Jean-Philippe Brucker
2021-Mar-03 17:25 UTC
[PATCH RFC v1 13/15] iommu/virtio: Attach Arm PASID tables when available
On Fri, Jan 15, 2021 at 05:43:40PM +0530, Vivek Gautam wrote: [...]> +static int viommu_setup_pgtable(struct viommu_endpoint *vdev, > + struct viommu_domain *vdomain) > +{ > + int ret, id; > + u32 asid; > + enum io_pgtable_fmt fmt; > + struct io_pgtable_ops *ops = NULL; > + struct viommu_dev *viommu = vdev->viommu; > + struct virtio_iommu_probe_table_format *desc = vdev->pgtf; > + struct iommu_pasid_table *tbl = vdomain->pasid_tbl; > + struct iommu_vendor_psdtable_cfg *pst_cfg; > + struct arm_smmu_cfg_info *cfgi; > + struct io_pgtable_cfg cfg = { > + .iommu_dev = viommu->dev->parent, > + .tlb = &viommu_flush_ops, > + .pgsize_bitmap = vdev->pgsize_mask ? vdev->pgsize_mask : > + vdomain->domain.pgsize_bitmap, > + .ias = (vdev->input_end ? ilog2(vdev->input_end) : > + ilog2(vdomain->domain.geometry.aperture_end)) + 1, > + .oas = vdev->output_bits, > + }; > + > + if (!desc) > + return -EINVAL; > + > + if (!vdev->output_bits) > + return -ENODEV; > + > + switch (le16_to_cpu(desc->format)) { > + case VIRTIO_IOMMU_FOMRAT_PGTF_ARM_LPAE: > + fmt = ARM_64_LPAE_S1; > + break; > + default: > + dev_err(vdev->dev, "unsupported page table format 0x%x\n", > + le16_to_cpu(desc->format)); > + return -EINVAL; > + } > + > + if (vdomain->mm.ops) { > + /* > + * TODO: attach additional endpoint to the domain. Check that > + * the config is sane. > + */ > + return -EEXIST; > + } > + > + vdomain->mm.domain = vdomain; > + ops = alloc_io_pgtable_ops(fmt, &cfg, &vdomain->mm); > + if (!ops) > + return -ENOMEM; > + > + pst_cfg = &tbl->cfg; > + cfgi = &pst_cfg->vendor.cfg; > + id = ida_simple_get(&asid_ida, 1, 1 << desc->asid_bits, GFP_KERNEL); > + if (id < 0) { > + ret = id; > + goto err_free_pgtable; > + } > + > + asid = id; > + ret = iommu_psdtable_prepare(tbl, pst_cfg, &cfg, asid); > + if (ret) > + goto err_free_asid; > + > + /* > + * Strange to setup an op here? > + * cd-lib is the actual user of sync op, and therefore the platform > + * drivers should assign this sync/maintenance ops as per need. > + */ > + tbl->ops->sync = viommu_flush_pasid;But this function deals with page tables, not pasid tables. As said on an earlier patch, the TLB flush ops should probably be passed during table registration - those ops are global so should really be const.> + > + /* Right now only PASID 0 supported ?? */ > + ret = iommu_psdtable_write(tbl, pst_cfg, 0, &cfgi->s1_cfg->cd); > + if (ret) > + goto err_free_asid; > + > + vdomain->mm.ops = ops; > + dev_dbg(vdev->dev, "using page table format 0x%x\n", fmt); > + > + return 0; > + > +err_free_asid: > + ida_simple_remove(&asid_ida, asid); > +err_free_pgtable: > + free_io_pgtable_ops(ops); > + return ret; > +} > + > +static int viommu_config_arm_pst(struct iommu_vendor_psdtable_cfg *pst_cfg, > + struct virtio_iommu_req_attach_pst_arm *req) > +{ > + struct arm_smmu_s1_cfg *s1_cfg = pst_cfg->vendor.cfg.s1_cfg; > + > + if (!s1_cfg) > + return -ENODEV; > + > + req->format = cpu_to_le16(VIRTIO_IOMMU_FORMAT_PSTF_ARM_SMMU_V3); > + req->s1fmt = s1_cfg->s1fmt; > + req->s1dss = VIRTIO_IOMMU_PSTF_ARM_SMMU_V3_DSS_0; > + req->s1contextptr = cpu_to_le64(pst_cfg->base); > + req->s1cdmax = cpu_to_le32(s1_cfg->s1cdmax); > + > + return 0; > +} > + > +static int viommu_config_pst(struct iommu_vendor_psdtable_cfg *pst_cfg, > + void *req, enum pasid_table_fmt fmt) > +{ > + int ret; > + > + switch (fmt) { > + case PASID_TABLE_ARM_SMMU_V3: > + ret = viommu_config_arm_pst(pst_cfg, req); > + break; > + default: > + ret = -EINVAL; > + WARN_ON(1); > + } > + > + return ret; > +} > + > +static int viommu_prepare_arm_pst(struct viommu_endpoint *vdev, > + struct iommu_vendor_psdtable_cfg *pst_cfg) > +{ > + struct virtio_iommu_probe_table_format *pgtf = vdev->pgtf; > + struct arm_smmu_cfg_info *cfgi = &pst_cfg->vendor.cfg; > + struct arm_smmu_s1_cfg *cfg; > + > + /* Some sanity checks */ > + if (pgtf->asid_bits != 8 && pgtf->asid_bits != 16) > + return -EINVAL;No need for this, next patch cheks asid size in viommu_config_arm_pgt()> + > + cfg = devm_kzalloc(pst_cfg->iommu_dev, sizeof(cfg), GFP_KERNEL); > + if (!cfg) > + return -ENOMEM; > + > + cfgi->s1_cfg = cfg; > + cfg->s1cdmax = vdev->pasid_bits; > + cfg->cd.asid = pgtf->asid_bits;That doesn't look right, cfg->cd.asid takes the ASID value of context 0 but here we're writing a limit. viommu_setup_pgtable() probably needs to set this field to the allocated ASID, since viommu_teardown_pgtable() uses it.> + > + pst_cfg->fmt = PASID_TABLE_ARM_SMMU_V3;Parent function can set this> + /* XXX HACK: set feature bit ARM_SMMU_FEAT_2_LVL_CDTAB */ > + pst_cfg->vendor.cfg.feat_flag |= (1 << 1);Oh right, this flag is missing. I'll add #define VIRTIO_IOMMU_PST_ARM_SMMU3_F_CD2L (1ULL << 1) to the spec.> + > + return 0; > +} > + > +static int viommu_prepare_pst(struct viommu_endpoint *vdev, > + struct iommu_vendor_psdtable_cfg *pst_cfg, > + enum pasid_table_fmt fmt) > +{ > + int ret; > + > + switch (fmt) { > + case PASID_TABLE_ARM_SMMU_V3: > + ret = viommu_prepare_arm_pst(vdev, pst_cfg); > + break; > + default: > + dev_err(vdev->dev, "unsupported PASID table format 0x%x\n", fmt); > + ret = -EINVAL; > + } > + > + return ret; > +} > + > +static int viommu_attach_pasid_table(struct viommu_endpoint *vdev, > + struct viommu_domain *vdomain) > +{ > + int ret; > + int i, eid; > + enum pasid_table_fmt fmt = -1; > + struct virtio_iommu_probe_table_format *desc = vdev->pstf; > + struct virtio_iommu_req_attach_table req = { > + .head.type = VIRTIO_IOMMU_T_ATTACH_TABLE, > + .domain = cpu_to_le32(vdomain->id), > + }; > + struct viommu_dev *viommu = vdev->viommu; > + struct iommu_pasid_table *tbl; > + struct iommu_vendor_psdtable_cfg *pst_cfg; > + > + if (!viommu->has_table) > + return 0; > + > + if (!desc) > + return -ENODEV; > + > + /* Prepare PASID tables configuration */ > + switch (le16_to_cpu(desc->format)) { > + case VIRTIO_IOMMU_FORMAT_PSTF_ARM_SMMU_V3: > + fmt = PASID_TABLE_ARM_SMMU_V3; > + break; > + default: > + dev_err(vdev->dev, "unsupported PASID table format 0x%x\n", > + le16_to_cpu(desc->format)); > + return 0; > + } > + > + if (!tbl) { > + tbl = iommu_register_pasid_table(fmt, viommu->dev->parent, vdomain); > + if (!tbl) > + return -ENOMEM; > + > + vdomain->pasid_tbl = tbl; > + pst_cfg = &tbl->cfg; > + > + pst_cfg->iommu_dev = viommu->dev->parent; > + > + /* Prepare PASID tables info to allocate a new table */ > + ret = viommu_prepare_pst(vdev, pst_cfg, fmt); > + if (ret) > + return ret; > + > + ret = iommu_psdtable_alloc(tbl, pst_cfg); > + if (ret) > + return ret; > + > + pst_cfg->iommu_dev = viommu->dev->parent;Already set by iommu_register_pasid_table() (and needed for DMA allocations in iommu_psdtable_alloc())> + pst_cfg->fmt = PASID_TABLE_ARM_SMMU_V3;Already set above> + > + ret = viommu_setup_pgtable(vdev, vdomain); > + if (ret) { > + dev_err(vdev->dev, "could not install page tables\n"); > + goto