KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs

When disabling LPIs (for example on reset) at the redistributor
level, it is expected that LPIs that was pending in the CPU
interface are eventually retired.

Currently, this is not what is happening, and these LPIs will
stay in the ap_list, eventually being acknowledged by the vcpu
(which didn't quite expect this behaviour).

The fix is thus to retire these LPIs from the list of pending
interrupts as we disable LPIs.

Reported-by: Heyi Guo <guoheyi@huawei.com>
Tested-by: Heyi Guo <guoheyi@huawei.com>
Fixes: 0e4e82f154e3 ("KVM: arm64: vgic-its: Enable ITS emulation as a virtual MSI controller")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 4a12322bf7df81215d705eb3f7b5ab825d625fdc..9f4843fe9cda64e6f527f1c3f5518b86d8b2d1d9 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -200,6 +200,9 @@ static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
 
        vgic_cpu->lpis_enabled = val & GICR_CTLR_ENABLE_LPIS;
 
+       if (was_enabled && !vgic_cpu->lpis_enabled)
+               vgic_flush_pending_lpis(vcpu);
+
        if (!was_enabled && vgic_cpu->lpis_enabled)
                vgic_enable_lpis(vcpu);
 }

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 3af69f2a38667308cf45e13e26540b379cbffb7c..191deccf60bf9c6dadc3afd3dab4f330e765262b 100644 (file)
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -151,6 +151,27 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
        kfree(irq);
 }
 
+void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu)
+{
+       struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+       struct vgic_irq *irq, *tmp;
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);
+
+       list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
+               if (irq->intid >= VGIC_MIN_LPI) {
+                       raw_spin_lock(&irq->irq_lock);
+                       list_del(&irq->ap_list);
+                       irq->vcpu = NULL;
+                       raw_spin_unlock(&irq->irq_lock);
+                       vgic_put_irq(vcpu->kvm, irq);
+               }
+       }
+
+       raw_spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);
+}
+
 void vgic_irq_set_phys_pending(struct vgic_irq *irq, bool pending)
 {
        WARN_ON(irq_set_irqchip_state(irq->host_irq,

diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index a90024718ca44b941e8b4d7aa0f6bf20233c4596..abeeffabc456cb284ff2397769b6d55986f3931f 100644 (file)
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -238,6 +238,7 @@ void vgic_v3_put(struct kvm_vcpu *vcpu);
 bool vgic_has_its(struct kvm *kvm);
 int kvm_vgic_register_its_device(void);
 void vgic_enable_lpis(struct kvm_vcpu *vcpu);
+void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu);
 int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi);
 int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr);
 int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,