On Thu, Jul 06, 2023 at 07:07:42PM +0000, Parav Pandit wrote: > > From: virtio-comm...@lists.oasis-open.org <virtio-comment@lists.oasis- > > open.org> On Behalf Of Michael S. Tsirkin > > Sent: Thursday, July 6, 2023 3:01 PM > > > > +\begin{lstlisting} > > > +struct virtio_pci_legacy_notify_region { > > > + u8 owner; /* When set to 1, notification region is of the > > > +owner device */ > > > > I propose we rename this to flags: > > 0x0 - end of list (driver should ignore following values until end of > > list) > > 0x1 - owner > > 0x2 - member > > other values - reserved > > > > > and prescribe that driver ignores any reserved values. > > > > basically we are following how the virtio capabilities work. > > > Looks good. Will change it. > > > > +The group owner device hardwires VF BAR0 to zero in the SR-IOV > > > +Extended capability. > > > + > > > +The group member device does not use PCI BAR0 in all the Virtio PCI > > > +capabilities listed in section \ref{sec:Virtio Transport Options / > > > Virtio Over > > PCI Bus / Virtio Structure PCI Capabilities}. > > > > Just drop this last one. How can they use it if there's no VF BAR0? > > > Hardwaring BAR0 is in BAR area of the VF. > But virtio pci capabilities without this can still report bar 0 and virtio > capabilities.
How do they do this? > Ofcourse, it is a broken device. > But skipping this line imply that "because VF BAR0 is hardwired", this > metadata in pci capability must not expose it. > > Why not write it extra thing instead of implying it? > We already wrote few duplicate things to make reader life easier. If you really want to go ahead, but prefix it with "In consequence" and do not start a new paragraph, so reader knows it's not an extra requirement. So I started writing it using correct grammar and spec terminology: In consequence, non of the group member devices has BAR0, and in particular none of the virtio structure capabilities of a member device has \field{bar} with the value of 0. However, this actually is kind of wrong (and so is your text). Not all caps have a RO bar value. virtio_pci_cfg_cap has bar that is RW by driver. So if we are going this route we also need to explain that it's true for all caps except virtio_pci_cfg_cap. And for virtio_pci_cfg_cap driver is not allowed to write 0 there. Frankly too much trouble but if you want to, keep trying. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org