[virtio-dev] RE: [PATCH 02/11] transport-pci: Move transitional device id to legacy section

Parav Pandit
2023-03-31T21:24:30Z

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Friday, March 31, 2023 2:44 AM
>
> On Fri, Mar 31, 2023 at 01:58:25AM +0300, Parav Pandit wrote:
> > Currently PCI device discovery details for the transitional device are
> > documented in two different sections.
> >
> > For example, PCI device and vendor ID registers are documented in
> > 'Device Requirements: PCI Device Discovery' section, while PCI
> > revision id is documented in 'Legacy Interfaces: A Note on PCI Device
> > Discovery' section.
> >
> > Transitional devices requirements should be documented in "legacy
> > interfaces" section as clearly mentioned in 'Legacy Interface: A Note
> > on Feature Bits'.
>
> I already commented on this, I disagree.
> Modern drivers must be able
> to completely ignore legacy interface sections, but they do bind to transitional
> device IDs.
> This change breaks this assumption.
>
Legacy interface section holds the detail about transitional devices.
We do not have,
"Legacy only" section.

It doesn't make sense to partial information in legacy and partial in other place.
Modern drivers are not mentioned in the spec terminology section.

Can you please explain, how can modern driver ignore the text " Transitional devices MUST have a PCI Revision ID of 0." written in legacy interface section?