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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 E3972C38A24 for ; Thu, 7 May 2020 07:18:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC335206B9 for ; Thu, 7 May 2020 07:18:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SfhvcyKq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725849AbgEGHSu (ORCPT ); Thu, 7 May 2020 03:18:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725802AbgEGHSt (ORCPT ); Thu, 7 May 2020 03:18:49 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAF62C061A10 for ; Thu, 7 May 2020 00:18:47 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id r26so5502623wmh.0 for ; Thu, 07 May 2020 00:18:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:reply-to:to:cc:references:in-reply-to:subject:date:message-id :mime-version:content-transfer-encoding:thread-index :content-language; bh=/83oAbY9HuET575P1iiSrUMJVpsBpJcdwnH0NxV4nfA=; b=SfhvcyKq+aOvm3nL0nAMhXO39Kpoq1JJfQca4QVwn6RXkijOlea7kaecoOWrGMYBJ3 X5kSSvyuz55P+HRFC7u5RXgUK4XqG6/NAunJ70CW0XWr4p6ZPYn66RR025yK88VEpOZJ f02xfE8+aTmUaVMqG5zOBORw5k+VLZv7Z7UFydx01udxW/dHsmCTSHt1yqQujXLrzs7o PwH7aDbtLKtXojNm37TWqNHFO/W7/so5fVyXPtaGRnXnE/OlWAM/m05+nl1nKxpmKj35 6nG8N1mffXZiwefnxQFnJTEznfCi3yK/bLJFLB3ce0kcKbET8z/eOcmAdEBe1buB41MM VDhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:reply-to:to:cc:references:in-reply-to :subject:date:message-id:mime-version:content-transfer-encoding :thread-index:content-language; bh=/83oAbY9HuET575P1iiSrUMJVpsBpJcdwnH0NxV4nfA=; b=B55DQIOnk1CP/2GWILtdak5LPPgZ8VHHdHxi4aFhSblCp3OZ9so0FPTbTyw1QPUixD 31VkqH34MPZzlJe3YkqwToW05iO8lOj9/dNeAxT7eAsCPHfrhlV7+06i78B423EzRubX No0Iap0sywRzX52SY5BML9uyEVWzxwZ7CkxucNhG44ILmvWsbCAXaFEVNf1QXYe9MBV0 4RDH3LkuXWevHoODRnwdiYcnlcSngKqQAfwLWbDPfmkmNmBW9MY49HmX+aTalVVtM69G NrnTykywrTP9lkTNZPSYp02zNxbgQjrOZvGIkwMZ6dC6i50+8keHbG9FKYQxuwNSXG33 tz9w== X-Gm-Message-State: AGi0PuY53TXsGPXXwdYFRDUiliIJOBP/v4XnK7Zwy+q8IgxzmXu7k0Ip rxUfdF7QelWJLhZ+RkCiLJE= X-Google-Smtp-Source: APiQypJGp+Dkh7Uu7E7S2A0UM29cbvbjhb0zPwz1y7c8gzfAH63mCWl3HA5L+ejlFVYxoQXb5BtJxw== X-Received: by 2002:a1c:44b:: with SMTP id 72mr8579112wme.58.1588835926327; Thu, 07 May 2020 00:18:46 -0700 (PDT) Received: from CBGR90WXYV0 ([54.239.6.185]) by smtp.gmail.com with ESMTPSA id l6sm6784317wrb.75.2020.05.07.00.18.44 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 May 2020 00:18:45 -0700 (PDT) From: Paul Durrant X-Google-Original-From: "Paul Durrant" Reply-To: To: "'Denis Kirjanov'" Cc: , , , References: <1588581474-18345-1-git-send-email-kda@linux-powerpc.org> <1588581474-18345-2-git-send-email-kda@linux-powerpc.org> <004201d622e8$2fff5cf0$8ffe16d0$@xen.org> <005a01d622fa$25745e40$705d1ac0$@xen.org> In-Reply-To: Subject: RE: [PATCH net-next v7 2/2] xen networking: add XDP offset adjustment to xen-netback Date: Thu, 7 May 2020 08:18:44 +0100 Message-ID: <00aa01d6243f$bedafad0$3c90f070$@xen.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQE3/rdtCvsSNPb5s7Kxs8cJj/qIbwLQYVL2AY7IqSUBQOo04QIlemOzALzHgDWplG3jsA== Content-Language: en-gb Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > -----Original Message----- > From: Denis Kirjanov > Sent: 06 May 2020 18:45 > To: paul@xen.org > Cc: netdev@vger.kernel.org; jgross@suse.com; wei.liu@kernel.org; = ilias.apalodimas@linaro.org > Subject: Re: [PATCH net-next v7 2/2] xen networking: add XDP offset = adjustment to xen-netback >=20 > On 5/5/20, Paul Durrant wrote: > >> -----Original Message----- > >> >> @@ -417,6 +431,11 @@ static void frontend_changed(struct = xenbus_device > >> >> *dev, > >> >> set_backend_state(be, XenbusStateConnected); > >> >> break; > >> >> > >> >> + case XenbusStateReconfiguring: > >> >> + read_xenbus_frontend_xdp(be, dev); > >> > > >> > Is the frontend always expected to trigger a re-configure, or = could > >> > feature-xdp already be enabled prior to connection? > >> > >> Yes, feature-xdp is set by the frontend when xdp code is loaded. > >> > > > > That's still ambiguous... what I'm getting at is whether you also = need to > > read the xdp state when transitioning into Connected as well as > > Reconfiguring? >=20 > I have to read the state only during the Reconfiguring state since > that's where an XDP program is loaded / unloaded and then we = transition > from Reconfigred to Connected >=20 Ok, but what about netback re-connection? It is possible that netback = can be disconnected, unloaded, reloaded and re-attached to a running = frontend. In this case XDP would be active so I still think = read_xenbus_frontend_xdp() needs to form part of ring connection (if = only in this case). Paul