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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9596FC43603 for ; Mon, 9 Dec 2019 11:58:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6E1AF2077B for ; Mon, 9 Dec 2019 11:58:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E1AF2077B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ieHfe-0001yb-Bb; Mon, 09 Dec 2019 11:57:46 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ieHfc-0001yT-VS for xen-devel@lists.xenproject.org; Mon, 09 Dec 2019 11:57:44 +0000 X-Inumbo-ID: 1bb1ede6-1a7b-11ea-88e7-bc764e2007e4 Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 1bb1ede6-1a7b-11ea-88e7-bc764e2007e4; Mon, 09 Dec 2019 11:57:44 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 36E8EAEE9; Mon, 9 Dec 2019 11:57:43 +0000 (UTC) To: "Durrant, Paul" , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xenproject.org" References: <20191205140123.3817-1-pdurrant@amazon.com> <20191205140123.3817-2-pdurrant@amazon.com> <38908166-6a4b-9dab-144c-71df691da167@suse.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <74b1c655-e107-51dd-e719-05a750f324a5@suse.com> Date: Mon, 9 Dec 2019 12:57:40 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Subject: Re: [Xen-devel] [PATCH 1/4] xenbus: move xenbus_dev_shutdown() into frontend code... X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Boris Ostrovsky , Stefano Stabellini Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" T24gMDkuMTIuMTkgMTI6NTUsIER1cnJhbnQsIFBhdWwgd3JvdGU6Cj4+IC0tLS0tT3JpZ2luYWwg TWVzc2FnZS0tLS0tCj4+IEZyb206IErDvHJnZW4gR3Jvw58gPGpncm9zc0BzdXNlLmNvbT4KPj4g U2VudDogMDkgRGVjZW1iZXIgMjAxOSAxMTozNAo+PiBUbzogRHVycmFudCwgUGF1bCA8cGR1cnJh bnRAYW1hem9uLmNvbT47IGxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmc7Cj4+IHhlbi1kZXZl bEBsaXN0cy54ZW5wcm9qZWN0Lm9yZwo+PiBDYzogQm9yaXMgT3N0cm92c2t5IDxib3Jpcy5vc3Ry b3Zza3lAb3JhY2xlLmNvbT47IFN0ZWZhbm8gU3RhYmVsbGluaQo+PiA8c3N0YWJlbGxpbmlAa2Vy bmVsLm9yZz4KPj4gU3ViamVjdDogUmU6IFtQQVRDSCAxLzRdIHhlbmJ1czogbW92ZSB4ZW5idXNf ZGV2X3NodXRkb3duKCkgaW50byBmcm9udGVuZAo+PiBjb2RlLi4uCj4+Cj4+IE9uIDA1LjEyLjE5 IDE1OjAxLCBQYXVsIER1cnJhbnQgd3JvdGU6Cj4+PiAuLi5hbmQgbWFrZSBpdCBzdGF0aWMKPj4+ Cj4+PiB4ZW5idXNfZGV2X3NodXRkb3duKCkgaXMgc2VlbWluZ2x5IGludGVuZGVkIHRvIGNhdXNl IGNsZWFuIHNodXRkb3duIG9mCj4+IFBWCj4+PiBmcm9udGVuZHMgd2hlbiBhIGd1ZXN0IGlzIHJl Ym9vdGVkLiBJbmRlZWQgdGhlIGZ1bmN0aW9uIHdhaXRzIGZvciBhCj4+PiBjb25wbGV0aW9uIHdo aWNoIGlzIG9ubHkgc2V0IGJ5IGEgY2FsbCB0byB4ZW5idXNfZnJvbnRlbmRfY2xvc2VkKCkuCj4+ Pgo+Pj4gVGhpcyBwYXRjaCByZW1vdmVzIHRoZSBzaHV0ZG93bigpIG1ldGhvZCBmcm9tIGJhY2tl bmRzIGFuZCBtb3Zlcwo+Pj4geGVuYnVzX2Rldl9zaHV0ZG93bigpIGZyb20geGVuYnVzX3Byb2Jl LmMgaW50byB4ZW5idXNfcHJvYmVfZnJvbnRlbmQuYywKPj4+IHJlbmFtaW5nIGl0IGFwcHJvcHJp YXRlbHkgYW5kIG1ha2luZyBpdCBzdGF0aWMuCj4+Cj4+IElzIHRoaXMgYSBnb29kIG1vdmUgY29u c2lkZXJpbmcgZHJpdmVyIGRvbWFpbnM/Cj4gCj4gSSBkb24ndCB0aGluayBpdCBjYW4gaGF2ZSBl dmVyIHdvcmtlZCBwcm9wZXJseSBmb3IgZHJpdmVyIGRvbWFpbnMsIGFuZCB3aXRoIHRoZSByZXN0 IG9mIHRoZSBwYXRjaGVzIGEgYmFja2VuZCBzaG91bGQgYmUgYWJsZSBnbyBhd2F5IGFuZCByZXR1 cm4gdW5hbm5vdW5jZWQgKGFzIGxvbmcgYXMgdGhlIGRvbWFpbiBpZCBpcyBrZXB0Li4uIGZvciB3 aGljaCBwYXRjaGVzIG5lZWQgdG8gYmUgdXBzdHJlYW1lZCBpbnRvIFhlbikuCj4gCj4+Cj4+IEF0 IGxlYXN0IEknZCBleHBlY3QgdGhlIGNvbW1pdCBtZXNzYWdlIGFkZHJlc3NpbmcgdGhlIGV4cGVj dGVkIGJlaGF2aW9yCj4+IHdpdGggcmVib290aW5nIGEgZHJpdmVyIGRvbWFpbiBhbmQgd2h5IHRo aXMgcGF0Y2ggaXNuJ3QgbWFraW5nIHRoaW5ncwo+PiB3b3JzZS4KPj4KPiAKPiBGb3IgYSBjbGVh biByZWJvb3QgSSdkIGV4cGVjdCB0aGUgdG9vbHN0YWNrIHRvIHNodXQgZG93biB0aGUgcHJvdG9j