Re: [PATCH rc v1 3/4] iommu/arm-smmu-v3: Ignore STE EATS when computing the update sequence

From: Nicolin Chen

Date: Sat Dec 06 2025 - 14:55:03 EST


On Sat, Dec 06, 2025 at 03:46:37PM -0400, Jason Gunthorpe wrote:
> On Fri, Dec 05, 2025 at 04:52:02PM -0800, Nicolin Chen wrote:
> > From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> >
> > If a VM want to toggle EATS off the hypervisor will see EATS change to 0
> > and insert a V=0 breaking update into the STE even though the VM did not
> > ask for that.
>
> "EATS off at the same time as changing CFG"
>
> In bare metal EATS is ignored by CFG=ABORT/BYPASS which is why this
> doesn't cause a problem until we have nested where CFG is always a
> variation of S2 trans that does use EATS.

Ack. Will add squash these two.

Nicolin