[PATCH v4 1/3] PCI: Allow ATS to be always on for CXL.cache capable devices

[Tian, Kevin]

> From: Jason Gunthorpe <jgg at nvidia.com>
> Sent: Thursday, May 21, 2026 9:06 PM
> 
> On Thu, May 21, 2026 at 03:31:46PM +0800, Yi Liu wrote:
> 
> > Does this hardware behavior satisfy the security expectation you have in
> > mind? Or do you still require that both the DTE bit and the PCI ATS
> > capability be explicitly disabled when a blocking domain is in effect?
> 
> If the HW rejects translated TLPs then you should be clearing the ATS
> enable bit in the device config space prior to rejecting them
> 
> But it does seem secure enough as-is.
> 

yeah we need disable ATS explicitly instead of relying on some implicit
behavior...