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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 4356AC433DF for ; Tue, 16 Jun 2020 08:55:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E43C2074D for ; Tue, 16 Jun 2020 08:55:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="W9vTyiCh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726467AbgFPIzZ (ORCPT ); Tue, 16 Jun 2020 04:55:25 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:47579 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725911AbgFPIzZ (ORCPT ); Tue, 16 Jun 2020 04:55:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592297723; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wPF4qSfy9sktQyy2eeERuhgmZWCBKew9r91uHe9yaxg=; b=W9vTyiChCmQkES6Szhkg4WOce43xzQ32dcFB/25w4rfogYCkQB/pDh2Bu5BzyG1ywPUsL7 +A2HylBN8K3aRz4cbwoflpcajDqFk2GbWOHjV1Z7RpMZqGIslpCH+/ZiZqHkD2OzPNJ1/3 jDLPtXA3vaoQlCwGvtXiyvVaLRarqAg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-217-AjfjPjU3O7eoLgJpO1VzbQ-1; Tue, 16 Jun 2020 04:55:20 -0400 X-MC-Unique: AjfjPjU3O7eoLgJpO1VzbQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 67A6C10AB647; Tue, 16 Jun 2020 08:55:19 +0000 (UTC) Received: from carbon (unknown [10.40.208.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id 243D01002396; Tue, 16 Jun 2020 08:55:07 +0000 (UTC) Date: Tue, 16 Jun 2020 10:55:06 +0200 From: Jesper Dangaard Brouer To: Hangbin Liu Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, Toke =?UTF-8?B?SMO4aWxh?= =?UTF-8?B?bmQtSsO4cmdlbnNlbg==?= , Jiri Benc , Eelco Chaudron , ast@kernel.org, Daniel Borkmann , Lorenzo Bianconi , brouer@redhat.com Subject: Re: [PATCHv4 bpf-next 1/2] xdp: add a new helper for dev map multicast support Message-ID: <20200616105506.163ea5a3@carbon> In-Reply-To: <20200612085408.GT102436@dhcp-12-153.nay.redhat.com> References: <20200415085437.23028-1-liuhangbin@gmail.com> <20200526140539.4103528-1-liuhangbin@gmail.com> <20200526140539.4103528-2-liuhangbin@gmail.com> <20200610121859.0412c111@carbon> <20200612085408.GT102436@dhcp-12-153.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, 12 Jun 2020 16:54:08 +0800 Hangbin Liu wrote: > On Wed, Jun 10, 2020 at 12:18:59PM +0200, Jesper Dangaard Brouer wrote: > > On Tue, 26 May 2020 22:05:38 +0800 > > Hangbin Liu wrote: > > > > > diff --git a/net/core/xdp.c b/net/core/xdp.c > > > index 90f44f382115..acdc63833b1f 100644 > > > --- a/net/core/xdp.c > > > +++ b/net/core/xdp.c > > > @@ -475,3 +475,29 @@ void xdp_warn(const char *msg, const char *func, const int line) > > > WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); > > > }; > > > EXPORT_SYMBOL_GPL(xdp_warn); > > > + > > > +struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf) > > > +{ > > > + unsigned int headroom, totalsize; > > > + struct xdp_frame *nxdpf; > > > + struct page *page; > > > + void *addr; > > > + > > > + headroom = xdpf->headroom + sizeof(*xdpf); > > > + totalsize = headroom + xdpf->len; > > > + > > > + if (unlikely(totalsize > PAGE_SIZE)) > > > + return NULL; > > > + page = dev_alloc_page(); > > > + if (!page) > > > + return NULL; > > > + addr = page_to_virt(page); > > > + > > > + memcpy(addr, xdpf, totalsize); > > > > I don't think this will work. You are assuming that the memory model > > (xdp_mem_info) is the same. > > > > You happened to use i40, that have MEM_TYPE_PAGE_SHARED, and you should > > have changed this to MEM_TYPE_PAGE_ORDER0, but it doesn't crash as they > > are compatible. If you were using mlx5, I suspect that this would > > result in memory leaking. > > Is there anything else I should do except add the following line? > nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0; You do realize that you also have copied over the mem.id, right? And as I wrote below you also need to update frame_sz. > > > > You also need to update xdpf->frame_sz, as you also cannot assume it is > > the same. > > Won't the memcpy() copy xdpf->frame_sz to nxdpf? You obviously cannot use the frame_sz from the existing frame, as you just allocated a new page for the new xdp_frame, that have another size (here PAGE_SIZE). > And I didn't see xdpf->frame_sz is set in xdp_convert_zc_to_xdp_frame(), > do we need a fix? Good catch, that sounds like a bug, that should be fixed. Will you send a fix? > > > + > > > + nxdpf = addr; > > > + nxdpf->data = addr + headroom; > > > + > > > + return nxdpf; > > > +} > > > +EXPORT_SYMBOL_GPL(xdpf_clone); > > > > > > struct xdp_frame { > > void *data; > > u16 len; > > u16 headroom; > > u32 metasize:8; > > u32 frame_sz:24; > > /* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time, > > * while mem info is valid on remote CPU. > > */ > > struct xdp_mem_info mem; > > struct net_device *dev_rx; /* used by cpumap */ > > }; > > > struct xdp_mem_info { u32 type; /* 0 4 */ u32 id; /* 4 4 */ /* size: 8, cachelines: 1, members: 2 */ /* last cacheline: 8 bytes */ }; -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer