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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 6EBBDC76191 for ; Mon, 15 Jul 2019 16:34:21 +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 4AA492081C for ; Mon, 15 Jul 2019 16:34:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4AA492081C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hn3vR-0007ZE-Pe; Mon, 15 Jul 2019 16:34:05 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hn3vQ-0007Z9-4J for xen-devel@lists.xenproject.org; Mon, 15 Jul 2019 16:34:04 +0000 X-Inumbo-ID: 5a8f18ca-a71e-11e9-8980-bc764e045a96 Received: from mga02.intel.com (unknown [134.134.136.20]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTPS id 5a8f18ca-a71e-11e9-8980-bc764e045a96; Mon, 15 Jul 2019 16:34:02 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jul 2019 09:34:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,493,1557212400"; d="scan'208";a="175145375" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by FMSMGA003.fm.intel.com with ESMTP; 15 Jul 2019 09:34:00 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 9AA04301AE9; Mon, 15 Jul 2019 09:34:00 -0700 (PDT) From: Andi Kleen To: Juergen Gross References: <20190715113739.17694-1-jgross@suse.com> Date: Mon, 15 Jul 2019 09:34:00 -0700 In-Reply-To: <20190715113739.17694-1-jgross@suse.com> (Juergen Gross's message of "Mon, 15 Jul 2019 13:37:37 +0200") Message-ID: <87y30zfe9z.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Subject: Re: [Xen-devel] [PATCH 0/2] Remove 32-bit Xen PV guest support X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , x86@kernel.org, Alok Kataria , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , xen-devel@lists.xenproject.org, Thomas Gleixner , Boris Ostrovsky Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" SnVlcmdlbiBHcm9zcyA8amdyb3NzQHN1c2UuY29tPiB3cml0ZXM6Cgo+IFRoZSBsb25nIHRlcm0g cGxhbiBoYXMgYmVlbiB0byByZXBsYWNlIFhlbiBQViBndWVzdHMgYnkgUFZILiBUaGUgZmlyc3QK PiB2aWN0aW0gb2YgdGhhdCBwbGFuIGFyZSBub3cgMzItYml0IFBWIGd1ZXN0cywgYXMgdGhvc2Ug YXJlIHVzZWQgb25seQo+IHJhdGhlciBzZWxkb20gdGhlc2UgZGF5cy4gWGVuIG9uIHg4NiByZXF1 aXJlcyA2NC1iaXQgc3VwcG9ydCBhbmQgd2l0aAo+IEdydWIyIG5vdyBzdXBwb3J0aW5nIFBWSCBv ZmZpY2lhbGx5IHNpbmNlIHZlcnNpb24gMi4wNCB0aGVyZSBpcyBubwo+IG5lZWQgdG8ga2VlcCAz Mi1iaXQgUFYgZ3Vlc3Qgc3VwcG9ydCBhbGl2ZSBpbiB0aGUgTGludXgga2VybmVsLgo+IEFkZGl0 aW9uYWxseSBNZWx0ZG93biBtaXRpZ2F0aW9uIGlzIG5vdCBhdmFpbGFibGUgaW4gdGhlIGtlcm5l bCBydW5uaW5nCj4gYXMgMzItYml0IFBWIGd1ZXN0LCBzbyBkcm9wcGluZyB0aGlzIG1vZGUgbWFr ZXMgc2Vuc2UgZnJvbSBzZWN1cml0eQo+IHBvaW50IG9mIHZpZXcsIHRvby4KCk5vcm1hbGx5IHdl IGhhdmUgYSBkZXByZWNhdGlvbiBwZXJpb2QgZm9yIGZlYXR1cmUgcmVtb3ZhbHMgbGlrZSB0aGlz LgpZb3Ugd291bGQgbWFrZSB0aGUga2VybmVsIHByaW50IGEgd2FybmluZyBmb3Igc29tZSByZWxl YXNlcywgYW5kIHdoZW4Kbm8gdXNlciBjb21wbGFpbnMgeW91IGNhbiB0aGVuIHJlbW92ZS4gSWYg YSB1c2VyIGNvbXBsYWlucyB5b3UgY2FuJ3QuCgotQW5kaQoKX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1haWxpbmcgbGlzdApYZW4tZGV2 ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0cy54ZW5wcm9qZWN0Lm9yZy9tYWls bWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== 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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 576BCC7618F for ; Mon, 15 Jul 2019 16:34:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A1772081C for ; Mon, 15 Jul 2019 16:34:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731189AbfGOQeC (ORCPT ); Mon, 15 Jul 2019 12:34:02 -0400 Received: from mga02.intel.com ([134.134.136.20]:8134 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729533AbfGOQeC (ORCPT ); Mon, 15 Jul 2019 12:34:02 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jul 2019 09:34:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,493,1557212400"; d="scan'208";a="175145375" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by FMSMGA003.fm.intel.com with ESMTP; 15 Jul 2019 09:34:00 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 9AA04301AE9; Mon, 15 Jul 2019 09:34:00 -0700 (PDT) From: Andi Kleen To: Juergen Gross Cc: xen-devel@lists.xenproject.org, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Boris Ostrovsky , Stefano Stabellini , Alok Kataria Subject: Re: [PATCH 0/2] Remove 32-bit Xen PV guest support References: <20190715113739.17694-1-jgross@suse.com> Date: Mon, 15 Jul 2019 09:34:00 -0700 In-Reply-To: <20190715113739.17694-1-jgross@suse.com> (Juergen Gross's message of "Mon, 15 Jul 2019 13:37:37 +0200") Message-ID: <87y30zfe9z.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Juergen Gross writes: > The long term plan has been to replace Xen PV guests by PVH. The first > victim of that plan are now 32-bit PV guests, as those are used only > rather seldom these days. Xen on x86 requires 64-bit support and with > Grub2 now supporting PVH officially since version 2.04 there is no > need to keep 32-bit PV guest support alive in the Linux kernel. > Additionally Meltdown mitigation is not available in the kernel running > as 32-bit PV guest, so dropping this mode makes sense from security > point of view, too. Normally we have a deprecation period for feature removals like this. You would make the kernel print a warning for some releases, and when no user complains you can then remove. If a user complains you can't. -Andi