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

["Michael S. Tsirkin" <mst@redhat.com>]

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?


> > ---
> >   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
> > 
> 
> -- 
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