On Sat, Oct 05, 2024 at 02:18:57PM +0100, Marc Zyngier wrote:
Mark Brown broonie@kernel.org wrote:
On Sat, Oct 05, 2024 at 12:34:20PM +0100, Marc Zyngier wrote:
Where is the handling of traps resulting of HFGITR_EL2.nGCSSTR_EL1?
These will trap with an EC of 0x2d which isn't known so I was expecting this to get handled in the same way as for example a return of false from kvm_hyp_handle_fpsimd() for SVE when unsupported, or for the simiarly unknown SME EC, currently. I gather from your comment that you're instead expecting to see an explicit exit handler for this EC that just injects the UNDEF directly?
Not just inject an UNDEF directly, but also track whether this needs to be forwarded when the guest's HFGITR_EL2.nGCSSTR_EL1 is 0 while not being not RES0. Basically following what the pseudocode describes.
Ah, I see. I'd been under the impression that the generic machinery was supposed to handle this already using the descriptions in emulate-nested.c and we only needed handlers for more specific actions.