Merge branch kvm-arm64/dirty-log-ordered into kvmarm-master/next

Merge branch kvm-arm64/dirty-log-ordered into kvmarm-master/next

* kvm-arm64/dirty-log-ordered:
  : .
  : Retrofit some ordering into the existing API dirty-ring by:
  :
  : - relying on acquire/release semantics which are the default on x86,
  :   but need to be explicit on arm64
  :
  : - adding a new capability that indicate which flavor is supported, either
  :   with explicit ordering (arm64) or both implicit and explicit (x86),
  :   as suggested by Paolo at KVM Forum
  :
  : - documenting the requirements for this new capability on weakly ordered
  :   architectures
  :
  : - updating the selftests to do the right thing
  : .
  KVM: selftests: dirty-log: Use KVM_CAP_DIRTY_LOG_RING_ACQ_REL if available
  KVM: selftests: dirty-log: Upgrade flag accesses to acquire/release semantics
  KVM: Document weakly ordered architecture requirements for dirty ring
  KVM: x86: Select CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL
  KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option
  KVM: Use acquire/release semantics when accessing dirty ring GFN state

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