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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 2918AC43603 for ; Thu, 4 Mar 2021 00:30:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0401B64E62 for ; Thu, 4 Mar 2021 00:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231915AbhCDAaH (ORCPT ); Wed, 3 Mar 2021 19:30:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1835542AbhCCSEC (ORCPT ); Wed, 3 Mar 2021 13:04:02 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9B90C061756 for ; Wed, 3 Mar 2021 10:03:21 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id l18so4833382pji.3 for ; Wed, 03 Mar 2021 10:03:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=EZB5FybRq8qQJzZjsg9RL1K43u6gdJrGvoqJbzpIOAc=; b=GANJnuzl+xBpfT33zHPOMsOvR4RJflbUT9Y3LNZuctKjFTjUKxQA6YNZvB4c6Xne5G vkxjkIekkM16DqdyPX/NsuPeYd7KifCT2H+A8XrcrhCFNsqHdknBoF4WZ+WNk4Iu3Xu5 bBHePIEy5bQJCY3cJRWdCR/TVHQ2pScActYFZkMeddBokyRgcMrmVt4DCIyWSpil43qd y0q86WeM6INR09Nb9hJZO8a2htWJdfz96mcoMAT7a9zfikwQy3sU3/bxnhqDEifKo2Xk W6VGP9eoc6QaQiD1qVmJzQD5UHb7mnGLuG/4Fr8FEO62N0qZaLK6y7GqpR/gffalUEc/ Ql3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=EZB5FybRq8qQJzZjsg9RL1K43u6gdJrGvoqJbzpIOAc=; b=eTb7sBwzmx0tqMyJBwgfOwd69PH7ZqKbE3sWBbv+ZV4OLmcGwr7nCEQ1WBLSp2o+9v MEiG/F/QXlxsUypo8Pe01A0mRf/lOxSal3nzxOx0FeYT6v/WyXb1eEiPi7vSyDlZ/tiq E7Jss5ut2LVk52TIn7EJj8BNq6brxP8atv9/w5MZk+CZ0wgFKPoL/q+5iFgmxCIBQ2je tErwUuGWzMvzUQRvMHiPgWrWeoeDRlFphYvV9g40BwYFOMQx6314C4rzk3u6XOgwhvDY aeqjnq5QsMsiYX79HYhPjM0j4xJoTyleszBdpifh4wznpIxIt7E9M5p7PLphgFlsBP1S Y4Lg== X-Gm-Message-State: AOAM533xAZQMnmKqJ3zasA0zpm2k3uXwon0SG+Hix4e+kDdclyqWek7D 2TDIRlG9QTPH0bVEACqNo9VXjA== X-Google-Smtp-Source: ABdhPJxHiz9ohG6+W8dNXmMiMy9EY9e2DVip+EPXLXe1/ag47U0Nhl3U7ARwSbOllz5+QQBx4mIOyw== X-Received: by 2002:a17:90b:4b0e:: with SMTP id lx14mr290874pjb.147.1614794601004; Wed, 03 Mar 2021 10:03:21 -0800 (PST) Received: from google.com ([2620:15c:f:10:805d:6324:3372:6183]) by smtp.gmail.com with ESMTPSA id v14sm1438168pju.19.2021.03.03.10.03.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Mar 2021 10:03:20 -0800 (PST) Date: Wed, 3 Mar 2021 10:03:14 -0800 From: Sean Christopherson To: Like Xu Cc: Peter Zijlstra , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Kan Liang , Dave Hansen , wei.w.wang@intel.com, Borislav Petkov , kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 9/9] KVM: x86: Add XSAVE Support for Architectural LBRs Message-ID: References: <20210303135756.1546253-1-like.xu@linux.intel.com> <20210303135756.1546253-10-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210303135756.1546253-10-like.xu@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Mar 03, 2021, Like Xu wrote: > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 034708a3df20..ec4593e0ee6d 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -7268,6 +7268,8 @@ static __init void vmx_set_cpu_caps(void) > supported_xss = 0; > if (!cpu_has_vmx_xsaves()) > kvm_cpu_cap_clear(X86_FEATURE_XSAVES); > + else if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) > + supported_xss |= XFEATURE_MASK_LBR; > > /* CPUID 0x80000001 */ > if (!cpu_has_vmx_rdtscp()) > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index d773836ceb7a..bca2e318ff24 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -10433,6 +10433,8 @@ int kvm_arch_hardware_setup(void *opaque) > > if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES)) > supported_xss = 0; > + else > + supported_xss &= host_xss; Not your fault by any means, but I would prefer to have matching logic for XSS and XCR0. The existing clearing of supported_xss here is pointless. E.g. I'd prefer something like the following, though Paolo may have a different opinion. diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 6d7e760fdfa0..c781034463e5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7244,12 +7244,15 @@ 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()) { + kvm_cpu_cap_clear(X86_FEATURE_ARCH_LBR); + supported_xss &= ~XFEATURE_MASK_LBR; + } if (vmx_umip_emulated()) kvm_cpu_cap_set(X86_FEATURE_UMIP); /* CPUID 0xD.1 */ - supported_xss = 0; if (!cpu_has_vmx_xsaves()) kvm_cpu_cap_clear(X86_FEATURE_XSAVES); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7b0adebec1ef..5f9eb1f5b840 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -205,6 +205,8 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs; | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ | XFEATURE_MASK_PKRU) +#define KVM_SUPPORTED_XSS XFEATURE_MASK_LBR + u64 __read_mostly host_efer; EXPORT_SYMBOL_GPL(host_efer); @@ -8037,6 +8039,11 @@ int kvm_arch_init(void *opaque) supported_xcr0 = host_xcr0 & KVM_SUPPORTED_XCR0; } + if (boot_cpu_has(X86_FEATURE_XSAVES)) + rdmsrl(MSR_IA32_XSS, host_xss); + supported_xss = host_xss & KVM_SUPPORTED_XSS; + } + if (pi_inject_timer == -1) pi_inject_timer = housekeeping_enabled(HK_FLAG_TIMER); #ifdef CONFIG_X86_64 @@ -10412,9 +10419,6 @@ int kvm_arch_hardware_setup(void *opaque) rdmsrl_safe(MSR_EFER, &host_efer); - if (boot_cpu_has(X86_FEATURE_XSAVES)) - rdmsrl(MSR_IA32_XSS, host_xss); - r = ops->hardware_setup(); if (r != 0) return r; @@ -10422,9 +10426,6 @@ int kvm_arch_hardware_setup(void *opaque) memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops)); kvm_ops_static_call_update(); - if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES)) - supported_xss = 0; - #define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f) cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_); #undef __kvm_cpu_cap_has