[PATCH v4 2/3] vhost/vsock: discard IOTLB when ACCESS_PLATFORM is cleared
Jia Jia <[email protected]>
| Newsgroups | org.kernel.vger.kvm,dev.linux.lists.virtualization,org.kernel.vger.linux-kernel,org.kernel.vger.netdev |
|---|---|
| Message-ID | <[email protected]> |
vhost_vsock_set_features() leaves the device IOTLB attached when
userspace clears VIRTIO_F_ACCESS_PLATFORM. Descriptors can therefore
continue to use translations installed before the feature change,
including HVAs made stale by a later memory table update.
Use the common vhost helper to detach the device IOTLB before
acknowledging a feature mask without ACCESS_PLATFORM. The helper clears
each virtqueue's IOTLB pointer and metadata cache under its mutex, then
frees the old IOTLB after all virtqueues have dropped their references.
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 | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 9aaab6bb8061..b69c260eaeff 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -863,7 +863,11 @@ static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&vsock->dev)) {
goto err;
}
+ if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)) &&
+ vsock->dev.iotlb)
+ vhost_clear_device_iotlb(&vsock->dev);
+
if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
if (vhost_init_device_iotlb(&vsock->dev))
goto err;
--
2.34.1