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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 6A195C352A2 for ; Fri, 7 Feb 2020 13:37:45 +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 34CB121741 for ; Fri, 7 Feb 2020 13:37:45 +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="iT44yD8r" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34CB121741 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]:56494 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j03pI-0004vA-E4 for qemu-devel@archiver.kernel.org; Fri, 07 Feb 2020 08:37:44 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33900) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j03oJ-0003dp-TE for qemu-devel@nongnu.org; Fri, 07 Feb 2020 08:36:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j03oI-0000vf-F5 for qemu-devel@nongnu.org; Fri, 07 Feb 2020 08:36:43 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:36345 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j03oI-0000sf-95 for qemu-devel@nongnu.org; Fri, 07 Feb 2020 08:36:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581082598; 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=r78P+OeZ8mXzhWTNlUJukDEI2NiuxbJT3nuVnClgWVw=; b=iT44yD8r9kAC82vhP1QoARH5s93Cra15yqmYHduWXz50oSeuDbsMDPUHxwKBoyGykJC4Qv C1UO9NVpGEcUZpesW8MnpxyT0pXFCr12xmMKK4jcXP+717Ogv6wcGrBwzke+alhQhNh7VT +NDXWEGK1Bfw3+Dl7zOj1GnDxBlnjqA= 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-97-XXoDksGIOoqYsLqsDsWuiw-1; Fri, 07 Feb 2020 08:36:34 -0500 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 2B4CBDB65; Fri, 7 Feb 2020 13:36:33 +0000 (UTC) Received: from [10.36.116.37] (ovpn-116-37.ams2.redhat.com [10.36.116.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1881D60BEC; Fri, 7 Feb 2020 13:36:22 +0000 (UTC) Subject: Re: [PATCH v14 08/11] virtio-iommu-pci: Introduce the x-dt-binding option To: Jean-Philippe Brucker References: <20200207093203.3788-1-eric.auger@redhat.com> <20200207093203.3788-9-eric.auger@redhat.com> <20200207052214-mutt-send-email-mst@kernel.org> <25d39300-46b9-571c-6fa6-44c5f8d0be99@redhat.com> <20200207111538.GB1999431@myrica> From: Auger Eric Message-ID: Date: Fri, 7 Feb 2020 14:36:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20200207111538.GB1999431@myrica> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: XXoDksGIOoqYsLqsDsWuiw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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@linaro.org, kevin.tian@intel.com, tnowicki@marvell.com, "Michael S. Tsirkin" , quintela@redhat.com, dgilbert@redhat.com, peterx@redhat.com, qemu-devel@nongnu.org, bharatb.linux@gmail.com, qemu-arm@nongnu.org, eric.auger.pro@gmail.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Jean, On 2/7/20 12:15 PM, Jean-Philippe Brucker wrote: > On Fri, Feb 07, 2020 at 11:51:55AM +0100, Auger Eric wrote: >> Hi, >> >> On 2/7/20 11:23 AM, Michael S. Tsirkin wrote: >>> On Fri, Feb 07, 2020 at 10:32:00AM +0100, Eric Auger wrote: >>>> At the moment, the kernel only supports device tree >>>> integration of the virtio-iommu. DT bindings between the >>>> PCI root complex and the IOMMU must be created by the machine >>>> in conformance to: >>>> >>>> Documentation/devicetree/bindings/virtio/iommu.txt. >>>> >>>> To make sure the end-user is aware of this, force him to use the >>>> temporary device option "x-dt-binding" and also double check the >>>> machine has a hotplug handler for the virtio-iommu-pci device. >>>> This hotplug handler is in charge of creating those DT bindings. >>>> >>>> Signed-off-by: Eric Auger >>>> Suggested-by: Michael S. Tsirkin >>> >>> how about setting it by default from machine class? >> Do you mean in ARM virt machine class? But this wouldn't prevent a user >> from