RE: [PATCH v3 6/8] admin: Add theory of operation for write recording commands

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Wednesday, November 8, 2023 1:47 PM

> Only for TX, and I'm pretty sure they had the foresight to test RX not just TX but
> let's confirm. Parav did you test both directions?
Rx is the main part to test for the dirty page tracking.
Tx only is around ring updates, so not very interesting test.

When page tracking is started, there is impact on Rx as natural throttle by slowing down rx packet rate.
And devices have implementation choice to covering the spectrum on amount of drop rate.
And has implementations evolve, it will improve as well.

PRI for sure is out of question. Most workload won't use it at all given other limitations of virtio on PCI front and existing PRI behaviors.

There is also a test with platform IOMMU dirty page tracking done as well but it is very early stage to comment in this forum.