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 653FCC433F5 for ; Wed, 27 Apr 2022 01:40:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356859AbiD0Bn1 (ORCPT ); Tue, 26 Apr 2022 21:43:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236166AbiD0BnW (ORCPT ); Tue, 26 Apr 2022 21:43:22 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14EE765FC for ; Tue, 26 Apr 2022 18:40:12 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id j24-20020a637a58000000b003ab45990247so169499pgn.17 for ; Tue, 26 Apr 2022 18:40:12 -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=fm2jFbot54PvFH20t4TxzybP3OE84ejhq1XxWwapvtM=; b=ILHHX56EFCxezIq3EQk2itS0pXFDo1O6lEKmmvkKR5gKRVOl2Y+a4cJXIzRR+zJaTI mcTvkTLdjSSKxzcNk+wvZqMLVYKVUvmqX5Ar8l913XfsqrlF3UGpDeHKdnfL9GqzfLdU nnE1FIo6IZvCB9kbYWzaJvNDeEb9KHxLvej6/tAWNl274K8TDUgqG7u2YsfP8oIuqINE 7d4eX0CnNCJINrjYW+DvVx19wlg0t2ar56EG9pze/viUxCWpaOu7ypXXah2+7HMmhtti nmX55ONv5BW7spf9BUS/qWHpSrJ6+jGLuU4cfuH/Cmu5Xbg32MdrBE4dGFdDfbRFmq/W YfyA== 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=fm2jFbot54PvFH20t4TxzybP3OE84ejhq1XxWwapvtM=; b=me+FODgJuNXu2BboV8OFOE7E1zPHLpPG7zPDS0bLCw7hU0BALvLtcPMgrIpeUf87Yo L3Yy5kWVK6W9UwQ9T9GKiRJ2kYrmnK6Lu5Fceaci3Wcj/1zH5K21z+73Kif6gnDwUlNa 2C9HXZp8FSQk1QI9JtKuK1gRofByGI7eaLGowndHRL0F+sY1EmZaVVrgjFIeo0Hlyn7K eZWJsY8EeIle4ZP5aPhFRb5wIxJ/SdLp4uHKT84d9d+5lcilHrS6nvGXesezaaby7QR4 Fq1mM4db6E13tlvUpMhertjGvgZQDO1gaiy9EgoCWoUuC5DC7EBotBbts9z3qdVKCQww b0zw== X-Gm-Message-State: AOAM531ZcNrx3wrR0YNFac3Qy1zaizbNFCAuydenIoPiqGR0b1iF/14z 7idLub7MqdiXPEYIaPSIWLO3iWrZ/L8= X-Google-Smtp-Source: ABdhPJwUekR1b6h0Z9yFRwjtbUYBs62GSJESl9pr1sbEnNpewT52TkTR2aZh+tu7EXL0TS1Cfa7TQ9YX2B8= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a17:902:b590:b0:153:a243:3331 with SMTP id a16-20020a170902b59000b00153a2433331mr27227659pls.129.1651023611573; Tue, 26 Apr 2022 18:40:11 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 27 Apr 2022 01:39:57 +0000 In-Reply-To: <20220427014004.1992589-1-seanjc@google.com> Message-Id: <20220427014004.1992589-2-seanjc@google.com> Mime-Version: 1.0 References: <20220427014004.1992589-1-seanjc@google.com> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v2 1/8] Revert "KVM: Do not speculatively mark pfn cache valid to "fix" race" 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, David Woodhouse , Mingwei Zhang , Maxim Levitsky 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.rc2.479.g8af0fa9b8e-goog