Ben Gardon c3cf9ffe8d KVM: x86/mmu: Ensure TDP MMU roots are freed after yield ... commit a889ea54b3daa63ee1463dc19ed699407d61458b upstream. Many TDP MMU functions which need to perform some action on all TDP MMU roots hold a reference on that root so that they can safely drop the MMU lock in order to yield to other threads. However, when releasing the reference on the root, there is a bug: the root will not be freed even if its reference count (root_count) is reduced to 0. To simplify acquiring and releasing references on TDP MMU root pages, and to ensure that these roots are properly freed, move the get/put operations into another TDP MMU root iterator macro. Moving the get/put operations into an iterator macro also helps simplify control flow when a root does need to be freed. Note that using the list_for_each_entry_safe macro would not have been appropriate in this situation because it could keep a pointer to the next root across an MMU lock release + reacquire, during which time that root could be freed. Reported-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Fixes: faaf05b00a ("kvm: x86/mmu: Support zapping SPTEs in the TDP MMU") Fixes: 063afacd87 ("kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU") Fixes: a6a0b05da9 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") Fixes: 1488199856 ("kvm: x86/mmu: Support disabling dirty logging for the tdp MMU") Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210107001935.3732070-1-bgardon@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-01-12 20:18:22 +01:00
..
mmu_audit.c
mmu_internal.h	kvm: x86/mmu: NX largepage recovery for TDP MMU	2020-10-23 03:42:16 -04:00
mmu.c	KVM: x86/mmu: Get root level from walkers when retrieving MMIO SPTE	2021-01-12 20:18:22 +01:00
mmutrace.h	kvm: x86/mmu: Add TDP MMU PF handler	2020-10-23 03:42:04 -04:00
page_track.c
paging_tmpl.h	kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg	2020-10-21 18:17:02 -04:00
spte.c	KVM: mmu: Fix SPTE encoding of MMIO generation upper half	2020-12-11 19:18:43 -05:00
spte.h	KVM: mmu: Fix SPTE encoding of MMIO generation upper half	2020-12-11 19:18:43 -05:00
tdp_iter.c	kvm: x86/mmu: Support zapping SPTEs in the TDP MMU	2020-10-21 18:17:02 -04:00
tdp_iter.h	kvm: x86/mmu: Support dirty logging for the TDP MMU	2020-10-23 03:42:13 -04:00
tdp_mmu.c	KVM: x86/mmu: Ensure TDP MMU roots are freed after yield	2021-01-12 20:18:22 +01:00
tdp_mmu.h	KVM: x86/mmu: Get root level from walkers when retrieving MMIO SPTE	2021-01-12 20:18:22 +01:00