KVM: arm64: Move vcpu WFIT flag to the state flag set

The host kernel uses the WFIT flag to remember that a vcpu has used
this instruction and wake it up as required. Move it to the state
set, as nothing in the hypervisor uses this information.

Reviewed-by: Fuad Tabba <[e-mail]>
Reviewed-by: Reiji Watanabe <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>

arch/arm64/include/asm/kvm_host.h

···
 #define HOST_SME_ENABLED	__vcpu_single_flag(sflags, BIT(1))
 /* Physical CPU not in supported_cpus */
 #define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(2))
+/* WFIT instruction trapped */
+#define IN_WFIT			__vcpu_single_flag(sflags, BIT(3))
 
 /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
 #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) +	\
···
 	__size_ret;							\
 })
 
-/* vcpu_arch flags field values: */
-#define KVM_ARM64_WFIT			(1 << 17) /* WFIT instruction trapped */
 #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \
 				 KVM_GUESTDBG_USE_SW_BP | \
 				 KVM_GUESTDBG_USE_HW | \

arch/arm64/kvm/arch_timer.c

···
 static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)
 {
 	return (cpus_have_final_cap(ARM64_HAS_WFXT) &&
-		(vcpu->arch.flags & KVM_ARM64_WFIT));
+		vcpu_get_flag(vcpu, IN_WFIT));
 }
 
 static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)

arch/arm64/kvm/arm.c

···
 	preempt_enable();
 
 	kvm_vcpu_halt(vcpu);
-	vcpu->arch.flags &= ~KVM_ARM64_WFIT;
+	vcpu_clear_flag(vcpu, IN_WFIT);
 	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
 
 	preempt_disable();

arch/arm64/kvm/handle_exit.c

···
 		kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
 	} else {
 		if (esr & ESR_ELx_WFx_ISS_WFxT)
-			vcpu->arch.flags |= KVM_ARM64_WFIT;
+			vcpu_set_flag(vcpu, IN_WFIT);
 
 		kvm_vcpu_wfi(vcpu);
 	}