From: David Stevens <stevensd@xxxxxxxxxxxx> Remove two warnings that require ref counts for pages to be non-zero, as mapped pfns from follow_pfn may not have an initialized ref count. Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 10 ---------- virt/kvm/kvm_main.c | 5 ++--- 2 files changed, 2 insertions(+), 13 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 86b74e7bccfa..46b3d6c0ff27 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -555,7 +555,6 @@ static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) kvm_pfn_t pfn; u64 old_spte = *sptep; int level = sptep_to_sp(sptep)->role.level; - struct page *page; if (!is_shadow_present_pte(old_spte) || !spte_has_volatile_bits(old_spte)) @@ -570,15 +569,6 @@ static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) pfn = spte_to_pfn(old_spte); - /* - * KVM doesn't hold a reference to any pages mapped into the guest, and - * instead uses the mmu_notifier to ensure that KVM unmaps any pages - * before they are reclaimed. Sanity check that, if the pfn is backed - * by a refcounted page, the refcount is elevated. - */ - page = kvm_pfn_to_refcounted_page(pfn); - WARN_ON(page && !page_count(page)); - if (is_accessed_spte(old_spte)) kvm_set_pfn_accessed(pfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 007dd984eeea..a80070cb04d7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -165,10 +165,9 @@ bool kvm_is_zone_device_page(struct page *page) /* * The metadata used by is_zone_device_page() to determine whether or * not a page is ZONE_DEVICE is guaranteed to be valid if and only if - * the device has been pinned, e.g. by get_user_pages(). WARN if the - * page_count() is zero to help detect bad usage of this helper. + * the device has been pinned, e.g. by get_user_pages(). */ - if (WARN_ON_ONCE(!page_count(page))) + if (!page_count(page)) return false; return is_zone_device_page(page); -- 2.40.0.348.gf938b09366-goog
