Re: [dpdk-dev] [PATCH] vhost: fix ANY_LAYOUT declaration

[Thomas Monjalon <thomas@monjalon.net>]

Hi,

There is a compilation error on Ubuntu 12.04 / kernel 3.8.
VIRTIO_F_ANY_LAYOUT is undeclared.


26/01/2018 14:04, Yuanhan Liu:
> On Sat, Jan 20, 2018 at 01:54:52AM +0800, Tan, Jianfeng wrote:
> > 
> > 
> > On 1/19/2018 10:42 PM, Yuanhan Liu wrote:
> > >On Fri, Jan 19, 2018 at 02:02:50PM -0500, Zhihong Wang wrote:
> > >>The VIRTIO_F_ANY_LAYOUT feature indicates the device accepts arbitrary
> > >>descriptor layouts. The vhost-user lib already supports it, but the
> > >>feature declaration is missing. This patch fixes the mismatch.
> > >I remembered there was a long discussion one year ago, that we can't
> > >blindly set this feature, as this flag is reserved (thus should not
> > >be set) for virtio 1.0.
> > 
> > We might need to read that old thread again. But as you said, this flag is
> > reserved for 1.0, but not used for other purpose yet. So that the feature is
> > negotiated does not affect anything, no?
> > 
> > >
> > >We should set it when v1.0 is not enabled.
> > 
> > But in fact, vhost kernel reports supported feature bits consisting of
> > ANY_LAYOUT and VERSION_1.
> 
> Yes, I was aware of that, and that was also one my points before.
> 
> I now also release that it's a must from migration from vhost-net to
> vhost-user. Thus, I'd like to merge it this time. So
> 
> Applied to dpdk-next-virtio.