On Thu, Mar 10, 2022 at 10:11:32PM +0900, Jiyong Park wrote: > Hi Michael, > > Thanks for looking into this. > > Would you mind if I ask what you mean by incomplete? Is it because non-updated > modules will still have the issue? Please elaborate. What stefano wrote: 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. looks like this will keep happening even with your patch, though I didn't try. I also don't like how patch 1 adds code that patch 2 removes. Untidy. Let's just squash and have downstreams worry about stable ABI. > > On Thu, Mar 10, 2022 at 10:02 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > > > On Thu, Mar 10, 2022 at 09:54:24PM +0900, Jiyong Park wrote: > > > When iterating over sockets using vsock_for_each_connected_socket, make > > > sure that a transport filters out sockets that don't belong to the > > > transport. > > > > > > There actually was an issue caused by this; 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/ > > > > > > Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") > > > Signed-off-by: Jiyong Park <jiyong@xxxxxxxxxx> > > > --- > > > drivers/vhost/vsock.c | 4 ++++ > > > net/vmw_vsock/virtio_transport.c | 7 +++++++ > > > net/vmw_vsock/vmci_transport.c | 5 +++++ > > > 3 files changed, 16 insertions(+) > > > > > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > > > index 37f0b4274113..853ddac00d5b 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 handle our own sockets */ > > > + 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; > > > > > > We know this is incomplete though. So I think it's the wrong thing to do > > when you backport, too. If all you worry about is breaking a binary > > module interface, how about simply exporting a new function when you > > backport. Thus you will have downstream both: > > > > void vsock_for_each_connected_socket(void (*fn)(struct sock *sk)); > > > > void vsock_for_each_connected_socket_new(struct vsock_transport *transport, > > void (*fn)(struct sock *sk)); > > > > > > and then upstream we can squash these two patches. > > > > Hmm? > > > > > > > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > > > index fb3302fff627..61b24eb31d4b 100644 > > > --- a/net/vmw_vsock/virtio_transport.c > > > +++ b/net/vmw_vsock/virtio_transport.c > > > @@ -24,6 +24,7 @@ > > > static struct workqueue_struct *virtio_vsock_workqueue; > > > static struct virtio_vsock __rcu *the_virtio_vsock; > > > static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */ > > > +static struct virtio_transport virtio_transport; /* forward declaration */ > > > > > > struct virtio_vsock { > > > struct virtio_device *vdev; > > > @@ -357,11 +358,17 @@ static void virtio_vsock_event_fill(struct virtio_vsock *vsock) > > > > > > static void virtio_vsock_reset_sock(struct sock *sk) > > > { > > > + struct vsock_sock *vsk = vsock_sk(sk); > > > + > > > /* vmci_transport.c doesn't take sk_lock here either. At least we're > > > * under vsock_table_lock so the sock cannot disappear while we're > > > * executing. > > > */ > > > > > > + /* Only handle our own sockets */ > > > + if (vsk->transport != &virtio_transport.transport) > > > + return; > > > + > > > sk->sk_state = TCP_CLOSE; > > > sk->sk_err = ECONNRESET; > > > sk_error_report(sk); > > > diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c > > > index 7aef34e32bdf..cd2f01513fae 100644 > > > --- a/net/vmw_vsock/vmci_transport.c > > > +++ b/net/vmw_vsock/vmci_transport.c > > > @@ -803,6 +803,11 @@ static void vmci_transport_handle_detach(struct sock *sk) > > > struct vsock_sock *vsk; > > > > > > vsk = vsock_sk(sk); > > > + > > > + /* Only handle our own sockets */ > > > + if (vsk->transport != &vmci_transport) > > > + return; > > > + > > > if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) { > > > sock_set_flag(sk, SOCK_DONE); > > > > > > -- > > > 2.35.1.723.g4982287a31-goog > >
