Devices with on-chip IOMMU may need to restore iotlb to 1:1 identity
mapping from IOVA to PA. Before vhost-vdpa is going away, give them
a chance to clean up and reset iotlb back to 1:1 identify mapping
mode. This is done so that any vdpa bus driver may start with 1:1
identity mapping by default.
Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
---
drivers/vhost/vdpa.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index eabac06..71fbd559 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -131,6 +131,15 @@ static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(struct vhost_vdpa *v,
return vhost_vdpa_alloc_as(v, asid);
}
+static void vhost_vdpa_reset_map(struct vhost_vdpa *v, u32 asid)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ if (ops->reset_map)
+ ops->reset_map(vdpa, asid);
+}
+
static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
{
struct vhost_vdpa_as *as = asid_to_as(v, asid);
@@ -140,6 +149,14 @@ static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
hlist_del(&as->hash_link);
vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1, asid);
+ /*
+ * Devices with on-chip IOMMU need to restore iotlb
+ * to 1:1 identity mapping before vhost-vdpa is going
+ * to be removed and detached from the device. Give
+ * them a chance to do so, as this cannot be done
+ * efficiently via the whole-range unmap call above.
+ */
+ vhost_vdpa_reset_map(v, asid);
kfree(as);
return 0;
--
1.8.3.1
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