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=-1.2 required=3.0 tests=DATE_IN_PAST_06_12, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C2014C06513 for ; Wed, 3 Jul 2019 13:26:56 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 8461D2187F for ; Wed, 3 Jul 2019 13:26:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="o8TZD2/h" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8461D2187F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36002 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hifHj-0007zT-Rl for qemu-devel@archiver.kernel.org; Wed, 03 Jul 2019 09:26:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39647) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hifGP-0006XF-AF for qemu-devel@nongnu.org; Wed, 03 Jul 2019 09:25:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hifGN-0002iH-17 for qemu-devel@nongnu.org; Wed, 03 Jul 2019 09:25:33 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:41919 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hifGK-0002d2-LS; Wed, 03 Jul 2019 09:25:29 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 45f20h4Vcnz9sQq; Wed, 3 Jul 2019 23:25:22 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1562160324; bh=AL042cX4QM6+sAXKH0xw0j9V5S7zrXc3jFdfINhufDM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o8TZD2/halFxXeD7RSoTwwhz1XoJ1titmT7gTKK1oP4OH08P1bI3K1S1dqGNWc8hD eLc5F8xDK862NX2VTwbNiMh6BaDowze/SH5K75a9yKwnCXUtcKyuH+6MNCrI/lzCYA MHCYSQlzeoSfeXYnXRYE03wwsxqoy3Xok04m/RLM= Date: Wed, 3 Jul 2019 16:39:15 +1000 From: David Gibson To: Greg Kurz Message-ID: <20190703063915.GM9442@umbus.fritz.box> References: <20190327204102.20925-1-maxiwell@linux.ibm.com> <20190328142151.7b0e00dd@bahia.lab.toulouse-stg.fr.ibm.com> <20190328183923.lcd3p6fpy4qvvxoo@maxibm> <20190329132951.451d4ef0@bahia.lan> <20190408042149.GH16627@umbus.fritz.box> <20190408183156.1f71c21d@bahia.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="oYAXToTM8kn9Ra/9" Content-Disposition: inline In-Reply-To: <20190408183156.1f71c21d@bahia.lan> User-Agent: Mutt/1.12.0 (2019-05-25) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 203.11.71.1 Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v7 0/2] spapr-rtas: add ibm, get-vpd RTAS interface X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, "Maxiwell S. Garcia" , Michael Roth Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --oYAXToTM8kn9Ra/9 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 08, 2019 at 06:31:56PM +0200, Greg Kurz wrote: > On Mon, 8 Apr 2019 14:21:50 +1000 > David Gibson wrote: >=20 > > On Fri, Mar 29, 2019 at 01:29:51PM +0100, Greg Kurz wrote: > > > On Thu, 28 Mar 2019 15:39:45 -0300 > > > "Maxiwell S. Garcia" wrote: > > > =20 > > > > Hi, > > > >=20 > > > > On Thu, Mar 28, 2019 at 02:21:51PM +0100, Greg Kurz wrote: =20 > > > > > On Wed, 27 Mar 2019 17:41:00 -0300 > > > > > "Maxiwell S. Garcia" wrote: > > > > > =20 > > > > > > Here are two patches to add a handler for ibm,get-vpd RTAS call= s. > > > > > > This RTAS exposes host information in case of set QEMU options > > > > > > 'host-serial' and 'host-model' as 'passthrough'. > > > > > >=20 > > > > > > The patch 1 creates helper functions to get valid 'host-serial' > > > > > > and 'host-model' parameters, guided by QEMU command line. These > > > > > > parameters are useful to build the guest device tree and to ret= urn > > > > > > get-vpd RTAS calls. The patch 2 adds the ibm,get-vpd itself. > > > > > >=20 > > > > > > Update v7: > > > > > > * rtas_get_vpd_fields as a static array in spapr machine state > > > > > >=20 > > > > > > Maxiwell S. Garcia (2): > > > > > > spapr: helper functions to get valid host fields > > > > > > spapr-rtas: add ibm,get-vpd RTAS interface > > > > > >=20 > > > > > > hw/ppc/spapr.c | 48 +++++++++++---------- > > > > > > hw/ppc/spapr_rtas.c | 96 ++++++++++++++++++++++++++++++++++= ++++++++ > > > > > > include/hw/ppc/spapr.h | 14 +++++- > > > > > > 3 files changed, 135 insertions(+), 23 deletions(-) > > > > > > =20 > > > > >=20 > > > > > Hi Maxiwell, > > > > >=20 > > > > > David sent a patch to rework how the host data is exposed to the = guest. > > > > > Especially, the special casing of the "none" and "passthrough" st= rings > > > > > is no more... I'm afraid you'll have to rework your patches accor= dingly: > > > > > code+changelog in patch 1 and at least changelog in patch 2. > > > > >=20 > > > > > Cheers, =20 > > > >=20 > > > > IIUC, the 'ibm,get-vpd' RTAS should return information about the > > > > platform/cabinet. Thus, it's not necessary to add new nodes in the = guest > > > > device tree to export information like that. =20 > > >=20 > > > I agree that these "host-model" and "host-serial" props, which aren't > > > described anywhere and not used by either the linux kernel or the > > > powerpc-utils, look like a QEMU-specific poor man's version of VPD. > > >=20 > > > Not quite sure why they were even created since this is the purpose > > > of "system-id" and "model" as explained in PAPR, and supposedly > > > exposed in /proc/ppc64/lparcfg according to the LPARCFG(5) manual > > > page: =20 > >=20 > > Yeah, I'm not sure why they were created either. I rather suspect > > nothing much is using them, and I'd kind of like to just kill them. > > But Daniel Berrange (and maybe others) are paranoid about this > > breaking things. >=20 > Speaking of that. The "host-model"/"host-serial" fix is associated to a > CVE which affects QEMU versions currently shipped by downstream vendors. > Isn't a good enough reason to break things in existing unsecure setups ? > Should we add this patch to Mike's patch round-up for stable 3.0.1 (and > therefore break something that used to _work_ with 3.0.0) ? I would say yes, but I can't really be bothered arguing it upstream. > > > serial_number > > > The serial number of the physical system in which the partitio= n resides > > >=20 > > > system_type > > > The machine,type-model of the physical system in which the = partition > > > resides > > >=20 > > > This is indeed what we get in a PowerVM LPAR running on a tuleta syst= em: > > >=20 > > > [root@furax1 ~]# head -3 /proc/ppc64/lparcfg=20 > > > lparcfg 1.9 > > > serial_number=3DIBM,032116A9A > > > system_type=3DIBM,8247-22L > > >=20 > > > [root@furax1 ~]# echo $(cat /proc/device-tree/system-id) > > > IBM,032116A9A > > > [root@furax1 ~]# echo $(cat /proc/device-tree/model) > > > IBM,8247-22L > > >=20 > > > But QEMU generates a hard coded "IBM pSeries (emulated by qemu)" mode= l, > > > which is clearly not PAPR compliant according to this requirement: > > >=20 > > > R1=E2=80=9312.2=E2=80=9313. There must be a property, =E2=80=9Cmodel= =E2=80=9D, under the root node > > > in the format, =E2=80=9C,xxxx-yyy=E2=80=9D, where i= s replaced by > > > one to five letters representing the stock symbol of the company > > > (for example, for IBM: =E2=80=9CIBM,xxxx-yyy=E2=80=9D), and where xx= xx-yyy is > > > derived from the VPD TM field (see Table 160=E2=80=9A =E2=80=9CLoPAP= R VPD Fields=E2=80=9A=E2=80=9D > > > on page 343) of the first or =E2=80=98marked=E2=80=99 processor encl= osure. > > >=20 > > > And worse, it mixes "vm,uuid" which is QEMU specific concept to uniqu= ely > > > identify guests, with "system-id" which is about the host :-\ =20 > >=20 > > Ugh, right. So, it's been this way for years, so it's clearly not > > breaking things in practice. Given that, it might be best to leave > > it, even though it violates PAPR technically. > >=20 > > Frankly, providing information about the *guest* virtual model and > > "serial number" =3D~=3D UUID makes more sense than providing information > > about the host that might be security sensitive. > >=20 >=20 > IIUC, the rationale of exposing to the guest something that uniquely > identifies the host is needed by some inventory or license validation > softwares [1]. So I'd say we need both a guest UUID, that doesn't change > during the VM lifetime, and host UUID that changes when migrating to > another host. Well, maybe. We can supply