From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756286Ab3BEIyE (ORCPT ); Tue, 5 Feb 2013 03:54:04 -0500 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:50688 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754644Ab3BEIyB (ORCPT ); Tue, 5 Feb 2013 03:54:01 -0500 Message-ID: <5110C8A0.5050405@linux.vnet.ibm.com> Date: Tue, 05 Feb 2013 16:53:52 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , Gleb Natapov , LKML , KVM Subject: [PATCH v3 2/5] KVM: MMU: clarify the logic in kvm_set_pte_rmapp References: <5110C853.4080705@linux.vnet.ibm.com> In-Reply-To: <5110C853.4080705@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13020508-5816-0000-0000-0000068D9952 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In kvm_set_pte_rmapp, if the new mapping is writable, we need to remove all spte pointing to that page otherwisewe we only need to adjust the sptes to let them point to the new page. This patch clarifys the logic and makes the later patch more clean [ Impact: no logic changed ] Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 17 ++++++++--------- 1 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 68d4d5f..a0dc0d7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1225,16 +1225,16 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, WARN_ON(pte_huge(*ptep)); new_pfn = pte_pfn(*ptep); - for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { - BUG_ON(!is_shadow_present_pte(*sptep)); - rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", sptep, *sptep); + if (pte_write(*ptep)) + need_flush = kvm_unmap_rmapp(kvm, rmapp, slot, data); + else + for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { + BUG_ON(!is_shadow_present_pte(*sptep)); + rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", + sptep, *sptep); - need_flush = 1; + need_flush = 1; - if (pte_write(*ptep)) { - drop_spte(kvm, sptep); - sptep = rmap_get_first(*rmapp, &iter); - } else { new_spte = *sptep & ~PT64_BASE_ADDR_MASK; new_spte |= (u64)new_pfn << PAGE_SHIFT; @@ -1246,7 +1246,6 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, mmu_spte_set(sptep, new_spte); sptep = rmap_get_next(&iter); } - } if (need_flush) kvm_flush_remote_tlbs(kvm); -- 1.7.7.6