From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: AF_VSOCK loopback Date: Thu, 10 Nov 2016 14:43:29 +0000 Message-ID: <20161110144329.GA19683@stefanha-x1.localdomain> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="u3/rZRmxL6MmkK24" Cc: cavery@redhat.com, netdev@vger.kernel.org To: Jorgen Hansen Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46110 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933541AbcKJOnb (ORCPT ); Thu, 10 Nov 2016 09:43:31 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: --u3/rZRmxL6MmkK24 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Jorgen, Cathy Avery found that the AF_VSOCK VMCI transport does loopback inside the guest (but not on the host?). The virtio transport currently does no loopback. The loopback scenario I'm thinking of is where process A listens on port 1234 and process B on the same machine connects to port 1234 both with the same CID. I'd like to make the virtio transport compatible with VMCI transport semantics so AF_VSOCK behaves the same regardless of the transport. This means loopback must be added to virtio-vsock. The core net/vmware/af_vsock.c code does not implement loopback. How does VMCI do loopback? Are the loopback packets reflected back from the host? Or does the guest driver notice the loopback and avoid passing packets to the host in the first place? Maybe we can make the loopback code common in af_vsock.c if that avoids code duplication. Thanks, Stefan --u3/rZRmxL6MmkK24 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJYJIeRAAoJEJykq7OBq3PInSAH/ivngCLpPeZLcw4YVOVSx2Gd kaWc2Y+4rc5qXW5SW6HNlMqY7KT/YU3CDTw7O+3efc3zh+edv3oHamlmLMF0FjzP DLatzVyrCpUuRaSgPH5gpLE4eVT9LTzII36tGVEkVNNqVP6+nz6h7NeF5vU+SUa+ 0BgqXJOWAWwnEilnLXt/jdmXgU4znAP5ThxGY7dO74FrEupzoSYhk7MVss1k9SpX EA+q11TIzt6XrcuywdXO9zAy3MGw6/QgeMEn3WFVmtHK9P4C329VHG4631Gt5KB6 xmWIdU4aCK+YC+wGSSnUTyhVLqxLCla6ccvqJnX9fEJ0NDZQC1pAwDJqr2Asu6c= =szN2 -----END PGP SIGNATURE----- --u3/rZRmxL6MmkK24--