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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 D1EFDC433E0 for ; Wed, 10 Jun 2020 14:53:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1434207F9 for ; Wed, 10 Jun 2020 14:53:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dWGo7jdK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729944AbgFJOxu (ORCPT ); Wed, 10 Jun 2020 10:53:50 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:41682 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726943AbgFJOxt (ORCPT ); Wed, 10 Jun 2020 10:53:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591800827; 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=SEnQxAW9uQsVBSiEtzbPpC8TpA8ftH1ryZnX+gay5Vs=; b=dWGo7jdKPxNgXqOC/KoZA8U0EwMl9Rb2u4454KYEt3PF9HRD9REPq+IHIZFNDHZ/qa1qIV Pc2oOJ7dIYVMU9eZPzQHl1AWaZ8Jm/KFpO7cXD7ogPyPJgMatPJDTuq4/EcvtPf6KHINS4 L4Skcaohvv3w76rQFjdQ8qVWMA7+1bI= 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-249-flirENk-PkmWukFoCP548w-1; Wed, 10 Jun 2020 10:53:43 -0400 X-MC-Unique: flirENk-PkmWukFoCP548w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 79F9318A4176; Wed, 10 Jun 2020 14:53:10 +0000 (UTC) Received: from gondolin (ovpn-112-196.ams2.redhat.com [10.36.112.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CFB75C296; Wed, 10 Jun 2020 14:53:08 +0000 (UTC) Date: Wed, 10 Jun 2020 16:53:05 +0200 From: Cornelia Huck To: Pierre Morel Cc: linux-kernel@vger.kernel.org, pasic@linux.ibm.com, borntraeger@de.ibm.com, frankja@linux.ibm.com, mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH] s390: protvirt: virtio: Refuse device without IOMMU Message-ID: <20200610165305.1a34c548.cohuck@redhat.com> In-Reply-To: <54b28498-a6a7-4be2-9d2c-aef46c7fc642@linux.ibm.com> References: <1591794711-5915-1-git-send-email-pmorel@linux.ibm.com> <20200610152431.358fded7.cohuck@redhat.com> <54b28498-a6a7-4be2-9d2c-aef46c7fc642@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 10 Jun 2020 16:37:55 +0200 Pierre Morel wrote: > On 2020-06-10 15:24, Cornelia Huck wrote: > > On Wed, 10 Jun 2020 15:11:51 +0200 > > Pierre Morel wrote: > > > >> Protected Virtualisation protects the memory of the guest and > >> do not allow a the host to access all of its memory. > >> > >> Let's refuse a VIRTIO device which does not use IOMMU > >> protected access. > >> > >> Signed-off-by: Pierre Morel > >> --- > >> drivers/s390/virtio/virtio_ccw.c | 5 +++++ > >> 1 file changed, 5 insertions(+) > >> > >> diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > >> index 5730572b52cd..06ffbc96587a 100644 > >> --- a/drivers/s390/virtio/virtio_ccw.c > >> +++ b/drivers/s390/virtio/virtio_ccw.c > >> @@ -986,6 +986,11 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) > >> if (!ccw) > >> return; > >> > >> + /* Protected Virtualisation guest needs IOMMU */ > >> + if (is_prot_virt_guest() && > >> + !__virtio_test_bit(vdev, VIRTIO_F_IOMMU_PLATFORM)) > >> + status &= ~VIRTIO_CONFIG_S_FEATURES_OK; > >> + > > > > set_status seems like an odd place to look at features; shouldn't that > > rather be done in finalize_features? > > Right, looks better to me too. > What about: > > > > diff --git a/drivers/s390/virtio/virtio_ccw.c > b/drivers/s390/virtio/virtio_ccw.c > index 06ffbc96587a..227676297ea0 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -833,6 +833,11 @@ static int virtio_ccw_finalize_features(struct > virtio_device *vdev) > ret = -ENOMEM; > goto out_free; > } > + > + if (is_prot_virt_guest() && > + !__virtio_test_bit(vdev, VIRTIO_F_IOMMU_PLATFORM)) Add a comment, and (maybe) a message? Otherwise, I think this is fine, as it should fail the probe, which is what we want. > + return -EIO; > + > /* Give virtio_ring a chance to accept features. */ > vring_transport_features(vdev); > > > > Thanks, > > Regards, > Pierre >