Re: [virtio] [PATCH] pci: strengthen requirement of the correct subsystem id

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 25 Nov 2019 03:22:13 -0500
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Mon, Nov 25, 2019 at 07:41:09AM +0100, Jan Kiszka wrote:
> > On 28.10.19 17:12, Michael S. Tsirkin wrote:  
> > > If a hardware implementation of virtio does not have
> > > the correct subsystem id, then drivers can't report
> > > ir properly, or detect and work around bugs.  
> > 
> > s/ir/it.
> > 
> > Jan
> >   
> > > Change the requirement from MAY to SHOULD.
> > > 
> > > We can't make it a MUST since we did not require this
> > > historically.
> > > 
> > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>  
> 
> 
> One thing I noticed is that for transitional devices, windows drivers
> bind to a specific vendor id. I guess we need to make this
> SHOULD for non-transitional only?

So, they have different binding behaviour for transitional vs
non-transitional devices? Or transitional vs non-transitional drivers?

> 
> 
> > > ---
> > >   content.tex | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/content.tex b/content.tex
> > > index 4bcb728..8f1518c 100644
> > > --- a/content.tex
> > > +++ b/content.tex
> > > @@ -562,7 +562,7 @@ \subsection{PCI Device Discovery}\label{sec:Virtio Transport Options / Virtio Ov
> > >   For example, the network card device with the Virtio Device ID 1
> > >   has the PCI Device ID 0x1041 or the Transitional PCI Device ID 0x1000.
> > > -The PCI Subsystem Vendor ID and the PCI Subsystem Device ID MAY reflect
> > > +The PCI Subsystem Vendor ID and the PCI Subsystem Device ID SHOULD reflect
> > >   the PCI Vendor and Device ID of the environment (for informational purposes by the driver).
> > >   Non-transitional devices SHOULD have a PCI Device ID in the range