virtio — archive

[Michael S. Tsirkin <david.edmondson@oracle.com>]

On Mon, Feb 13, 2023 at 01:06:32PM +0100, Cornelia Huck wrote: > On Thu, Feb 09 2023, David Edmondson <david.edmondson@oracle.com> wrote: > > > On Thursday, 2023-02-09 at 07:13:32 -05, Michael S. Tsirkin wrote: > >> +In particular, this is > >> +especially important for features limited to specific transports, > >> +as enabling these for more transports in future versions of the > >> +specification is highly likely to require changing the behaviour > >> +from drivers and devices. Drivers and devices supporting > > > > "changing the behaviour of" or "changed behaviour from" (prefer the > > former). > > Agreed, I'd prefer the former as well. > > > > >> +multiple transports need to carefully maintain per-transport > >> +lists of allowed features. > >> + > >> \drivernormative{\subsection}{Feature Bits}{Basic Facilities of a Virtio Device / Feature Bits} > >> The driver MUST NOT accept a feature which the device did not offer, > >> and MUST NOT accept a feature which requires another feature which was > >> not accepted. > >> > >> +The driver MUST validate the feature bits offered by the device. > >> +The driver MUST ignore and MUST NOT accept any feature bit that is > >> +\begin{itemize} > >> +\item not described in this specification, > >> +\item marked as reserved, > >> +\item not supported for the specific transport, > > > > What does "supported" mean here? By the driver? By the specification in > > respect of this transport? > > Maybe "not specified for the specific transport"? given in mmio and ccw sections we say things like +At this time, devices and drivers utilizing Virtio Over MMIO +do not support the following features: I tend to agree. > > > >> +\item not defined for the device type. > >> +\end{itemize}