to fill in the dirty ring entries. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201014182700.2888246-7-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: use struct_size() and flex_array_size() helpers in ↵Rustam Kovhaev1-2/+2
kvm_io_bus_unregister_dev() Make use of the struct_size() helper to avoid any potential type mistakes and protect against potential integer overflows Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure Suggested-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com> Message-Id: <20200918120500.954436-1-rkovhaev@gmail.com> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28kvm/eventfd: move wildcard calculation outside loopYi Li1-1/+3
There is no need to calculate wildcard in each iteration since wildcard is not changed. Signed-off-by: Yi Li <yili@winhong.com> Message-Id: <20200911055652.3041762-1-yili@winhong.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-11KVM: fix memory leak in kvm_io_bus_unregister_dev()Rustam Kovhaev1-9/+12
when kmalloc() fails in kvm_io_bus_unregister_dev(), before removing the bus, we should iterate over all other devices linked to it and call kvm_iodevice_destructor() for them Fixes: 90db10434b16 ("KVM: kvm_io_bus_unregister_dev() should never fail") Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+f196caa45793d6374707@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=f196caa45793d6374707 Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200907185535.233114-1-rkovhaev@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-11Merge tag 'kvmarm-fixes-5.9-1' of ↵Paolo Bonzini4-9/+13
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for Linux 5.9, take #1 - Multiple stolen time fixes, with a new capability to match x86 - Fix for hugetlbfs mappings when PUD and PMD are the same level - Fix for hugetlbfs mappings when PTE mappings are enforced (dirty logging, for example) - Fix tracing output of 64bit values
2020-08-21KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()Will Deacon1-1/+2
The 'flags' field of 'struct mmu_notifier_range' is used to indicate whether invalidate_range_{start,end}() are permitted to block. In the case of kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded on to the architecture-specific implementation of kvm_unmap_hva_range() and therefore the backend cannot sensibly decide whether or not to block. Add an extra 'flags' parameter to kvm_unmap_hva_range() so that architectures are aware as to whether or not they are permitted to block. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20200811102725.7121-2-will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-12Merge branch 'akpm' (patches from Andrew)Linus Torvalds2-2/+2
Merge more updates from Andrew Morton: - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction, mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util, memory-hotplug, cleanups, uaccess, migration, gup, pagemap), - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops, checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump, exec, kdump, rapidio, panic, kcov, kgdb, ipc). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits) mm/gup: remove task_struct pointer for all gup code mm: clean up the last pieces of page fault accountings mm/xtensa: use general page fault accounting mm/x86: use general page fault accounting mm/sparc64: use general page fault accounting mm/sparc32: use general page fault accounting mm/sh: use general page fault accounting mm/s390: use general page fault accounting mm/riscv: use general page fault accounting mm/powerpc: use general page fault accounting mm/parisc: use general page fault accounting mm/openrisc: use general page fault accounting mm/nios2: use general page fault accounting mm/nds32: use general page fault accounting mm/mips: use general page fault accounting mm/microblaze: use general page fault accounting mm/m68k: use general page fault accounting mm/ia64: use general page fault accounting mm/hexagon: use general page fault accounting mm/csky: use general page fault accounting ...
2020-08-12mm/gup: remove task_struct pointer for all gup codePeter Xu2-2/+2
After the cleanup of page fault accounting, gup does not need to pass task_struct around any more. Remove that parameter in the whole gup stack. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-11Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-6/+10
Pull virtio updates from Michael Tsirkin: - IRQ bypass support for vdpa and IFC - MLX5 vdpa driver - Endianness fixes for virtio drivers - Misc other fixes * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (71 commits) vdpa/mlx5: fix up endian-ness for mtu vdpa: Fix pointer math bug in vdpasim_get_config() vdpa/mlx5: Fix pointer math in mlx5_vdpa_get_config() vdpa/mlx5: fix memory allocation failure checks vdpa/mlx5: Fix uninitialised variable in core/mr.c vdpa_sim: init iommu lock virtio_config: fix up warnings on parisc vdpa/mlx5: Add VDPA driver for supported mlx5 devices vdpa/mlx5: Add shared memory registration code vdpa/mlx5: Add support library for mlx5 VDPA implementation vdpa/mlx5: Add hardware descriptive header file vdpa: Modify get_vq_state() to return error code net/vdpa: Use struct for set/get vq state vdpa: remove hard coded virtq num vdpasim: support batch updating vhost-vdpa: support IOTLB batching hints vhost-vdpa: support get/set backend features vhost: generialize backend features setting/getting vhost-vdpa: refine ioctl pre-processing vDPA: dont change vq irq after DRIVER_OK ...
