> From: Michael S. Tsirkin <[email protected]> > Sent: Sunday, April 16, 2023 4:44 PM > > On Sun, Apr 16, 2023 at 01:41:55PM +0000, Parav Pandit wrote: > > > From: [email protected] > > > <[email protected] open.org> On Behalf Of Michael S. > > > Tsirkin > > > Sent: Friday, April 14, 2023 2:57 AM > > > > > Do you refer to the trick Jason proposed where BAR0 is memory but > > > otherwise matches legacy BAR0 exactly? Is this your preferred solution at > this point then? > > > > We look at it again. > > Above solution can work reliably only for a very small number of PF and that > too with very special hardware circuitry due to the reset flow. > > > > Therefore, for virtualization below interface is preferred. > > a. For transitional device legacy configuration register transport > > over AQ, > > I don't get what this has to do with transitional ... > Typically, in current wordings, transitional is the device that supports legacy interface. So, it doesn't have to be for the transitional.
I just wanted to highlight that a PCI VF device with its parent PCI PF device can transport the legacy interface commands. > > Notification to utilize transitional device notification area of the BAR. > > The vq transport does something like this, no? > Notifications over a queuing interface unlikely can be a performant interface because one is configuration task and other is data path task. > > b. Non legacy interface of transitional and non-transitional PCI device to > access direct PCI device without mediation. > > So VF can either be accessed through AQ of PF, or through direct mapping? Right. VF to access legacy registers using AQ of PF and continue non-legacy registers using direct mapping as done today. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
