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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DED49C433DB for ; Fri, 19 Feb 2021 15:50:58 +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 7152064DFD for ; Fri, 19 Feb 2021 15:50:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7152064DFD Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=xenproject.org 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.86951.163648 (Exim 4.92) (envelope-from ) id 1lD83K-00044D-8r; Fri, 19 Feb 2021 15:50:46 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 86951.163648; Fri, 19 Feb 2021 15:50:46 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lD83K-000446-5k; Fri, 19 Feb 2021 15:50:46 +0000 Received: by outflank-mailman (input) for mailman id 86951; Fri, 19 Feb 2021 15:50:45 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lD83J-00043k-N6 for xen-devel@lists.xenproject.org; Fri, 19 Feb 2021 15:50:45 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lD83J-0003K6-M8 for xen-devel@lists.xenproject.org; Fri, 19 Feb 2021 15:50:45 +0000 Received: from iwj (helo=mariner.uk.xensource.com) by xenbits.xenproject.org with local-bsmtp (Exim 4.92) (envelope-from ) id 1lD83J-0006KL-Kq for xen-devel@lists.xenproject.org; Fri, 19 Feb 2021 15:50:45 +0000 Received: from iwj by mariner.uk.xensource.com with local (Exim 4.89) (envelope-from ) id 1lD83G-0001EC-Cl; Fri, 19 Feb 2021 15:50:42 +0000 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" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xenproject.org; s=20200302mail; h=References:In-Reply-To:Subject:Cc:To:Date :Message-ID:Content-Transfer-Encoding:Content-Type:MIME-Version:From; bh=u8nZQgrCi40A/rBG4PVPftmjeH8BU5sMLURTLylJDSo=; b=4j+ayX1tIq3ozDwnqyyMmNyiHL nQZXJi2qfh6fSN8j7c6cmFNYqgwa9gpvw51RJ1xxiKiJ/WQjEOx/hx1mQIPBdULjVasWyp0jj19RT MtuYvCRuo5HEgRP6RSdSfBTa0ha9ppDBSaC06V5/znrzyMN5tavWXtcwv7EhT8zHPUAk=; From: Ian Jackson MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <24623.56913.290437.499946@mariner.uk.xensource.com> Date: Fri, 19 Feb 2021 15:50:41 +0000 To: Jan Beulich Cc: "xen-devel\@lists.xenproject.org" , Andrew Cooper , Wei Liu , Roger Pau =?iso-8859-1?Q?Monn=E9?= , George Dunlap Subject: Re: [PATCH v2 0/8] x86/PV: avoid speculation abuse through guest accessors In-Reply-To: References: X-Mailer: VM 8.2.0b under 24.5.1 (i686-pc-linux-gnu) Jan Beulich writes ("[PATCH v2 0/8] x86/PV: avoid speculation abuse through guest accessors"): > Re-sending primarily for the purpose of getting a release ack, an > explicit release nak, or an indication of there not being a need, > all for at least the first three patches here (which are otherwise > ready to go in). I've dropped the shadow part of the series from > this re-submission, because it has all got reviewed by Tim already > and is intended for 4.16 only anyway. I'm re-including the follow > up patches getting the code base in consistent shape again, as I > continue to think this consistency goal is at least worth a > consideration towards a freeze exception. > > 1: split __{get,put}_user() into "guest" and "unsafe" variants > 2: split __copy_{from,to}_user() into "guest" and "unsafe" variants > 3: PV: harden guest memory accesses against speculative abuse These three: Release-Acked-by: Ian Jackson On the grounds that this is probably severe enough to be a blocking issue for 4.15. > 4: rename {get,put}_user() to {get,put}_guest() > 5: gdbsx: convert "user" to "guest" accesses > 6: rename copy_{from,to}_user() to copy_{from,to}_guest_pv() > 7: move stac()/clac() from {get,put}_unsafe_asm() ... > 8: PV: use get_unsafe() instead of copy_from_unsafe() These have not got a maintainer review yet. To grant a release-ack I'd like an explanation of the downsides and upsides of taking this series in 4.15 ? You say "consistency" but in practical terms, what will happen if the code is not "conxistent" in this sense ? I'd also like to hear from aother hypervisor maintainer. Thanks, Ian.