lkml.org 
[lkml]   [2023]   [Oct]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 2/7] vhost-vdpa: reset vendor specific mapping to initial state in .release
Date
Devices with on-chip IOMMU or vendor specific IOTLB implementation may
need to restore iotlb mapping to the initial or default state using the
.reset_map op, as it's desirable for some parent devices to not work
with DMA ops and maintain a simple IOMMU model with .reset_map. In
particular, device reset should not cause mapping to go away on such
IOTLB model, so persistent mapping is implied across reset. Before the
userspace process using vhost-vdpa is gone, give it a chance to reset
iotlb back to the initial state in vhost_vdpa_cleanup().

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/vdpa.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 851535f57b95..c6bfe9bdde42 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 vendor specific IOMMU may need to restore
+ * iotlb to the initial or default state, which cannot be
+ * cleaned up in the all range unmap call above. Give them
+ * a chance to clean up or reset the map to the desired
+ * state.
+ */
+ vhost_vdpa_reset_map(v, asid);
kfree(as);

return 0;
--
2.39.3
\
 
 \ /
  Last update: 2023-10-21 11:29    [W:1.264 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site