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[0/2] vhost-user: Back SET/GET_CONFIG with a protocol feature

Message ID 20180328155657.6434-1-maxime.coquelin@redhat.com
Headers show
Series vhost-user: Back SET/GET_CONFIG with a protocol feature | expand

Message

Maxime Coquelin March 28, 2018, 3:56 p.m. UTC 
Hi,

While reviewing DPDK series adding support to VHOST_USER_SET_CONFIG
and VHOST_USER_GET_CONFIG request, I found that it was not backed
with a dedicated protocol feature.

This series addresses this by adding a new protocol feature bit,
and by only negotiating it if the device supports it, as suggested
by Michael. Indeed, if the feature is supported by other type of
devices in the future, it would confuse the backends as it couldn't
know whether the device really support it or not.

To know whether the vhost device support config feature, the trick
is to check whether it implemented the config_ops. That's the 
reason why the first patch moves setting the config ops in
vhost-user-blk befoire calling vhost_user_init().

The series targets v2.12 release, else we may have to disable these
requests in this release.

*NOTE*: The series has only been tested as I don't have the
environment to try it. Changpeng, can you please test it?

Thanks,
Maxime

Maxime Coquelin (2):
  vhost-user-blk: set config ops before vhost-user init
  vhost-user: back SET/GET_CONFIG requests with a protocol feature

 docs/interop/vhost-user.txt | 21 ++++++++++++---------
 hw/block/vhost-user-blk.c   |  4 ++--
 hw/virtio/vhost-user.c      | 17 +++++++++++++++++
 3 files changed, 31 insertions(+), 11 deletions(-)

Comments

Maxime Coquelin March 28, 2018, 3:58 p.m. UTC | #1 
On 03/28/2018 05:56 PM, Maxime Coquelin wrote:
> Hi,
> 
> While reviewing DPDK series adding support to VHOST_USER_SET_CONFIG
> and VHOST_USER_GET_CONFIG request, I found that it was not backed
> with a dedicated protocol feature.
> 
> This series addresses this by adding a new protocol feature bit,
> and by only negotiating it if the device supports it, as suggested
> by Michael. Indeed, if the feature is supported by other type of
> devices in the future, it would confuse the backends as it couldn't
> know whether the device really support it or not.
> 
> To know whether the vhost device support config feature, the trick
> is to check whether it implemented the config_ops. That's the
> reason why the first patch moves setting the config ops in
> vhost-user-blk befoire calling vhost_user_init().
> 
> The series targets v2.12 release, else we may have to disable these
> requests in this release.
> 
> *NOTE*: The series has only been tested as I don't have the

s/tested/build tested/

> environment to try it. Changpeng, can you please test it?
> 
> Thanks,
> Maxime
> 
> Maxime Coquelin (2):
>    vhost-user-blk: set config ops before vhost-user init
>    vhost-user: back SET/GET_CONFIG requests with a protocol feature
> 
>   docs/interop/vhost-user.txt | 21 ++++++++++++---------
>   hw/block/vhost-user-blk.c   |  4 ++--
>   hw/virtio/vhost-user.c      | 17 +++++++++++++++++
>   3 files changed, 31 insertions(+), 11 deletions(-)
>