Subject: Re: [virtio] [PATCH v2] transitional issues: add new IDs for all devices
"Michael S. Tsirkin" <firstname.lastname@example.org> writes: > On Fri, Sep 13, 2013 at 10:19:45AM +0930, Rusty Russell wrote: >> "Michael S. Tsirkin" <email@example.com> writes: >> > +Non-transitional devices must use the larger of the IDs. >> > +For example use Device ID=0x101 for a network card. >> > + >> > +Both transitional and non-transitional drivers must match all >> > +IDs for a given device type. >> >> The last one doesn't make sense. Non-transitional drivers should only >> care about 0x10x. That would be achieved by not listing the smaller >> numbers outside the Legacy Interface section. >> > > I thought so originally, but this won't work. > Recall that transitional devices have IDs 0x1 0x2 etc. > > We definitely want transitional devices to support > non-transitional drivers so non-transitional drivers must support > IDs 0x101 etc. > > In other words IDs should not be used to distinguish between > legacy and non-legacy devices - we have a feature bit for that. > They are only a means to distinguish between transitional > and non-transitional devices. OK, that needs to be spelled out clearly in the spec, since we both thought the same thing. The eventual spec is supposed to use RFC-2119-style MUST etc. language. This would be a good place to start, IMHO. Cheers, Rusty.