As discussed, here's the combined series of Marc + I's patches that implement all the trap forwarding / merging logic required to observe the L1 CPTR configuration when running an L2 guest. Like before, this was tested on Neoverse-V2 with L0, L1, and L2 running fpsimd-test and sve-test on top of one another. v1 [1] -> v2: - Grab Marc's CPTR trap patches [2] - Avoid taking two traps when L1 accesses ZCR_EL2 while the host owns FP regs. The fast path will now load the FP regs and forward the sysreg trap to the slow path for complete handling. - Add a comment describing the above behavior (Marc) - Avoid the use of guest_hyp_*_traps_enabled() in __activate_cptr_traps() for better codegen (Marc) - Document the reason for only testing bit[0] of CPTR_EL2.xEN when folding L1 traps into the hardware CPTR value. - Add a helper for synthesizing SVE traps, rather than open-coding the ESR value in access_zcr_el2() [1]: https://lore.kernel.org/kvmarm/20240531231358.1000039-1-oliver.upton@xxxxxxxxx/ [2]: https://lore.kernel.org/kvmarm/20240604130553.199981-1-maz@xxxxxxxxxx/ Jintack Lim (1): KVM: arm64: nv: Forward FP/ASIMD traps to guest hypervisor Marc Zyngier (4): KVM: arm64: nv: Handle CPACR_EL1 traps KVM: arm64: nv: Add TCPAC/TTA to CPTR->CPACR conversion helper KVM: arm64: nv: Add trap description for CPTR_EL2 KVM: arm64: nv: Add additional trap setup for CPTR_EL2 Oliver Upton (10): KVM: arm64: nv: Forward SVE traps to guest hypervisor KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap KVM: arm64: nv: Load guest hyp's ZCR into EL1 state KVM: arm64: nv: Handle ZCR_EL2 traps KVM: arm64: nv: Save guest's ZCR_EL2 when in hyp context KVM: arm64: nv: Use guest hypervisor's max VL when running nested guest KVM: arm64: nv: Ensure correct VL is loaded before saving SVE state KVM: arm64: Spin off helper for programming CPTR traps KVM: arm64: nv: Honor guest hypervisor's FP/SVE traps in CPTR_EL2 KVM: arm64: Allow the use of SVE+NV arch/arm64/include/asm/kvm_emulate.h | 55 +++++++++ arch/arm64/include/asm/kvm_host.h | 7 ++ arch/arm64/include/asm/kvm_nested.h | 5 +- arch/arm64/kvm/arm.c | 5 - arch/arm64/kvm/emulate-nested.c | 91 ++++++++++++++ arch/arm64/kvm/fpsimd.c | 22 +++- arch/arm64/kvm/handle_exit.c | 19 ++- arch/arm64/kvm/hyp/include/hyp/switch.h | 24 +++- arch/arm64/kvm/hyp/vhe/switch.c | 156 ++++++++++++++++++++---- arch/arm64/kvm/nested.c | 3 +- arch/arm64/kvm/sys_regs.c | 38 ++++++ 11 files changed, 380 insertions(+), 45 deletions(-) base-commit: c3f38fa61af77b49866b006939479069cd451173 -- 2.45.2.627.g7a2c4fd464-goog