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=-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 F41F5C433B4 for ; Sat, 24 Apr 2021 00:52:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C13D161465 for ; Sat, 24 Apr 2021 00:52:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244528AbhDXAxR (ORCPT ); Fri, 23 Apr 2021 20:53:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244612AbhDXAvt (ORCPT ); Fri, 23 Apr 2021 20:51:49 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F36AC061345 for ; Fri, 23 Apr 2021 17:48:00 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id n11-20020a25808b0000b02904d9818b80e8so26106960ybk.14 for ; Fri, 23 Apr 2021 17:48:00 -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=JqcOnCGExfR3YjMtsB4lLkNrTfGGIsxEsg5SkDkGdDA=; b=hTIMu62j1JfVoMqUJDMRxt4mX6dRaa2v8VIO52tvPHuQXjRNo0B9jHOMT4XZ66Ge8h /OafbtDyprXRunXNaiH0JuDl+PhiPUF1F91bHHOkmTWu20fMrd+4/2lporx6mFkHLz/Q 53/btJAj3u5jCLr4l8M/FVswWMOcZFPHi5yObFtdEf5FGPv/ntYqMDsE/6HUniIWceLa UDlZz/XxdEuF8pNOW75zu1kPSBXUOuDz3ztcQ1zlQkCziPqxlZU/JyzbnAme7Bc26E9b e0jzQLjBdMzi4QrKpoa/olCS85DNJsb9g3SuAF0rJ4yfVDujU0y29sqcGcFb8DLkBAKw YlDA== 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=JqcOnCGExfR3YjMtsB4lLkNrTfGGIsxEsg5SkDkGdDA=; b=eEPJAsG040OT6SR2EOJVjPRiKLUPv0LUhHuXUpnmyRR1HcH0RYX2rki/8MiGLzzPGm sZ4yPsF5PC4XdrUKlsP7Dh1C4cQHmwgZBFAmvIVlkM+f0mnOsOT/KlrO7BlTyNhjRmWJ pDWHOfoVBlcndNPKJDje57M5Hf4iinDN6qv51/rkWgjBPY2Mnkmx00LCtO6A0s0L+v0g APY48apvADZ2Px/6ydSLbnVC9NQsCAt6iDZhXlaFaCkbRTsQ/j3072FInfiqxLw/76vI gbmb354QXO3LN8Ga9zQOsjV/p7xTBzIWYj/RLBMTtZFzlbfju+Kcr9+Tu4FBZ/FV1Fe1 vSFA== X-Gm-Message-State: AOAM531L/8SMTrJw10EpFlHXbsOB8C9kz0luvwqrT+J7Pf1ge5Zr44ta 042ivsPU4OyVszWjQIHTEjhqnq9JMfc= X-Google-Smtp-Source: ABdhPJwVdft0X93b33hr5Zga9hH9TiTwaqFgtZy6VqZeveX1PGKa6J1UAlQo8+Z0r4MKQLjWN2y5mbO25r8= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:ad52:3246:e190:f070]) (user=seanjc job=sendgmr) by 2002:a25:d152:: with SMTP id i79mr10295563ybg.328.1619225279897; Fri, 23 Apr 2021 17:47:59 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 23 Apr 2021 17:46:29 -0700 In-Reply-To: <20210424004645.3950558-1-seanjc@google.com> Message-Id: <20210424004645.3950558-28-seanjc@google.com> Mime-Version: 1.0 References: <20210424004645.3950558-1-seanjc@google.com> X-Mailer: git-send-email 2.31.1.498.g6c1eba8ee3d-goog Subject: [PATCH 27/43] KVM: VMX: Skip emulation required checks during pmode/rmode transitions 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Don't refresh "emulation required" when stuffing segments during transitions to/from real mode when running without unrestricted guest. The checks are unnecessary as vmx_set_cr0() unconditionally rechecks "emulation required". They also happen to be broken, as enter_pmode() and enter_rmode() run with a stale vcpu->arch.cr0. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 5f30181fd240..37bfa20a04dd 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2827,6 +2827,8 @@ static __init int alloc_kvm_area(void) return 0; } +static void __vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); + static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg, struct kvm_segment *save) { @@ -2843,7 +2845,7 @@ static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg, save->dpl = save->selector & SEGMENT_RPL_MASK; save->s = 1; } - vmx_set_segment(vcpu, save, seg); + __vmx_set_segment(vcpu, save, seg); } static void enter_pmode(struct kvm_vcpu *vcpu) @@ -2864,7 +2866,7 @@ static void enter_pmode(struct kvm_vcpu *vcpu) vmx->rmode.vm86_active = 0; - vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR); + __vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR); flags = vmcs_readl(GUEST_RFLAGS); flags &= RMODE_GUEST_OWNED_EFLAGS_BITS; @@ -3399,7 +3401,7 @@ static u32 vmx_segment_access_rights(struct kvm_segment *var) return ar; } -void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) +static void __vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) { struct vcpu_vmx *vmx = to_vmx(vcpu); const struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg]; @@ -3412,7 +3414,7 @@ void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) vmcs_write16(sf->selector, var->selector); else if (var->s) fix_rmode_seg(seg, &vmx->rmode.segs[seg]); - goto out; + return; } vmcs_writel(sf->base, var->base); @@ -3434,9 +3436,13 @@ void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) var->type |= 0x1; /* Accessed */ vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(var)); +} -out: - vmx->emulation_required = emulation_required(vcpu); +void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) +{ + __vmx_set_segment(vcpu, var, seg); + + to_vmx(vcpu)->emulation_required = emulation_required(vcpu); } static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l) -- 2.31.1.498.g6c1eba8ee3d-goog