err_free_psdtable; > + } > + > + /* Add arch-specific configuration */ > + ret = viommu_config_pst(pst_cfg, (void *)&req, fmt); > + if (ret) > + goto err_free_ops; > + > + vdev_for_each_id(i, eid, vdev) { > + req.endpoint = cpu_to_le32(eid); > + ret = viommu_send_req_sync(viommu, &req, sizeof(req)); > + if (ret) > + goto err_free_ops; > + } > + } else { > + /* TODO: otherwise, check for compatibility with vdev. */ > + return -ENOSYS; > + } > + > + dev_dbg(vdev->dev, "uses PASID table format 0x%x\n", fmt); > + > + return 0; > + > +err_free_ops: > + if (vdomain->mm.ops) > + viommu_teardown_pgtable(vdomain); > +err_free_psdtable: > + iommu_psdtable_free(tbl, &tbl->cfg); > + > + return ret; > +} > + > static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) > { > int ret = 0; > @@ -928,6 +1213,17 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) > if (vdev->vdomain) > vdev->vdomain->nr_endpoints--; > > + ret = viommu_attach_pasid_table(vdev, vdomain); > + if (ret) { > + /* > + * No PASID support, too bad. Perhaps we can bind a single set > + * of page tables? > + */ > + ret = viommu_setup_pgtable(vdev, vdomain);This cannot work at the moment because viommu_setup_pgtable() writes to the non-existing pasid table. Probably best to leave this call for next patch. Thanks, Jean> + if (ret) > + dev_err(vdev->dev, "could not install tables\n"); > + } > + > if (!vdomain->mm.ops) { > /* If we couldn't bind any table, use the mapping tree */ > ret = viommu_simple_attach(vdomain, vdev); > @@ -948,6 +1244,10 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, > u32 flags; > struct virtio_iommu_req_map map; > struct viommu_domain *vdomain = to_viommu_domain(domain); > + struct io_pgtable_ops *ops = vdomain->mm.ops; > + > + if (ops) > + return ops->map(ops, iova, paddr, size, prot, gfp); > > flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | > (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | > @@ -986,6 +1286,10 @@ static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova, > size_t unmapped; > struct virtio_iommu_req_unmap unmap; > struct viommu_domain *vdomain = to_viommu_domain(domain); > + struct io_pgtable_ops *ops = vdomain->mm.ops; > + > + if (ops) > + return ops->unmap(ops, iova, size, gather); > > unmapped = viommu_del_mappings(vdomain, iova, size); > if (unmapped < size) > @@ -1014,6 +1318,10 @@ static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, > struct viommu_mapping *mapping; > struct interval_tree_node *node; > struct viommu_domain *vdomain = to_viommu_domain(domain); > + struct io_pgtable_ops *ops = vdomain->mm.ops; > + > + if (ops) > + return ops->iova_to_phys(ops, iova); > > spin_lock_irqsave(&vdomain->mappings_lock, flags); > node = interval_tree_iter_first(&vdomain->mappings, iova, iova); > @@ -1264,7 +1572,12 @@ static int viommu_probe(struct virtio_device *vdev) > struct virtio_iommu_config, probe_size, > &viommu->probe_size); > > + viommu->has_table = virtio_has_feature(vdev, VIRTIO_IOMMU_F_ATTACH_TABLE); > viommu->has_map = virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP); > + if (!viommu->has_table && !viommu->has_map) { > + ret = -EINVAL; > + goto err_free_vqs; > + } > > viommu->geometry = (struct iommu_domain_geometry) { > .aperture_start = input_start, > @@ -1356,6 +1669,7 @@ static unsigned int features[] = { > VIRTIO_IOMMU_F_DOMAIN_RANGE, > VIRTIO_IOMMU_F_PROBE, > VIRTIO_IOMMU_F_MMIO, > + VIRTIO_IOMMU_F_ATTACH_TABLE, > }; > > static struct virtio_device_id id_table[] = { > -- > 2.17.1 >