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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 7266DC433E0 for ; Tue, 23 Jun 2020 19:36:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36D052098B for ; Tue, 23 Jun 2020 19:36:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387573AbgFWTf7 (ORCPT ); Tue, 23 Jun 2020 15:35:59 -0400 Received: from mga11.intel.com ([192.55.52.93]:11007 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387505AbgFWTfp (ORCPT ); Tue, 23 Jun 2020 15:35:45 -0400 IronPort-SDR: iX/RIRyPcRQJQim+jrPafeWR8C/TAVHEn1Hnkayf3zZzwVeQL7jJhePfNYru3h8Rcvz6OaBrS2 CwEXkxT9mvCA== X-IronPort-AV: E=McAfee;i="6000,8403,9661"; a="142430980" X-IronPort-AV: E=Sophos;i="5.75,272,1589266800"; d="scan'208";a="142430980" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jun 2020 12:35:44 -0700 IronPort-SDR: OOlI9c2EJF66vE1ak8KQJ1mxYF3k9rYe5Kz0ZWgNE/88d7eFDl9xLCxcKTUuja3Gk+TOu9IBBH nqyCGnbh/aUA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,272,1589266800"; d="scan'208";a="263428300" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.152]) by fmsmga007.fm.intel.com with ESMTP; 23 Jun 2020 12:35:44 -0700 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 v2 4/4] KVM: x86/mmu: Exit to userspace on make_mmu_pages_available() error Date: Tue, 23 Jun 2020 12:35:42 -0700 Message-Id: <20200623193542.7554-5-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200623193542.7554-1-sean.j.christopherson@intel.com> References: <20200623193542.7554-1-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 Propagate any error returned by make_mmu_pages_available() out to userspace instead of resuming the guest if the error occurs while handling a page fault. Now that zapping the oldest MMU pages skips active roots, i.e. fails if and only if there are no zappable pages, there is no chance for a false positive, i.e. no chance of returning a spurious error to userspace. Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 3 ++- arch/x86/kvm/mmu/paging_tmpl.h | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4d40b21a67bd..82086d9eecb0 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4157,7 +4157,8 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) goto out_unlock; - if (make_mmu_pages_available(vcpu) < 0) + r = make_mmu_pages_available(vcpu); + if (r) goto out_unlock; r = __direct_map(vcpu, gpa, write, map_writable, max_level, pfn, prefault, is_tdp && lpage_disallowed); diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 58234bfaca07..a2db6971231d 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -865,7 +865,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, goto out_unlock; kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); - if (make_mmu_pages_available(vcpu) < 0) + r = make_mmu_pages_available(vcpu); + if (r) goto out_unlock; r = FNAME(fetch)(vcpu, addr, &walker, write_fault, max_level, pfn, map_writable, prefault, lpage_disallowed); -- 2.26.0