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 0E8F6C433E3 for ; Thu, 23 Jul 2020 06:36:23 +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 CCC6E206D7 for ; Thu, 23 Jul 2020 06:36:22 +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="U/VXp9Y3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CCC6E206D7 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]:35510 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jyUq6-0001cQ-3q for qemu-devel@archiver.kernel.org; Thu, 23 Jul 2020 02:36:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51956) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jyUpK-00019i-Ne for qemu-devel@nongnu.org; Thu, 23 Jul 2020 02:35:34 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42472 helo=us-smtp-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 1jyUpJ-0000PU-3T for qemu-devel@nongnu.org; Thu, 23 Jul 2020 02:35:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595486132; 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=0sa6zTJFWmnzJMuDzG4xtWOkKIjeg8jF7Ob0tj+Z4mM=; b=U/VXp9Y3vobgdtJIYgTVKTn6Q75sP32isFmneFFn0dV3oFjSwmQkp3Pii5M7G1xBYN5zmJ Z8cwMnfA0AfdTqcrXvCTJNCLVIHF/YVHRmdwM+koKL/sh6au9e+gY27cMnfpOLqCpQhSJM DJNVuxZx1Xc+Y/ICZGHY8hS5GyOhtgA= 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-63--c3Afsi7MzmZw2HrZR-OcQ-1; Thu, 23 Jul 2020 02:35:28 -0400 X-MC-Unique: -c3Afsi7MzmZw2HrZR-OcQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5CD0E10059A8; Thu, 23 Jul 2020 06:35:27 +0000 (UTC) Received: from gondolin (ovpn-112-228.ams2.redhat.com [10.36.112.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id B49AA5F7D8; Thu, 23 Jul 2020 06:35:20 +0000 (UTC) Date: Thu, 23 Jul 2020 08:35:18 +0200 From: Cornelia Huck To: Halil Pasic Subject: Re: [PATCH 0/2] virtio: non-legacy device handling Message-ID: <20200723083518.5076eb60.cohuck@redhat.com> In-Reply-To: <20200720115406.508f2115.pasic@linux.ibm.com> References: <20200707105446.677966-1-cohuck@redhat.com> <20200720115406.508f2115.pasic@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=cohuck@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/22 22:13:02 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_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: Eric Auger , qemu-s390x@nongnu.org, qemu-devel@nongnu.org, "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, 20 Jul 2020 11:54:06 +0200 Halil Pasic wrote: > On Tue, 7 Jul 2020 12:54:44 +0200 > Cornelia Huck wrote: > > > As discussed in "virtio-fs: force virtio 1.x usage", it seems like > > a good idea to make sure that any new virtio device (which does not > > support legacy virtio) is indeed a non-transitional device, just to > > catch accidental misconfigurations. We can easily compile a list > > of virtio devices with legacy support and have transports verify > > in their plugged callbacks that legacy support is off for any device > > not in that list. > > > > Most new virtio devices force non-transitional already, so nothing > > changes for them. vhost-user-fs-pci even does not allow to configure > > a non-transitional device, so it is fine as well. > > > > One problematic device, however, is virtio-iommu-pci. It currently > > offers both the transitional and the non-transitional variety of the > > device, and does not force anything. I'm unsure whether we should > > consider transitional virtio-iommu unsupported, or if we should add > > some compat handling. (The support for legacy or not generally may > > change based upon the bus, IIUC, so I'm unsure how to come up with > > something generic.) > > > > Both patches look good to me (Acked-by: Halil Pasic > ). I tend to agree with Davids comment on how > this information is coded: the more object oriented way would have > been to store this at the something like VirtioDeviceClass, but > Michael's argument stands. > > Another OO option would be to expose this as a virtio property. Would > enable introspection, and would also give the host admin means to > force non-legacy for transitional devices. But the juice is probably not > worth the squeeze. I agree, that would be a lot of hassle for exposing what is basically static information.