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: Thursday, November 16, 2023 1:06 PM
> 
> On Thu, Nov 16, 2023 at 12:51:40AM -0500, Michael S. Tsirkin wrote:
> > On Thu, Nov 16, 2023 at 05:29:54AM +0000, Parav Pandit wrote:
> > > We should expose a limit of the device in the proposed
> WRITE_RECORD_CAP_QUERY command, that how much range it can track.
> > > So that future provisioning framework can use it.
> > >
> > > I will cover this in v5 early next week.
> >
> > I do worry about how this can even work though. If you want a generic
> > device you do not get to dictate how much memory VM has.
> >
> > Aren't we talking bit per page? With 1TByte of memory to track ->
> > 256Gbit -> 32Gbit -> 8Gbyte per VF?
> 
> Ugh. Actually of course:
> With 1TByte of memory to track -> 256Mbit -> 32Mbit -> 8Mbyte per VF
> 
> 8Gbyte per *PF* with 1K VFs.
> 
Device may not maintain as a bitmap.
I have hard time using calculator for 1TB * 1K DDR memory. :)