[PATCH v5 2/7] vfio/type1: Check reserve region conflict and update iova list

Shameer Kolothum
2018-03-15T16:35:04Z

This retrieves the reserved regions associated with dev group and
checks for conflicts with any existing dma mappings. Also update
the iova list excluding the reserved regions.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
drivers/vfio/vfio_iommu_type1.c | 90 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 1123c74..cfe2bb2 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1313,6 +1313,82 @@ static int vfio_iommu_aper_resize(struct list_head *iova,
return 0;
}

+/*
+ * Check reserved region conflicts with existing dma mappings
+ */
+static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
+ struct list_head *resv_regions)
+{
+ struct iommu_resv_region *region;
+
+ /* Check for conflict with existing dma mappings */
+ list_for_each_entry(region, resv_regions, list) {
+ if (vfio_find_dma(iommu, region->start, region->length))
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Check iova region overlap with reserved regions and
+ * exclude them from the iommu iova range
+ */
+static int vfio_iommu_resv_exclude(struct list_head *iova,
+ struct list_head *resv_regions)
+{
+ struct iommu_resv_region *resv;
+ struct vfio_iova *n, *next;
+
+ list_for_each_entry(resv, resv_regions, list) {
+ phys_addr_t start, end;
+
+ start = resv->start;
+ end = resv->start + resv->length - 1;
+
+ list_for_each_entry_safe(n, next, iova, list) {
+ int ret = 0;
+
+ /* No overlap */
+ if ((start > n->end) || (end < n->start))
+ continue;
+ /*
+ * Insert a new node if current node overlaps with the
+ * reserve region to exlude that from valid iova range.
+ * Note that, new node is inserted before the current
+ * node and finally the current node is deleted keeping
+ * the list updated and sorted.
+ */
+ if (start > n->start)
+ ret = vfio_iommu_iova_insert(&n->list,
+ n->start, start - 1);
+ if (!ret && end < n->end)
+ ret = vfio_iommu_iova_insert(&n->list,
+ end + 1, n->end);
+ if (ret)
+ return ret;
+
+ list_del(&n->list);
+ kfree(n);
+ }
+ }
+
+ if (list_empty(iova))
+ return -EINVAL;
+
+ return 0;
+}
+
+static void vfio_iommu_resv_free(struct list_head *resv_regions)
+{
+ struct iommu_resv_region *n, *next;
+
+ list_for_each_entry_safe(n, next, resv_regions, list) {
+ list_del(&n->list);
+ kfree(n);
+ }
+}
+
static void vfio_iommu_iova_free(struct list_head *iova)
{
struct vfio_iova *n, *next;
@@ -1366,6 +1442,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
phys_addr_t resv_msi_base;
struct iommu_domain_geometry geo;
LIST_HEAD(iova_copy);
+ LIST_HEAD(group_resv_regions);

mutex_lock(&iommu->lock);

@@ -1444,6 +1521,13 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
goto out_detach;
}

+ iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
+
+ if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
+ ret = -EINVAL;
+ goto out_detach;
+ }
+
/* Get a copy of the current iova list and work on it */
ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
if (ret)
@@ -1454,6 +1538,10 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
if (ret)
goto out_detach;

+ ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
+ if (ret)
+ goto out_detach;
+
resv_msi = vfio_iommu_has_sw_msi(iommu_group, &resv_msi_base);

INIT_LIST_HEAD(&domain->group_list);
@@ -1514,6 +1602,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
/* Delete the old one and insert new iova list */
vfio_iommu_iova_insert_copy(iommu, &iova_copy);
mutex_unlock(&iommu->lock);
+ vfio_iommu_resv_free(&group_resv_regions);

return 0;

@@ -1522,6 +1611,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
out_domain:
iommu_domain_free(domain->domain);
vfio_iommu_iova_free(&iova_copy);
+ vfio_iommu_resv_free(&group_resv_regions);
out_free:
kfree(domain);
kfree(group);
--
2.7.4