2020-08-10Merge tag 'locking-urgent-2020-08-10' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Thomas Gleixner: "A set of locking fixes and updates: - Untangle the header spaghetti which causes build failures in various situations caused by the lockdep additions to seqcount to validate that the write side critical sections are non-preemptible. - The seqcount associated lock debug addons which were blocked by the above fallout. seqcount writers contrary to seqlock writers must be externally serialized, which usually happens via locking - except for strict per CPU seqcounts. As the lock is not part of the seqcount, lockdep cannot validate that the lock is held. This new debug mechanism adds the concept of associated locks. sequence count has now lock type variants and corresponding initializers which take a pointer to the associated lock used for writer serialization. If lockdep is enabled the pointer is stored and write_seqcount_begin() has a lockdep assertion to validate that the lock is held. Aside of the type and the initializer no other code changes are required at the seqcount usage sites. The rest of the seqcount API is unchanged and determines the type at compile time with the help of _Generic which is possible now that the minimal GCC version has been moved up. Adding this lockdep coverage unearthed a handful of seqcount bugs which have been addressed already independent of this. While generally useful this comes with a Trojan Horse twist: On RT kernels the write side critical section can become preemtible if the writers are serialized by an associated lock, which leads to the well known reader preempts writer livelock. RT prevents this by storing the associated lock pointer independent of lockdep in the seqcount and changing the reader side to block on the lock when a reader detects that a writer is in the write side critical section. - Conversion of seqcount usage sites to associated types and initializers" * tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) locking/seqlock, headers: Untangle the spaghetti monster locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header x86/headers: Remove APIC headers from <asm/smp.h> seqcount: More consistent seqprop names seqcount: Compress SEQCNT_LOCKNAME_ZERO() seqlock: Fold seqcount_LOCKNAME_init() definition seqlock: Fold seqcount_LOCKNAME_t definition seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g hrtimer: Use sequence counter with associated raw spinlock kvm/eventfd: Use sequence counter with associated spinlock userfaultfd: Use sequence counter with associated spinlock NFSv4: Use sequence counter with associated spinlock iocost: Use sequence counter with associated spinlock raid5: Use sequence counter with associated spinlock vfs: Use sequence counter with associated spinlock timekeeping: Use sequence counter with associated raw spinlock xfrm: policy: Use sequence counters with associated lock netfilter: nft_set_rbtree: Use sequence counter with associated rwlock netfilter: conntrack: Use sequence counter with associated spinlock sched: tasks: Use sequence counter with associated spinlock ...
2020-08-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-6/+73
Pull KVM updates from Paolo Bonzini: "s390: - implement diag318 x86: - Report last CPU for debugging - Emulate smaller MAXPHYADDR in the guest than in the host - .noinstr and tracing fixes from Thomas - nested SVM page table switching optimization and fixes Generic: - Unify shadow MMU cache data structures across architectures" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits) KVM: SVM: Fix sev_pin_memory() error handling KVM: LAPIC: Set the TDCR settable bits KVM: x86: Specify max TDP level via kvm_configure_mmu() KVM: x86/mmu: Rename max_page_level to max_huge_page_level KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR KVM: VXM: Remove temporary WARN on expected vs. actual EPTP level mismatch KVM: x86: Pull the PGD's level from the MMU instead of recalculating it KVM: VMX: Make vmx_load_mmu_pgd() static KVM: x86/mmu: Add separate helper for shadow NPT root page role calc KVM: VMX: Drop a duplicate declaration of construct_eptp() KVM: nSVM: Correctly set the shadow NPT root level in its MMU role KVM: Using macros instead of magic values MIPS: KVM: Fix build error caused by 'kvm_run' cleanup KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support KVM: VMX: optimize #PF injection when MAXPHYADDR does not match KVM: VMX: Add guest physical address check in EPT violation and misconfig KVM: VMX: introduce vmx_need_pf_intercept KVM: x86: update exception bitmap on CPUID changes KVM: x86: rename update_bp_intercept to update_exception_bitmap ...
