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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4954C54FB3 for ; Mon, 26 May 2025 20:57:34 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.997808.1378624 (Exim 4.92) (envelope-from ) id 1uJess-0002GP-3Y; Mon, 26 May 2025 20:57:22 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 997808.1378624; Mon, 26 May 2025 20:57:22 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uJesr-0002GI-WC; Mon, 26 May 2025 20:57:21 +0000 Received: by outflank-mailman (input) for mailman id 997808; Mon, 26 May 2025 20:57:20 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uJesq-0002GC-Sv for xen-devel@lists.xenproject.org; Mon, 26 May 2025 20:57:20 +0000 Received: from chassiron.antioche.eu.org (chassiron.antioche.eu.org [2001:41d0:fc2c:4d01::1]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 02df9a39-3a74-11f0-b893-0df219b8e170; Mon, 26 May 2025 22:57:19 +0200 (CEST) Received: from rochebonne.antioche.eu.org ([IPv6:2001:41d0:fc2c:4d00:96de:80ff:fe21:bec0]) by chassiron.antioche.eu.org (8.18.1/8.16.1) with ESMTP id 54QKvGBN014557; Mon, 26 May 2025 22:57:16 +0200 (MEST) Received: by rochebonne.antioche.eu.org (Postfix, from userid 1210) id 470451A4D0; Mon, 26 May 2025 22:56:41 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 02df9a39-3a74-11f0-b893-0df219b8e170 Date: Mon, 26 May 2025 22:56:41 +0200 From: Manuel Bouyer To: Andrew Cooper Cc: xen-devel@lists.xenproject.org Subject: Re: Xen 4.18.5 PV dbregs fail Message-ID: References: <0733f3dc-9f01-4e15-98ab-d7fd7c3e303d@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.4 (chassiron.antioche.eu.org [IPv6:2001:41d0:fc2c:4d01:0:0:0:1]); Mon, 26 May 2025 22:57:16 +0200 (MEST) On Mon, May 26, 2025 at 09:30:53PM +0100, Andrew Cooper wrote: > On 26/05/2025 9:13 pm, Manuel Bouyer wrote: > > On Mon, May 26, 2025 at 07:50:14PM +0100, Andrew Cooper wrote: > >> [...] > >> Well, that range does include the aforementioned commit. > >> > >> Can you bisect around d32c77f471fb8400b6512c171a14cdd58f04f0a3 which is > >> the backport of ^ in 4.18 ? > > Sure, > > with 0d5f15e and d32c77f the test pass, with cecee35 it fails. > > > > Oh interesting, so the basic forwarding of #DB back into a guest > (d32c77f) works fine, but the changes to emulated debug exceptions > (cecee35) break. > > Anyway, I think I've spotted a logical error.  We do indeed end up > calling x86_merge_dr6() twice, because of the TODO just out of context.  > Does this help? Yes, it works for cecee35; now testing with 4.18.5 -- Manuel Bouyer NetBSD: 26 ans d'experience feront toujours la difference --