From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752918AbaH2Kbf (ORCPT ); Fri, 29 Aug 2014 06:31:35 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:33718 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752016AbaH2Kb3 (ORCPT ); Fri, 29 Aug 2014 06:31:29 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: stable@vger.kernel.org Subject: [PATCH 1/3] KVM: do not bias the generation number in kvm_current_mmio_generation Date: Fri, 29 Aug 2014 12:31:15 +0200 Message-Id: <1409308277-4021-2-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1409308277-4021-1-git-send-email-pbonzini@redhat.com> References: <1409308277-4021-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The next patch will give a meaning (a la seqcount) to the low bit of the generation number. Ensure that it matches between kvm->memslots->generation and kvm_current_mmio_generation(). Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 7 +------ virt/kvm/kvm_main.c | 7 +++++++ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 931467881da7..323c3f5f5c84 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -236,12 +236,7 @@ static unsigned int get_mmio_spte_generation(u64 spte) static unsigned int kvm_current_mmio_generation(struct kvm *kvm) { - /* - * Init kvm generation close to MMIO_MAX_GEN to easily test the - * code of handling generation number wrap-around. - */ - return (kvm_memslots(kvm)->generation + - MMIO_MAX_GEN - 150) & MMIO_GEN_MASK; + return kvm_memslots(kvm)->generation & MMIO_GEN_MASK; } static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7176929a4cda..0bfdb673db26 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -477,6 +477,13 @@ static struct kvm *kvm_create_vm(unsigned long type) kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!kvm->memslots) goto out_err_no_srcu; + + /* + * Init kvm generation close to the maximum to easily test the + * code of handling generation number wrap-around. + */ + kvm->memslots->generation = -150; + kvm_init_memslots_id(kvm); if (init_srcu_struct(&kvm->srcu)) goto out_err_no_srcu; -- 1.8.3.1