On Tue, Apr 18, 2023 at 12:59 AM Parav Pandit <pa...@nvidia.com> wrote: > > > > From: Michael S. Tsirkin <m...@redhat.com> > > Sent: Sunday, April 16, 2023 4:44 PM > > > > On Sun, Apr 16, 2023 at 01:41:55PM +0000, Parav Pandit wrote: > > > > From: virtio-comm...@lists.oasis-open.org > > > > <virtio-comment@lists.oasis- 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.
Note that current transport virtqueue only allows the notification via MMIO. It introduces a command to get the address of the notification area. Thanks > > > > 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: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
