Apply the common device IOTLB teardown when userspace clears
VIRTIO_F_ACCESS_PLATFORM. This drops stale translations and avoids
rebuilding an existing IOTLB during feature updates that keep
ACCESS_PLATFORM enabled.
The transition invalidates cached vring access even with an attached
backend. The backend remains attached, but userspace must configure the
vring addresses for the new address mode after a successful live
transition.
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Link:
https://lore.kernel.org/all/[email protected]/
Signed-off-by: Jia Jia <[email protected]>
---
drivers/vhost/net.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 77b59f49bddb..64671cf77a35 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1673,6 +1673,7 @@ static long vhost_net_reset_owner(struct vhost_net *n)
static int vhost_net_set_features(struct vhost_net *n, const u64 *features)
{
size_t vhost_hlen, sock_hlen, hdr_len;
+ int ret = -EFAULT;
int i;
hdr_len = virtio_features_test_bit(features, VIRTIO_NET_F_MRG_RXBUF) ||
@@ -1701,8 +1702,11 @@ static int vhost_net_set_features(struct vhost_net *n,
const u64 *features)
goto out_unlock;
if (virtio_features_test_bit(features, VIRTIO_F_ACCESS_PLATFORM)) {
- if (vhost_init_device_iotlb(&n->dev))
+ ret = vhost_init_device_iotlb(&n->dev);
+ if (ret)
goto out_unlock;
+ } else {
+ vhost_clear_device_iotlb(&n->dev);
}
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
@@ -1718,7 +1722,7 @@ static int vhost_net_set_features(struct vhost_net *n,
const u64 *features)
out_unlock:
mutex_unlock(&n->dev.mutex);
- return -EFAULT;
+ return ret;
}
static long vhost_net_set_owner(struct vhost_net *n)
