From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:21210 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728935AbgHFQfp (ORCPT ); Thu, 6 Aug 2020 12:35:45 -0400 From: Pierre Morel Subject: [PATCH v1 1/1] s390: virtio-ccw: PV needs VIRTIO I/O device protection Date: Thu, 6 Aug 2020 16:23:02 +0200 Message-Id: <1596723782-12798-2-git-send-email-pmorel@linux.ibm.com> In-Reply-To: <1596723782-12798-1-git-send-email-pmorel@linux.ibm.com> References: <1596723782-12798-1-git-send-email-pmorel@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: pasic@linux.ibm.com, borntraeger@de.ibm.com, frankja@linux.ibm.com, mst@redhat.com, jasowang@redhat.com, cohuck@redhat.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org, virtualization@lists.linux-foundation.org If protected virtualization is active on s390, the virtio queues are not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been negotiated. Use ccw_transport_features() to fail feature negociation and consequently probe if that's not the case, preventing a host error on access attempt. Signed-off-by: Pierre Morel --- drivers/s390/virtio/virtio_ccw.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index 5730572b52cd..cc8d8064c6c4 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -803,11 +803,23 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) return rc; } -static void ccw_transport_features(struct virtio_device *vdev) +static int ccw_transport_features(struct virtio_device *vdev) { - /* - * Currently nothing to do here. - */ + if (!is_prot_virt_guest()) + return 0; + + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + dev_warn(&vdev->dev, + "device must provide VIRTIO_F_VERSION_1\n"); + return -ENODEV; + } + + if (!virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { + dev_warn(&vdev->dev, + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); + return -ENODEV; + } + return 0; } static int virtio_ccw_finalize_features(struct virtio_device *vdev) @@ -837,7 +849,9 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev) vring_transport_features(vdev); /* Give virtio_ccw a chance to accept features. */ - ccw_transport_features(vdev); + ret = ccw_transport_features(vdev); + if (ret) + goto out_free; features->index = 0; features->features = cpu_to_le32((u32)vdev->features); -- 2.25.1