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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 A6462C433E0 for ; Fri, 29 May 2020 15:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 847C92077D for ; Fri, 29 May 2020 15:42:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JVlSf7f1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728285AbgE2PmA (ORCPT ); Fri, 29 May 2020 11:42:00 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:56371 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727870AbgE2Pjp (ORCPT ); Fri, 29 May 2020 11:39:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590766783; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=d09fPXz7TDN6ZMcbO8XhvqfbiUFuuyxOObxJ4lRcDlE=; b=JVlSf7f1oJ388ZoDDS+OXUSgPjHZRPHTOr4GJ6AyNKIDGLcqU/7m9DqWHcgoKRJbNrSi7O ymc+j1W3K6CBCgIpdOIXtLYPYJqSPzqDHK0L+rO7TNPICBjLXHITRnHWvmzqx0S0tTLcnL rs2ZTd2wnSgeq2NHiMnMuloY3lfEVBQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-178-0NTK00AfPqae3ayxsyI7zg-1; Fri, 29 May 2020 11:39:39 -0400 X-MC-Unique: 0NTK00AfPqae3ayxsyI7zg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AF2D38005AA; Fri, 29 May 2020 15:39:38 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 56A025D9D5; Fri, 29 May 2020 15:39:38 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH 06/30] KVM: SVM: always update CR3 in VMCB Date: Fri, 29 May 2020 11:39:10 -0400 Message-Id: <20200529153934.11694-7-pbonzini@redhat.com> In-Reply-To: <20200529153934.11694-1-pbonzini@redhat.com> References: <20200529153934.11694-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org svm_load_mmu_pgd is delaying the write of GUEST_CR3 to prepare_vmcs02 as an optimization, but this is only correct before the nested vmentry. If userspace is modifying CR3 with KVM_SET_SREGS after the VM has already been put in guest mode, the value of CR3 will not be updated. Remove the optimization, which almost never triggers anyway. This was was added in commit 689f3bf21628 ("KVM: x86: unify callbacks to load paging root", 2020-03-16) just to keep the two vendor-specific modules closer, but we'll fix VMX too. Fixes: 689f3bf21628 ("KVM: x86: unify callbacks to load paging root") Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/nested.c | 6 +----- arch/x86/kvm/svm/svm.c | 16 +++++----------- 2 files changed, 6 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index dcac4c3510ab..8756c9f463fd 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -256,11 +256,7 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, svm_set_efer(&svm->vcpu, nested_vmcb->save.efer); svm_set_cr0(&svm->vcpu, nested_vmcb->save.cr0); svm_set_cr4(&svm->vcpu, nested_vmcb->save.cr4); - if (npt_enabled) { - svm->vmcb->save.cr3 = nested_vmcb->save.cr3; - svm->vcpu.arch.cr3 = nested_vmcb->save.cr3; - } else - (void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3); + (void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3); /* Guest paging mode is active - reset mmu */ kvm_mmu_reset_context(&svm->vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 545f63ebc720..feb96a410f2d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3447,7 +3447,6 @@ static fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long root) { struct vcpu_svm *svm = to_svm(vcpu); - bool update_guest_cr3 = true; unsigned long cr3; cr3 = __sme_set(root); @@ -3456,18 +3455,13 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long root) mark_dirty(svm->vmcb, VMCB_NPT); /* Loading L2's CR3 is handled by enter_svm_guest_mode. */ - if (is_guest_mode(vcpu)) - update_guest_cr3 = false; - else if (test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail)) - cr3 = vcpu->arch.cr3; - else /* CR3 is already up-to-date. */ - update_guest_cr3 = false; + if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail)) + return; + cr3 = vcpu->arch.cr3; } - if (update_guest_cr3) { - svm->vmcb->save.cr3 = cr3; - mark_dirty(svm->vmcb, VMCB_CR); - } + svm->vmcb->save.cr3 = cr3; + mark_dirty(svm->vmcb, VMCB_CR); } static int is_disabled(void) -- 2.26.2