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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 D8A88C2D0F0 for ; Wed, 1 Apr 2020 13:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF50F20705 for ; Wed, 1 Apr 2020 13:00:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732593AbgDANAR (ORCPT ); Wed, 1 Apr 2020 09:00:17 -0400 Received: from foss.arm.com ([217.140.110.172]:51222 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732252AbgDANAR (ORCPT ); Wed, 1 Apr 2020 09:00:17 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B5BCE30E; Wed, 1 Apr 2020 06:00:16 -0700 (PDT) Received: from [10.57.60.204] (unknown [10.57.60.204]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C6DF53F71E; Wed, 1 Apr 2020 06:00:14 -0700 (PDT) Subject: Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint To: Bharat Bhushan , jean-philippe@linaro.org, joro@8bytes.org, mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, eric.auger.pro@gmail.com, eric.auger@redhat.com References: <20200401113804.21616-1-bbhushan2@marvell.com> From: Robin Murphy Message-ID: Date: Wed, 1 Apr 2020 14:00:13 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200401113804.21616-1-bbhushan2@marvell.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-04-01 12:38 pm, Bharat Bhushan wrote: > Different endpoint can support different page size, probe > endpoint if it supports specific page size otherwise use > global page sizes. > > Signed-off-by: Bharat Bhushan > --- > drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++---- > include/uapi/linux/virtio_iommu.h | 7 +++++++ > 2 files changed, 36 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > index cce329d71fba..c794cb5b7b3e 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -78,6 +78,7 @@ struct viommu_endpoint { > struct viommu_dev *viommu; > struct viommu_domain *vdomain; > struct list_head resv_regions; > + u64 pgsize_bitmap; > }; > > struct viommu_request { > @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct viommu_domain *vdomain) > return ret; > } > > +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev, > + struct virtio_iommu_probe_pgsize_mask *mask, > + size_t len) > + > +{ > + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap); > + > + if (len < sizeof(*mask)) > + return -EINVAL; > + > + vdev->pgsize_bitmap = pgsize_bitmap; > + return 0; > +} > + > static int viommu_add_resv_mem(struct viommu_endpoint *vdev, > struct virtio_iommu_probe_resv_mem *mem, > size_t len) > @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) > while (type != VIRTIO_IOMMU_PROBE_T_NONE && > cur < viommu->probe_size) { > len = le16_to_cpu(prop->length) + sizeof(*prop); > - > switch (type) { > case VIRTIO_IOMMU_PROBE_T_RESV_MEM: > ret = viommu_add_resv_mem(vdev, (void *)prop, len); > break; > + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK: > + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len); > + break; > default: > dev_err(dev, "unknown viommu prop 0x%x\n", type); > } > @@ -607,16 +624,23 @@ static struct iommu_domain *viommu_domain_alloc(unsigned type) > return &vdomain->domain; > } > > -static int viommu_domain_finalise(struct viommu_dev *viommu, > +static int viommu_domain_finalise(struct viommu_endpoint *vdev, > struct iommu_domain *domain) > { > int ret; > struct viommu_domain *vdomain = to_viommu_domain(domain); > + struct viommu_dev *viommu = vdev->viommu; > > vdomain->viommu = viommu; > vdomain->map_flags = viommu->map_flags; > > - domain->pgsize_bitmap = viommu->pgsize_bitmap; > + /* Devices in same domain must support same size pages */ AFAICS what the code appears to do is enforce that the first endpoint attached to any domain has the same pgsize_bitmap as the most recently probed viommu_dev instance, then ignore any subsequent endpoints attached to the same domain. Thus I'm not sure that comment is accurate. Robin. > + if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) && > + (domain->pgsize_bitmap != vdev->pgsize_bitmap)) > + return -EINVAL; > + > + domain->pgsize_bitmap = vdev->pgsize_bitmap; > + > domain->geometry = viommu->geometry; > > ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, > @@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) > * Properly initialize the domain now that we know which viommu > * owns it. > */ > - ret = viommu_domain_finalise(vdev->viommu, domain); > + ret = viommu_domain_finalise(vdev, domain); > } else if (vdomain->viommu != vdev->viommu) { > dev_err(dev, "cannot attach to foreign vIOMMU\n"); > ret = -EXDEV; > @@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev) > > vdev->dev = dev; > vdev->viommu = viommu; > + vdev->pgsize_bitmap = viommu->pgsize_bitmap; > INIT_LIST_HEAD(&vdev->resv_regions); > fwspec->iommu_priv = vdev; > > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h > index 237e36a280cb..dc9d3f40bcd8 100644 > --- a/include/uapi/linux/virtio_iommu.h > +++ b/include/uapi/linux/virtio_iommu.h > @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap { > > #define VIRTIO_IOMMU_PROBE_T_NONE 0 > #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1 > +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2 > > #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff > > @@ -119,6 +120,12 @@ struct virtio_iommu_probe_property { > __le16 length; > }; > > +struct virtio_iommu_probe_pgsize_mask { > + struct virtio_iommu_probe_property head; > + __u8 reserved[4]; > + __u64 pgsize_bitmap; > +}; > + > #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0 > #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1 > >