From: Marc Zyngier <marc.zyngier@arm.com>
Date: Fri, 27 Oct 2017 15:28:50 +0100
Subject: KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
Patch-mainline: v4.15-rc1
Git-commit: 6277579778d63125671509e2502597fdf6a56c00
References: bsc#1077761

The redistributor needs to be told which vPE is about to be run,
and tells us whether there is any pending VLPI on exit.

Let's add the scheduling calls to the vgic flush/sync functions,
allowing the VLPIs to be delivered to the guest.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Alexander Graf <agraf@suse.de>
---
 virt/kvm/arm/vgic/vgic-v4.c |   39 +++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic.c    |    4 ++++
 virt/kvm/arm/vgic/vgic.h    |    2 ++
 3 files changed, 45 insertions(+)

--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -131,6 +131,45 @@
 	its_vm->vpes = NULL;
 }
 
+int vgic_v4_sync_hwstate(struct kvm_vcpu *vcpu)
+{
+	if (!vgic_supports_direct_msis(vcpu->kvm))
+		return 0;
+
+	return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, false);
+}
+
+int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu)
+{
+	int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;
+	int err;
+
+	if (!vgic_supports_direct_msis(vcpu->kvm))
+		return 0;
+
+	/*
+	 * Before making the VPE resident, make sure the redistributor
+	 * corresponding to our current CPU expects us here. See the
+	 * doc in drivers/irqchip/irq-gic-v4.c to understand how this
+	 * turns into a VMOVP command at the ITS level.
+	 */
+	err = irq_set_affinity(irq, cpumask_of(smp_processor_id()));
+	if (err)
+		return err;
+
+	err = its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, true);
+	if (err)
+		return err;
+
+	/*
+	 * Now that the VPE is resident, let's get rid of a potential
+	 * doorbell interrupt that would still be pending.
+	 */
+	err = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, false);
+
+	return err;
+}
+
 static struct vgic_its *vgic_get_its(struct kvm *kvm,
 				     struct kvm_kernel_irq_routing_entry *irq_entry)
 {
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -718,6 +718,8 @@
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 
+	WARN_ON(vgic_v4_sync_hwstate(vcpu));
+
 	/* An empty ap_list_head implies used_lrs == 0 */
 	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 		return;
@@ -730,6 +732,8 @@
 /* Flush our emulation state into the GIC hardware before entering the guest. */
 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 {
+	WARN_ON(vgic_v4_flush_hwstate(vcpu));
+
 	/*
 	 * If there are no virtual interrupts active or pending for this
 	 * VCPU, then there is no work to do and we can bail out without
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -244,5 +244,7 @@
 bool vgic_supports_direct_msis(struct kvm *kvm);
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
+int vgic_v4_sync_hwstate(struct kvm_vcpu *vcpu);
+int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu);
 
 #endif