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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 E5B32C433EC for ; Wed, 22 Jul 2020 08:27:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A5E3B20714 for ; Wed, 22 Jul 2020 08:27:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="U7LhliwV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5E3B20714 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 223026B0003; Wed, 22 Jul 2020 04:27:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D3AF6B0005; Wed, 22 Jul 2020 04:27:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C2B06B0006; Wed, 22 Jul 2020 04:27:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0069.hostedemail.com [216.40.44.69]) by kanga.kvack.org (Postfix) with ESMTP id E9C8D6B0003 for ; Wed, 22 Jul 2020 04:27:57 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9F4AD18001187 for ; Wed, 22 Jul 2020 08:27:57 +0000 (UTC) X-FDA: 77065033794.10.boats69_570ec0f26f34 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 6847B840C725 for ; Wed, 22 Jul 2020 08:27:57 +0000 (UTC) X-HE-Tag: boats69_570ec0f26f34 X-Filterd-Recvd-Size: 8089 Received: from esa3.hc3370-68.iphmx.com (esa3.hc3370-68.iphmx.com [216.71.145.155]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Wed, 22 Jul 2020 08:27:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1595406477; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=FN40+KHzDRqn99k21tmlYB+H9TCBGBR1w3tvJcN9Tgs=; b=U7LhliwVAfIMeZPCY+FfZT83Cein06au+W98G3Foebm08hgK7iK5+UC+ VLGnWMxar5bL1MMUztIMlPggoZC3YBWA1uJ2TdkXI/W6qy3Lgyw47oK0k 0aAdS4I+XM23Abj6OL9OwvJfCcd5zoAQRao/BwoYn+W61vf/71zEXf+9/ Q=; Authentication-Results: esa3.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: mlqzl0cWqd5gabQyWtfyst+GqUDqk2plDTUvwmrYJ8XALOOL3c4pwsZ14wIgTuqSOrWdAsqabU U3z4rBnJN46Le58mC9XaMMoAN3S3s0bqLbgiivLfDLVwkpF/RX2WQDULvW4T8zVE5XCVH++AU3 OUWlO6ngvCzlLeLZixzTsry09fylayuaS5boFcXYZna62kTmuNMGKttp0dIuWif7hkABJgwyxK ikPkcGIF9TKekbeq9FWw+LIYJMaFgyhyMnNs+N/qmuLzuxVJUkXnzCjftz5DjOIOBeOWFolL+4 yw4= X-SBRS: 2.7 X-MesageID: 22916032 X-Ironport-Server: esa3.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,381,1589256000"; d="scan'208";a="22916032" Date: Wed, 22 Jul 2020 10:27:46 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Anchal Agarwal CC: , Boris Ostrovsky , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 01/11] xen/manage: keep track of the on-going suspend mode Message-ID: <20200722082746.GS7191@Air-de-Roger> References: <20200702182136.GA3511@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> <50298859-0d0e-6eb0-029b-30df2a4ecd63@oracle.com> <20200715204943.GB17938@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> <0ca3c501-e69a-d2c9-a24c-f83afd4bdb8c@oracle.com> <20200717191009.GA3387@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> <5464f384-d4b4-73f0-d39e-60ba9800d804@oracle.com> <20200720093705.GG7191@Air-de-Roger> <20200721001736.GB19610@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> <20200721083018.GM7191@Air-de-Roger> <20200721195509.GA14682@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20200721195509.GA14682@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> X-ClientProxiedBy: AMSPEX02CAS02.citrite.net (10.69.22.113) To AMSPEX02CL02.citrite.net (10.69.22.126) X-Rspamd-Queue-Id: 6847B840C725 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 21, 2020 at 07:55:09PM +0000, Anchal Agarwal wrote: > On Tue, Jul 21, 2020 at 10:30:18AM +0200, Roger Pau Monn=C3=A9 wrote: > > CAUTION: This email originated from outside of the organization. Do n= ot click links or open attachments unless you can confirm the sender and = know the content is safe. > >=20 > >=20 > >=20 > > Marek: I'm adding you in case you could be able to give this a try an= d > > make sure it doesn't break suspend for dom0. > >=20 > > On Tue, Jul 21, 2020 at 12:17:36AM +0000, Anchal Agarwal wrote: > > > On Mon, Jul 20, 2020 at 11:37:05AM +0200, Roger Pau Monn=C3=A9 wrot= e: > > > > CAUTION: This email originated from outside of the organization. = Do not click links or open attachments unless you can confirm