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=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 71E3CC11F67 for ; Tue, 13 Jul 2021 16:35:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5756860FF3 for ; Tue, 13 Jul 2021 16:35:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235460AbhGMQh4 (ORCPT ); Tue, 13 Jul 2021 12:37:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235448AbhGMQhk (ORCPT ); Tue, 13 Jul 2021 12:37:40 -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 12CB9C0611BF for ; Tue, 13 Jul 2021 09:34:28 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id q10-20020a056902150ab02905592911c932so27952635ybu.15 for ; Tue, 13 Jul 2021 09:34:28 -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=cW8BIVTxIgKroIq7kMrutoUZpTyYwV90yWvpiIBilPc=; b=kjC+N6ZAjKJ76JOx9gw1poeBnbs7f2TUs96FtDfxukpM4jgMbWSbGEY4ji86iiS3da KjaDmuQnpnv9YMt0GJJ5mLcyddJ7cyucks0rzrSCc97QJHriPtUTLgcgZQhXR/wREnsB Hi8yzV5oxqD0ZATDXTpeX9dFpPq/SOKOg8i+1OyvFYVtItvfEhM7UWBJVwYyd4IHtA3C xrFrNdRpDpeBZT95BiCTp8u2oyOjjhaGXDOgpVf2RS/8KwKEahNN5ih+bY0W8Ufey0J6 hrYhTvbqsehiS8KNt5AnCLByJtyZ3T99WFm7TuCPhZl6eakojNa4eikhhB847boP3n5s gI/Q== 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=cW8BIVTxIgKroIq7kMrutoUZpTyYwV90yWvpiIBilPc=; b=fTR+mmaAptUkpFE+c3kIZXX7qjdbFkup1w97QresTEQETfyRnIvO/1AUEQuxacF7kw GUtVV0kBpOLKOpXeCLz6NGT4euDanJfJ49J5bL9BBeUIUXdUyOQWEQGz5jvp6WKBq8Ez V94BY3zrP/fByJ5n8BAwXwNOiqd0vz9xflIuTBHplj6sSrTSuGz10hFNolEL+er14bbi eT5N0bkg/OBnRuuevV5J/dSELvdMA6ceLqn76+cS8zPS57hlwAVyqTkB+aKXJc5r511P Zj6JeUOgPVm9QRAYWnMclL8wAhUX9k8a0vS9tSegIT4cuVIaH5VL5723kAOGVdoXEkpj fKqA== X-Gm-Message-State: AOAM530owQcg4VQoF06WufKrRWXbQIvUnGymRqSp47ssVt3Z/2AOXB3i SzvCK0DFhj3QCcPglA3SDpU1yR8/p4A= X-Google-Smtp-Source: ABdhPJxxEY5h40hwjxnBrqRbvxMDcqYn0Pq1pp/svYskxe9JHvsyD6AN1JmqX+UdGZbHRnRL801DTneK6PU= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:825e:11a1:364b:8109]) (user=seanjc job=sendgmr) by 2002:a25:1e57:: with SMTP id e84mr7107672ybe.308.1626194067266; Tue, 13 Jul 2021 09:34:27 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 13 Jul 2021 09:33:06 -0700 In-Reply-To: <20210713163324.627647-1-seanjc@google.com> Message-Id: <20210713163324.627647-29-seanjc@google.com> Mime-Version: 1.0 References: <20210713163324.627647-1-seanjc@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog Subject: [PATCH v2 28/46] 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, Reiji Watanabe Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 45b123bb5aaa..7ab493708b06 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2719,6 +2719,8 @@ 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) { @@ -2735,7 +2737,7 @@ 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) @@ -2756,7 +2758,7 @@ 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; @@ -3291,7 +3293,7 @@ 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]; @@ -3304,7 +3306,7 @@ 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); @@ -3326,9 +3328,13 @@ 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) -- 2.32.0.93.g670b81a890-goog