| Message ID | 20191119110121.14480-6-sgarzare@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vsock: add local transport support | expand |
On Tue, Nov 19, 2019 at 12:01:20PM +0100, Stefano Garzarella wrote: > @@ -420,9 +436,10 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) > new_transport = transport_dgram; > break; > case SOCK_STREAM: > - if (remote_cid <= VMADDR_CID_HOST || > - (transport_g2h && > - remote_cid == transport_g2h->get_local_cid())) > + if (vsock_use_local_transport(remote_cid)) > + new_transport = transport_local; > + else if (remote_cid == VMADDR_CID_HOST || > + remote_cid == VMADDR_CID_HYPERVISOR) > new_transport = transport_g2h; > else > new_transport = transport_h2g; We used to send VMADDR_CID_RESERVED to the host. Now we send VMADDR_CID_RESERVED (LOCAL) to the guest when there is no transport_local loaded? If this is correct, is there a justification for this change? It seems safest to retain existing behavior.
On Thu, Nov 21, 2019 at 09:46:14AM +0000, Stefan Hajnoczi wrote: > On Tue, Nov 19, 2019 at 12:01:20PM +0100, Stefano Garzarella wrote: > > @@ -420,9 +436,10 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) > > new_transport = transport_dgram; > > break; > > case SOCK_STREAM: > > - if (remote_cid <= VMADDR_CID_HOST || > > - (transport_g2h && > > - remote_cid == transport_g2h->get_local_cid())) > > + if (vsock_use_local_transport(remote_cid)) > > + new_transport = transport_local; > > + else if (remote_cid == VMADDR_CID_HOST || > > + remote_cid == VMADDR_CID_HYPERVISOR) > > new_transport = transport_g2h; > > else > > new_transport = transport_h2g; > > We used to send VMADDR_CID_RESERVED to the host. Now we send > VMADDR_CID_RESERVED (LOCAL) to the guest when there is no > transport_local loaded? > > If this is correct, is there a justification for this change? It seems > safest to retain existing behavior. You're right, I'll revert this change in v2. Thanks, Stefano
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index c9e5bad59dc1..40bbb2a17e3d 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -388,6 +388,21 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected) } EXPORT_SYMBOL_GPL(vsock_enqueue_accept); +static bool vsock_use_local_transport(unsigned int remote_cid) +{ + if (!transport_local) + return false; + + if (remote_cid == VMADDR_CID_LOCAL) + return true; + + if (transport_g2h) { + return remote_cid == transport_g2h->get_local_cid(); + } else { + return remote_cid == VMADDR_CID_HOST; + } +} + static void vsock_deassign_transport(struct vsock_sock *vsk) { if (!vsk->transport) @@ -404,9 +419,10 @@ static void vsock_deassign_transport(struct vsock_sock *vsk) * (e.g. during the connect() or when a connection request on a listener * socket is received). * The vsk->remote_addr is used to decide which transport to use: - * - remote CID <= VMADDR_CID_HOST will use guest->host transport; - * - remote CID == local_cid (guest->host transport) will use guest->host - * transport for loopback (host->guest transports don't support loopback); + * - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if + * g2h is not loaded, will use local transport; + * - remote CID == VMADDR_CID_HOST or VMADDR_CID_HYPERVISOR, will use + * guest->host transport; * - remote CID > VMADDR_CID_HOST will use host->guest transport; */ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) @@ -420,9 +436,10 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) new_transport = transport_dgram; break; case SOCK_STREAM: - if (remote_cid <= VMADDR_CID_HOST || - (transport_g2h && - remote_cid == transport_g2h->get_local_cid())) + if (vsock_use_local_transport(remote_cid)) + new_transport = transport_local; + else if (remote_cid == VMADDR_CID_HOST || + remote_cid == VMADDR_CID_HYPERVISOR) new_transport = transport_g2h; else new_transport = transport_h2g; @@ -459,6 +476,9 @@ bool vsock_find_cid(unsigned int cid) if (transport_h2g && cid == VMADDR_CID_HOST) return true; + if (transport_local && cid == VMADDR_CID_LOCAL) + return true; + return false; } EXPORT_SYMBOL_GPL(vsock_find_cid);
Now that we have a transport that can handle the local communication, we can use it when it is loaded. A socket will use the local transport (loopback) when the remote CID is: - equal to VMADDR_CID_LOCAL - or equal to transport_g2h->get_local_cid(), if transport_g2h is loaded (this allows us to keep the same behavior implemented by virtio and vmci transports) - or equal to VMADDR_CID_HOST, if transport_g2h is not loaded Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> --- net/vmw_vsock/af_vsock.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-)