diff options
| -rw-r--r-- | drivers/vfio/vfio_iommu_type1.c | 184 |
1 files changed, 181 insertions, 3 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 054391f30fa8..6a69652b406b 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -62,6 +62,7 @@ MODULE_PARM_DESC(dma_entry_limit, struct vfio_iommu { struct list_head domain_list; + struct list_head iova_list; struct vfio_domain *external_domain; /* domain for external user */ struct mutex lock; struct rb_root dma_list; @@ -97,6 +98,12 @@ struct vfio_group { bool mdev_group; /* An mdev group */ }; +struct vfio_iova { + struct list_head list; + dma_addr_t start; + dma_addr_t end; +}; + /* * Guest RAM pinning working set or DMA target */ @@ -1388,6 +1395,146 @@ static int vfio_mdev_iommu_device(struct device *dev, void *data) return 0; } +/* + * This is a helper function to insert an address range to iova list. + * The list is initially created with a single entry corresponding to + * the IOMMU domain geometry to which the device group is attached. + * The list aperture gets modified when a new domain is added to the + * container if the new aperture doesn't conflict with the current one + * or with any existing dma mappings. The list is also modified to + * exclude any reserved regions associated with the device group. + */ +static int vfio_iommu_iova_insert(struct list_head *head, + dma_addr_t start, dma_addr_t end) +{ + struct vfio_iova *region; + + region = kmalloc(sizeof(*region), GFP_KERNEL); + if (!region) + return -ENOMEM; + + INIT_LIST_HEAD(®ion->list); + region->start = start; + region->end = end; + + list_add_tail(®ion->list, head); + return 0; +} + +/* + * Check the new iommu aperture conflicts with existing aper or with any + * existing dma mappings. + */ +static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu, + dma_addr_t start, dma_addr_t end) +{ + struct vfio_iova *first, *last; + struct list_head *iova = &iommu->iova_list; + + if (list_empty(iova)) + return false; + + /* Disjoint sets, return conflict */ + first = list_first_entry(iova, struct vfio_iova, list); + last = list_last_entry(iova, struct vfio_iova, list); + if (start > last->end || end < first->start) + return true; + + /* Check for any existing dma mappings below the new start */ + if (start > first->start) { + if (vfio_find_dma(iommu, first->start, start - first->start)) + return true; + } + + /* Check for any existing dma mappings beyond the new end */ + if (end < last->end) { + if (vfio_find_dma(iommu, end + 1, last->end - end)) + return true; + } + + return false; +} + +/* + * Resize iommu iova aperture window. This is called only if the new + * aperture has no conflict with existing aperture and dma mappings. + */ +static int vfio_iommu_aper_resize(struct list_head *iova, + dma_addr_t start, dma_addr_t end) +{ + struct vfio_iova *node, *next; + + if (list_empty(iova)) + return vfio_iommu_iova_insert(iova, start, end); + + /* Adjust iova list start */ + list_for_each_entry_safe(node, next, iova, list) { + if (start < node->start) + break; + if (start >= node->start && start < node->end) { + node->start = start; + break; + } + /* Delete nodes before new start */ + list_del(&node->list); + kfree(node); + } + + /* Adjust iova list end */ + list_for_each_entry_safe(node, next, iova, list) { + if (end > node->end) + continue; + if (end > node->start && end <= node->end) { + node->end = end; + continue; + } + /* Delete nodes after new end */ + list_del(&node->list); + kfree(node); + } + + return 0; +} + +static void vfio_iommu_iova_free(struct list_head *iova) +{ + struct vfio_iova *n, *next; + + list_for_each_entry_safe(n, next, iova, list) { + list_del(&n->list); + kfree(n); + } +} + +static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu, + struct list_head *iova_copy) +{ + struct list_head *iova = &iommu->iova_list; + struct vfio_iova *n; + int ret; + + list_for_each_entry(n, iova, list) { + ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end); + if (ret) + goto out_free; + } + + return 0; + +out_free: + vfio_iommu_iova_free(iova_copy); + return ret; +} + +static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu, + struct list_head *iova_copy) +{ + struct list_head *iova = &iommu->iova_list; + + vfio_iommu_iova_free(iova); + + list_splice_tail(iova_copy, iova); +} static int vfio_iommu_type1_attach_group(void *iommu_data, struct iommu_group *iommu_group) { @@ -1398,6 +1545,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, int ret; bool resv_msi, msi_remap; phys_addr_t resv_msi_base; + struct iommu_domain_geometry geo; + LIST_HEAD(iova_copy); mutex_lock(&iommu->lock); @@ -1474,6 +1623,29 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, if (ret) goto out_domain; + /* Get aperture info */ + iommu_domain_get_attr(domain->domain, DOMAIN_ATTR_GEOMETRY, &geo); + + if (vfio_iommu_aper_conflict(iommu, geo.aperture_start, + geo.aperture_end)) { + ret = -EINVAL; + goto out_detach; + } + + /* + * We don't want to work on the original iova list as the list + * gets modified and in case of failure we have to retain the + * original list. Get a copy here. + */ + ret = vfio_iommu_iova_get_copy(iommu, &iova_copy); + if (ret) + goto out_detach; + + ret = vfio_iommu_aper_resize(&iova_copy, geo.aperture_start, + geo.aperture_end); + if (ret) + goto out_detach; + resv_msi = vfio_iommu_has_sw_msi(iommu_group, &resv_msi_base); INIT_LIST_HEAD(&domain->group_list); @@ -1507,8 +1679,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, list_add(&group->next, &d->group_list); iommu_domain_free(domain->domain); kfree(domain); - mutex_unlock(&iommu->lock); - return 0; + goto done; } ret = vfio_iommu_attach_group(domain, group); @@ -1531,7 +1702,9 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, } list_add(&domain->next, &iommu->domain_list); - +done: + /* Delete the old one and insert new iova list */ + vfio_iommu_iova_insert_copy(iommu, &iova_copy); mutex_unlock(&iommu->lock); return 0; @@ -1540,6 +1713,7 @@ out_detach: vfio_iommu_detach_group(domain, group); out_domain: iommu_domain_free(domain->domain); + vfio_iommu_iova_free(&iova_copy); out_free: kfree(domain); kfree(group); @@ -1679,6 +1853,7 @@ static void *vfio_iommu_type1_open(unsigned long arg) } INIT_LIST_HEAD(&iommu->domain_list); + INIT_LIST_HEAD(&iommu->iova_list); iommu->dma_list = RB_ROOT; iommu->dma_avail = dma_entry_limit; mutex_init(&iommu->lock); @@ -1722,6 +1897,9 @@ static void vfio_iommu_type1_release(void *iommu_data) list_del(&domain->next); kfree(domain); } + + vfio_iommu_iova_free(&iommu->iova_list); + kfree(iommu); } |