[PULL 21/27] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered

[Christoffer Dall]

From: Marc Zyngier <marc.zyngier at arm.com>

In order for VLPIs to be delivered to the guest, we must make sure that
the virtual cpuif is always enabled, irrespective of the presence of
virtual interrupt in the LRs.

Acked-by: Christoffer Dall <cdall at linaro.org>
Reviewed-by: Eric Auger <eric.auger at redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
 virt/kvm/arm/hyp/vgic-v3-sr.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 91728faa13fd..f5c3d6d7019e 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -258,7 +258,8 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 			cpu_if->vgic_ap1r[0] = __vgic_v3_read_ap1rn(0);
 		}
 	} else {
-		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
+		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
+		    cpu_if->its_vpe.its_vm)
 			write_gicreg(0, ICH_HCR_EL2);
 
 		cpu_if->vgic_elrsr = 0xffff;
@@ -337,9 +338,11 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 		/*
 		 * If we need to trap system registers, we must write
 		 * ICH_HCR_EL2 anyway, even if no interrupts are being
-		 * injected,
+		 * injected. Same thing if GICv4 is used, as VLPI
+		 * delivery is gated by ICH_HCR_EL2.En.
 		 */
-		if (static_branch_unlikely(&vgic_v3_cpuif_trap))
+		if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
+		    cpu_if->its_vpe.its_vm)
 			write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
 	}
 
-- 
2.14.2