From patchwork Tue Jun 15 16:45:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12322413 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 EB658C49361 for ; Tue, 15 Jun 2021 16:45:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3D0B6191A for ; Tue, 15 Jun 2021 16:45:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231324AbhFOQr4 (ORCPT ); Tue, 15 Jun 2021 12:47:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230205AbhFOQrx (ORCPT ); Tue, 15 Jun 2021 12:47:53 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95113C061283 for ; Tue, 15 Jun 2021 09:45:48 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id v184-20020a257ac10000b02904f84a5c5297so20776264ybc.16 for ; Tue, 15 Jun 2021 09:45:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=XJacYOCj9BZGvWs61g7748RC1H4h4/tN+J594W0xPcg=; b=T8v/HLtZvU81tX+n01GbDL/U0aO2OQ+BoapIR2tZ3hbBHS9DoFqeukZBnu9NEgy+y7 zS+E16VAsGkLv+8ZKU0s0oU4iEY87LIo/qszXU+1jtmAqBTncaWQXhER7+lOn6JHFEWz EsOdZhs6b2ywtBt152/0M8XyVn1ikUIYxYYG0B8Ddrh3a1AO/UJ3NLn44dZoSGulUaaN 2camCjJgNk9N0o1+cNk+wZBPmjKj+RJSQGMh68FaF7YGfzBHtwcqb6+yuwwDCy4dtE4C v9WYIKxZk9FyAJVtJdp9OztS9A0LVDpq6rVtjQDexRJv4DZRtMEfaKgQrRANMNMYBnim 1A/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=XJacYOCj9BZGvWs61g7748RC1H4h4/tN+J594W0xPcg=; b=MwNHn8oEK5kcGiA3570xHkjiCMqIUE2/vPhtlfqYUl3UPhm5gVjFoTK2pqAg8J2JZP J6uowlGpU2Y2UlYKP0QzWcfrvN5E1blI8enAqwz3GuqnFxXI5yWF6tQR2atGdthkF+9W w/z2nDQ2+CYScf+ufCz9W17xq+RxtSiLIvRXx6MhWkRpw6IJ2kt2S5HI9DuRtp6j1rfR bqM+v4ZKvgU6FwcLeUEX7YGzm4hzh588tiLdGe8xSeV88Ixx5u2Jvmdm3nGzi3iB+jkW XuBWT782+JQKfkJmvnJd6c4LpgdE/QZmFrOBq43chMhjoed/qL/2Peb66WvheZaFrze7 +rDA== X-Gm-Message-State: AOAM531DK69VJNq61SjxqadNY5z940Rhenc4bt26HlbFBZpd4fgRuxxe fTYVLFh4TINQ9U431wbJXuUFx+JviaI= X-Google-Smtp-Source: ABdhPJypTRjYIvyklZyabwZOPiUD8X5oGr7ScObtZ7Ya9rN8bbMDwVz84LxCjAoYj4FpMU1/HMGoGNFluxc= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:13fc:a8bd:9d6b:e5]) (user=seanjc job=sendgmr) by 2002:a25:aac7:: with SMTP id t65mr16428ybi.501.1623775547658; Tue, 15 Jun 2021 09:45:47 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 15 Jun 2021 09:45:35 -0700 In-Reply-To: <20210615164535.2146172-1-seanjc@google.com> Message-Id: <20210615164535.2146172-5-seanjc@google.com> Mime-Version: 1.0 References: <20210615164535.2146172-1-seanjc@google.com> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog Subject: [PATCH 4/4] KVM: x86: Simplify logic to handle lack of host NX support From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Use boot_cpu_has() to check for NX support now that KVM requires host_efer.NX=1 if NX is supported. Opportunistically avoid the guest CPUID lookup in cpuid_fix_nx_cap() if NX is supported, which is by far the common case. Signed-off-by: Sean Christopherson Reviewed-by: Jim Mattson --- arch/x86/kvm/cpuid.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index b4da665bb892..786f556302cd 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -208,16 +208,14 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) kvm_mmu_reset_context(vcpu); } -static int is_efer_nx(void) -{ - return host_efer & EFER_NX; -} - static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) { int i; struct kvm_cpuid_entry2 *e, *entry; + if (boot_cpu_has(X86_FEATURE_NX)) + return; + entry = NULL; for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { e = &vcpu->arch.cpuid_entries[i]; @@ -226,7 +224,7 @@ static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) break; } } - if (entry && cpuid_entry_has(entry, X86_FEATURE_NX) && !is_efer_nx()) { + if (entry && cpuid_entry_has(entry, X86_FEATURE_NX)) { cpuid_entry_clear(entry, X86_FEATURE_NX); printk(KERN_INFO "kvm: guest NX capability removed\n"); } @@ -401,7 +399,6 @@ static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) void kvm_set_cpu_caps(void) { - unsigned int f_nx = is_efer_nx() ? F(NX) : 0; #ifdef CONFIG_X86_64 unsigned int f_gbpages = F(GBPAGES); unsigned int f_lm = F(LM); @@ -515,7 +512,7 @@ void kvm_set_cpu_caps(void) F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | F(PAT) | F(PSE36) | 0 /* Reserved */ | - f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | + F(NX) | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) | 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW) );