From 005ba37cb89bcc0cf63c2029a41f8db165aeb615 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 8 Jan 2020 12:24:36 -0800 Subject: mm: thp: KVM: Explicitly check for THP when populating secondary MMU Add a helper, is_transparent_hugepage(), to explicitly check whether a compound page is a THP and use it when populating KVM's secondary MMU. The explicit check fixes a bug where a remapped compound page, e.g. for an XDP Rx socket, is mapped into a KVM guest and is mistaken for a THP, which results in KVM incorrectly creating a huge page in its secondary MMU. Fixes: 936a5fe6e6148 ("thp: kvm mmu transparent hugepage support") Reported-by: syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com Cc: Andrea Arcangeli Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- include/linux/kvm_host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/kvm_host.h') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 48e139c293c2..46fdb7533678 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -976,6 +976,7 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu); bool kvm_is_reserved_pfn(kvm_pfn_t pfn); bool kvm_is_zone_device_pfn(kvm_pfn_t pfn); +bool kvm_is_transparent_hugepage(kvm_pfn_t pfn); struct kvm_irq_ack_notifier { struct hlist_node link; -- cgit v1.2.3