2020-08-05irqbypass: do not start cons/prod when failed connectZhu Lingshan1-6/+10
If failed to connect, there is no need to start consumer nor producer. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Suggested-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200731065533.4144-7-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-29kvm/eventfd: Use sequence counter with associated spinlockAhmed S. Darwish1-1/+1
A sequence counter write side critical section must be protected by some form of locking to serialize writers. A plain seqcount_t does not contain the information of which lock must be held when entering a write side critical section. Use the new seqcount_spinlock_t data type, which allows to associate a spinlock with the sequence counter. This enables lockdep to verify that the spinlock used for writer serialization is held when the write side critical section is entered. If lockdep is disabled this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lkml.kernel.org/r/20200720155530.1173732-24-a.darwish@linutronix.de
2020-07-24entry: Provide infrastructure for work before transitioning to guest modeThomas Gleixner1-0/+3
Entering a guest is similar to exiting to user space. Pending work like handling signals, rescheduling, task work etc. needs to be handled before that. Provide generic infrastructure to avoid duplication of the same handling code all over the place. The transfer to guest mode handling is different from the exit to usermode handling, e.g. vs. rseq and live patching, so a separate function is used. The initial list of work items handled is: TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME Architecture specific TIF flags can be added via defines in the architecture specific include files. The calling convention is also different from the syscall/interrupt entry functions as KVM invokes this from the outer vcpu_run() loop with interrupts and preemption enabled. To prevent missing a pending work item it invokes a check for pending TIF work from interrupt disabled code right before transitioning to guest mode. The lockdep, RCU and tracing state handling is also done directly around the switch to and from guest mode. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200722220519.833296398@linutronix.de
2020-07-09KVM: Move x86's MMU memory cache helpers to common KVM codeSean Christopherson1-0/+55
Move x86's memory cache helpers to common KVM code so that they can be reused by arm64 and MIPS in future patches. Suggested-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200703023545.8771-16-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09KVM: x86: take as_id into account when checking PGDVitaly Kuznetsov1-0/+8
OVMF booted guest running on shadow pages crashes on TRIPLE FAULT after enabling paging from SMM. The crash is triggered from mmu_check_root() and is caused by kvm_is_visible_gfn() searching through memslots with as_id = 0 while vCPU may be in a different context (address space). Introduce kvm_vcpu_is_visible_gfn() and use it from mmu_check_root(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200708140023.1476020-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08KVM: async_pf: change kvm_setup_async_pf()/kvm_arch_setup_async_pf() return ↵Vitaly Kuznetsov1-6/+10
type to bool Unlike normal 'int' functions returning '0' on success, kvm_setup_async_pf()/ kvm_arch_setup_async_pf() return '1' when a job to handle page fault asynchronously was scheduled and '0' otherwise. To avoid the confusion change return type to 'bool'. No functional change intended. Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200615121334.91300-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-02kvm: use more precise cast and do not drop __userPaolo Bonzini1-1/+2
Sparse complains on a call to get_compat_sigset, fix it. The "if" right above explains that sigmask_arg->sigset is basically a compat_sigset_t. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-12Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-39/+35
Pull more KVM updates from Paolo Bonzini: "The guest side of the asynchronous page fault work has been delayed to 5.9 in order to sync with Thomas's interrupt entry rework, but here's the rest of the KVM updates for this merge window. MIPS: - Loongson port PPC: - Fixes ARM: - Fixes x86: - KVM_SET_USER_MEMORY_REGION optimizations - Fixes - Selftest fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (62 commits) KVM: x86: do not pass poisoned hva to __kvm_set_memory_region KVM: selftests: fix sync_with_host() in smm_test KVM: async_pf: Inject 'page ready' event only if 'page not present' was previously injected KVM: async_pf: Cleanup kvm_setup_async_pf() kvm: i8254: remove redundant assignment to pointer s KVM: x86: respect singlestep when emulating instruction KVM: selftests: Don't probe KVM_CAP_HYPERV_ENLIGHTENED_VMCS when nested VMX is unsupported KVM: selftests: do not substitute SVM/VMX check with KVM_CAP_NESTED_STATE check KVM: nVMX: Consult only the "basic" exit reason when routing nested exit KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts KVM: arm64: Remove host_cpu_context member from vcpu structure KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr KVM: arm64: Handle PtrAuth traps early KVM: x86: Unexport x86_fpu_cache and make it static KVM: selftests: Ignore KVM 5-level paging support for VM_MODE_PXXV48_4K KVM: arm64: Save the host's PtrAuth keys in non-preemptible context KVM: arm64: Stop save/restoring ACTLR_EL1 KVM: arm64: Add emulation for 32bit guests accessing ACTLR2 ...