the anonymized host identifier through /etc/machine-id (already used by Openstack on x86), and I guess we can present it to the guest via this get-vpd interface. Heaven knows what to do about caching / notifications, since in the qemu model (unlike the PAPR / pHyp model) the guest is not aware of migrations. >=20 > The fact that "system-id" =3D=3D "vm,uuid" in the current code didn't > break anything would rather indicate that there are no inventory > or license validation softwares users yet in the KVM+PAPR+linux > ecosystem... Well, maybe. > [1] https://bugs.launchpad.net/nova/+bug/1337349/comments/6 >=20 > > > All of this is very confusing and need to be sorted out before buildi= ng > > > anything on top of it. Especially since "model" and "system-id" are > > > supposed to derive from VPD IIUC. > > >=20 > > > I guess that we should first decide what we really want to expose > > > in "system-id" and "model": what we have now ? the same as in > > > "host-serial" and "host-model", ie. user configurable ? Must we > > > stay compatible with existing setups ? In any case, I'm afraid that > > > we have to diverge from PAPR somehow, since it obviously doesn't > > > care about the security concerns that motivated recent changes > > > for "host-serial" and "host-model"... =20 > >=20 > > We absolutely should not expose the real host information without the > > user explicitly requesting it. >=20 > I agree, but it seems that we may need something in between: an ID that > uniquely identifies a given system but that doesn't reveal security > sensitive information. >=20 > Looking again at PAPR, nothing much is said on the format of "system-id" > or VPD SN. Only "model" is expected to follow some formatting rules: > ,xxxx-yyy. >=20 > For "system-id", this could be addressed pretty much like in OpenStack > with systemd's /etc/machine-id. For "model", I'm not sure... Right, but do license systems need the model as well? I can't see why they would. > > > > Since it's a POWER specific > > > > functionality, may 'ibm,get-vpd' export host information if the > > > > guest instance allows it? Or is it better return only the 'host-ser= ial' > > > > and 'host-model' content, like in the patch "spapr: Simplify handli= ng > > > > of host-serial and host-model values"? > > > > =20 > > >=20 > > > I've spent some time reading PAPR on this topic and I'm not sure that > > > "ibm,get-vpd" is the way to go for what you were trying to achieve > > > initially (ie, obtain up-to-date host model and serial after migratio= n). > > >=20 > > > Have you looked at RTAS "ibm,update-properties" ? > > >=20 > > > 7.4.8 ibm,update-properties RTAS Call > > >=20 > > > This RTAS call is used to report updates to the properties changed > > > due to a massive platform reconfiguration such as when the partition > > > is migrated between machines. =20 > >=20 > > Yeah.. the thing here is that partition migration kind of means > > something different in PAPR than it does in the qemu world. It uses a > > guest-aware model of migration (which frankly I think is broken > > verging on unworkable). qemu and uses a guest-(mostly)-unaware > > migration model. >=20 > Yeah... >=20 > > > This explicitly covers updates to "system-id" and "model". Maybe it is > > > time to do as Ben was suggesting a long time ago when "host-serial" > > > and "host-model" were introduced [1]: > > >=20 > > > On Tue, 2014-07-08 at 12:49 +0200, Alexander Graf wrote: =20 > > > > Please be aware that all of the above is bogus when you start > > > > thinking=20 > > > > about live migration. =20 > > >=20 > > > What's probably where we need to start thinking about implementing > > > migration according to PAPR :-) > > >=20 > > > IE. With pre and post-migration notifications to the guest including > > > device-tree updates. > > >=20 > > >=20 > > > [1] https://patchwork.ozlabs.org/patch/367792/#813547 > > > =20 > >=20 >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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