Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754767Ab2EWJDT (ORCPT ); Wed, 23 May 2012 05:03:19 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:43842 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141Ab2EWJDR (ORCPT ); Wed, 23 May 2012 05:03:17 -0400 Message-ID: <4FBCA555.5020303@linux.vnet.ibm.com> Date: Wed, 23 May 2012 16:52:37 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Xiao Guangrong CC: Avi Kivity , Marcelo Tosatti , LKML , KVM Subject: [PATCH v5 2/9] KVM: MMU: abstract spte write-protect References: <4FBCA4FB.8050501@linux.vnet.ibm.com> In-Reply-To: <4FBCA4FB.8050501@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12052222-5490-0000-0000-0000017173DC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2942 Lines: 112 Introduce a common function to abstract spte write-protect to cleanup the code Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 58 +++++++++++++++++++++++++++------------------------ 1 files changed, 31 insertions(+), 27 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ddbf89f..337ff0a 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1051,36 +1051,48 @@ static void drop_spte(struct kvm *kvm, u64 *sptep) rmap_remove(kvm, sptep); } +/* Return true if the spte is dropped. */ +static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush) +{ + u64 spte = *sptep; + + if (!is_writable_pte(spte)) + return false; + + rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep); + + *flush |= true; + if (is_large_pte(spte)) { + WARN_ON(page_header(__pa(sptep))->role.level == + PT_PAGE_TABLE_LEVEL); + drop_spte(kvm, sptep); + --kvm->stat.lpages; + return true; + } + + spte = spte & ~PT_WRITABLE_MASK; + mmu_spte_update(sptep, spte); + return false; +} + static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, int level) { u64 *sptep; struct rmap_iterator iter; - bool write_protected = false; + bool flush = false; for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { BUG_ON(!(*sptep & PT_PRESENT_MASK)); - rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep); - - if (!is_writable_pte(*sptep)) { - sptep = rmap_get_next(&iter); - continue; - } - - if (level == PT_PAGE_TABLE_LEVEL) { - mmu_spte_update(sptep, *sptep & ~PT_WRITABLE_MASK); - sptep = rmap_get_next(&iter); - } else { - BUG_ON(!is_large_pte(*sptep)); - drop_spte(kvm, sptep); - --kvm->stat.lpages; + if (spte_write_protect(kvm, sptep, &flush)) { sptep = rmap_get_first(*rmapp, &iter); + continue; } - write_protected = true; + sptep = rmap_get_next(&iter); } - return write_protected; + return flush; } /** @@ -3887,6 +3899,7 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu) void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) { struct kvm_mmu_page *sp; + bool flush = false; list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) { int i; @@ -3901,16 +3914,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) !is_last_spte(pt[i], sp->role.level)) continue; - if (is_large_pte(pt[i])) { - drop_spte(kvm, &pt[i]); - --kvm->stat.lpages; - continue; - } - - /* avoid RMW */ - if (is_writable_pte(pt[i])) - mmu_spte_update(&pt[i], - pt[i] & ~PT_WRITABLE_MASK); + spte_write_protect(kvm, &pt[i], &flush); } } kvm_flush_remote_tlbs(kvm); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/