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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4718CC433F5 for ; Thu, 12 May 2022 11:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353472AbiELL5m (ORCPT ); Thu, 12 May 2022 07:57:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344488AbiELL5h (ORCPT ); Thu, 12 May 2022 07:57:37 -0400 Received: from out203-205-221-239.mail.qq.com (out203-205-221-239.mail.qq.com [203.205.221.239]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 622A96C569 for ; Thu, 12 May 2022 04:57:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1652356651; bh=iY2yJcOLbtsYvLDgfwb1awyh7iPMEY/G3mZOTKxuvSo=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=h5YTEOcUp/cSeBcfW5vICGhwBpZ8fQWphC8O8CNtbO6yCuBJ1TBmABfyA9bfaDlNO cskk+Ind6Zj+EED2dxH38Foe6ykWMiAp5rbv9CD2aBmrI/Zo6RcxppLcP59K3TdheD mD+Jn+oV3m6hJR70qm6ZHTkO1XMbthvgidLV4dHc= Received: from [192.168.0.110] ([36.57.146.152]) by newxmesmtplogicsvrszc8.qq.com (NewEsmtp) with SMTP id E5B18659; Thu, 12 May 2022 19:57:27 +0800 X-QQ-mid: xmsmtpt1652356647tckuvhfck Message-ID: X-QQ-XMAILINFO: N7h1OCCDntujtdw9xm6YqEJCpuOaHp7geMFL7LuaYCdhh86xQ58E5X0S1COleI g6J2yMjukbzR7JdZZ6k88mMftRMWnk0gNotf4G9j+N74QRTYmvn4aiiu91evfDmELV2wtPr7IXqd Rn6M0R34PwYUxJELpiqjxc1hUot8ADAMJKK5sNSyFWrN33Q33MbSSsUL9zOtVPddDSX3+vrjttoI I/fvLzR1puBh5l24yT72z4GvroL1LNrNj3ylsuJp7R6RrPdhvDlexxyoGL5kZb/vgq+n25O/BJn3 TdES50w336OX53XHuIr89wNpX0gJlv4A4vI8z5Wq8z4SfLaB6WX2siyKI+4RdTmsxcP0P6qTsYxF uj/zShH4mLFDxwRc5zI4dXvhxUkB9+SEBdZ2XTkVEGeopZRFwiSpc2wMT+mudDbAgigFD/gbKMhr F1n0zENLia7unuI9lC58b9fbEAN9PjtlWKObcIF4FVVAKPwkc5Nz8FwJvsyWaOtcao8dFoEMKeMo 7FsmA+6JodrlKGxQRixF8evrN30lbm3aNHb2n+6Kbk106J3QRybFlRcMsWaC3nMrj4+ROfwbTRhl ObNlAzR2RSm42de5O0zL52a58Z+Gk7zif3KalKCR05GmCIw8oO//SzpHuv+cSGHvJfUPWJBO1hRo QMWAxbYot9O8LG0JjO/b+n5sQS/N0WsJINq93VT6EeX0+hP9mPchs22cjH8wEakkKFeXSbDtNKXi hB+CPqa9FjGmHezgb3AD3U7Z4xDBRVBfmqyMSrvOESg4mCFdRyIxYf2Pp4aGx3A/MLfGDEuD6ELY vPZQNbwmknt7373yOoVGtRPuVkYu3PbWISa8vNSNTecBUiKNts1q4NdUoTdUSHPL0fEjml42DWgf Gi4TguWS5OzOmkvPGMivPNVShZxwaNNtFUfdXRjcuTFPw1MoX3czmflR+hq1h/12O8+eq6vy2XZo /NE/4UcMFQ6e2dpm8l1Q== Subject: Re: [PATCH] vfio: Remove VFIO_TYPE1_NESTING_IOMMU To: Jason Gunthorpe , Zhangfei Gao Cc: Jean-Philippe Brucker , kvm@vger.kernel.org, Will Deacon , Cornelia Huck , Alex Williamson , Vivek Kumar Gautam , iommu@lists.linux-foundation.org, Robin Murphy , linux-arm-kernel@lists.infradead.org References: <0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com> <0e2f7cb8-f0d9-8209-6bc2-ca87fff57f1f@arm.com> <20220510181327.GM49344@nvidia.com> <6c6f3ecb-6339-4093-a15a-fcf95a7c61fb@linaro.org> <20220512113241.GQ49344@nvidia.com> From: "zhangfei.gao@foxmail.com" X-OQ-MSGID: <95041b28-c676-4063-9a85-838f1b971b98@foxmail.com> Date: Thu, 12 May 2022 19:57:26 +0800 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: <20220512113241.GQ49344@nvidia.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2022/5/12 下午7:32, Jason Gunthorpe via iommu wrote: > On Thu, May 12, 2022 at 03:07:09PM +0800, Zhangfei Gao wrote: >>>> I can't help feeling a little wary about removing this until IOMMUFD >>>> can actually offer a functional replacement - is it in the way of >>>> anything upcoming? >>> From an upstream perspective if someone has a patched kernel to >>> complete the feature, then they can patch this part in as well, we >>> should not carry dead code like this in the kernel and in the uapi. >>> >>> It is not directly in the way, but this needs to get done at some >>> point, I'd rather just get it out of the way. >> We are using this interface for nested mode. > How are you using it? It doesn't do anything. Do you have out of tree > patches as well? Yes, there are some patches out of tree, since they are pending for almost one year. By the way, I am trying to test nesting mode based on iommufd, still requires iommu_enable_nesting, which is removed in this patch as well. So can we wait for alternative patch then remove them? Thanks