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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 63A13C43381 for ; Mon, 4 Mar 2019 18:53:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B58A206BA for ; Mon, 4 Mar 2019 18:53:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727067AbfCDSx2 (ORCPT ); Mon, 4 Mar 2019 13:53:28 -0500 Received: from mga17.intel.com ([192.55.52.151]:25999 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726162AbfCDSx1 (ORCPT ); Mon, 4 Mar 2019 13:53:27 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2019 10:53:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,440,1544515200"; d="scan'208";a="304306280" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.181]) by orsmga005.jf.intel.com with ESMTP; 04 Mar 2019 10:53:27 -0800 Date: Mon, 4 Mar 2019 10:53:27 -0800 From: Sean Christopherson To: Yang Weijiang Cc: pbonzini@redhat.com, rkrcmar@redhat.com, jmattson@google.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mst@redhat.com, yu-cheng.yu@intel.com, Zhang Yi Z Subject: Re: [PATCH v3 5/8] KVM:VMX: Pass through host CET related MSRs to Guest. Message-ID: <20190304185326.GE17120@linux.intel.com> References: <20190225132716.6982-1-weijiang.yang@intel.com> <20190225132716.6982-6-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190225132716.6982-6-weijiang.yang@intel.com> 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 Mon, Feb 25, 2019 at 09:27:13PM +0800, Yang Weijiang wrote: > The CET runtime settings, i.e., CET state control bits(IA32_U_CET/ > IA32_S_CET), CET SSP(IA32_PL3_SSP/IA32_PL0_SSP) and SSP table address > (IA32_INTERRUPT_SSP_TABLE_ADDR) are task/thread specific, therefore, > OS needs to save/restore the states properly during context switch, > e.g., task/thread switching, interrupt/exception handling, it uses > xsaves/xrstors to achieve that. > > The difference between VMCS CET area fields and xsave CET area, is that > the former is for state retention during Guest/Host context > switch while the latter is for state retention during OS execution. > > Linux currently doesn't support CPL1 and CPL2, so SSPs for these level > are skipped here. But don't we want to allow a guest to access the MSRs regardless of the host kernel's behavior? > Signed-off-by: Zhang Yi Z > Signed-off-by: Yang Weijiang > --- > arch/x86/kvm/vmx.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 7bbb8b26e901..89ee086e1729 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -11769,6 +11769,7 @@ static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu) > static void vmx_cpuid_update(struct kvm_vcpu *vcpu) > { > struct vcpu_vmx *vmx = to_vmx(vcpu); > + unsigned long *msr_bitmap; > > if (cpu_has_secondary_exec_ctrls()) { > vmx_compute_secondary_exec_control(vmx); > @@ -11786,6 +11787,18 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu) > nested_vmx_cr_fixed1_bits_update(vcpu); > nested_vmx_entry_exit_ctls_update(vcpu); > } > + > + msr_bitmap = vmx->vmcs01.msr_bitmap; > + > + if (guest_cpuid_has(vcpu, X86_FEATURE_SHSTK) | This should be a logical OR, not a bitwise OR. > + guest_cpuid_has(vcpu, X86_FEATURE_IBT)) { > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_U_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_S_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_INT_SSP_TAB, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL0_SSP, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL3_SSP, MSR_TYPE_RW); > + } > + > } > > static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry) > -- > 2.17.1 >