the sender = and know the content is safe. > > > > > > > > > > > > > > > > On Sat, Jul 18, 2020 at 09:47:04PM -0400, Boris Ostrovsky wrote: > > > > > (Roger, question for you at the very end) > > > > > > > > > > On 7/17/20 3:10 PM, Anchal Agarwal wrote: > > > > > > On Wed, Jul 15, 2020 at 05:18:08PM -0400, Boris Ostrovsky wro= te: > > > > > >> CAUTION: This email originated from outside of the organizat= ion. Do not click links or open attachments unless you can confirm the se= nder and know the content is safe. > > > > > >> > > > > > >> > > > > > >> > > > > > >> On 7/15/20 4:49 PM, Anchal Agarwal wrote: > > > > > >>> On Mon, Jul 13, 2020 at 11:52:01AM -0400, Boris Ostrovsky w= rote: > > > > > >>>> CAUTION: This email originated from outside of the organiz= ation. Do not click links or open attachments unless you can confirm the = sender and know the content is safe. > > > > > >>>> > > > > > >>>> > > > > > >>>> > > > > > >>>> On 7/2/20 2:21 PM, Anchal Agarwal wrote: > > > > > >>>> And PVH dom0. > > > > > >>> That's another good use case to make it work with however, = I still > > > > > >>> think that should be tested/worked upon separately as the f= eature itself > > > > > >>> (PVH Dom0) is very new. > > > > > >> > > > > > >> Same question here --- will this break PVH dom0? > > > > > >> > > > > > > I haven't tested it as a part of this series. Is that a block= er here? > > > > > > > > > > > > > > > I suspect dom0 will not do well now as far as hibernation goes,= in which > > > > > case you are not breaking anything. > > > > > > > > > > > > > > > Roger? > > > > > > > > I sadly don't have any box ATM that supports hibernation where I > > > > could test it. We have hibernation support for PV dom0, so while = I > > > > haven't done anything specific to support or test hibernation on = PVH > > > > dom0 I would at least aim to not make this any worse, and hence t= he > > > > check should at least also fail for a PVH dom0? > > > > > > > > if (!xen_hvm_domain() || xen_initial_domain()) > > > > return -ENODEV; > > > > > > > > Ie: none of this should be applied to a PVH dom0, as it doesn't h= ave > > > > PV devices and hence should follow the bare metal device suspend. > > > > > > > So from what I understand you meant for any guest running on pvh do= m0 should not > > > hibernate if hibernation is triggered from within the guest or shou= ld they? > >=20 > > Er no to both I think. What I meant is that a PVH dom0 should be able > > to properly suspend, and we should make sure this work doesn't make > > this any harder (or breaks it if it's currently working). > >=20 > > Or at least that's how I understood the question raised by Boris. > >=20 > > You are adding code to the generic suspend path that's also used by d= om0 > > in order to perform bare metal suspension. This is fine now for a PV > > dom0 because the code is gated on xen_hvm_domain, but you should also > > take into account that a PVH dom0 is considered a HVM domain, and > > hence will get the notifier registered. > > > Ok that makes sense now. This is good to be safe, but my patch series i= s only to > support domU hibernation, so I am not sure if this will affect pvh dom0= . > However, since I do not have a good way of testing sure I will add the = check. >=20 > Moreover, in Patch-0004, I do register suspend/resume syscore_ops speci= fically for domU > hibernation only if its xen_hvm_domain. So if the hooks are only registered for domU, do you still need this xen_hvm_domain check here? I have to admit I'm not familiar with Linux PM suspend. > I don't see any reason that should not > be registered for domU's running on pvh dom0. To be clear: it should be registered for all HVM domUs, regardless of whether they are running on a PV or a PVH dom0. My intention was never to suggest otherwise. It should be enabled for all HVM domUs, but shouldn't be enabled for HVM dom0. > Those suspend/resume callbacks will > only be invoked in case hibernation and will be skipped if generic susp= end path > is in progress. Do you see any issue with that? No, I think it's fine. Roger.