Re: [dpdk-dev] [PATCH 0/6] vhost: add vhost-user client mode and reconnect ability

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Tue, May 10, 2016 at 03:23:15AM +0000, Xu, Qian Q wrote:
> Do we need patch qemu for the reconnect case?  

Yes, we need some support from QEMU: currently QEMU will not be able
to detect disconnection and hence will not establish the connection
when DPDK vhost restarts.

Following patchset from Marc resolves above issue.

    http://lists.nongnu.org/archive/html/qemu-devel/2016-05/msg01507.html

And note that unlike the vhost-user multiple queue support that depends
on some new vhost-uesr message from QEMU, this patchset does not depond
on QEMU.

	--yliu
> 
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yuanhan Liu
> Sent: Saturday, May 07, 2016 2:40 PM
> To: dev@dpdk.org
> Cc: Xie, Huawei; Yuanhan Liu
> Subject: [dpdk-dev] [PATCH 0/6] vhost: add vhost-user client mode and reconnect ability
> 
> Both the vhost-user backend (DPDK here) and frontend (QEMU) could be server, as well as client. DPDK just acts as server so far. This patch set would make it possible to act as both.
> 
> A new arg (flags) is introduced for API rte_vhost_driver_register(). And the client mode is enabled when RTE_VHOST_USER_CLIENT is given. Note that this implies an API breakage. However, since this release deals with ABI/API refactoring, it should not be an issue.
> 
> With the DPDK as client, it's easier to implement the "reconnect" ability, which means we could still make vhost-user work after DPDK restarts.
> 
> 
> ---
> Yuanhan Liu (6):
>   vhost: rename structs for enabling client mode
>   vhost: add vhost-user client mode
>   vhost: add reconnect ability
>   vhost: workaround stale vring base
>   examples/vhost: add client and reconnect option
>   vhost: add pmd client and reconnect option
> 
>  drivers/net/vhost/rte_eth_vhost.c            |  54 +++-
>  examples/vhost/main.c                        |  23 +-
>  lib/librte_vhost/rte_virtio_net.h            |  12 +-
>  lib/librte_vhost/vhost_user/vhost-net-user.c | 355 ++++++++++++++++++---------
>  lib/librte_vhost/vhost_user/vhost-net-user.h |   6 -
>  lib/librte_vhost/virtio-net.c                |   8 +
>  6 files changed, 313 insertions(+), 145 deletions(-)
> 
> --
> 1.9.0