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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 43B19C28CBC for ; Tue, 2 Mar 2021 15:57:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07B4C64F21 for ; Tue, 2 Mar 2021 15:57:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1838939AbhCBPzb (ORCPT ); Tue, 2 Mar 2021 10:55:31 -0500 Received: from mga18.intel.com ([134.134.136.126]:11224 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378010AbhCBIxy (ORCPT ); Tue, 2 Mar 2021 03:53:54 -0500 IronPort-SDR: 52eoHLCxIQB1yD7JsOgfH1I1Rdwn10H/utiQjj+P0pK3dDC8qMFnEJU/h8Cl70hK2VSVm1VmeN tN7NQScd82Fw== X-IronPort-AV: E=McAfee;i="6000,8403,9910"; a="174379005" X-IronPort-AV: E=Sophos;i="5.81,216,1610438400"; d="scan'208";a="174379005" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Mar 2021 00:52:45 -0800 IronPort-SDR: h4wmwP64YA75l1weRsePnlDmwwnsHRBLz5jMd2VSDVGSSFRVuF2S7JVCHcUE/tQdz3bqKumSeo r0zt1gW5PcqA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,216,1610438400"; d="scan'208";a="406623086" Received: from unknown (HELO localhost) ([10.239.159.166]) by orsmga008.jf.intel.com with ESMTP; 02 Mar 2021 00:52:43 -0800 Date: Tue, 2 Mar 2021 17:05:32 +0800 From: Yang Weijiang To: Sean Christopherson Cc: Yang Weijiang , pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vitaly Kuznetsov Subject: Re: [PATCH v2] KVM: nVMX: Sync L2 guest CET states between L1/L2 Message-ID: <20210302090532.GA5372@local-michael-cet-test> References: <20210225030951.17099-1-weijiang.yang@intel.com> <20210225030951.17099-2-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Mar 01, 2021 at 09:46:19AM -0800, Sean Christopherson wrote: > +Vitaly > > On Thu, Feb 25, 2021, Yang Weijiang wrote: > > These fields are rarely updated by L1 QEMU/KVM, sync them when L1 is trying to > > read/write them and after they're changed. If CET guest entry-load bit is not > > set by L1 guest, migrate them to L2 manaully. > > > > Suggested-by: Sean Christopherson > > Signed-off-by: Yang Weijiang > > > > change in v2: > > - Per Sean's review feedback, change CET guest states as rarely-updated fields. > > And also migrate L1's CET states to L2 if the entry-load bit is not set. > > - Opportunistically removed one blank line. > > --- > > arch/x86/kvm/cpuid.c | 1 - > > arch/x86/kvm/vmx/nested.c | 29 +++++++++++++++++++++++++++++ > > arch/x86/kvm/vmx/vmx.h | 3 +++ > > 3 files changed, 32 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > > index 46087bca9418..afc97122c05c 100644 > > --- a/arch/x86/kvm/cpuid.c > > +++ b/arch/x86/kvm/cpuid.c > > @@ -143,7 +143,6 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) > > } > > vcpu->arch.guest_supported_xss = > > (((u64)best->edx << 32) | best->ecx) & supported_xss; > > - > > } else { > > vcpu->arch.guest_supported_xss = 0; > > } > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > > index 9728efd529a1..1703b8874fad 100644 > > --- a/arch/x86/kvm/vmx/nested.c > > +++ b/arch/x86/kvm/vmx/nested.c > > @@ -2516,6 +2516,12 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) > > vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr); > > > > set_cr4_guest_host_mask(vmx); > > + > > + if (kvm_cet_supported()) { > > This needs to be conditioned on CET coming from vmcs12, it's on the loading of > host state on VM-Exit that is unconditional (if CET is supported). > > if (kvm_cet_supported() && vmx->nested.nested_run_pending && > (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_CET_STATE)) { > Thanks Sean! Will change it. > I also assume these should be guarded by one of the eVMCS fields, though a quick > search of the public docs didn't provide a hit on the CET fields. > I got some description from MSFT as below, do you mean that: GuestSsp uses clean field GUEST_BASIC (bit 10) GuestSCet/GuestInterruptSspTableAddr uses GUEST_GRP1 (bit 11) HostSCet/HostSsp/HostInterruptSspTableAddr uses HOST_GRP1 (bit 14) If it is, should these go into separate patch series for Hyper-v nested support? I have some pending patches for the enabling. > Vitaly, any idea if these will be GUEST_GRP2 or something else? > > > + vmcs_writel(GUEST_SSP, vmcs12->guest_ssp); > > + vmcs_writel(GUEST_S_CET, vmcs12->guest_s_cet); > > + vmcs_writel(GUEST_INTR_SSP_TABLE, vmcs12->guest_ssp_tbl); > > + } > > }