Clear the device IOTLB when userspace clears VIRTIO_F_ACCESS_PLATFORM.
Otherwise descriptor translation can continue to use mappings installed
before the feature change.
The common helper invalidates cached vring access and applies the
transition even while a backend is attached. The backend remains attached,
but userspace must configure the vring addresses for the new address mode
after a successful live transition.
Fixes: e13a6915a03f ("vhost/vsock: add IOTLB API support")
Suggested-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Jia Jia <[email protected]>
---
drivers/vhost/vsock.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 9aaab6bb8061..77a5a6775c86 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -854,6 +854,7 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock,
u64 guest_cid)
static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
{
struct vhost_virtqueue *vq;
+ int ret = -EFAULT;
int i;
if (features & ~VHOST_VSOCK_FEATURES)
@@ -865,9 +866,12 @@ static int vhost_vsock_set_features(struct vhost_vsock
*vsock, u64 features)
goto err;
}
- if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
- if (vhost_init_device_iotlb(&vsock->dev))
+ if (features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)) {
+ ret = vhost_init_device_iotlb(&vsock->dev);
+ if (ret)
goto err;
+ } else {
+ vhost_clear_device_iotlb(&vsock->dev);
}
vsock->seqpacket_allow = features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET);
@@ -883,7 +887,7 @@ static int vhost_vsock_set_features(struct vhost_vsock
*vsock, u64 features)
err:
mutex_unlock(&vsock->dev.mutex);
- return -EFAULT;
+ return ret;
}
static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
