From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36036 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725944AbgGGLN7 (ORCPT ); Tue, 7 Jul 2020 07:13:59 -0400 Subject: Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection References: <1594111477-15401-1-git-send-email-pmorel@linux.ibm.com> <1594111477-15401-3-git-send-email-pmorel@linux.ibm.com> From: Christian Borntraeger Message-ID: <862dce70-1aed-ace0-cb7b-54844e812be3@de.ibm.com> Date: Tue, 7 Jul 2020 13:12:28 +0200 MIME-Version: 1.0 In-Reply-To: <1594111477-15401-3-git-send-email-pmorel@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Pierre Morel , linux-kernel@vger.kernel.org Cc: pasic@linux.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, thomas.lendacky@amd.com, david@gibson.dropbear.id.au, linuxram@us.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com On 07.07.20 10:44, Pierre Morel wrote: > S390, protecting the guest memory against unauthorized host access > needs to enforce VIRTIO I/O device protection through the use of > VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. > > Signed-off-by: Pierre Morel > --- > arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > index c296e5c8dbf9..106330f6eda1 100644 > --- a/arch/s390/kernel/uv.c > +++ b/arch/s390/kernel/uv.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -413,3 +414,27 @@ static int __init uv_info_init(void) > } > device_initcall(uv_info_init); > #endif > + > +/* > + * arch_validate_virtio_iommu_platform > + * @dev: the VIRTIO device being added > + * > + * Return value: returns -ENODEV if any features of the > + * device breaks the protected virtualization > + * 0 otherwise. > + */ > +int arch_validate_virtio_features(struct virtio_device *dev) > +{ > + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); I think you only want to warn if is_prot_virt_guest is true? We certainly want to be able to run as a guest of older hypervisors with virtio 0.95, no? > + return is_prot_virt_guest() ? -ENODEV : 0; > + } > + > + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > + dev_warn(&dev->dev, > + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); same here. > + return is_prot_virt_guest() ? -ENODEV : 0; > + } > + > + return 0; > +} >