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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 A8B91C3F2CD for ; Fri, 28 Feb 2020 22:52:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88DBC246A8 for ; Fri, 28 Feb 2020 22:52:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726811AbgB1Wwu (ORCPT ); Fri, 28 Feb 2020 17:52:50 -0500 Received: from mga01.intel.com ([192.55.52.88]:64083 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726277AbgB1Wwm (ORCPT ); Fri, 28 Feb 2020 17:52:42 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Feb 2020 14:52:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,497,1574150400"; d="scan'208";a="439387486" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by fmsmga006.fm.intel.com with ESMTP; 28 Feb 2020 14:52:42 -0800 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 Subject: [PATCH 1/2] KVM: x86/mmu: Ignore guest CR3 on fast root switch for direct MMU Date: Fri, 28 Feb 2020 14:52:39 -0800 Message-Id: <20200228225240.8646-2-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200228225240.8646-1-sean.j.christopherson@intel.com> References: <20200228225240.8646-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ignore the guest's CR3 when looking for a cached root for a direct MMU, the guest's CR3 has no impact on the direct MMU's shadow pages (the role check ensures compatibility with CR0.WP, etc...). Zero out root_cr3 when allocating the direct roots to make it clear that it's ignored. Cc: Vitaly Kuznetsov Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index c4e0b97f82ac..9d617b9dc78f 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3730,7 +3730,9 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root); } else BUG(); - vcpu->arch.mmu->root_cr3 = vcpu->arch.mmu->get_cr3(vcpu); + + /* root_cr3 is ignored for direct MMUs. */ + vcpu->arch.mmu->root_cr3 = 0; return 0; } @@ -4272,8 +4274,8 @@ static bool cached_root_available(struct kvm_vcpu *vcpu, gpa_t new_cr3, for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { swap(root, mmu->prev_roots[i]); - if (new_cr3 == root.cr3 && VALID_PAGE(root.hpa) && - page_header(root.hpa) != NULL && + if ((new_role.direct || new_cr3 == root.cr3) && + VALID_PAGE(root.hpa) && page_header(root.hpa) && new_role.word == page_header(root.hpa)->role.word) break; } -- 2.24.1