[virtio-dev] RE: [virtio-comment] Re: [PATCH 10/11] transport-pci: Use driver notification PCI capability

Parav Pandit
2023-04-12T05:06:14Z

> From: virtio-comment@lists.oasis-open.org <virtio-comment@lists.oasis-
> open.org> On Behalf Of Michael S. Tsirkin

> > On that occurrence, hypervisor driver forwards the q notification using the q
> notification region which is defined by struct virtio_pci_notify_cap.
>
> What is wrong with forwarding it on the legacy window?
Legacy window is configuration registers.
One has sandwitched q notification register in middle of all the config registers.
Such registers do not start the VQ data path engines.
1.x spec has done the right thing to have dedicated notification region which something an actual pci hw can implement.