2020-06-11KVM: async_pf: Inject 'page ready' event only if 'page not present' was ↵Vitaly Kuznetsov1-1/+1
previously injected 'Page not present' event may or may not get injected depending on guest's state. If the event wasn't injected, there is no need to inject the corresponding 'page ready' event as the guest may get confused. E.g. Linux thinks that the corresponding 'page not present' event wasn't delivered *yet* and allocates a 'dummy entry' for it. This entry is never freed. Note, 'wakeup all' events have no corresponding 'page not present' event and always get injected. s390 seems to always be able to inject 'page not present', the change is effectively a nop. Suggested-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200610175532.779793-2-vkuznets@redhat.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=208081 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-11KVM: async_pf: Cleanup kvm_setup_async_pf()Vitaly Kuznetsov1-13/+6
schedule_work() returns 'false' only when the work is already on the queue and this can't happen as kvm_setup_async_pf() always allocates a new one. Also, to avoid potential race, it makes sense to to schedule_work() at the very end after we've added it to the queue. While on it, do some minor cleanup. gfn_to_pfn_async() mentioned in a comment does not currently exist and, moreover, we can check kvm_is_error_hva() at the very beginning, before we try to allocate work so 'retry_sync' label can go away completely. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200610175532.779793-1-vkuznets@redhat.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse2-6/+6
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport1-1/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08mm/gup.c: convert to use get_user_{page|pages}_fast_only()Souptick Joarder1-5/+3
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08KVM: x86: Fix APIC page invalidation raceEiichi Tsukata1-10/+16
Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-04KVM: Use vmemdup_user()Denis Efremov1-11/+8
Replace opencoded alloc and copy with vmemdup_user(). Signed-off-by: Denis Efremov <efremov@linux.com> Message-Id: <20200603101131.2107303-1-efremov@linux.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-04KVM: let kvm_destroy_vm_debugfs clean up vCPU debugfs directoriesPaolo Bonzini1-4/+4
After commit 63d0434 ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") we are creating the pre-vCPU debugfs files after the creation of the vCPU file descriptor. This makes it possible for userspace to reach kvm_vcpu_release before kvm_create_vcpu_debugfs has finished. The vcpu->debugfs_dentry then does not have any associated inode anymore, and this causes a NULL-pointer dereference in debugfs_create_file. The solution is simply to avoid removing the files; they are cleaned up when the VM file descriptor is closed (and that must be after KVM_CREATE_VCPU returns). We can stop storing the dentry in struct kvm_vcpu too, because it is not needed anywhere after kvm_create_vcpu_debugfs returns. Reported-by: syzbot+705f4401d5a93a59b87d@syzkaller.appspotmail.com Fixes: 63d04348371b ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01Merge tag 'kvmarm-5.8' of ↵Paolo Bonzini32-19576/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.8: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches
2020-06-01KVM: check userspace_addr for all memslotsPaolo Bonzini1-3/+2
The userspace_addr alignment and range checks are not performed for private memory slots that are prepared by KVM itself. This is unnecessary and makes it questionable to use __*_user functions to access memory later on. We also rely on the userspace address being aligned since we have an entire family of functions to map gfn to pfn. Fortunately skipping the check is completely unnecessary. Only x86 uses private memslots and their userspace_addr is obtained from vm_mmap, therefore it must be below PAGE_OFFSET. In fact, any attempt to pass an address above PAGE_OFFSET would have failed because such an address would return true for kvm_is_error_hva. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: acknowledgment mechanism for async pf page ready notificationsVitaly Kuznetsov1-0/+10
If two page ready notifications happen back to back the second one is not delivered and the only mechanism we currently have is kvm_check_async_pf_completion() check in vcpu_run() loop. The check will only be performed with the next vmexit when it happens and in some cases it may take a while. With interrupt based page ready notification delivery the situation is even worse: unlike exceptions, interrupts are not handled immediately so we must check if the slot is empty. This is slow and unnecessary. Introduce dedicated MSR_KVM_ASYNC_PF_ACK MSR to communicate the fact that the slot is free and host should check its notification queue. Mandate using it for interrupt based 'page ready' APF event delivery. As kvm_check_async_pf_completion() is going away from vcpu_run() we need a way to communicate the fact that vcpu->async_pf.done queue has transitioned from empty to non-empty state. Introduce kvm_arch_async_page_present_queued() and KVM_REQ_APF_READY to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-7-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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