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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 65151C433F5 for ; Tue, 15 Feb 2022 20:27:12 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.273540.468765 (Exim 4.92) (envelope-from ) id 1nK4Pe-00037A-7W; Tue, 15 Feb 2022 20:27:02 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 273540.468765; Tue, 15 Feb 2022 20:27:02 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nK4Pe-000373-3r; Tue, 15 Feb 2022 20:27:02 +0000 Received: by outflank-mailman (input) for mailman id 273540; Tue, 15 Feb 2022 20:27:01 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nK4Pd-00036t-4s for xen-devel@lists.xenproject.org; Tue, 15 Feb 2022 20:27:01 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nK4Pd-0001RP-1Q; Tue, 15 Feb 2022 20:27:01 +0000 Received: from 54-240-197-231.amazon.com ([54.240.197.231] helo=[192.168.8.20]) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1nK4Pc-0002f3-SQ; Tue, 15 Feb 2022 20:27:01 +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=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID; bh=oqfpihFNn+BLrt42di9PuxzkmDDvafbpeo3tQfeK3QA=; b=aLiYcwoz7afy7Y4Tlcq52yv++X Y6fqNdUZRh+/WtwqauBvpCGpBpI1GC5bwe4nE7PShQT61y9/T+Hb6ykyXlgKhcC8RbvJzVi2mLW42 35jcoj3+Tb+TtI8bTAeivrCJ8rfTtR+mU6+UvnsCCaYOMfch18t9Bg6BC/FGCbVolhJ0=; Message-ID: <1df77480-bb6b-4ac8-dfa2-f167bce51ffb@xen.org> Date: Tue, 15 Feb 2022 20:26:59 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: [PATCH v6 03/11] xen/arm: Allow device-passthrough even the IOMMU is off To: Penny Zheng , xen-devel@lists.xenproject.org, sstabellini@kernel.org Cc: Bertrand.Marquis@arm.com, Wei.Chen@arm.com References: <20220214031956.3726764-1-penny.zheng@arm.com> <20220214031956.3726764-4-penny.zheng@arm.com> From: Julien Grall In-Reply-To: <20220214031956.3726764-4-penny.zheng@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 14/02/2022 03:19, Penny Zheng wrote: > From: Stefano Stabellini > > At the moment, we are only supporting device-passthrough when Xen has > enabled the IOMMU. There are some use cases where it is not possible to > use the IOMMU (e.g. doesn't exist, hardware limitation, performance) yet > it would be OK to assign a device to trusted domain so long they are > direct-mapped or the device doesn't do DMA. > > Note that when the IOMMU is disabled, it will be necessary to add > xen,force-assign-without-iommu for every device that needs to be assigned. > > Signed-off-by: Stefano Stabellini > Signed-off-by: Penny Zheng > Tested-by: Stefano Stabellini Acked-by: Julien Grall Cheers, -- Julien Grall