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=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 BBF8BC433E2 for ; Thu, 17 Sep 2020 10:02:19 +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 393A420838 for ; Thu, 17 Sep 2020 10:02:19 +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="ALQr0n59" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 393A420838 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]:42838 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIqk6-0004rw-4A for qemu-devel@archiver.kernel.org; Thu, 17 Sep 2020 06:02:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57628) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIqi9-0003Ux-Es for qemu-devel@nongnu.org; Thu, 17 Sep 2020 06:00:17 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:39531 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 1kIqi6-00022l-8f for qemu-devel@nongnu.org; Thu, 17 Sep 2020 06:00:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600336813; 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=WwIxy4EkReBWYK9jYstrs0vt3Qndski37ELRnuCv0SI=; b=ALQr0n59PRm5IyWPmSOtxaDtreDLvFUuXq3fu/Y2At8oCNiG3dhxHHeIH02wyJWBFgh47R XsA1a5JNP2c9VeO7zT8Lw+QBQoU+dry+HzYZ+mbki4e+feeLEF4B+0I4c4iWkj7gk+Anwu s9iujnbv3qUPe+tgjxG2PnYHfFfnglo= 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-543-lINkpIXCN_K5CFPedC6EEw-1; Thu, 17 Sep 2020 06:00:11 -0400 X-MC-Unique: lINkpIXCN_K5CFPedC6EEw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5547780EF9C; Thu, 17 Sep 2020 10:00:10 +0000 (UTC) Received: from work-vm (ovpn-114-108.ams2.redhat.com [10.36.114.108]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 78CE07514E; Thu, 17 Sep 2020 10:00:03 +0000 (UTC) Date: Thu, 17 Sep 2020 11:00:00 +0100 From: "Dr. David Alan Gilbert" To: Cornelia Huck Subject: Re: [PATCH v2] virtio: skip legacy support check on machine types less than 5.1 Message-ID: <20200917100000.GF2793@work-vm> References: <20200915130514.80989-1-sgarzare@redhat.com> <20200916110848.47395807.cohuck@redhat.com> <20200917084828.p7j3fc6p4almxbxw@steredhat> <20200917112256.796f620d.cohuck@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200917112256.796f620d.cohuck@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/17 02:16:16 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.999, 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_H2=-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: Eduardo Habkost , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Cornelia Huck (cohuck@redhat.com) wrote: > On Thu, 17 Sep 2020 10:48:28 +0200 > Stefano Garzarella wrote: > > > On Wed, Sep 16, 2020 at 11:08:48AM +0200, Cornelia Huck wrote: > > > On Tue, 15 Sep 2020 15:05:14 +0200 > > > Stefano Garzarella wrote: > > > > > > > Commit 9b3a35ec82 ("virtio: verify that legacy support is not accidentally > > > > on") added a check that returns an error if legacy support is on, but the > > > > device is not legacy. > > > > > > > > Unfortunately some devices were wrongly declared legacy even if they > > > > were not (e.g vhost-vsock). > > > > > > > > To avoid migration issues, we disable this error for machine types < 5.1, > > > > but we print a warning. > > > > > > > > Cc: qemu-stable@nongnu.org > > > > Fixes: 9b3a35ec82 ("virtio: verify that legacy support is not accidentally on") > > > > Suggested-by: Dr. David Alan Gilbert > > > > Suggested-by: Cornelia Huck > > > > Signed-off-by: Stefano Garzarella > > > > --- > > > > v2: > > > > - fixed Cornelia's e-mail address > > > > --- > > > > include/hw/virtio/virtio.h | 1 + > > > > hw/core/machine.c | 1 + > > > > hw/virtio/virtio.c | 18 ++++++++++++++++-- > > > > 3 files changed, 18 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > > > > index 807280451b..ed7cee348b 100644 > > > > --- a/include/hw/virtio/virtio.h > > > > +++ b/include/hw/virtio/virtio.h > > > > @@ -103,6 +103,7 @@ struct VirtIODevice > > > > bool use_started; > > > > bool started; > > > > bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */ > > > > + bool disable_legacy_check; > > > > VMChangeStateEntry *vmstate; > > > > char *bus_name; > > > > uint8_t device_endian; > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > > > index ea26d61237..b686eab798 100644 > > > > --- a/hw/core/machine.c > > > > +++ b/hw/core/machine.c > > > > @@ -44,6 +44,7 @@ GlobalProperty hw_compat_5_0[] = { > > > > { "vmport", "x-signal-unsupported-cmd", "off" }, > > > > { "vmport", "x-report-vmx-type", "off" }, > > > > { "vmport", "x-cmds-v2", "off" }, > > > > + { "virtio-device", "x-disable-legacy-check", "true" }, > > > > > > Hm... not sure if we actually should add a new device property for > > > that. Maybe we can use a flag in the base machine type instead? > > > > I am not very experienced with machine types. > > I used the device property to easily access it from virtio devices. > > > > Please, can you give me some suggestions where to look for the flags? > > I was thinking about adding a new virtio_legacy_check flag into > MachineClass to get a machine-wide config and avoid introducing a new > config knob. The drawback is that every machine type supporting compat > machines would need to take care about disabling the check in their > 5.1-or-older machines themselves. > > Not sure what the preferable solution is; I'm not really opposed to > your approach, though. I think a device property is fine - they make it easy to add it to the global compat list. Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK