Messages in this thread | | | Subject | Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint | From | Robin Murphy <> | Date | Wed, 1 Apr 2020 14:00:13 +0100 |
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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 <bbhushan2@marvell.com> > --- > 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 > >
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