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,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 D4B7EC43381 for ; Thu, 28 Feb 2019 15:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA952218B0 for ; Thu, 28 Feb 2019 15:59:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732803AbfB1P7m (ORCPT ); Thu, 28 Feb 2019 10:59:42 -0500 Received: from mga05.intel.com ([192.55.52.43]:34523 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730843AbfB1P7l (ORCPT ); Thu, 28 Feb 2019 10:59:41 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Feb 2019 07:59:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,423,1544515200"; d="scan'208";a="322922049" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.181]) by fmsmga006.fm.intel.com with ESMTP; 28 Feb 2019 07:59:40 -0800 Date: Thu, 28 Feb 2019 07:59:40 -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 3/8] KVM:CPUID: Add CPUID support for Guest CET Message-ID: <20190228155939.GD6166@linux.intel.com> References: <20190225132716.6982-1-weijiang.yang@intel.com> <20190225132716.6982-4-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190225132716.6982-4-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 09:27:11PM +0800, Yang Weijiang wrote: > Guest CET SHSTK and IBT capability are reported via > CPUID.(EAX=7, ECX=0):ECX[bit 7] and EDX[bit 20] respectively. > Guest user mode and supervisor mode xsaves component size > is reported via CPUID.(EAX=0xD, ECX=1):ECX[bit 11] and ECX[bit 12] > respectively. > > Signed-off-by: Zhang Yi Z > Signed-off-by: Yang Weijiang > --- > arch/x86/kvm/cpuid.c | 60 +++++++++++++++++++++++++++++++++----------- > arch/x86/kvm/x86.h | 4 +++ > 2 files changed, 50 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index cb1aece25b17..5e05756cc6db 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -65,6 +65,16 @@ u64 kvm_supported_xcr0(void) > return xcr0; > } > > +u64 kvm_supported_xss(void) > +{ > + u64 xss; > + > + rdmsrl(MSR_IA32_XSS, xss); > + xss &= KVM_SUPPORTED_XSS; > + return xss; > +} > +EXPORT_SYMBOL(kvm_supported_xss); > + > #define F(x) bit(X86_FEATURE_##x) > > /* For scattered features from cpufeatures.h; we currently expose none */ > @@ -323,6 +333,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > u32 index, int *nent, int maxnent) > { > int r; > + u32 eax, ebx, ecx, edx; > unsigned f_nx = is_efer_nx() ? F(NX) : 0; > #ifdef CONFIG_X86_64 > unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) > @@ -503,6 +514,20 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > * if the host doesn't support it. > */ > entry->edx |= F(ARCH_CAPABILITIES); > + > + /* > + * Guest OS CET enabling is designed independent to > + * host enabling, it only has dependency on Host HW > + * capability, if it has, report CET support to > + * Guest. > + */ > + cpuid_count(7, 0, &eax, &ebx, &ecx, &edx); > + if (ecx & F(SHSTK)) > + entry->ecx |= F(SHSTK); > + > + if (edx & F(IBT)) > + entry->edx |= F(IBT); There's no need to manually add these flags. They will be automatically kept if supported in hardware because your previous patch, 02/08, added them to the mask of features that can be exposed to the guest, i.e. set them in kvm_cpuid_7_0_e{c,d}x_x86_features. > + > } else { > entry->ebx = 0; > entry->ecx = 0; > @@ -564,14 +589,17 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > } > case 0xd: { > int idx, i; > - u64 supported = kvm_supported_xcr0(); > + u64 u_supported = kvm_supported_xcr0(); > + u64 s_supported = kvm_supported_xss(); > + u64 supported; > + int compacted; > > - entry->eax &= supported; > - entry->ebx = xstate_required_size(supported, false); > + entry->eax &= u_supported; > + entry->ebx = xstate_required_size(u_supported, false); > entry->ecx = entry->ebx; > - entry->edx &= supported >> 32; > + entry->edx &= u_supported >> 32; > entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; > - if (!supported) > + if (!u_supported && !s_supported) > break; > > for (idx = 1, i = 1; idx < 64; ++idx) { > @@ -583,19 +611,23 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > if (idx == 1) { > entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; > cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); > - entry[i].ebx = 0; > - if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) > - entry[i].ebx = > - xstate_required_size(supported, > - true); > + supported = u_supported | s_supported; > + compacted = entry[i].eax & > + (F(XSAVES) | F(XSAVEC)); > + entry[i].ebx = xstate_required_size(supported, > + compacted); > + entry[i].ecx &= s_supported; > + entry[i].edx = 0; > } else { > + supported = (entry[i].ecx & 1) ? s_supported : > + u_supported; > if (entry[i].eax == 0 || !(supported & mask)) > continue; > - if (WARN_ON_ONCE(entry[i].ecx & 1)) > - continue; > + entry[i].ecx &= 1; > + entry[i].edx = 0; > + if (entry[i].ecx) > + entry[i].ebx = 0; > } > - entry[i].ecx = 0; > - entry[i].edx = 0; > entry[i].flags |= > KVM_CPUID_FLAG_SIGNIFCANT_INDEX; > ++*nent; > diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h > index 224cd0a47568..c61da41c3c5c 100644 > --- a/arch/x86/kvm/x86.h > +++ b/arch/x86/kvm/x86.h > @@ -283,6 +283,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, > | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \ > | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ > | XFEATURE_MASK_PKRU) > + > +#define KVM_SUPPORTED_XSS (XFEATURE_MASK_SHSTK_USER \ > + | XFEATURE_MASK_SHSTK_KERNEL) > + > extern u64 host_xcr0; > > extern u64 kvm_supported_xcr0(void); > -- > 2.17.1 >