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=-16.8 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_GIT 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 CD911C43333 for ; Sun, 14 Mar 2021 16:01:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E0A164EB3 for ; Sun, 14 Mar 2021 16:01:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234595AbhCNQBb (ORCPT ); Sun, 14 Mar 2021 12:01:31 -0400 Received: from mga14.intel.com ([192.55.52.115]:7174 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234015AbhCNQA4 (ORCPT ); Sun, 14 Mar 2021 12:00:56 -0400 IronPort-SDR: XJgfbQfToSSTzcUc7hdItZzb5+M/YTy+8AN3XlUQZ+3HhFI7cDIlHQ19S/aUygCZleEatN8l6b 3mxSzGob0z2w== X-IronPort-AV: E=McAfee;i="6000,8403,9923"; a="188360764" X-IronPort-AV: E=Sophos;i="5.81,248,1610438400"; d="scan'208";a="188360764" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2021 09:00:56 -0700 IronPort-SDR: lc+ow3R5Kk4ix3YIjqkit245+MKgI0kYw6w9k1FMsmcM+Y9qwnxXYpp7rpBtv4fpEmGm3Pjw2v KG+/EZBkfOng== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,248,1610438400"; d="scan'208";a="439530741" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by FMSMGA003.fm.intel.com with ESMTP; 14 Mar 2021 09:00:54 -0700 From: Like Xu To: Paolo Bonzini , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, x86@kernel.org, wei.w.wang@intel.com, linux-kernel@vger.kernel.org, Like Xu Subject: [PATCH v4 11/11] KVM: x86: Add XSAVE Support for Architectural LBRs Date: Sun, 14 Mar 2021 23:52:24 +0800 Message-Id: <20210314155225.206661-12-like.xu@linux.intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210314155225.206661-1-like.xu@linux.intel.com> References: <20210314155225.206661-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On processors whose XSAVE feature set supports XSAVES and XRSTORS, the availability of support for Architectural LBR configuration state save and restore can be determined from CPUID.(EAX=0DH, ECX=1):EDX:ECX[bit 15]. The detailed leaf for Arch LBRs is enumerated in CPUID.(EAX=0DH, ECX=0FH). XSAVES provides a faster means than RDMSR for guest to read all LBRs. When guest IA32_XSS[bit 15] is set, the Arch LBRs state can be saved using XSAVES and restored by XRSTORS with the appropriate RFBM. If the KVM fails to pass-through the LBR msrs to the guest, the LBR msrs will be reset to prevent the leakage of host records via XSAVES. In this case, the guest results may be inaccurate as the legacy LBR. Signed-off-by: Like Xu --- arch/x86/kvm/vmx/pmu_intel.c | 2 ++ arch/x86/kvm/vmx/vmx.c | 4 +++- arch/x86/kvm/x86.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 9199d3974d57..7666292094ec 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -772,6 +772,8 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu) return; warn: + if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) + wrmsrl(MSR_ARCH_LBR_DEPTH, lbr_desc->records.nr); pr_warn_ratelimited("kvm: vcpu-%d: fail to passthrough LBR.\n", vcpu->vcpu_id); } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 14ed3251376f..659be0d708ac 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7295,8 +7295,10 @@ static __init void vmx_set_cpu_caps(void) kvm_cpu_cap_clear(X86_FEATURE_INVPCID); if (vmx_pt_mode_is_host_guest()) kvm_cpu_cap_check_and_set(X86_FEATURE_INTEL_PT); - if (!cpu_has_vmx_arch_lbr()) + if (!cpu_has_vmx_arch_lbr()) { kvm_cpu_cap_clear(X86_FEATURE_ARCH_LBR); + supported_xss &= ~XFEATURE_MASK_LBR; + } if (vmx_umip_emulated()) kvm_cpu_cap_set(X86_FEATURE_UMIP); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 171605dcbd65..2e0935795502 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -205,7 +205,7 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs; | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ | XFEATURE_MASK_PKRU) -#define KVM_SUPPORTED_XSS 0 +#define KVM_SUPPORTED_XSS XFEATURE_MASK_LBR u64 __read_mostly host_efer; EXPORT_SYMBOL_GPL(host_efer); -- 2.29.2