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 0FB4CC3DA6F for ; Thu, 24 Aug 2023 16:09:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242359AbjHXQIi (ORCPT ); Thu, 24 Aug 2023 12:08:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242379AbjHXQIT (ORCPT ); Thu, 24 Aug 2023 12:08:19 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 161BE1996 for ; Thu, 24 Aug 2023 09:08:18 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-58fbc0e0c6dso726187b3.0 for ; Thu, 24 Aug 2023 09:08:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692893297; x=1693498097; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=6ixXU2vNex2+1id+8Rly6dixara1UC2RdpyLH0XPBAg=; b=A9kEnqI0HK2memtoFt706uJhZM7N7xDMbtmemAHGlIm1eOkCLsGNXiW7FLVvY05J9P ETqLsxun/tk+RXvLh23UQjYbSRYhEZ9V510uNVjG4RPv9cv4eptel9Vj9R8S0ppxD/06 Qizu9c+eNq+u/3DNdekU3zqsmJ5hgJ5j1LfpzhY194N3i9fEDEKwrKYAWCJkmxyzfe8S WlY1cnwQ0g1wwGxWShGOEFCCyOo29vjonYFnOfP8D7/QTuvNz63vBwXZ2yOGkZwZwvbe O6UtspFl1MPBJMtRckLSd8drpEIIwXtqNKt87ZmVxsrxCytOSLhhQrE60MBCe4t6acW5 Ko7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692893297; x=1693498097; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6ixXU2vNex2+1id+8Rly6dixara1UC2RdpyLH0XPBAg=; b=I/HIPciBRCmeXUDIIJHgsEbHBnwj36WBjSLdvMSnl/4BhXrw7gDcs0ERC1887Jbmq3 WNCbRwRksmsXK1vh9kK1FwnRJmMT1XYuhq0heKf2KdkXgAwykPKIlA0YqMl8rsAh5j7G 5ViWj9InVuTA5wKfv+82Aumveha3bdP5BbQSFI6CBCjLVp7ioX3i7FfrUBnrxtgKeaHG 9c3KY+3U/qYU058/3Y9v80mE0GxeMT9L8nOKP2MlYyDPHbnyNmRdNjUV+2xXIGNYVkLV BmcgS2VQBu8U7VrUozIGz9KU6UwP8zGsnnjim0rJg2xv6fTADX1jteLBcw933Fx5N68X n4NA== X-Gm-Message-State: AOJu0YzQTzOa/0Px7B2/Q1B60QN/kBi0+JDUSNBEM5y/Ty8crIbXq6qH t8LqhpUAoOWN/fJ7J8ph5FWcvIMVF58= X-Google-Smtp-Source: AGHT+IF4tuSw46JD7qw+5gQdRlBrlVirqCEscZWNprAlepko0RaD8sLBVYb5gppzeZaW50s9t8fpYJ9q8Ec= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a81:b71c:0:b0:573:8316:8d04 with SMTP id v28-20020a81b71c000000b0057383168d04mr227266ywh.4.1692893297340; Thu, 24 Aug 2023 09:08:17 -0700 (PDT) Date: Thu, 24 Aug 2023 09:08:15 -0700 In-Reply-To: Mime-Version: 1.0 References: <20230810234919.145474-1-seanjc@google.com> Message-ID: Subject: Re: [PATCH 0/2] KVM: SVM: Fix unexpected #UD on INT3 in SEV guests From: Sean Christopherson To: Tom Lendacky Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Wu Zongyo Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Aug 23, 2023, Sean Christopherson wrote: > One idea to make the original bug repro on every run would be to constantly > toggle nx_huge_pages between "off" and "force" while the guest is booting. Toggling > nx_huge_pages should force KVM to rebuild the SPTEs and all but guarantee trying > to deliver the #BP will hit a #NPF. Mwhahaha. That, plus a delay in the guest and disabling THP, makes this 100% reproducible. I'll verify the fix actually works before posting v2.