Re: [PATCH rc v1 3/4] iommu/arm-smmu-v3: Ignore STE EATS when computing the update sequence
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2025-12-06 19:46:41
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On Fri, Dec 05, 2025 at 04:52:02PM -0800, Nicolin Chen wrote:
From: Jason Gunthorpe <jgg@nvidia.com> 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. Jason