Merge branch kvm-arm64/pkvm-no-mte into kvmarm-master/next

Merge branch kvm-arm64/pkvm-no-mte into kvmarm-master/next

* kvm-arm64/pkvm-no-mte:
  : .
  : pKVM updates preventing the host from using MTE-related system
  : sysrem registers when the feature is disabled from the kernel
  : command-line (arm64.nomte), courtesy of Fuad Taba.
  :
  : From the cover letter:
  :
  : "If MTE is supported by the hardware (and is enabled at EL3), it remains
  : available to lower exception levels by default. Disabling it in the host
  : kernel (e.g., via 'arm64.nomte') only stops the kernel from advertising
  : the feature; it does not physically disable MTE in the hardware.
  :
  : The ability to disable MTE in the host kernel is used by some systems,
  : such as Android, so that the physical memory otherwise used as tag
  : storage can be used for other things (i.e. treated just like the rest of
  : memory). In this scenario, a malicious host could still access tags in
  : pages donated to a guest using MTE instructions (e.g., STG and LDG),
  : bypassing the kernel's configuration."
  : .
  KVM: arm64: Use kvm_has_mte() in pKVM trap initialization
  KVM: arm64: Inject UNDEF when accessing MTE sysregs with MTE disabled
  KVM: arm64: Trap MTE access and discovery when MTE is disabled
  KVM: arm64: Remove dead code resetting HCR_EL2 for pKVM

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