Re: [PATCH v19 02/14] KVM: arm64: Fix FGT mapping for HFGITR_EL2.nGCSEPP

Leonardo Bras <[email protected]>
Newsgroups org.kernel.vger.linux-doc,dev.linux.lists.kvmarm,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest
Message-ID <aoXc6FAZf9GFo0cg@LeoBrasDK>
On Wed, Aug 19, 2026 at 02:55:23PM +0100, Leonardo Bras wrote:
> On Wed, Aug 12, 2026 at 08:12:01PM +0100, Mark Brown wrote:
> > The encoding to trap mapping currently maps a FGT on OP_GCSPOPX to
> > HFGITR_EL2.nGCSEPP but as per DDI0601 2026-06 this FGT controls trapping
> > of GCSPUSHX and GCSPOPCX, and not the separate GCSPOPX instruction.
> > Update the mapping to reflect the architecture.
> 
> That information seems to match the one in Arm ARM version M.c.
> nGCSEPP, bit [59]
> 	When FEAT_GCS is implemented:
> 	Trap execution of any of the following AArch64 instructions at EL1 to EL2:
> 		• GCSPUSHX.
> 		• GCSPOPCX.
> 
> It looks like GCSPOPX can fault if the record is not a valid entry, but 
> there seems to be no trap register bit for that.
> 
> Thanks!
> Leo, 
> 
> 

Ah, FWIW:
Reviewed-by: Leonardo Bras <[email protected]>
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