Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753196AbdLMNhG (ORCPT ); Wed, 13 Dec 2017 08:37:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60830 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752807AbdLMNhD (ORCPT ); Wed, 13 Dec 2017 08:37:03 -0500 Subject: Re: [PATCH v8 4/4] KVM: X86: Add flush_on_enter before guest enter To: Peter Zijlstra , Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Wanpeng Li References: <1513128784-5924-1-git-send-email-wanpeng.li@hotmail.com> <1513128784-5924-5-git-send-email-wanpeng.li@hotmail.com> <20171213133554.hy3mocgbpu7rmh3m@hirez.programming.kicks-ass.net> From: Paolo Bonzini Message-ID: <445145f5-8f4d-09db-a4cd-32c5b2e331e7@redhat.com> Date: Wed, 13 Dec 2017 14:37:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20171213133554.hy3mocgbpu7rmh3m@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 13 Dec 2017 13:37:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 491 Lines: 15 On 13/12/2017 14:35, Peter Zijlstra wrote: >> + if (xchg(&vcpu->arch.st.steal.preempted, KVM_VCPU_NOT_PREEMPTED) == >> + (KVM_VCPU_SHOULD_FLUSH | KVM_VCPU_PREEMPTED)) { >> + /* >> + * Do TLB_FLUSH before entering the guest, its passed >> + * the stage of request checking >> + */ >> + kvm_vcpu_flush_tlb(vcpu, false); >> + } > And not a single word, _anywhere_ on why this doesn't need > invalidate_gpa or wtf that actually is. FWIW I've fixed the changelogs in kvm/queue. Paolo