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=-1.0 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 31925C433DF for ; Tue, 23 Jun 2020 17:33:00 +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 08072206EB for ; Tue, 23 Jun 2020 17:32:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08072206EB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass 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 4.92) (envelope-from ) id 1jnmmq-0001p4-Et; Tue, 23 Jun 2020 17:32:44 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jnmmp-0001oz-9b for xen-devel@lists.xenproject.org; Tue, 23 Jun 2020 17:32:43 +0000 X-Inumbo-ID: 8a53e80d-b577-11ea-bfc5-12813bfff9fa Received: from esa1.hc3370-68.iphmx.com (unknown [216.71.145.142]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 8a53e80d-b577-11ea-bfc5-12813bfff9fa; Tue, 23 Jun 2020 17:32:42 +0000 (UTC) Authentication-Results: esa1.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: KMqMGmiijij0OIAJMqHUOsU3FlHQIXg/ANNSXcGBJplcIpnAyFM/ThPUrvIn/X9HhLqGp0JN9Y z5IaRkDA0ScHIYV3UB7bqCyGdvtaKTYVsXCS1303S1xMBXkb8sQfS1ynl5y5Kmz2sHK2XMfSb+ AnTFue4mt52suyr7H665iBGC/Z2j95FfmFdcMiEiVgvblQ7li+Icc7/v98LyRnGmRpZX2MQC8f 3jdFRgo37F6FpoAHWocp8HeYcyNIVjhgQKofLhAzPcr5JZ1gyal27HCmbp7s3piRdlX5iFF2WM ivQ= X-SBRS: 2.7 X-MesageID: 21051973 X-Ironport-Server: esa1.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,272,1589256000"; d="scan'208";a="21051973" Date: Tue, 23 Jun 2020 19:32:34 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Subject: Re: [PATCH for-4.14] mm: fix public declaration of struct xen_mem_acquire_resource Message-ID: <20200623173150.GV735@Air-de-Roger> References: <20200623135246.66170-1-roger.pau@citrix.com> <044c278b-e0df-e389-b21a-66c7307997c4@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <044c278b-e0df-e389-b21a-66c7307997c4@suse.com> X-ClientProxiedBy: AMSPEX02CAS01.citrite.net (10.69.22.112) To AMSPEX02CL02.citrite.net (10.69.22.126) X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , paul@xen.org, Andrew Cooper , Ian Jackson , George Dunlap , xen-devel@lists.xenproject.org Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Tue, Jun 23, 2020 at 05:04:53PM +0200, Jan Beulich wrote: > On 23.06.2020 15:52, Roger Pau Monne wrote: > > XENMEM_acquire_resource and it's related structure is currently inside > > a __XEN__ or __XEN_TOOLS__ guarded section to limit it's scope to the > > hypervisor or the toolstack only. This is wrong as the hypercall is > > already being used by the Linux kernel at least, and as such needs to > > be public. > > Actually - how does this work for the Linux kernel, seeing > > rc = rcu_lock_remote_domain_by_id(xmar.domid, &d); > if ( rc ) > return rc; > > rc = xsm_domain_resource_map(XSM_DM_PRIV, d); > if ( rc ) > goto out; > > in the function? It's my understanding (I haven't tried to use that hypercall yet on FreeBSD, so I cannot say I've tested it), that xmar.domid is the remote domain, which the functions locks and then uses xsm_domain_resource_map to check whether the current domain has permissions to do privileged operations against it. Roger.