From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH v3 1/1] s390: virtio: let arch accept devices without IOMMU feature References: <1592390637-17441-1-git-send-email-pmorel@linux.ibm.com> <1592390637-17441-2-git-send-email-pmorel@linux.ibm.com> <20200618002956.5f179de4.pasic@linux.ibm.com> <20200619112051.74babdb1.cohuck@redhat.com> <20200619140213.69f4992d.pasic@linux.ibm.com> From: Pierre Morel Message-ID: <833c71f2-0057-896a-5e21-2c6263834402@linux.ibm.com> Date: Mon, 29 Jun 2020 15:15:49 +0200 MIME-Version: 1.0 In-Reply-To: <20200619140213.69f4992d.pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Halil Pasic , Cornelia Huck Cc: linux-kernel@vger.kernel.org, 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, thomas.lendacky@amd.com, david@gibson.dropbear.id.au, linuxram@us.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com On 2020-06-19 14:02, Halil Pasic wrote: > On Fri, 19 Jun 2020 11:20:51 +0200 > Cornelia Huck wrote: > >>>> + if (arch_needs_virtio_iommu_platform(dev) && >>>> + !virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { >>>> + dev_warn(&dev->dev, >>>> + "virtio: device must provide VIRTIO_F_IOMMU_PLATFORM\n"); >>> >>> I'm not sure, divulging the current Linux name of this feature bit is a >>> good idea, but if everybody else is fine with this, I don't care that >> >> Not sure if that feature name will ever change, as it is exported in >> headers. At most, we might want to add the new ACCESS_PLATFORM define >> and keep the old one, but that would still mean some churn. >> >>> much. An alternative would be: >>> "virtio: device falsely claims to have full access to the memory, >>> aborting the device" >> >> "virtio: device does not work with limited memory access" ? >> >> But no issue with keeping the current message. > > I think I prefer Conny's version, but no strong feelings here. > The reason why the device is not accepted without IOMMU_PLATFORM is arch specific, I think it should be clearly stated. If no strong oposition... Thanks, Pierre -- Pierre Morel IBM Lab Boeblingen