KVM: arm64: Count VMID-wide TLB invalidations

KVM/ARM has an architecture-specific implementation of
kvm_flush_remote_tlbs; however, unlike the generic one,
it does not count the flushes in kvm->stat.remote_tlb_flush,
so that it inexorably remained stuck to zero.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210727103251.16561-1-pbonzini@redhat.com

arch/arm64/kvm/mmu.c

@@ -81,6 +81,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)
 void kvm_flush_remote_tlbs(struct kvm *kvm)
 {
 	kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
+	++kvm->stat.generic.remote_tlb_flush;
 }
 
 static bool kvm_is_device_pfn(unsigned long pfn)