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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05702C67863 for ; Wed, 24 Oct 2018 11:01:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C95F62075D for ; Wed, 24 Oct 2018 11:01:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C95F62075D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727751AbeJXT2s (ORCPT ); Wed, 24 Oct 2018 15:28:48 -0400 Received: from mga02.intel.com ([134.134.136.20]:26424 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727204AbeJXT2s (ORCPT ); Wed, 24 Oct 2018 15:28:48 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Oct 2018 04:01:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,420,1534834800"; d="scan'208";a="84043490" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.193]) by orsmga008.jf.intel.com with ESMTP; 24 Oct 2018 04:01:09 -0700 Date: Wed, 24 Oct 2018 04:01:09 -0700 From: Sean Christopherson To: KarimAllah Ahmed Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org Subject: Re: [PATCH] KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned Message-ID: <20181024110109.GA15991@linux.intel.com> References: <1540071779-20848-1-git-send-email-karahmed@amazon.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1540071779-20848-1-git-send-email-karahmed@amazon.de> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 20, 2018 at 11:42:59PM +0200, KarimAllah Ahmed wrote: > The spec only requires the posted interrupt descriptor address to be > 64-bytes aligned (i.e. bits[0:5] == 0). Using page_address_valid also > forces the address to be page aligned. > > Only validate that the address does not cross the maximum physical address > without enforcing a page alignment. > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: H. Peter Anvin > Cc: x86@kernel.org > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Fixes: 6de84e581c0 ("nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2") > Signed-off-by: KarimAllah Ahmed > --- > arch/x86/kvm/vmx.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 30bf860..47962f2 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -11668,7 +11668,7 @@ static int nested_vmx_check_apicv_controls(struct kvm_vcpu *vcpu, > !nested_exit_intr_ack_set(vcpu) || > (vmcs12->posted_intr_nv & 0xff00) || > (vmcs12->posted_intr_desc_addr & 0x3f) || > - (!page_address_valid(vcpu, vmcs12->posted_intr_desc_addr)))) > + (vmcs12->posted_intr_desc_addr >> cpuid_maxphyaddr(vcpu))) > return -EINVAL; Can you update the comment for this code block? It has a stale blurb about "the descriptor address has been already checked in nested_get_vmcs12_pages" and it'd be nice to state why bits[5:0] must be zero (your changelog is much more helpful than the current comment). With that: Reviewed-by: Sean Christopherson > > /* tpr shadow is needed by all apicv features. */ > -- > 2.7.4 >