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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 579C8C33CB1 for ; Thu, 16 Jan 2020 16:21:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 372DA208C3 for ; Thu, 16 Jan 2020 16:21:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726744AbgAPQVE (ORCPT ); Thu, 16 Jan 2020 11:21:04 -0500 Received: from mga07.intel.com ([134.134.136.100]:43485 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbgAPQVE (ORCPT ); Thu, 16 Jan 2020 11:21:04 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jan 2020 08:21:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,326,1574150400"; d="scan'208";a="219732066" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.202]) by fmsmga007.fm.intel.com with ESMTP; 16 Jan 2020 08:21:02 -0800 Date: Thu, 16 Jan 2020 08:21:02 -0800 From: Sean Christopherson To: Vitaly Kuznetsov Cc: Liran Alon , kvm@vger.kernel.org, Paolo Bonzini , Jim Mattson , linux-kernel@vger.kernel.org, Roman Kagan Subject: Re: [PATCH RFC 3/3] x86/kvm/hyper-v: don't allow to turn on unsupported VMX controls for nested guests Message-ID: <20200116162101.GD20561@linux.intel.com> References: <20200115171014.56405-1-vkuznets@redhat.com> <20200115171014.56405-4-vkuznets@redhat.com> <874kwvixuq.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <874kwvixuq.fsf@vitty.brq.redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Jan 16, 2020 at 09:55:57AM +0100, Vitaly Kuznetsov wrote: > Liran Alon writes: > > >> On 15 Jan 2020, at 19:10, Vitaly Kuznetsov wrote: > >> > >> Sane L1 hypervisors are not supposed to turn any of the unsupported VMX > >> controls on for its guests and nested_vmx_check_controls() checks for > >> that. This is, however, not the case for the controls which are supported > >> on the host but are missing in enlightened VMCS and when eVMCS is in use. > >> > >> It would certainly be possible to add these missing checks to > >> nested_check_vm_execution_controls()/_vm_exit_controls()/.. but it seems > >> preferable to keep eVMCS-specific stuff in eVMCS and reduce the impact on > >> non-eVMCS guests by doing less unrelated checks. Create a separate > >> nested_evmcs_check_controls() for this purpose. > >> > >> Signed-off-by: Vitaly Kuznetsov > >> --- > >> arch/x86/kvm/vmx/evmcs.c | 56 ++++++++++++++++++++++++++++++++++++++- > >> arch/x86/kvm/vmx/evmcs.h | 1 + > >> arch/x86/kvm/vmx/nested.c | 3 +++ > >> 3 files changed, 59 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c > >> index b5d6582ba589..88f462866396 100644 > >> --- a/arch/x86/kvm/vmx/evmcs.c > >> +++ b/arch/x86/kvm/vmx/evmcs.c > >> @@ -4,9 +4,11 @@ > >> #include > >> > >> #include "../hyperv.h" > >> -#include "evmcs.h" > >> #include "vmcs.h" > >> +#include "vmcs12.h" > >> +#include "evmcs.h" > >> #include "vmx.h" > >> +#include "trace.h" > >> > >> DEFINE_STATIC_KEY_FALSE(enable_evmcs); > >> > >> @@ -378,6 +380,58 @@ void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata) > >> *pdata = ctl_low | ((u64)ctl_high << 32); > >> } > >> > >> +int nested_evmcs_check_controls(struct vmcs12 *vmcs12) > >> +{ > >> + int ret = 0; > >> + u32 unsupp_ctl; > >> + > >> + unsupp_ctl = vmcs12->pin_based_vm_exec_control & > >> + EVMCS1_UNSUPPORTED_PINCTRL; > >> + if (unsupp_ctl) { > >> + trace_kvm_nested_vmenter_failed( > >> + "eVMCS: unsupported pin-based VM-execution controls", > >> + unsupp_ctl); > > > > Why not move "CC” macro from nested.c to nested.h and use it here as-well instead of replicating it’s logic? > > > > Because error messages I add are both human readable and conform to SDM! > :-) > > On a more serious not yes, we should probably do that. We may even want > to use it in non-nesting (and non VMX) code in KVM. No, the CC() macro is short for Consistency Check, i.e. specific to nVMX. Even if KVM ends up adding nested_evmcs_check_controls(), which I'm hoping can be avoided, I'd still be hesitant to expose CC() in nested.h.