Re: [PATCH net-next v1 2/3] virtio_transport_common: Set sibling VMs flag on the receive path
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2020-12-01 16:23:54
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On Tue, Dec 01, 2020 at 05:25:04PM +0200, Andra Paraschiv wrote:
quoted hunk ↗ jump to hunk
The vsock flag can be set during the connect() setup logic, when initializing the vsock address data structure variable. Then the vsock transport is assigned, also considering this flag. The vsock transport is also assigned on the (listen) receive path. The flag needs to be set considering the use case. Set the vsock flag of the remote address to the one targeted for sibling VMs communication if the following conditions are met: * The source CID of the packet is higher than VMADDR_CID_HOST. * The destination CID of the packet is higher than VMADDR_CID_HOST. Signed-off-by: Andra Paraschiv <redacted> --- net/vmw_vsock/virtio_transport_common.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 5956939eebb78..871c84e0916b1 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c@@ -1062,6 +1062,14 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid), le32_to_cpu(pkt->hdr.src_port));
Maybe is better to create an helper function that other transports can use for the same purpose or we can put this code in the vsock_assign_transport() and set this flag only when the 'psk' argument is not NULL (this is the case when it's called by the transports when we receive a new connection request and 'psk' is the listener socket). The second way should allow us to support all the transports without touching them.
+ /* If the packet is coming with the source and destination CIDs higher + * than VMADDR_CID_HOST, then a vsock channel should be established for + * sibling VMs communication. + */ + if (vchild->local_addr.svm_cid > VMADDR_CID_HOST && + vchild->remote_addr.svm_cid > VMADDR_CID_HOST) + vchild->remote_addr.svm_flag = VMADDR_FLAG_SIBLING_VMS_COMMUNICATION;
svm_flag is always initialized to 0 in vsock_addr_init(), so this assignment is the first one and it's okay, but to avoid future issues I'd use |= here to set the flag. Thanks, Stefano
+ ret = vsock_assign_transport(vchild, vsk); /* Transport assigned (looking at remote_addr) must be the same * where we received the request. -- 2.20.1 (Apple Git-117) Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.