From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83C78C433EF for ; Wed, 24 Nov 2021 00:24:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234973AbhKXA2B (ORCPT ); Tue, 23 Nov 2021 19:28:01 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:39774 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233027AbhKXA2B (ORCPT ); Tue, 23 Nov 2021 19:28:01 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=laijs@linux.alibaba.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---0Uy17Q8s_1637713489; Received: from 192.168.2.97(mailfrom:laijs@linux.alibaba.com fp:SMTPD_---0Uy17Q8s_1637713489) by smtp.aliyun-inc.com(127.0.0.1); Wed, 24 Nov 2021 08:24:49 +0800 Message-ID: Date: Wed, 24 Nov 2021 08:24:48 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH MANUALSEL 5.15 2/8] KVM: X86: Don't reset mmu context when X86_CR4_PCIDE 1->0 Content-Language: en-US To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sean Christopherson , Paolo Bonzini , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, kvm@vger.kernel.org References: <20211123163630.289306-1-sashal@kernel.org> <20211123163630.289306-2-sashal@kernel.org> From: Lai Jiangshan In-Reply-To: <20211123163630.289306-2-sashal@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hello, [PATCH MANUALSEL 5.15 2/8] KVM: X86: Don't reset mmu context when X86_CR4_PCIDE 1->0 [PATCH MANUALSEL 5.15 3/8] KVM: X86: Don't check unsync if the original spte is writible are pure cleanups, they don't need to backport to stable. Thanks Lai On 2021/11/24 00:36, Sasha Levin wrote: > From: Lai Jiangshan > > [ Upstream commit 552617382c197949ff965a3559da8952bf3c1fa5 ] > > X86_CR4_PCIDE doesn't participate in kvm_mmu_role, so the mmu context > doesn't need to be reset. It is only required to flush all the guest > tlb. > > Signed-off-by: Lai Jiangshan > Reviewed-by: Sean Christopherson > Message-Id: <20210919024246.89230-2-jiangshanlai@gmail.com> > Signed-off-by: Paolo Bonzini > Signed-off-by: Sasha Levin > --- > arch/x86/kvm/x86.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 0644f429f848c..98a0f3c28caec 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1042,9 +1042,10 @@ EXPORT_SYMBOL_GPL(kvm_is_valid_cr4); > > void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4) > { > - if (((cr4 ^ old_cr4) & KVM_MMU_CR4_ROLE_BITS) || > - (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))) > + if ((cr4 ^ old_cr4) & KVM_MMU_CR4_ROLE_BITS) > kvm_mmu_reset_context(vcpu); > + else if (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)) > + kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu); > } > EXPORT_SYMBOL_GPL(kvm_post_set_cr4); > >