Commit 82221a4e authored by Oliver Upton's avatar Oliver Upton
Browse files

KVM: arm64: Disambiguate support for vSGIs v. vLPIs 



vgic_supports_direct_msis() is a bit of a misnomer, as it returns true
if either vSGIs or vLPIs are supported. Pick it apart into a few
predicates and replace some open-coded checks for vSGIs, including an
opportunistic fix to always check if the CPUIF is capable of handling
vSGIs.

Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250724062805.2658919-2-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 86731a2a

arch/arm64/kvm/vgic/vgic-init.c

+4 −5
Original line number Diff line number Diff line
@@ -391,11 +391,10 @@ int vgic_init(struct kvm *kvm) 
		goto out;



	/*

	 * If we have GICv4.1 enabled, unconditionally request enable the

	 * v4 support so that we get HW-accelerated vSGIs. Otherwise, only

	 * enable it if we present a virtual ITS to the guest.

	 * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs,

	 * vLPIs) is supported.

	 */

	if (vgic_supports_direct_msis(kvm)) {

	if (vgic_supports_direct_irqs(kvm)) {

		ret = vgic_v4_init(kvm);

		if (ret)

			goto out;
@@ -443,7 +442,7 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm) 
		dist->vgic_cpu_base = VGIC_ADDR_UNDEF;

	}



	if (vgic_supports_direct_msis(kvm))

	if (vgic_supports_direct_irqs(kvm))

		vgic_v4_teardown(kvm);



	xa_destroy(&dist->lpi_xa);

arch/arm64/kvm/vgic/vgic-mmio-v3.c

+10 −6
Original line number Diff line number Diff line
@@ -50,8 +50,12 @@ bool vgic_has_its(struct kvm *kvm) 


bool vgic_supports_direct_msis(struct kvm *kvm)

{

	return (kvm_vgic_global_state.has_gicv4_1 ||

		(kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));

	return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);

}



bool vgic_supports_direct_sgis(struct kvm *kvm)

{

	return kvm_vgic_global_state.has_gicv4_1 && gic_cpuif_has_vsgi();

}



/*
@@ -86,7 +90,7 @@ static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu, 
		}

		break;

	case GICD_TYPER2:

		if (kvm_vgic_global_state.has_gicv4_1 && gic_cpuif_has_vsgi())

		if (vgic_supports_direct_sgis(vcpu->kvm))

			value = GICD_TYPER2_nASSGIcap;

		break;

	case GICD_IIDR:
@@ -119,7 +123,7 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu, 
		dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;



		/* Not a GICv4.1? No HW SGIs */

		if (!kvm_vgic_global_state.has_gicv4_1 || !gic_cpuif_has_vsgi())

		if (!vgic_supports_direct_sgis(vcpu->kvm))

			val &= ~GICD_CTLR_nASSGIreq;



		/* Dist stays enabled? nASSGIreq is RO */
@@ -133,7 +137,7 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu, 
		if (is_hwsgi != dist->nassgireq)

			vgic_v4_configure_vsgis(vcpu->kvm);



		if (kvm_vgic_global_state.has_gicv4_1 &&

		if (vgic_supports_direct_sgis(vcpu->kvm) &&

		    was_enabled != dist->enabled)

			kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_RELOAD_GICv4);

		else if (!was_enabled && dist->enabled)
@@ -178,7 +182,7 @@ static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu, 
		}

	case GICD_CTLR:

		/* Not a GICv4.1? No HW SGIs */

		if (!kvm_vgic_global_state.has_gicv4_1)

		if (!vgic_supports_direct_sgis(vcpu->kvm))

			val &= ~GICD_CTLR_nASSGIreq;



		dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;

arch/arm64/kvm/vgic/vgic-v4.c

+2 −2
Original line number Diff line number Diff line
@@ -356,7 +356,7 @@ int vgic_v4_put(struct kvm_vcpu *vcpu) 
{

	struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;



	if (!vgic_supports_direct_msis(vcpu->kvm) || !vpe->resident)

	if (!vgic_supports_direct_irqs(vcpu->kvm) || !vpe->resident)

		return 0;



	return its_make_vpe_non_resident(vpe, vgic_v4_want_doorbell(vcpu));
@@ -367,7 +367,7 @@ int vgic_v4_load(struct kvm_vcpu *vcpu) 
	struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;

	int err;



	if (!vgic_supports_direct_msis(vcpu->kvm) || vpe->resident)

	if (!vgic_supports_direct_irqs(vcpu->kvm) || vpe->resident)

		return 0;



	if (vcpu_get_flag(vcpu, IN_WFI))

arch/arm64/kvm/vgic/vgic.c

+2 −2
Original line number Diff line number Diff line
@@ -951,7 +951,7 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) 
	 * can be directly injected (GICv4).

	 */

	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head) &&

	    !vgic_supports_direct_msis(vcpu->kvm))

	    !vgic_supports_direct_irqs(vcpu->kvm))

		return;



	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
@@ -965,7 +965,7 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) 
	if (can_access_vgic_from_kernel())

		vgic_restore_state(vcpu);



	if (vgic_supports_direct_msis(vcpu->kvm))

	if (vgic_supports_direct_irqs(vcpu->kvm))

		vgic_v4_commit(vcpu);

}

arch/arm64/kvm/vgic/vgic.h

+7 −0
Original line number Diff line number Diff line
@@ -370,6 +370,13 @@ int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq); 
int vgic_its_invall(struct kvm_vcpu *vcpu);



bool vgic_supports_direct_msis(struct kvm *kvm);

bool vgic_supports_direct_sgis(struct kvm *kvm);



static inline bool vgic_supports_direct_irqs(struct kvm *kvm)

{

	return vgic_supports_direct_msis(kvm) || vgic_supports_direct_sgis(kvm);

}



int vgic_v4_init(struct kvm *kvm);

void vgic_v4_teardown(struct kvm *kvm);

void vgic_v4_configure_vsgis(struct kvm *kvm);