RE: [PATCH v1 0/8] Add IO page table replacement support

[Tian, Kevin]

> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Friday, February 3, 2023 11:04 PM
> 
> On Fri, Feb 03, 2023 at 08:09:30AM +0000, Tian, Kevin wrote:
> > > From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > > Sent: Thursday, February 2, 2023 3:05 PM
> > >
> > > QEMU with this feature should have the vIOMMU maintain a cache of the
> > > guest io page table addresses and assign a unique IOAS to each unique
> > > guest page table.
> >
> > I didn't get why we impose such requirement to userspace.
> 
> I read this as implementation guidance for qemu. qemu can do what it
> wants of course
> 

sure but I still didn't get why this is a guidance specific to the
new replace cmd...