Merge branch kvm-arm64/nv-eret-pauth into kvmarm-master/next

* kvm-arm64/nv-eret-pauth:
  : .
  : Add NV support for the ERETAA/ERETAB instructions. From the cover letter:
  :
  : "Although the current upstream NV support has *some* support for
  : correctly emulating ERET, that support is only partial as it doesn't
  : support the ERETAA and ERETAB variants.
  :
  : Supporting these instructions was cast aside for a long time as it
  : involves implementing some form of PAuth emulation, something I wasn't
  : overly keen on. But I have reached a point where enough of the
  : infrastructure is there that it actually makes sense. So here it is!"
  : .
  KVM: arm64: nv: Work around lack of pauth support in old toolchains
  KVM: arm64: Drop trapping of PAuth instructions/keys
  KVM: arm64: nv: Advertise support for PAuth
  KVM: arm64: nv: Handle ERETA[AB] instructions
  KVM: arm64: nv: Add emulation for ERETAx instructions
  KVM: arm64: nv: Add kvm_has_pauth() helper
  KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0
  KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently
  KVM: arm64: nv: Honor HFGITR_EL2.ERET being set
  KVM: arm64: nv: Fast-track 'InHost' exception returns
  KVM: arm64: nv: Add trap forwarding for ERET and SMC
  KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2
  KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag
  KVM: arm64: Constraint PAuth support to consistent implementations
  KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET*
  KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values

Signed-off-by: Marc Zyngier <maz@kernel.org>