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 899ADC4332F for ; Tue, 13 Dec 2022 18:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235718AbiLMSAV (ORCPT ); Tue, 13 Dec 2022 13:00:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236371AbiLMSAN (ORCPT ); Tue, 13 Dec 2022 13:00:13 -0500 Received: from mail-yw1-x1136.google.com (mail-yw1-x1136.google.com [IPv6:2607:f8b0:4864:20::1136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BED7123EA1 for ; Tue, 13 Dec 2022 10:00:04 -0800 (PST) Received: by mail-yw1-x1136.google.com with SMTP id 00721157ae682-3cbdd6c00adso203318937b3.11 for ; Tue, 13 Dec 2022 10:00:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=2q+Rlxn3qcFlUNSciCIoJUlAxGRPH5SvwBIqL2VlTbA=; b=Y3EKdkCCz47F1VcdeSbmrq5L87OKF9hcbaSJwl+vnhkaDTm4pAPVaJZO4qSLylN1xy nQHd/9Sp9UuHEXiH71uQLKDNxISd9dPDhYG8MiRaq40MHC8Qq1fF7RORHu1FbGaM2NCU WsslMSfLGkh7joBah22hpO7VN5hJywdRuWVFsC4VtxHQRJ49lH+VOH5R5Eo5kf9S0iNY BGyRcciuSQs0JM+eHv4Mhq5z+ZGRQwewYZH5HNPJmwcqamUFnpWXUnXQIeXdddTJVj4S yDNs/5OKiz/comNWoMoMz464dgZDU93zMff+ff7rF/0gEK0SMZ4O3MLHIxJNPv04xURx 5/ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=2q+Rlxn3qcFlUNSciCIoJUlAxGRPH5SvwBIqL2VlTbA=; b=mpZKrCHAmtSSMoEqpwocn9SvJ4b+pftOvR8FzKCwBZSxQDwD9MXMCa1/1ig/r7mp7C dhlXXPTUGbtBAYaKVtd96L0GmE66R3l14C6N5bxbjctWjB4BOfbFRYkJhshvc+MFlC92 bRha4tVpj7Fb2IyTCUvcJhReQ3DwkfWKQs052HhGt6Cq4268vtXQVS1YFfOlZS8nvyM1 0cSiqyrRQAy00aYZ79ty1hrmKSOSSl4tOQPbW1B5xB11ZsF9w1PrE8Jjt2uVDHGxfMZX TvsCVVH2ymoyDtbwnnCRq+0ivApi6ctcsjjOUtxELor4QE+sGypkbqPYzOAblyoBdTZL CTYw== X-Gm-Message-State: ANoB5pllmRdGGbuyGx9ExOjTtD8pemw1c9rsKVCaBS5FBDsGgYGXBZvm ekTJ0Rte3UdCHkbw1oSx8j2yg0cr3itYNuIWCjDsFA== X-Google-Smtp-Source: AA0mqf7zoDhSCFGuitR+bTdKPjJ9ycAs0uqWym5d/fV6e9qthNhf0Km8CAYRdu3t68xP5sDvEPd8+ipZWf/nrVbz9CM= X-Received: by 2002:a81:1401:0:b0:3b0:b9aa:46eb with SMTP id 1-20020a811401000000b003b0b9aa46ebmr3924120ywu.150.1670954403842; Tue, 13 Dec 2022 10:00:03 -0800 (PST) MIME-Version: 1.0 References: <20221213033030.83345-1-seanjc@google.com> <20221213033030.83345-5-seanjc@google.com> In-Reply-To: <20221213033030.83345-5-seanjc@google.com> From: David Matlack Date: Tue, 13 Dec 2022 09:59:37 -0800 Message-ID: Subject: Re: [PATCH 4/5] KVM: x86/mmu: Don't install TDP MMU SPTE if SP has unexpected level To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Robert Hoo , Greg Thelen , Ben Gardon , Mingwei Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 12, 2022 at 7:30 PM Sean Christopherson wrote: > > Don't install a leaf TDP MMU SPTE if the parent page's level doesn't > match the target level of the fault, and instead have the vCPU retry the > faulting instruction after warning. Continuing on is completely > unnecessary as the absolute worst case scenario of retrying is DoSing > the vCPU, whereas continuing on all but guarantees bigger explosions, e.g. Would it make sense to kill the VM instead via KVM_BUG()?