[PATCH v2 00/15] KVM: arm64: nv: FPSIMD/SVE, plus some other CPTR goodies

Oliver Upton
2024-06-13T20:18:31Z

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@linux.dev/
[2]: https://lore.kernel.org/kvmarm/20240604130553.199981-1-maz@kernel.org/

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