user/sven/linux.git/virt, branch v5.10.36

KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped()

2021-02-26T09:13:01Z

commit a9545779ee9e9e103648f6f2552e73cfe808d0f4 upstream. 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 Message-Id: <20210208201940.1258328-1-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

mm: provide a saner PTE walking API for modules

2021-02-26T09:13:01Z

commit 9fd6dad1261a541b3f5fa7dc5b152222306e6702 upstream. 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 Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: do not assume PTE is writable after follow_pfn

2021-02-26T09:13:01Z

commit bd2fae8da794b55bf2ac02632da3a151b10e664c upstream. 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 Cc: 3pvd@google.com Cc: Jann Horn Cc: Jason Gunthorpe Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: Forbid the use of tagged userspace addresses for memslots

2021-02-03T22:28:41Z

commit 139bc8a6146d92822c866cf2fd410159c56b3648 upstream. 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 Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

kvm: check tlbs_dirty directly

2021-01-12T19:18:22Z

commit 88bf56d04bc3564542049ec4ec168a8b60d0b48c upstream. 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 Message-Id: <20201217154118.16497-1-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

kvm: x86/mmu: Support dirty logging for the TDP MMU

2020-10-23T07:42:13Z

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 Message-Id: <20201014182700.2888246-16-bgardon@google.com> Signed-off-by: Paolo Bonzini

KVM: Cache as_id in kvm_memory_slot

2020-10-21T22:17:01Z

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 Suggested-by: Sean Christopherson Reviewed-by: Sean Christopherson Signed-off-by: Peter Xu Message-Id: <20201014182700.2888246-7-bgardon@google.com> Signed-off-by: Paolo Bonzini

KVM: use struct_size() and flex_array_size() helpers in kvm_io_bus_unregister_dev()

2020-09-28T11:57:17Z

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 Signed-off-by: Rustam Kovhaev Message-Id: <20200918120500.954436-1-rkovhaev@gmail.com> Reviewed-by: Gustavo A. R. Silva Signed-off-by: Paolo Bonzini

kvm/eventfd: move wildcard calculation outside loop

2020-09-28T11:57:08Z

There is no need to calculate wildcard in each iteration since wildcard is not changed. Signed-off-by: Yi Li Message-Id: <20200911055652.3041762-1-yili@winhong.com> Signed-off-by: Paolo Bonzini

KVM: fix memory leak in kvm_io_bus_unregister_dev()

2020-09-11T17:15:11Z

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 Reviewed-by: Vitaly Kuznetsov Message-Id: <20200907185535.233114-1-rkovhaev@gmail.com> Signed-off-by: Paolo Bonzini