Commit eebc538d authored May 28, 2022 by Marc Zyngier

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 <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

parent aff3ccd7

arch/arm64/include/asm/kvm_host.h

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -521,6 +521,8 @@ struct kvm_vcpu_arch {
	#define HOST_SME_ENABLED __vcpu_single_flag(sflags, BIT(1))		#define HOST_SME_ENABLED __vcpu_single_flag(sflags, BIT(1))
	/* Physical CPU not in supported_cpus */		/* Physical CPU not in supported_cpus */
	#define ON_UNSUPPORTED_CPU __vcpu_single_flag(sflags, BIT(2))		#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() */		/* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
	#define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) + \		#define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) + \
	@@ -542,8 +544,6 @@ struct kvm_vcpu_arch {
	__size_ret; \		__size_ret; \
	})		})

	/* vcpu_arch flags field values: */
	#define KVM_ARM64_WFIT (1 << 17) /* WFIT instruction trapped */
	#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE \| \		#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE \| \
	KVM_GUESTDBG_USE_SW_BP \| \		KVM_GUESTDBG_USE_SW_BP \| \
	KVM_GUESTDBG_USE_HW \| \		KVM_GUESTDBG_USE_HW \| \

arch/arm64/kvm/arch_timer.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -242,7 +242,7 @@ static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
	static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)		static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)
	{		{
	return (cpus_have_final_cap(ARM64_HAS_WFXT) &&		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)		static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)

arch/arm64/kvm/arm.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -657,7 +657,7 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
	preempt_enable();		preempt_enable();

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

	preempt_disable();		preempt_disable();

arch/arm64/kvm/handle_exit.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -120,7 +120,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu)
	kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));		kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
	} else {		} else {
	if (esr & ESR_ELx_WFx_ISS_WFxT)		if (esr & ESR_ELx_WFx_ISS_WFxT)
	vcpu->arch.flags \|= KVM_ARM64_WFIT;		vcpu_set_flag(vcpu, IN_WFIT);

	kvm_vcpu_wfi(vcpu);		kvm_vcpu_wfi(vcpu);
	}		}