This way the tree can store/map a completely new virtual address space,
in the range the device admits.
It does not limit the range it will allocate, but the IOVA address of
the maps are allocated growing. A range limitation will be need for the
cases where start_addr != 0.
Tools for remove mappings will be needed also.
Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
hw/virtio/vhost-iova-tree.h | 11 +++---
hw/virtio/vhost-iova-tree.c | 72 +++++++++++++++++++++++++++++++------
2 files changed, 69 insertions(+), 14 deletions(-)
diff --git a/hw/virtio/vhost-iova-tree.h b/hw/virtio/vhost-iova-tree.h
index 589e86bd91..92e2d992b3 100644
--- a/hw/virtio/vhost-iova-tree.h
+++ b/hw/virtio/vhost-iova-tree.h
@@ -22,16 +22,17 @@ typedef struct VhostDMAMap {
} VhostDMAMap;
typedef enum VhostDMAMapNewRC {
+ VHOST_DMA_MAP_NO_SPACE = -3,
VHOST_DMA_MAP_OVERLAP = -2,
VHOST_DMA_MAP_INVALID = -1,
VHOST_DMA_MAP_OK = 0,
} VhostDMAMapNewRC;
/**
- * VhostIOVATree
- *
- * Store and search IOVA -> Translated mappings and the reverse, from
- * translated address to IOVA.
+ * VhostIOVATree, able to:
+ * - Translate iova address
+ * - Reverse translate iova address (from translated to iova)
+ * - Allocate IOVA regions for translated range (potentially slow operation)
*
* Note that it cannot remove nodes.
*/
@@ -54,5 +55,7 @@ const VhostDMAMap *vhost_iova_tree_find_taddr(const
VhostIOVATree *iova_rm,
const VhostDMAMap *map);
VhostDMAMapNewRC vhost_iova_tree_insert(VhostIOVATree *iova_rm,
VhostDMAMap *map);
+VhostDMAMapNewRC vhost_iova_tree_alloc(VhostIOVATree *iova_rm,
+ VhostDMAMap *map);
#endif
diff --git a/hw/virtio/vhost-iova-tree.c b/hw/virtio/vhost-iova-tree.c
index 2900390a1e..7699d96bbb 100644
--- a/hw/virtio/vhost-iova-tree.c
+++ b/hw/virtio/vhost-iova-tree.c
@@ -187,8 +187,30 @@ const VhostDMAMap *vhost_iova_tree_find_taddr(const
VhostIOVATree *tree,
vhost_iova_tree_cmp_iova);
}
+static bool vhost_iova_tree_find_iova_hole(const GArray *iova_map,
+ const VhostDMAMap *map,
+ const VhostDMAMap **prev_elem)
+{
+ size_t i;
+ hwaddr iova = 0;
+
+ *prev_elem = NULL;
+ for (i = 0; i < iova_map->len; i++) {
+ const VhostDMAMap *next = &g_array_index(iova_map, typeof(*next), i);
+ hwaddr hole_end = next->iova;
+ if (map->size < hole_end - iova) {
+ return true;
+ }
+
+ iova = next->iova + next->size + 1;
+ *prev_elem = next;
+ }
+
+ return ((hwaddr)-1 - iova) > iova_map->len;
+}
+
/**
- * Insert a new map
+ * Insert a new map - internal
*
* @tree The iova tree
* @map The iova map
@@ -197,10 +219,13 @@ const VhostDMAMap *vhost_iova_tree_find_taddr(const
VhostIOVATree *tree,
* - VHOST_DMA_MAP_OK if the map fits in the container
* - VHOST_DMA_MAP_INVALID if the map does not make sense (like size overflow)
* - VHOST_DMA_MAP_OVERLAP if the tree already contains that map
- * Can query the assignated iova in map.
+ * - VHOST_DMA_MAP_NO_SPACE if iova_rm cannot allocate more space.
+ *
+ * It returns assignated iova in map->iova if return value is VHOST_DMA_MAP_OK.
*/
-VhostDMAMapNewRC vhost_iova_tree_insert(VhostIOVATree *tree,
- VhostDMAMap *map)
+static VhostDMAMapNewRC vhost_iova_tree_insert_int(VhostIOVATree *tree,
+ VhostDMAMap *map,
+ bool allocate)
{
const VhostDMAMap *qemu_prev, *iova_prev;
int find_prev_rc;
@@ -210,12 +235,27 @@ VhostDMAMapNewRC vhost_iova_tree_insert(VhostIOVATree
*tree,
return VHOST_DMA_MAP_INVALID;
}
- /* Check for duplicates, and save position for insertion */
- find_prev_rc = vhost_iova_tree_find_prev(tree->iova_taddr_map,
- vhost_iova_tree_cmp_iova, map,
- &iova_prev);
- if (find_prev_rc == VHOST_DMA_MAP_OVERLAP) {
- return VHOST_DMA_MAP_OVERLAP;
+ if (allocate) {
+ /* Search for a hole in iova space big enough */
+ bool fit = vhost_iova_tree_find_iova_hole(tree->iova_taddr_map, map,
+ &iova_prev);
+ if (!fit) {
+ return VHOST_DMA_MAP_NO_SPACE;
+ }
+
+ map->iova = iova_prev ? (iova_prev->iova + iova_prev->size) + 1 : 0;
+ } else {
+ if (map->iova + map->size < map->iova) {
+ return VHOST_DMA_MAP_INVALID;
+ }
+
+ /* Check for duplicates, and save position for insertion */
+ find_prev_rc = vhost_iova_tree_find_prev(tree->iova_taddr_map,
+ vhost_iova_tree_cmp_iova, map,
+ &iova_prev);
+ if (find_prev_rc == VHOST_DMA_MAP_OVERLAP) {
+ return VHOST_DMA_MAP_OVERLAP;
+ }
}
find_prev_rc = vhost_iova_tree_find_prev(tree->taddr_iova_map,
@@ -229,3 +269,15 @@ VhostDMAMapNewRC vhost_iova_tree_insert(VhostIOVATree
*tree,
vhost_iova_tree_insert_after(tree->taddr_iova_map, qemu_prev, map);
return VHOST_DMA_MAP_OK;
}
+
+VhostDMAMapNewRC vhost_iova_tree_insert(VhostIOVATree *tree,
+ VhostDMAMap *map)
+{
+ return vhost_iova_tree_insert_int(tree, map, false);
+}
+
+VhostDMAMapNewRC vhost_iova_tree_alloc(VhostIOVATree *tree,
+ VhostDMAMap *map)
+{
+ return vhost_iova_tree_insert_int(tree, map, true);
+}
--
2.27.0
