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=-0.8 required=3.0 tests=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 E434BC433E0 for ; Tue, 30 Jun 2020 09:42:31 +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 AD004206A1 for ; Tue, 30 Jun 2020 09:42:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZDhaeSwP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD004206A1 Authentication-Results: mail.kernel.org; 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]:32866 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jqCmd-0006N6-0h for qemu-devel@archiver.kernel.org; Tue, 30 Jun 2020 05:42:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51178) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jqCkD-0003iL-KZ for qemu-devel@nongnu.org; Tue, 30 Jun 2020 05:40:01 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:24052 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jqCkB-0000aH-P1 for qemu-devel@nongnu.org; Tue, 30 Jun 2020 05:40:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593509999; 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: in-reply-to:in-reply-to:references:references; bh=G7U1eDyaFVKc4xIgFDlBscwNxSL+RWJFQCOyDTR2WB4=; b=ZDhaeSwPxtrii0uyvck43/ByhaB083k72uqPcW13YVMn+4FsyB+Umv4j8EaYjgbYcrlPrr tG0HsrzhbkXlps8vTFZHwmVFXzcp9zZUPAiyKymvAGB2BnB7s/xEUsaj0iUB2KV3U1W+Hc 3OMaNJgpGakkCEsPGVFanD78cwY/DOQ= 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-457-y03lNSTIOdaSg26QhIHJ1Q-1; Tue, 30 Jun 2020 05:39:56 -0400 X-MC-Unique: y03lNSTIOdaSg26QhIHJ1Q-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 691B619067E6; Tue, 30 Jun 2020 09:39:55 +0000 (UTC) Received: from gondolin (ovpn-113-12.ams2.redhat.com [10.36.113.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC64D60C81; Tue, 30 Jun 2020 09:39:44 +0000 (UTC) Date: Tue, 30 Jun 2020 11:39:32 +0200 From: Cornelia Huck To: Stefan Hajnoczi Subject: Re: [RFC 0/4] Enable virtio-fs on s390x Message-ID: <20200630113932.484b3fde.cohuck@redhat.com> In-Reply-To: <20200630090451.GE81930@stefanha-x1.localdomain> References: <20200625100430.22407-1-mhartmay@linux.ibm.com> <20200629125305.GH31392@stefanha-x1.localdomain> <20200629130716.GQ1298906@redhat.com> <20200630090451.GE81930@stefanha-x1.localdomain> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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: multipart/signed; boundary="Sig_/EdTKuiXSaLBVO8rGMFs_Bes"; protocol="application/pgp-signature"; micalg=pgp-sha256 Received-SPF: pass client-ip=207.211.31.81; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/30 02:00:02 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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: "Daniel P. =?UTF-8?B?QmVycmFuZ8Op?=" , "Michael S. Tsirkin" , Stefan Hajnoczi , qemu-devel@nongnu.org, Halil Pasic , Marc Hartmayer , =?UTF-8?B?TWFyYy1BbmRyw6k=?= Lureau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --Sig_/EdTKuiXSaLBVO8rGMFs_Bes Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 30 Jun 2020 10:04:51 +0100 Stefan Hajnoczi wrote: > On Mon, Jun 29, 2020 at 02:07:16PM +0100, Daniel P. Berrang=C3=A9 wrote: > > On Mon, Jun 29, 2020 at 01:53:05PM +0100, Stefan Hajnoczi wrote: =20 > > > On Thu, Jun 25, 2020 at 12:04:26PM +0200, Marc Hartmayer wrote: =20 > > > > This RFC is about enabling virtio-fs on s390x. For that we need > > > > + some shim code (first patch), and we need > > > > + libvhost-user to deal with virtio endiannes as mandated by the s= pec. > > > > =20 > > > > The second part is trickier, because unlike QEMU we are not certain > > > > about the guest's native endianness, which is needed to handle the > > > > legacy-interface appropriately. In fact, this is the reason why jus= t > > > > RFC. > > > >=20 > > > > One of the open questions is whether to build separate versions, on= e > > > > for guest little endian and one for guest big endian, or do we want > > > > something like a command line option? (Digression on the libvirt > > > > modeling) > > > >=20 > > > > A third option would be to refuse legacy altogether. =20 > > >=20 > > > I suggest the following: > > >=20 > > > 1. Combinations that worked with libvhost-user in the past must not b= reak. > > >=20 > > > 2. New combinations should only support VIRTIO 1.0 and later. > > >=20 > > > This means continue to allow Legacy mode devices where they already r= un > > > today but don't add new code for the cases that didn't work. =20 > >=20 > > What I'm missing here is what PCI product ID was being used when the > > current impl is in legacy/transitional mode ? > >=20 > > Normally legacy and transitional mode devices need an explicit PCI ID > > reserved, where as modern-only devices have a PCI ID derived from their > > VirtIO ID + a fixed offset. > >=20 > > Was this mistakenly using a VirtIO ID + fixed offset for the legacy > > mode too ? =20 >=20 > vhost-user-fs-pci does not support Legacy or Transitional mode. See > hw/virtio/vhost-user-fs-pci.c: >=20 > static const VirtioPCIDeviceTypeInfo vhost_user_fs_pci_info =3D { > .base_name =3D TYPE_VHOST_USER_FS_PCI, > .non_transitional_name =3D "vhost-user-fs-pci", > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > .instance_size =3D sizeof(VHostUserFSPCI), > .instance_init =3D vhost_user_fs_pci_instance_init, > .class_init =3D vhost_user_fs_pci_class_init, > }; This makes it very unlikely that someone accidentally configures non-modern, but does not prevent it AFAICS. See <20200630113527.7b27f34f.cohuck@redhat.com>, which I just sent. 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