From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754027AbcCMD22 (ORCPT ); Sat, 12 Mar 2016 22:28:28 -0500 Received: from mga14.intel.com ([192.55.52.115]:34187 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020AbcCMD1U (ORCPT ); Sat, 12 Mar 2016 22:27:20 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,328,1455004800"; d="scan'208";a="65186165" From: Lan Tianyu To: gleb@kernel.org, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, guangrong.xiao@linux.intel.com Cc: Lan Tianyu , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/7] KVM/x86: Call smp_wmb() before increasing tlbs_dirty Date: Sun, 13 Mar 2016 11:10:27 +0800 Message-Id: <1457838631-26775-5-git-send-email-tianyu.lan@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1457838631-26775-1-git-send-email-tianyu.lan@intel.com> References: <1457838631-26775-1-git-send-email-tianyu.lan@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Update spte before increasing tlbs_dirty to make sure no tlb flush in lost after spte is zapped. This pairs with the barrier in the kvm_flush_remote_tlbs(). Signed-off-by: Lan Tianyu --- arch/x86/kvm/paging_tmpl.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index e159a81..d34475e 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -949,6 +949,12 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return 0; if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { + /* + * Update spte before increasing tlbs_dirty to make sure + * no tlb flush in lost after spte is zapped, see the + * comments in kvm_flush_remote_tlbs(). + */ + smp_wmb(); vcpu->kvm->tlbs_dirty++; continue; } @@ -964,6 +970,11 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) if (gfn != sp->gfns[i]) { drop_spte(vcpu->kvm, &sp->spt[i]); + /* + * The same as above where we are doing + * prefetch_invalid_gpte(). + */ + smp_wmb(); vcpu->kvm->tlbs_dirty++; continue; } -- 1.8.4.rc0.1.g8f6a3e5.dirty