virtio — archive

[PATCH] pci: use revision id 1 or higher for non transitional devices

From: Rusty Russell <[email protected]>
To: [email protected]
Date: Tue, 05 Nov 2013 07:07:00 -0000

"Michael S. Tsirkin" <[email protected]> writes: > VIRTIO-34 > > Signed-off-by: Michael S. Tsirkin <[email protected]> > --- > virtio-v1.0-wd01-part1-specification.txt 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt > index 6ab4ff8..b3f7c9e 100644 > --- a/virtio-v1.0-wd01-part1-specification.txt > +++ b/virtio-v1.0-wd01-part1-specification.txt > @@ -802,10 +802,18 @@ supported by the device. The Subsystem Vendor ID should reflect > the PCI Vendor ID of the environment (it's currently only used > for informational purposes by the guest). > > +All Drivers must match devices with any Revision ID, this > +is to allow devices to be versioned without breaking drivers. > + > 2.3.1.1.1 Legacy Interfaces: A Note on PCI Device Discovery > ------------------------- > -Transitional devices must also have a Revision ID of 0 to match > -this specification. > +Transitional devices must have a Revision ID of 0 to match > +legacy drivers. > + > +Non-transitional devices must have a Revision ID of 1 or higher. > + > +Both transitional and non-transitional drivers must match > +any Revision ID value. Hmm, so a non-transitional driver should match revision ID 0? Sure, it'll fail gracefully when it doesn't find the capability, but it's a bit weird. Cheers, Rusty.