Hi Jiyong,
On Thu, Mar 10, 2022 at 05:18:54PM +0900, Jiyong Park wrote:
Filtering non-h2g connections out when determining orphaned connections.
Otherwise, in a nested VM configuration, destroying the nested VM (which
often involves the closing of /dev/vhost-vsock if there was h2g
connections to the nested VM) kills not only the h2g connections, but
also all existing g2h connections to the (outmost) host which are
totally unrelated.
Tested: Executed the following steps on Cuttlefish (Android running on a
VM) [1]: (1) Enter into an `adb shell` session - to have a g2h
connection inside the VM, (2) open and then close /dev/vhost-vsock by
`exec 3< /dev/vhost-vsock && exec 3<&-`, (3) observe that the adb
session is not reset.
[1] https://android.googlesource.com/device/google/cuttlefish/
Signed-off-by: Jiyong Park <jiyong@xxxxxxxxxx>
---
drivers/vhost/vsock.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 37f0b4274113..2f6d5d66f5ed 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -722,6 +722,10 @@ static void vhost_vsock_reset_orphans(struct sock *sk)
* executing.
*/
+ /* Only the h2g connections are reset */
+ if (vsk->transport != &vhost_transport.transport)
+ return;
+
/* If the peer is still valid, no need to reset connection */
if (vhost_vsock_get(vsk->remote_addr.svm_cid))
return;
--
2.35.1.723.g4982287a31-goog
Thanks for your patch!
Yes, I see the problem and I think I introduced it with the
multi-transports support (ooops).
So we should add this fixes tag:
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
IIUC the problem is for all transports that should only cycle on their
own sockets. Indeed I think there is the same problem if the g2h driver
will be unloaded (or a reset event is received after a VM migration), it
will close all sockets of the nested h2g.
So I suggest a more generic solution, modifying
vsock_for_each_connected_socket() like this (not tested):
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 38baeb189d4e..f04abf662ec6 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -334,7 +334,8 @@ void vsock_remove_sock(struct vsock_sock *vsk)
}
EXPORT_SYMBOL_GPL(vsock_remove_sock);
-void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
+void vsock_for_each_connected_socket(struct vsock_transport *transport,
+ void (*fn)(struct sock *sk))
{
int i;
@@ -343,8 +344,12 @@ void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
struct vsock_sock *vsk;
list_for_each_entry(vsk, &vsock_connected_table[i],
- connected_table)
+ connected_table) {
+ if (vsk->transport != transport)
+ continue;
+
fn(sk_vsock(vsk));
+ }
}
And all transports that call it.
Thanks,
Stefano
