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 X-Spam-Level: X-Spam-Status: No, score=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 235AEC433ED for ; Wed, 7 Apr 2021 07:55:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C83A460BD3 for ; Wed, 7 Apr 2021 07:55:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C83A460BD3 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.106450.203554 (Exim 4.92) (envelope-from ) id 1lU31T-0002M2-4F; Wed, 07 Apr 2021 07:54:47 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 106450.203554; Wed, 07 Apr 2021 07:54:47 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lU31T-0002Lv-1B; Wed, 07 Apr 2021 07:54:47 +0000 Received: by outflank-mailman (input) for mailman id 106450; Wed, 07 Apr 2021 07:54:45 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lU31R-0002Lq-6I for xen-devel@lists.xenproject.org; Wed, 07 Apr 2021 07:54:45 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 0af082a5-4b7c-48b6-bf0b-c729fe319e15; Wed, 07 Apr 2021 07:54:44 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 5BF30AF39; Wed, 7 Apr 2021 07:54:43 +0000 (UTC) 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: 0af082a5-4b7c-48b6-bf0b-c729fe319e15 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1617782083; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=trqA/CX1H2/rPui5/OkyYkNberezRL+pK08vzT5qvKM=; b=URorqoJSrfEAww9xnNhy9OcPYhXkg1Ep4KJL86SvKOHM6JqNbdxL7DbaKmBG227tGEzyqE MeCU/Rrzs/nhEji39fMgMUreobWZ4uVJlHyPjWeTMPW3xNj4gvTrU0gjly70V5gcrLK7Cm euow5NvC/C8+rxrodApVc8T++xjLuVs= Subject: Re: [PATCH 5/5] x86: don't build unused entry code when !PV32 To: Andrew Cooper Cc: Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , "xen-devel@lists.xenproject.org" References: <46d83c92-0b06-fc09-4832-7a7d7935d5c2@suse.com> From: Jan Beulich Message-ID: Date: Wed, 7 Apr 2021 09:54:40 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 06.04.2021 19:34, Andrew Cooper wrote: > On 01/04/2021 15:37, Jan Beulich wrote: >> On 01.04.2021 16:31, Andrew Cooper wrote: >>> On 25/11/2020 08:51, Jan Beulich wrote: >>>> @@ -102,19 +102,21 @@ void __dummy__(void) >>>> BLANK(); >>>> #endif >>>> >>>> -#ifdef CONFIG_PV >>>> +#ifdef CONFIG_PV32 >>>> OFFSET(DOMAIN_is_32bit_pv, struct domain, arch.pv.is_32bit); >>> Even if PV32 is compiled out, the is_32bit field still exists, and is >>> still necessary for crash analysis.  XCA parses this offset information >>> as part of dissecting /proc/vmcore. >>> >>> It's one single bool in a fixed size allocation which we've got plenty >>> of room in.  It can and should stay to avoid impacting the existing >>> diagnostic tools. >> I'm afraid I don't understand at all: I'm not removing the field. > > You talked about removing it in the commit message. Oh, in a post-commit message TBD remark, yes. Is your objection here then merely to this possible further plan of removing that field, but not against the changes in this patch? >> All I'm removing is the entry for it in asm-offsets.h. > > Yes, and that will break XCA, which is used by several downstreams, not > just XenServer. > > For RPM package reasons, you can't use debuginfo packages, because > what's on disk doesn't match what's in memory until you've rebooted.  > Livepatching adds an extra dimension of fun here.  There's not enough > space in the vmcoreinfo page to pass enough structure information, so > asm offsets is appended to the symbol table.  Yes its a gross hack, but > its how things currently work. Would you mind pointing me at where this appending is happening? You can't mean the ELF symbol table in xen-syms - there's no entry for DOMAIN_is_32bit_pv there. Plus I don't see the problem here, as the asm-offsets entry already is conditional - it's merely the condition which gets changed. Or if you mean the is_32bit field - there's no representation there either in xen-syms (except, when enabled, in debug info). Jan