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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 002ECC3E8C5 for ; Fri, 27 Nov 2020 20:07:54 +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 881E922228 for ; Fri, 27 Nov 2020 20:07:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="L4AOfNVv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 881E922228 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.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.39750.72751 (Exim 4.92) (envelope-from ) id 1kik1u-0000SF-Bh; Fri, 27 Nov 2020 20:07:42 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 39750.72751; Fri, 27 Nov 2020 20:07:42 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kik1u-0000S8-7e; Fri, 27 Nov 2020 20:07:42 +0000 Received: by outflank-mailman (input) for mailman id 39750; Fri, 27 Nov 2020 20:07:41 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kik1s-0000S3-V9 for xen-devel@lists.xenproject.org; Fri, 27 Nov 2020 20:07:40 +0000 Received: from esa1.hc3370-68.iphmx.com (unknown [216.71.145.142]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 064e1b16-8d08-4c7b-b429-975f070b6184; Fri, 27 Nov 2020 20:07:40 +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: 064e1b16-8d08-4c7b-b429-975f070b6184 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1606507659; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=C9n1oQhEsOHMBx+KbrK1gnFhFHJ6nRyCPoPSDo4N4EA=; b=L4AOfNVvUG1NLEGDug7gVrmO+GdRhyCzAPB31rmUa7nklzCWpxBd8P+q JCFLMpGNWbEXxHXJ9dLYEhtNYWm9LN9bNS237imtIMybFDtlmA2blFleo cPpxa9wOdqghydB0k72IctRvSJ2S7rQQM54RxpYg+8jvxwzvCEnd8szn5 Y=; Authentication-Results: esa1.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: 5pjND+uApVf2uh0XkcuNaA8W0kHzL4eGZF4BJEi43HE5N2jakdToZ7BjBMrnIBdyp9tEJ0BHB+ w5s0/xhO5WFHuAxIisv+crNAEv96NqOpy0WaaJi/pUFiG0kKiuAzHNf0vN2CN5y297WrbY7ny+ bd6QUolDDx6LgTyEG40uYqvGWu8XyBOjVHl/GNXcx7MbUJVBBJ3boblBw60ThyhD0K9qxyGWxY AgQe6Ziu0G6jvNgf6hyuGSFz9OfAJo51lEBZ7K5KznxMM04BlZyIPUTDzLV14V06BDD8dn7c06 uAg= X-SBRS: None X-MesageID: 32405802 X-Ironport-Server: esa1.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.78,375,1599537600"; d="scan'208";a="32405802" Subject: Re: [PATCH 0/7] xen/arm: Emulate ID registers To: Bertrand Marquis , CC: Stefano Stabellini , Julien Grall , Volodymyr Babchuk References: From: Andrew Cooper Message-ID: <45b8aac3-75a6-670f-d6f2-b427c497ee2d@citrix.com> Date: Fri, 27 Nov 2020 20:07:24 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-GB X-ClientProxiedBy: AMSPEX02CAS01.citrite.net (10.69.22.112) To FTLPEX02CL04.citrite.net (10.13.108.177) On 26/11/2020 15:51, Bertrand Marquis wrote: > The goal of this serie is to emulate coprocessor ID registers so that > Xen only publish to guest features that are supported by Xen and can > actually be used by guests. > One practical example where this is required are SVE support which is > forbidden by Xen as it is not supported, but if Linux is compiled with > it, it will crash on boot. An other one is AMU which is also forbidden > by Xen but one Linux compiled with it would crash if the platform > supports it. > > To be able to emulate the coprocessor registers defining what features > are supported by the hardware, the TID3 bit of HCR must be disabled and > Xen must emulated the values of those registers when an exception is > catched when a guest is accessing it. > > This serie is first creating a guest cpuinfo structure which will > contain the values that we want to publish to the guests and then > provides the proper emulationg for those registers when Xen is getting > an exception due to an access to any of those registers. > > This is a first simple implementation to solve the problem and the way > to define the values that we provide to guests and which features are > disabled will be in a future patchset enhance so that we could decide > per guest what can be used or not and depending on this deduce the bits > to activate in HCR and the values that we must publish on ID registers. > > Bertrand Marquis (7): > xen/arm: Add ID registers and complete cpufinfo > xen/arm: Add arm64 ID registers definitions > xen/arm: create a cpuinfo structure for guest > xen/arm: Add handler for ID registers on arm64 > xen/arm: Add handler for cp15 ID registers > xen/arm: Add CP10 exception support to handle VMFR > xen/arm: Activate TID3 in HCR_EL2 CI found an ARM randconfig failure against this series. https://gitlab.com/xen-project/patchew/xen/-/pipelines/221798884 I have admit that I can't spot an obvious connection so it might be collateral damage from elsewhere, but does need looking at irrespective. ~Andrew (in lieu of a real CI robot).