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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_RED autolearn=unavailable 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 C2FAEC47089 for ; Wed, 26 May 2021 14:34:34 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 589626113D for ; Wed, 26 May 2021 14:34:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 589626113D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 16DB440262; Wed, 26 May 2021 14:34:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mwjLndrf_hZp; Wed, 26 May 2021 14:34:33 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTP id 3DAF840424; Wed, 26 May 2021 14:34:32 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id EF066C000E; Wed, 26 May 2021 14:34:31 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id F3D3DC0001 for ; Wed, 26 May 2021 14:34:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id D06C64044C for ; Wed, 26 May 2021 14:34:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ajr5_ad4AHCn for ; Wed, 26 May 2021 14:34:30 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by smtp4.osuosl.org (Postfix) with ESMTPS id F1BC64044D for ; Wed, 26 May 2021 14:34:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622039668; 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=cqBPgPyUlAbZ7Kk+oGgbHiAKQDgT/aGEeIFiCp5+zq4=; b=AJIPNQODLzMGr5LmdNbow5R7RhEeEg6wAx/xDimQus7OZurLrX51Rd+iJ6ITph27YvNQjC toSjRPgc7Vx+Gfr+gGw2ikKPfKzwFG/gESYQItGC90GBN9kb+iwf2yQbutae0Hwb3n67Qq vgLr7mg603rT37TDIDxLdFlOkUwECvA= 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-384-D2hxjXQtPpStZr2pCmQUGA-1; Wed, 26 May 2021 10:34:25 -0400 X-MC-Unique: D2hxjXQtPpStZr2pCmQUGA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3911A107AD35; Wed, 26 May 2021 14:34:24 +0000 (UTC) Received: from gondolin.fritz.box (ovpn-113-79.ams2.redhat.com [10.36.113.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id C85BA1037F21; Wed, 26 May 2021 14:34:22 +0000 (UTC) Date: Wed, 26 May 2021 16:34:20 +0200 From: Cornelia Huck To: Halil Pasic , "Michael S. Tsirkin" , Jason Wang Subject: Re: [PATCH RFC 0/2] virtio-ccw: allow to disable legacy virtio Message-ID: <20210526163420.4620f342.cohuck@redhat.com> In-Reply-To: <20210304132715.1587211-1-cohuck@redhat.com> References: <20210304132715.1587211-1-cohuck@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Cc: linux-s390@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" On Thu, 4 Mar 2021 14:27:13 +0100 Cornelia Huck wrote: Just found this old series sitting there... does anyone have an opinion on the general approach? > Unlike virtio-pci, virtio-ccw is currently always a transitional > driver (i.e. it always includes support for legacy devices.) The > differences between legacy and virtio-1+ virtio-ccw devices are not > that big (the most interesting things are in common virtio code > anyway.) > > It might be beneficial to make support for legacy virtio generally > configurable, in case we want to remove it completely in a future > where we all have flying cars. As a prereq, we need to make it > configurable for virtio-ccw. > > Patch 1 introduces a parameter; now that I look at it, it's probably > not that useful (not even for testing), so I'm inclined to drop it > again. > > Patch 2 adds a new config symbol for generic legacy virtio support, > which currently does not do anything but being selected by the > legacy options for virtio-pci and virtio-ccw. A virtio-ccw driver > without legacy support will require a revision of 1 or higher to > be supported by the device. > > A virtio-ccw driver with legacy turned off works well for me with > transitional devices and fails onlining gracefully for legacy devices > (max_revision=0 in QEMU). > > (I also have some code that allows to make devices non-transitional > in QEMU, but I haven't yet found time to polish the patches.) > > Cornelia Huck (2): > virtio/s390: add parameter for minimum revision > virtio/s390: make legacy support configurable > > arch/s390/Kconfig | 11 ++ > drivers/s390/virtio/Makefile | 1 + > drivers/s390/virtio/virtio_ccw.c | 179 ++++++++---------------- > drivers/s390/virtio/virtio_ccw_common.h | 113 +++++++++++++++ > drivers/s390/virtio/virtio_ccw_legacy.c | 138 ++++++++++++++++++ > drivers/virtio/Kconfig | 8 ++ > 6 files changed, 330 insertions(+), 120 deletions(-) > create mode 100644 drivers/s390/virtio/virtio_ccw_common.h > create mode 100644 drivers/s390/virtio/virtio_ccw_legacy.c > > > base-commit: cf6acb8bdb1d829b85a4daa2944bf9e71c93f4b9 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization