Hi Thomas, A basic vHost use case will work, for example a single Virtual Machine with a vHost port. However normal vSwitching use cases will require the use of multiple vHost ports and multiple VMs. With that in mind, it is essential that the vSwitch has some way of knowing which vHost port it is sending to and receiving packets from. This patch resolves this issue by exposing the tap device name of the vHost device. Without that information we cannot determine the particular vHost port to send/receive from, which in the context of switching, is a critical problem.
Thanks, Ciara -----Original Message----- From: Thomas Monjalon [mailto:thomas.monja...@6wind.com] Sent: Thursday, December 18, 2014 3:33 PM To: Loftus, Ciara Cc: dev at dpdk.org; Anthony Fee Subject: Re: [dpdk-dev] [PATCH] vhost: add interface name to virtio-net struct 2014-12-18 14:55, ciara.loftus at intel.com: > This patch fixes the issue whereby when using userspace vhost ports in > the context of vSwitching, the name provided to the hypervisor/QEMU of > the vhost tap device needs to be exposed in the library, in order for > the vSwitch to be able to direct packets to the correct device. Do you mean that vhost was not working at all? Please precise the context and how it is critical. More informations are needed to understand wether it should be merged in release 1.8.0 or not. > --- a/lib/librte_vhost/rte_virtio_net.h > +++ b/lib/librte_vhost/rte_virtio_net.h > @@ -96,6 +96,7 @@ struct virtio_net { > uint64_t features; /**< Negotiated feature set. */ > uint64_t device_fh; /**< device identifier. */ > uint32_t flags; /**< Device flags. Only used to > check if device is running on data core. */ > + char ifname[32]; /** Name of the tap device **/ Wrong comment style. -- Thomas -------------------------------------------------------------- Intel Shannon Limited Registered in Ireland Registered Office: Collinstown Industrial Park, Leixlip, County Kildare Registered Number: 308263 Business address: Dromore House, East Park, Shannon, Co. Clare This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.
