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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C189FC433FE for ; Fri, 29 Apr 2022 21:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381166AbiD2VD4 (ORCPT ); Fri, 29 Apr 2022 17:03:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381154AbiD2VDx (ORCPT ); Fri, 29 Apr 2022 17:03:53 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C813D3AD4 for ; Fri, 29 Apr 2022 14:00:32 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id p18-20020aa78612000000b0050d1c170018so4679021pfn.15 for ; Fri, 29 Apr 2022 14:00:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=LPVkLBPwEAjA8SToO1l83Vg1lu2tQY9qN9/CiKwVlGU=; b=IsuclB30S32MomEEZnx7eKe3YnpywIDDJ3ugO+zUmBmA0U7FjNOrRXhxz8mEqiCI/4 Tvz5jcIVNNULVi9NPLdtTQzJbS4NAYQnN4+IRtqufEnNf+EfYLGD0lGWhGwFpwedrjxY JjfxOH70aDEO18Jn7H4WZt3EV7hHpdrNhK6zCU2927NNekHZu7AgRNdLuivppHKPDzPY 8OX8/4WD6vHuhbsyGd+PUGXmeh7NZSG9coxaq7+8+lpMMN8EuMZud7fdzW90EgukBLlU vU/w7Q0j4A0HYxsvEfW9Cc1qkMpolziiuUAV8PV6pxmcTici3d3wQ7DFOOUzywTX2EkU Eqng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=LPVkLBPwEAjA8SToO1l83Vg1lu2tQY9qN9/CiKwVlGU=; b=MpDleNVSqSPhJzvmWmQnL1hFXCu/CfXD8dMz6xuIcix387HsLtHttGOF9RtnJHpQMI ccPuqm91S0D2HLZNJKeCB1o59OFnmIg/3OH/R9VOI/qEiwftZje5BYhUhjMBnHW+9/wV M/inguRP7JFnzbpQOua2zu3BMf6s1jZhD4dRVNjuUKMjNEklUAgBFwTGLLQd8r9Cs5g2 fiG+aq02cq/BdIqDR9y5xO1esTcD5+3dx8KKbjyh2VSh3u7wpW7iEwAWzgYZNwa0OFQD a34/ytBRalxCRr4fxc6e9EpFzJAKG7kErjt4H4fbbzNmJwe40uhGBJcPbCmQ+PekLqYH GODg== X-Gm-Message-State: AOAM531cnWHOu2Ow8eI2c/YRmxUZvoOkVlcpNWmLLSCGtmKdh4UOus2G IRNYD/hiQwJEmvSN2RuzgSklUwEI9ck= X-Google-Smtp-Source: ABdhPJwF72ZyuLedAAJsbXXnQhkqmpfiH1j4YWQDOOIF9AkF4nAk9MZU1II2RY3xDZCxYwYOWXB0pVgjTr4= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a63:5917:0:b0:39c:c450:3143 with SMTP id n23-20020a635917000000b0039cc4503143mr861303pgb.531.1651266031469; Fri, 29 Apr 2022 14:00:31 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 29 Apr 2022 21:00:18 +0000 In-Reply-To: <20220429210025.3293691-1-seanjc@google.com> Message-Id: <20220429210025.3293691-2-seanjc@google.com> Mime-Version: 1.0 References: <20220429210025.3293691-1-seanjc@google.com> X-Mailer: git-send-email 2.36.0.464.gb9c8b46e94-goog Subject: [PATCH v3 1/8] Revert "KVM: Do not speculatively mark pfn cache valid to "fix" race" From: Sean Christopherson To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Sean Christopherson , Lai Jiangshan , David Woodhouse , Mingwei Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit 55111927df1cd140aa7b7ea3f33f524b87776381. Signed-off-by: Sean Christopherson --- virt/kvm/pfncache.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index 72eee096a7cd..71c84a43024c 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -81,8 +81,6 @@ bool kvm_gfn_to_pfn_cache_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, { struct kvm_memslots *slots = kvm_memslots(kvm); - lockdep_assert_held_read(&gpc->lock); - if ((gpa & ~PAGE_MASK) + len > PAGE_SIZE) return false; @@ -228,6 +226,11 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, if (!old_valid || old_uhva != gpc->uhva) { void *new_khva = NULL; + /* Placeholders for "hva is valid but not yet mapped" */ + gpc->pfn = KVM_PFN_ERR_FAULT; + gpc->khva = NULL; + gpc->valid = true; + new_pfn = hva_to_pfn_retry(kvm, gpc); if (is_error_noslot_pfn(new_pfn)) { ret = -EFAULT; @@ -256,7 +259,7 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpc->pfn = KVM_PFN_ERR_FAULT; gpc->khva = NULL; } else { - gpc->valid = true; + /* At this point, gpc->valid may already have been cleared */ gpc->pfn = new_pfn; gpc->khva = new_khva; } -- 2.36.0.464.gb9c8b46e94-goog