b2wgYmVmb3JlIHJlYm9vdGluZyB0aGUgZHJpdmVyIGRvbWFpbiwgc28gdGhlIGJhY2tlbmQgc2h1 dGRvd24gbWV0aG9kIGlzIG1vb3QuIEFuZCBJIGRvbid0IGJlbGlldmUgcmUtc3RhcnRhYmxlIGRy aXZlciBkb21haW5zIHdlcmUgc29tZXRoaW5nIHRoYXQgZXZlciBtYWRlIGl0IGludG8gc3VwcG9y dCAoYmVjYXVzZSBvZiB0aGUgbm9uLXBlcnNpc3RlbnQgZG9taWQgcHJvYmxlbSkuIEkgY2FuIGFk ZCBzb21ldGhpbmcgdG8gdGhlIGNvbW1pdCBjb21tZW50IHRvIHRoYXQgZWZmZWN0IGlmIHlvdSdk IGxpa2UuCgpZZXMsIHBsZWFzZSBkbyBzby4KCldpdGggdGhpcyB5b3UgY2FuIGFkZCBteToKClJl dmlld2VkLWJ5OiBKdWVyZ2VuIEdyb3NzIDxqZ3Jvc3NAc3VzZS5jb20+CgoKSnVlcmdlbgoKX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1h aWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0cy54 ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 77488C43603 for ; Mon, 9 Dec 2019 11:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 492E32077B for ; Mon, 9 Dec 2019 11:57:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727643AbfLIL5p (ORCPT ); Mon, 9 Dec 2019 06:57:45 -0500 Received: from mx2.suse.de ([195.135.220.15]:45710 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727163AbfLIL5p (ORCPT ); Mon, 9 Dec 2019 06:57:45 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 36E8EAEE9; Mon, 9 Dec 2019 11:57:43 +0000 (UTC) Subject: Re: [PATCH 1/4] xenbus: move xenbus_dev_shutdown() into frontend code... To: "Durrant, Paul" , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xenproject.org" Cc: Boris Ostrovsky , Stefano Stabellini References: <20191205140123.3817-1-pdurrant@amazon.com> <20191205140123.3817-2-pdurrant@amazon.com> <38908166-6a4b-9dab-144c-71df691da167@suse.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <74b1c655-e107-51dd-e719-05a750f324a5@suse.com> Date: Mon, 9 Dec 2019 12:57:40 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09.12.19 12:55, Durrant, Paul wrote: >> -----Original Message----- >> From: Jürgen Groß >> Sent: 09 December 2019 11:34 >> To: Durrant, Paul ; linux-kernel@vger.kernel.org; >> xen-devel@lists.xenproject.org >> Cc: Boris Ostrovsky ; Stefano Stabellini >> >> Subject: Re: [PATCH 1/4] xenbus: move xenbus_dev_shutdown() into frontend >> code... >> >> On 05.12.19 15:01, Paul Durrant wrote: >>> ...and make it static >>> >>> xenbus_dev_shutdown() is seemingly intended to cause clean shutdown of >> PV >>> frontends when a guest is rebooted. Indeed the function waits for a >>> conpletion which is only set by a call to xenbus_frontend_closed(). >>> >>> This patch removes the shutdown() method from backends and moves >>> xenbus_dev_shutdown() from xenbus_probe.c into xenbus_probe_frontend.c, >>> renaming it appropriately and making it static. >> >> Is this a good move considering driver domains? > > I don't think it can have ever worked properly for driver domains, and with the rest of the patches a backend should be able go away and return unannounced (as long as the domain id is kept... for which patches need to be upstreamed into Xen). > >> >> At least I'd expect the commit message addressing the expected behavior >> with rebooting a driver domain and why this patch isn't making things >> worse. >> > > For a clean reboot I'd expect the toolstack to shut down the protocol before rebooting the driver domain, so the backend shutdown method is moot. And I don't believe re-startable driver domains were something that ever made it into support (because of the non-persistent domid problem). I can add something to the commit comment to that effect if you'd like. Yes, please do so. With this you can add my: Reviewed-by: Juergen Gross Juergen