launching an ACPI booted guest. I thought you wanted the end-user >> to know what he does. >> >> I don't figure out a way to know if the guest is booted in dt or acpi >> mode. I can get access to those info: >> - whether acpi is enabled > > That's the default on virt machine right? I think that's the default for qemu. you can siwtch it off on the cmd line using "-no-acpi" Then if there is a FW it can > choose either ACPI or DT? yes that's why I can't actually know which one is going to be used. > >> - whether a FW is loaded In case there is no FW I am sure this is dt mode. So I would be inclined to only support that mode atm. >> >> But a FW can be loaded, acpi enabled and eventually the guest is DT >> booted with acpi=off in kernel opts. >> >> Maybe at this point I could only support the case where no FW is loaded. >> In machvirt I would not register the virtio-iommu-pci hotplug handler in >> case a FW is loaded. Then I could get rid of the new x-dt-binding prop. >> >> Thoughts? > > Yes, I'm hoping we can get the topology description into next version of > Linux, and it would be nicer not to introduce backward-compatible baggage > for something that should be solved within a few month I agree. So I am inclined to remove the x-dt-binding prop then I just expose allow the virtio-iommu-pci to be instantiated if no FW is loaded. The constraint will be removed when we get topology description support in kernel. Thanks Eric If we have to > warn the user then checking the FW seems like a good compromise, and easy > to remove later. > > Thanks, > Jean > >> >> Eric >>> See >>> [PATCH 1/2] spapr: Disable legacy virtio devices for pseries-5.0 and later >>> [PATCH 2/2] spapr: Enable virtio iommu_platform=on by default >>> which does it for spapr. >> >>> >>>> --- >>>> >>>> May be squashed with previous patch >>>> --- >>>> hw/virtio/virtio-iommu-pci.c | 18 ++++++++++++++++++ >>>> 1 file changed, 18 insertions(+) >>>> >>>> diff --git a/hw/virtio/virtio-iommu-pci.c b/hw/virtio/virtio-iommu-pci.c >>>> index d539fcce75..3d06e14000 100644 >>>> --- a/hw/virtio/virtio-iommu-pci.c >>>> +++ b/hw/virtio/virtio-iommu-pci.c >>>> @@ -14,6 +14,7 @@ >>>> #include "virtio-pci.h" >>>> #include "hw/virtio/virtio-iommu.h" >>>> #include "hw/qdev-properties.h" >>>> +#include "qapi/error.h" >>>> >>>> typedef struct VirtIOIOMMUPCI VirtIOIOMMUPCI; >>>> >>>> @@ -27,10 +28,12 @@ typedef struct VirtIOIOMMUPCI VirtIOIOMMUPCI; >>>> struct VirtIOIOMMUPCI { >>>> VirtIOPCIProxy parent_obj; >>>> VirtIOIOMMU vdev; >>>> + bool dt_binding; >>>> }; >>>> >>>> static Property virtio_iommu_pci_properties[] = { >>>> DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0), >>>> + DEFINE_PROP_BOOL("x-dt-binding", VirtIOIOMMUPCI, dt_binding, false), >>>> DEFINE_PROP_END_OF_LIST(), >>>> }; >>>> >>>> @@ -39,6 +42,21 @@ static void virtio_iommu_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) >>>> VirtIOIOMMUPCI *dev = VIRTIO_IOMMU_PCI(vpci_dev); >>>> DeviceState *vdev = DEVICE(&dev->vdev); >>>> >>>> + if (!dev->dt_binding) { >>>> + error_setg(errp, >>>> + "Instantiation currently only is possible if the machine " >>>> + "creates device tree iommu-map bindings, ie. ACPI is not " >>>> + "yet supported"); >>>> + error_append_hint(errp, "use -virtio-iommu-pci,x-dt-binding\n"); >>>> + return; >>>> + } >>>> + >>>> + if (!qdev_get_machine_hotplug_handler(DEVICE(vpci_dev))) { >>>> + error_setg(errp, >>>> + "The machine does not implement a virtio-iommu-pci hotplug " >>>> + " handler that creates the device tree iommu-map bindings"); >>>> + return; >>>> + } >>>> qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus)); >>>> object_property_set_link(OBJECT(dev), >>>> OBJECT(pci_get_bus(&vpci_dev->pci_dev)), >>>> -- >>>> 2.20.1 >>> >> >