On Wed, Feb 22, 2023 at 01:07:07PM +0100, Cornelia Huck wrote: > On Wed, Feb 22 2023, "Michael S. Tsirkin" <m...@redhat.com> wrote: > > > On Wed, Feb 22, 2023 at 10:01:24AM +0100, Cornelia Huck wrote: > >> On Tue, Feb 21 2023, "Michael S. Tsirkin" <m...@redhat.com> wrote: > >> > >> > On Tue, Feb 21, 2023 at 05:59:52PM +0000, Parav Pandit wrote: > >> >> > >> >> > From: Michael S. Tsirkin <m...@redhat.com> > >> >> > Sent: Tuesday, February 21, 2023 12:52 PM > >> >> > > >> >> > On Tue, Feb 21, 2023 at 05:50:09PM +0000, Parav Pandit wrote: > >> >> > > Hence, it should be mentioned as read-only fields, so when the > >> >> > > driver writes > >> >> > something to read-only fields, it can be considered as undefined > >> >> > behavior on > >> >> > such fields. > >> >> > > > >> >> > > >> >> > In the description not in the normative statements. normative > >> >> > sections just tell > >> >> > driver what it must and must not do, in the standard RFC terms. > >> >> > > >> >> Got it. > >> >> I will shift them as read-only in the description section. > >> >> And normative in the device and driver section. > >> >> Device section: > >> >> Any writes to config space fields is ignored by the device, because > >> >> these are read-only fields for the driver. > >> > > >> > writes is plural so "are ignored" > >> > > >> > but more importantly use rfc terms in normative sections. > >> > >> I don't think you need to talk about "read-only" in the normative > >> sections (that belongs to the descriptive sections.) I'd use > >> > >> "The device MUST ignore any writes to config space fields by the > >> driver." > > > > Hmm. Is this something we previously required for read only fields? > > So, better make it SHOULD? > > (The only alternative to ignoring I see is breaking the device, and I > think ignoring is preferable.)
We can just skip adding a new requirement completely - we'll never get there with a compliant driver. This is what we do e.g. for MMIO. Why not? This has an advantage as this allows backing config with regular RAM. Also I feel that since it always said "read only for driver" then this implies a restriction on driver not the device. > > > > > >> > > >> >> > >> >> Driver section: > >> >> Driver must not write to read-only fields. > >> > >> "The driver MUST NOT write to any config space field." --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
