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=BAYES_00,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, URIBL_BLOCKED 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 14C0DC55179 for ; Fri, 23 Oct 2020 16:30:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9FD721D47 for ; Fri, 23 Oct 2020 16:30:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XslsxuWU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751546AbgJWQaf (ORCPT ); Fri, 23 Oct 2020 12:30:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:36330 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514AbgJWQac (ORCPT ); Fri, 23 Oct 2020 12:30:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603470631; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9XP8+73+4MPF4qF13p2CcXbfnB2Aa5OPRsJarmBdtcw=; b=XslsxuWUDJz4/Evb1BXVZz7ti5TjtoA2GtK1/AqcJNNt1d0F0o7atpl7aE+hrWjf5XLIMe bbBbGL7jIfIWIXspbkVDYHvySLnOSplRLEr2c1gSPYmKJVstbVQPKowZ8OCu0WV2oGFufw Y1/NDx2rQXFqF3NlWCeuDIGTGCJu6ZQ= 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-238-sQMR7binMT2F2UfX8F0xbg-1; Fri, 23 Oct 2020 12:30:27 -0400 X-MC-Unique: sQMR7binMT2F2UfX8F0xbg-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 062A6ADC5E; Fri, 23 Oct 2020 16:30:26 +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 86E705DA78; Fri, 23 Oct 2020 16:30:25 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: bgardon@google.com, Peter Shier Subject: [PATCH 02/22] kvm: x86/mmu: Separate making SPTEs from set_spte Date: Fri, 23 Oct 2020 12:30:04 -0400 Message-Id: <20201023163024.2765558-3-pbonzini@redhat.com> In-Reply-To: <20201023163024.2765558-1-pbonzini@redhat.com> References: <20201023163024.2765558-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ben Gardon Separate the functions for generating leaf page table entries from the function that inserts them into the paging structure. This refactoring will facilitate changes to the MMU sychronization model to use atomic compare / exchanges (which are not guaranteed to succeed) instead of a monolithic MMU lock. No functional change expected. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This commit introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon Reviewed-by: Peter Shier Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 49 ++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 60103fd07bd2..ef4a63af8fce 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2996,20 +2996,15 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) #define SET_SPTE_NEED_REMOTE_TLB_FLUSH BIT(1) #define SET_SPTE_SPURIOUS BIT(2) -static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, - unsigned int pte_access, int level, - gfn_t gfn, kvm_pfn_t pfn, bool speculative, - bool can_unsync, bool host_writable) +static int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level, + gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool speculative, + bool can_unsync, bool host_writable, bool ad_disabled, + u64 *new_spte) { u64 spte = 0; int ret = 0; - struct kvm_mmu_page *sp; - if (set_mmio_spte(vcpu, sptep, gfn, pfn, pte_access)) - return 0; - - sp = sptep_to_sp(sptep); - if (sp_ad_disabled(sp)) + if (ad_disabled) spte |= SPTE_AD_DISABLED_MASK; else if (kvm_vcpu_ad_need_write_protect(vcpu)) spte |= SPTE_AD_WRPROT_ONLY_MASK; @@ -3062,8 +3057,8 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, * is responsibility of mmu_get_page / kvm_sync_page. * Same reasoning can be applied to dirty page accounting. */ - if (!can_unsync && is_writable_pte(*sptep)) - goto set_pte; + if (!can_unsync && is_writable_pte(old_spte)) + goto out; if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { pgprintk("%s: found shadow page for %llx, marking ro\n", @@ -3074,15 +3069,37 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, } } - if (pte_access & ACC_WRITE_MASK) { - kvm_vcpu_mark_page_dirty(vcpu, gfn); + if (pte_access & ACC_WRITE_MASK) spte |= spte_shadow_dirty_mask(spte); - } if (speculative) spte = mark_spte_for_access_track(spte); -set_pte: +out: + *new_spte = spte; + return ret; +} + +static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, + unsigned int pte_access, int level, + gfn_t gfn, kvm_pfn_t pfn, bool speculative, + bool can_unsync, bool host_writable) +{ + u64 spte; + struct kvm_mmu_page *sp; + int ret; + + if (set_mmio_spte(vcpu, sptep, gfn, pfn, pte_access)) + return 0; + + sp = sptep_to_sp(sptep); + + ret = make_spte(vcpu, pte_access, level, gfn, pfn, *sptep, speculative, + can_unsync, host_writable, sp_ad_disabled(sp), &spte); + + if (spte & PT_WRITABLE_MASK) + kvm_vcpu_mark_page_dirty(vcpu, gfn); + if (*sptep == spte) ret |= SET_SPTE_SPURIOUS; else if (mmu_spte_update(sptep, spte)) -- 2.26.2