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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40094 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kf48C-0000BY-En for qemu-devel@archiver.kernel.org; Tue, 17 Nov 2020 11:47:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41210) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kf44s-0005fl-Mc for qemu-devel@nongnu.org; Tue, 17 Nov 2020 11:43:34 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:36824) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kf44q-0003iA-Hy for qemu-devel@nongnu.org; Tue, 17 Nov 2020 11:43:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605631411; 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=4dzab1PX/wsBvsGwXzfoelb3XfWxSzyHCA69Xv5d2iY=; b=HzX1hF31iR9J2J81vBFoM79VPLQjXLfvZpD1Q9SdAatET2G7mptpyBsxoYtslMXVguNONy IpmY5V0CVxYx1Tv4EO2BGVFrZN4782DD/QQdo+VMMhR22ojUA7BAOEiDT5RXb8J3sHkL9m IKZR3TnnjrcT2PwTyWVVBaOXCQ298Go= 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-121-zVYpCH0iPUKJWCGEpviHVw-1; Tue, 17 Nov 2020 11:43:28 -0500 X-MC-Unique: zVYpCH0iPUKJWCGEpviHVw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 480601008302; Tue, 17 Nov 2020 16:43:26 +0000 (UTC) Received: from gondolin (ovpn-113-115.ams2.redhat.com [10.36.113.115]) by smtp.corp.redhat.com (Postfix) with ESMTP id D29085C1CF; Tue, 17 Nov 2020 16:43:17 +0000 (UTC) Date: Tue, 17 Nov 2020 17:43:15 +0100 From: Cornelia Huck To: Matthew Rosato Subject: Re: [RFC PATCH-for-5.2] hw/s390x/pci: Fix endianness issue Message-ID: <20201117174315.27df98f0.cohuck@redhat.com> In-Reply-To: <9dc43e4b-a857-f86f-da77-ae8e5e322f67@linux.ibm.com> References: <20201117120115.1234994-1-philmd@redhat.com> <20201117143117.4b05db78.cohuck@redhat.com> <20201117151340.539d55b2.cohuck@redhat.com> <20201117161716.7e3e67ca.cohuck@redhat.com> <9dc43e4b-a857-f86f-da77-ae8e5e322f67@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=cohuck@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=216.205.24.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/17 01:18:45 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Peter Maydell , Thomas Huth , Pierre Morel , David Hildenbrand , qemu-s390x , Richard Henderson , QEMU Developers , Halil Pasic , Christian Borntraeger , Alex Williamson , Philippe =?UTF-8?B?TWF0aGlldS1EYXVkw6k=?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 17 Nov 2020 11:01:31 -0500 Matthew Rosato wrote: > On 11/17/20 10:17 AM, Cornelia Huck wrote: > > On Tue, 17 Nov 2020 09:34:41 -0500 > > Matthew Rosato wrote: > > =20 > >> On 11/17/20 9:13 AM, Cornelia Huck wrote: =20 > >>> On Tue, 17 Nov 2020 09:02:37 -0500 > >>> Matthew Rosato wrote: > >>> =20 > >>>> On 11/17/20 8:31 AM, Cornelia Huck wrote: =20 > >>>>> On Tue, 17 Nov 2020 14:23:57 +0100 > >>>>> Pierre Morel wrote: > >>>>> =20 > >>>>>> On 11/17/20 2:00 PM, Peter Maydell wrote: =20 > >>>>>>> On Tue, 17 Nov 2020 at 12:03, Philippe Mathieu-Daud=C3=A9 wrote: =20 > >>>>>>>> > >>>>>>>> Fix an endianness issue reported by Cornelia: > >>>>>>>> =20 > >>>>>>>>> s390x tcg guest on x86, virtio-pci devices are not detected. Th= e > >>>>>>>>> relevant feature bits are visible to the guest. Same breakage w= ith > >>>>>>>>> different guest kernels. > >>>>>>>>> KVM guests and s390x tcg guests on s390x are fine. =20 > >>>>>>>> > >>>>>>>> Fixes: 28dc86a0729 ("s390x/pci: use a PCI Group structure") > >>>>>>>> Reported-by: Cornelia Huck > >>>>>>>> Signed-off-by: Philippe Mathieu-Daud=C3=A9 > >>>>>>>> --- > >>>>>>>> RFC because review-only patch, untested > >>>>>>>> --- > >>>>>>>> hw/s390x/s390-pci-inst.c | 2 +- > >>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>>>>>>> > >>>>>>>> diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c > >>>>>>>> index 58cd041d17f..cfb54b4d8ec 100644 > >>>>>>>> --- a/hw/s390x/s390-pci-inst.c > >>>>>>>> +++ b/hw/s390x/s390-pci-inst.c > >>>>>>>> @@ -305,7 +305,7 @@ int clp_service_call(S390CPU *cpu, uint8_t r= 2, uintptr_t ra) > >>>>>>>> ClpReqQueryPciGrp *reqgrp =3D (ClpReqQueryPciGrp *)= reqh; > >>>>>>>> S390PCIGroup *group; > >>>>>>>> > >>>>>>>> - group =3D s390_group_find(reqgrp->g); > >>>>>>>> + group =3D s390_group_find(ldl_p(&reqgrp->g)); =20 > >>>>>>> > >>>>>>> 'g' in the ClpReqQueryPciGrp struct is a uint32_t, so > >>>>>>> adding the ldl_p() will have no effect unless (a) the > >>>>>>> structure is not 4-aligned and (b) the host will fault on > >>>>>>> unaligned accesses, which isn't the case for x86 hosts. > >>>>>>> > >>>>>>> Q: is this struct really in host order, or should we > >>>>>>> be using ldl_le_p() or ldl_be_p() and friends here and > >>>>>>> elsewhere? > >>>>>>> > >>>>>>> thanks > >>>>>>> -- PMM > >>>>>>> =20 > >>>>>> > >>>>>> Hi, I think we better modify the structure here, g should be a byt= e. > >>>>>> > >>>>>> Connie, can you please try this if it resolves the issue? > >>>>>> > >>>>>> diff --git a/hw/s390x/s390-pci-inst.h b/hw/s390x/s390-pci-inst.h > >>>>>> index fa3bf8b5aa..641d19c815 100644 > >>>>>> --- a/hw/s390x/s390-pci-inst.h > >>>>>> +++ b/hw/s390x/s390-pci-inst.h > >>>>>> @@ -146,7 +146,8 @@ typedef struct ClpReqQueryPciGrp { > >>>>>> uint32_t fmt; > >>>>>> uint64_t reserved1; > >>>>>> #define CLP_REQ_QPCIG_MASK_PFGID 0xff > >>>>>> - uint32_t g; > >>>>>> + uint32_t g0 :24; > >>>>>> + uint32_t g :8; > >>>>>> uint32_t reserved2; > >>>>>> uint64_t reserved3; > >>>>>> } QEMU_PACKED ClpReqQueryPciGrp; > >>>>>> =20 > >>>>> > >>>>> No, same crash... I fear there are more things broken wrt endiannes= s. > >>>>> =20 > >>>> > >>>> Sorry, just getting online now, looking at the code.... Are the 2 > >>>> memcpy calls added in 9670ee75 and 28dc86a0 the issue? Won't they j= ust > >>>> present the Q PCI FN / Q PCI FN GRP results in host endianness? > >>>> =20 > >>> > >>> I just re-added some st?_p operations in set_pbdev_info and that fixe= s > >>> at least the crash I was seeing with Phil's patch applied. Still, no > >>> pci functions get detected, so that's not enough. Those memcpy calls > >>> look like a possible culprit. > >>> =20 > >> > >> OK, so if everything in set_pbdev_info and s390_pci_init_default_group= () > >> is handled with st?_p operations, then the memcpy should be OK... > >> > >> Pierre was on to something with his recommendation, as the group id is > >> only 1B of the 'g' field (see CLP_REQ_QPCIG_MASK_PFGID) - the other bi= ts > >> just happen to be unused. > >> > >> Did you include his change with your st?_p changes to set_pbdev_info > >> (sorry, I don't have this environment set up but clearly need to do so > >> for future testing) =20 > >=20 > > I tried in conjunction with Phil's patch (otherwise, I don't even get > > to the part where it crashes.) Do we need to apply that mask somewhere? > > It is hard to guess if you don't know what the structure is supposed to > > look like :) > > =20 >=20 > OK, I just got the issue reproduced here (no PCI without Phil's patch,=20 > crash with Phil's patch); Let me investigate and I will get back. I think I may have something (there were some more fields that needed care). Let me check whether it works on s390x-on-s390x as well, then I'll polish it and post. (Still hoping to get that included; I have two other fixes queued.)