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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAAE6C433F5 for ; Thu, 18 Nov 2021 18:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A69F561B1E for ; Thu, 18 Nov 2021 18:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232992AbhKRSdb (ORCPT ); Thu, 18 Nov 2021 13:33:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232712AbhKRSda (ORCPT ); Thu, 18 Nov 2021 13:33:30 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EC3BC061574; Thu, 18 Nov 2021 10:30:30 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id fv9-20020a17090b0e8900b001a6a5ab1392so6516513pjb.1; Thu, 18 Nov 2021 10:30:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=mmspkO1+kPp2+rBfPcrNFF0KAZ/yEbitomitKki1F4c=; b=XRtmBkzOuEkF7fbB19qsHET67f9ylIAhemTwj0vY9oKXWLr9hCB0cwV+nxw8o2stj0 GltcY7l2K5tONJxOquuV7L2TIN57YZJrJmw7y9PV9ZxF0ZLwEjheWjRBvyQhzmVakSrk PbDgBSWiH91ite0gOJlgdbDos1H/0AYsxt2RGlhNvwycoZcUQ6/5iz07sd69JTksW/Iu +KaHny4SmGhvAWhoVrGJDNvyfNKpVutlqmFg5PWkDtRMjSY0X0HX4B6ljRB8eyWlOBva Q0x63QNi0e41C925oVbGx5yJCGJ/Ts+/GgDZVJZwl6lisD3Uen2AEJM2XOPa6z9J/iRH arLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=mmspkO1+kPp2+rBfPcrNFF0KAZ/yEbitomitKki1F4c=; b=jYzJc5al2quDchjICknZ9AyViaWq420CaWEojwc0pBxXnVZNkK+nyo0GEfQPErRIz+ 0ZDtsi3jqOHaK1tfCe4nRy3g9u1GI/cfAgzonR8ZQYBIOysfnbNTaEsOFIh3tUg1l5Ox +yjTEeCGwTMlwggJAYi48/Umr3ghtWLahQUy/qbapjES3Qx0Gj/v0i5qhjL4Xzixqzka tuCE+nosXxkf6TOMc0GGIKaFdxr/Tb4phoRssUC3Dvm8YIEu9mC1C15nhdgLbFBRgWDT f9CctW1EYBlUkdkDYXCqdQ9pikdY4vGGhoASayP1DPqj02t4wGDcNZgPS005sRbglpMS 8aWQ== X-Gm-Message-State: AOAM5316ENLESkN6XV/FM6lsj/aptRvu1nrQEF1vcor+esZLu7FbCKJK q1NxaMKy9NfUOpRTFQj2Qu8= X-Google-Smtp-Source: ABdhPJz9wj7HKK9knl1Ytfr+vDJMKwINA2ORQdacsublH0aSjcqqJiK6TuFVyzwadYh7BoK0c10X1w== X-Received: by 2002:a17:902:c145:b0:142:50c3:c2a with SMTP id 5-20020a170902c14500b0014250c30c2amr68183395plj.32.1637260229980; Thu, 18 Nov 2021 10:30:29 -0800 (PST) Received: from localhost ([2405:201:6014:d064:502e:73f4:8af1:9522]) by smtp.gmail.com with ESMTPSA id u2sm293799pfi.120.2021.11.18.10.30.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 10:30:29 -0800 (PST) Date: Fri, 19 Nov 2021 00:00:22 +0530 From: Kumar Kartikeya Dwivedi To: Yonghong Song Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Pavel Emelyanov , Alexander Mihalicyn , Andrei Vagin , criu@openvz.org, io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH bpf-next v1 2/8] bpf: Add bpf_page_to_pfn helper Message-ID: <20211118183022.tiijkhno57uwtytm@apollo.localdomain> References: <20211116054237.100814-1-memxor@gmail.com> <20211116054237.100814-3-memxor@gmail.com> <7efcf912-46be-1ed4-7e12-88c2baeaab12@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7efcf912-46be-1ed4-7e12-88c2baeaab12@fb.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Thu, Nov 18, 2021 at 10:57:15PM IST, Yonghong Song wrote: > > > On 11/15/21 9:42 PM, Kumar Kartikeya Dwivedi wrote: > > In CRIU, we need to be able to determine whether the page pinned by > > io_uring is still present in the same range in the process VMA. > > /proc//pagemap gives us the PFN, hence using this helper we can > > establish this mapping easily from the iterator side. > > > > It is a simple wrapper over the in-kernel page_to_pfn helper, and > > ensures the passed in pointer is a struct page PTR_TO_BTF_ID. This is > > obtained from the bvec of io_uring_ubuf for the CRIU usecase. > > > > Signed-off-by: Kumar Kartikeya Dwivedi > > --- > > fs/io_uring.c | 17 +++++++++++++++++ > > include/linux/bpf.h | 1 + > > include/uapi/linux/bpf.h | 9 +++++++++ > > kernel/trace/bpf_trace.c | 2 ++ > > scripts/bpf_doc.py | 2 ++ > > tools/include/uapi/linux/bpf.h | 9 +++++++++ > > 6 files changed, 40 insertions(+) > > > > diff --git a/fs/io_uring.c b/fs/io_uring.c > > index 46a110989155..9e9df6767e29 100644 > > --- a/fs/io_uring.c > > +++ b/fs/io_uring.c > > @@ -11295,6 +11295,23 @@ static struct bpf_iter_reg io_uring_buf_reg_info = { > > .seq_info = &bpf_io_uring_buf_seq_info, > > }; > > +BPF_CALL_1(bpf_page_to_pfn, struct page *, page) > > +{ > > + /* PTR_TO_BTF_ID can be NULL */ > > + if (!page) > > + return U64_MAX; > > + return page_to_pfn(page); > > +} > > + > > +BTF_ID_LIST_SINGLE(btf_page_to_pfn_ids, struct, page) > > + > > +const struct bpf_func_proto bpf_page_to_pfn_proto = { > > + .func = bpf_page_to_pfn, > > + .ret_type = RET_INTEGER, > > + .arg1_type = ARG_PTR_TO_BTF_ID, > > + .arg1_btf_id = &btf_page_to_pfn_ids[0], > > Does this helper need to be gpl_only? > Not sure about it, it wraps over a macro. > > +}; > > + > > static int __init io_uring_iter_init(void) > > { > > io_uring_buf_reg_info.ctx_arg_info[0].btf_id = btf_io_uring_ids[0]; > [...] -- Kartikeya